ISSN: 2165-3259 JAOCR - cdn.ymaws.com · Posterior Mediastinal Mass 32 Anagha Joshi, M.D., DMRE, hintan Trivedi, M.D., DN, Ashank ansal, MS . JAOCR at the Viewbox ... impaired growth.5

ISSN: 2165-3259

JAOCR

Official Journal of the American Osteopathic College of Radiology

CHEST IMAGING

Guest Editors: Les Folio, D.O., MPH, FAOCR Bernard F. Laya, D.O.

Editor-in Chief: William T. O’Brien, Sr., D.O.

April 2014, Vol. 3, Issue 2

J Am Osteopath Coll Radiol 2014; Vol. 3, Issue 2 Page i

JAOCR About the Journal

Aims and Scope The Journal of the American Osteopathic College of Radiology (JAOCR) is designed to provide practical up-to-date reviews of critical topics in radiology for practicing radiologists and radiology trainees. Each quarterly issue covers a particular radiology subspecialty and is composed of high quality review articles and case reports that highlight differential diagnoses and important teaching points. Access to Articles All articles published in the JAOCR are open access online. Subscriptions to the journal are not required to view or download articles. Reprints are not available. Copyrights Materials published in the JAOCR are protected by copyright. No part of this publication may be reproduced without written permission from the AOCR. Guide for Authors Submissions for the JAOCR are by invitation only. If you were invited to submit an article and have questions regarding the content or format, please contact the appropriate Guest Editor for that particular issue. Although contributions are invited, they are subject to peer review and final acceptance. Editor-in-Chief William T. O’Brien, Sr., D.O. San Antonio, TX Design Editor Jessica Roberts Communications Director, AOCR Managing Editor Tammam Beydoun, D.O. Farmington Hills, MI Editorial Board Susann Schetter, D.O. Daniel J. Abbis, D.O. Les R. Folio, D.O. Michael W. Keleher, D.O. Rocky Saenz, D.O. Kipp A. Van Camp, D.O. John Wherthey, D.O.

Page ii J Am Osteopath Coll Radiol 2014; Vol. 3, Issue 2

Table of Contents

Chest Imaging

Title/Author(s) Page No.

From the Editor 1

Review Articles

Does This Chest Radiograph Belong to a Survivor of Childhood Cancer?

Radiographic Findings Suggesting Previous Treatment for Childhood Cancer – A Review 2

Aswin V. Kumar, OMS3, Sue C. Kaste, D.O.

Interpretive Approach and Reporting the Intensive Care Bedside Chest X-Ray 12

Les Folio, D.O., MPH, FAOCR

Case Reports

Cavitary Lung Mass in a Febrile Child 21

Rachel Pevsner Crum, D.O., Ricardo Restrepo, M.D., Nolan Altman, M.D.

Pulmonary Vascular Anomaly 25

David P. Concepcion, M.D., Bernard F. Laya, D.O., Ana Maria Saulog, M.D.

Interstitial Lung Disease 28

Shereef Takla, B.S., Aaron M. Betts, M.D.

Posterior Mediastinal Mass 32

Anagha Joshi, M.D., DMRE, Chintan Trivedi, M.D., DNB, Ashank Bansal, MBBS

JAOCR at the Viewbox

Pulmonary Lymphangioleiomyomatosis 35

Bernard F. Laya, D.O., Regina C. Nava, M.D.

Hydatid Cyst of the Lung 36

Ali Yikilmaz, M.D.


Bernard F. Laya, D.O.

Guest Editors:

J Am Osteopath Coll Radiol 2014; Vol. 3, Issue 2 Page 1

From the Guest Editor

In This Issue


Lead Radiologist for CT, Radiology and Imaging Sciences, Clinical Center, National Institutes of Health, Bethesda, MD

When Lt Col (Dr.) O’Brien asked me to serve as guest editor for the first chest edition of JAOCR, I quickly involved our friend and AOCR colleague, Bernard Laya, DO. With his expertise in chest imaging and as a world expert on tuberculosis in children, combined with Bill O’Brien’s tireless dedication to make this Journal a success, I felt as though we were in great hands to develop a chest imaging edition worth keeping on your bookshelf for reference.

I am confident you will find the included topics informative, practical to your practice, and up-to-date. For example, “The Posterior Mediastinal Mass” case report by Anagha Joshi, MD, DMRE, Chintan Trivedi, MD, DNB, and Ashank Bansal, MBBS, has a representative biopsy proven mass with differentials and great discussion.

Similarly, Dr. Rachel Crum’s skillful description of a pediatric cavitary lung mass is supported with great images and differentials that allow radiologists to approach this scenario more confidently.

Aswin V. Kumar, OMS3, and Sue C. Kaste, DO, provide a thrilling review of chest x-ray findings that should make one consider that the patient might be a childhood cancer survivor. Knowing these clues will help radiologists identify the effects of both the cancer and its therapies.

Nathan David P. Concepcion, MD, Bernard F. Laya, DO, and Ana Maria Saulog, MD, orchestrated an astounding yet concise summary on

congenital bronchopulmonary foregut anomalies while highlighting a particular case.

Shereef Takla, BS, and Aaron M. Betts, MD, tackled the challenge of interstitial lung disease, something that I thought to be impossible in a case report. Yet, they met and exceeded their goal with great images, differentials, and discussion.

Ali Yikilmaz, MD, presents an interesting case that although seemingly uncommon, could show up at our viewbox at any time. Knowing the water-lily sign associated with hydatid cysts will help us make the diagnosis.

Although I see cases of lymphangioleiomyomatosis (LAM) nearly every day, Bernard Laya, DO, and Regina C. Nava, MD, put LAM into the needed perspective with representative lung and extrapulmonary findings.

I sought Bill and Bernie’s advice on making my ICU chest x-ray article useful to the majority of radiologists in this audience. I included the basics of line and tube placement, pulmonary pathology, newer imaging techniques, and tips on reporting.

Lastly, I would like to recognize Lt Col William T. O'Brien, Sr., USAF, MC, for pioneering and bringing the JAOCR to its current status. Having served with the Air Force myself for 20 years and the AOCR for nearly the same amount of time on various committees, taking on the JAOCR is a major undertaking and is the epitome of the quote I selected.

"We choose to go the

moon in this decade

and do the other

things, not because

they are easy, but

because they are

hard..."

-President John F. Kennedy

Page 2 J Am Osteopath Coll Radiol 2014; Vol. 3, Issue 2

Childhood Cancer, Kumar et al.

Introduction

Advances in the detection, treatment, and supportive care of pediatric malignancies has allowed for improved long-term survival among childhood cancer survivors. At present, the 5-year survival for those diagnosed with a pediatric malignancy exceeds 80% with a 10-year survival rate of 75%.1 The increasing number of adult survivors of childhood malignancies now approaches an estimated 360,000 individuals, allowing for more extensive studies of the delayed manifestations of adverse effects related to cancer treatment.1, 2 Medical conditions that persist or present in 5 or more years following treatment are referred to as late effects. Studies that investigate the late effects of pediatric cancer treatment have shown that 73.4% of survivors will experience a chronic medical condition, with over 40% experiencing a serious or life-threatening problem.3

The manifestations of late effects are wide ranging and involve all organ systems, with differential presentation largely dependent on both the primary malignancy and the treatment received. Some of the most common late effects observed in childhood cancer survivors are pulmonary and cardiac complications, with skeletal complications and secondary malignancies being less common.4 The increased survivorship and incidence of morbidity amongst those treated for childhood malignancies necessitates increased vigilance on the part of the adult survivors’ health-care providers to both detect and treat the anticipatory late effects in this population. The manifestations of tissue injury from therapy administered during childhood may not become apparent until the patient enters a phase of rapid growth, such as adolescence. At such times, the treatment insult on normal tissues may result in impaired growth.5 Diagnostic imaging can provide a robust means through which many late effects can be detected.

The aim of this article is to provide an overview of selected radiographic manifestations of thoracic findings that may be associated with previous treatment for pediatric cancers and their late effects by providing an image-based approach to identifying unique radiographic characteristics that may be seen on chest radiographs obtained for reasons unrelated to a history of previous childhood cancer. The risk factors for and prevalence of tumor recurrence and secondary malignant neoplasms are well-described in the literature and will not be included in this pictorial review.

Residual Mediastinal Mass After Treatment For

Lymphoma

The presence of residual abnormality of the mediastinum or hila after completion of therapy for lymphoma can induce anxiety in patients, parents, and healthcare providers. Approximately two-thirds of patients with Hodgkin lymphoma and one-third of patients with non-Hodgkin lymphoma have been reported to have residual mediastinal masses after completion of therapy,6 which can be apparent on chest radiographs (Fig. 1). These residual masses more often occur in patients presenting with bulky mediastinal disease7 or those with nodular sclerosing subtype of Hodgkin disease.8 The residual soft tissue masses are usually composed of benign fibrotic or inflammatory tissue and may be seen in up to 41% of chest radiographs and 46% of chest CTs in pediatric patients treated for Hodgkin disease9; these masses may calcify (Fig. 2).9 Typically, residual fibrotic masses continue to regress over time.7,8

Particularly in pediatric patients, thymic rebound, developing after completion of therapy, may mimic a residual mass.8 Comparison with prior chest imaging can resolve whether or not the original mass has

Does This Chest Radiograph Belong to a Survivor of Childhood Cancer? Radiographic Findings Suggesting Previous Treatment for Childhood Cancer – A Review

Aswin V. Kumar, OMS3a,b , Sue C. Kaste, D.O.b-d

aLincoln Memorial University, Harrogate, TN

bDepartment of Radiological Sciences, Division of Diagnostic Imaging, Memphis TN cOncology, St. Jude Children’s Research Hospital, Memphis TN

dDepartment of Radiology, University of Tennessee School of Health Sciences, Memphis, TN



Figure 1. Residual Post-Therapy Mediastinal Mass. 18-year-old man diagnosed with Stage IV B nodular sclerosing Hodgkin disease was treated with chemotherapy and 2550cGy mantle and 800 cGy whole lung irradiation. Residual mediastinal mass persisted over the subsequent 8 years from initial imaging at diagnosis through follow-up. Posteroanterior chest radiograph at the time of diagnosis (A) shows a large anterior mediastinal mass which extends bilaterally from the midline. A follow-up posteroanterior chest radiograph obtained 8 years from diagnosis (B) shows residual superior mediastinal widening that corresponds to the residual masses shown on the corresponding computed tomography image (C).

changed in size and contour. Increase in the residual mass or new adenopathy warrants further evaluation for the possibility of recurrent disease (Fig. 3). Such can be accomplished using MR10, 11 or CT for anatomic characterization of changes seen on chest radiographs.6 However, MR and CT have limited ability to differentiate between active disease and fibrosis or scarring.9-13 Thus, 18F-FDG PET/PET-CT may be used to assess for metabolic activity (having largely replaced 67Gallium imaging) that may indicate disease relapse.6,13

Pulmonary Complications

The lungs are one of the most radiation- and chemo-sensitive organs in the body.14 Functional compromise arising from radiation is compounded by

chemotherapy-induced toxicities, all of which may progress from initial injury to the pulmonary interstitium to pulmonary fibrosis over time.14 Pulmonary complications after therapy for childhood cancer include pulmonary fibrosis (Fig. 4), chronic cough, recurrent pneumonia, requirement for supplemental oxygen, and pleurisy. Mertens, et al. reporting on the prevalence of self-reported pulmonary complications from the Childhood Cancer Survivor Study, found that chest radiation was statistically associated with all of these adverse late effects, as were various chemotherapeutic agents.14 Chemotherapeutic agents associated with development of pulmonary insufficiency include busulfan, carmustine14,15, cyclophosphamide, lomustine, and bleomycin.15 At 20 years from diagnosis of the primary malignancy, a 3.5% cumulative incidence of pulmonary fibrosis was

A

Figure 2. Calcification of Residual Mediastinal Mass. 24-year-old survivor of Stage IIIB nodular sclerosing Hodgkin disease diagnosed at 15 years of age. His disease was refractory to standard chemotherapy, prompting autologous bone marrow transplantation and 2100 cGy mediastinal radiation. Posteroanterior

(A) and lateral (B) chest radiographs at the time of diagnosis show a bulky anterior mediastinal mass. Follow -up posteroanterior chest radiograph 6 years later (C) shows significant reduction in the mediastinal mass with development of dense calcifications.

C B A

C B



associated with chest radiation14, due to injury to type II pneumocytes and endothelial cells.5,16 Chronic pulmonary impairment results from compromise of alveolar growth and generation of new alveoli.5 Radiographic findings of fibrosis include pleural thickening, regional or focal pulmonary contraction, linear scarring, and streaking that may extend beyond the distribution of radiation portals.5

The likelihood and severity of development of pulmonary complications is dependent on the dose of radiation and chemotherapy, younger patient age at the time of therapy, and smoking.17 Pulmonary function longitudinally declines after therapy18 and may compound the decrease in pulmonary function normally seen with aging.19 Further, chemotherapy, surgery, and bone marrow transplantation may compound the effects of radiation therapy.20

Cardiomyopathy

An increased risk for cardiovascular disease is seen in survivors of childhood cancer treated with radiation therapy or chemotherapy, independently or in combination, and represents a cause of cardiac morbidity and mortality.21 Risk factors particularly identified to increase the likelihood of developing anthracycline-associated cardiovascular toxicity include age younger than 5 years at the time of treatment, female sex, cumulative doses of 300 mg/m2 or greater, cardiac irradiation of 3000 cGy or more, and chemotherapy combined with radiation therapy.22,23 In addition, Orgel, et al. recently reported that an elevated body mass index and Hispanic ethnicity are also independent risk factors for the development of declining left ventricular shortening fraction in anthracycline-based therapy for acute

Figure 3. Relapse Lymphoma. 9- year-old boy diagnosed with Stage IA Hodgkin disease right neck achieved complete remission with chemotherapy. At routine follow-up 3.5 years later, left hilar relapse was suspected. Posteroanterior (A) and lateral (B) chest radiographs show stable post-therapy appearance of the thoracic structures. Follow-up posteroanterior chest radiograph (C) shows slight increased density left hilum which, on the lateral view (D), is shown to represent an ovoid nodule (lines). Axial non-contrast T1 (E) and T2 (F) weighted MR images of the chest show right paratracheal (long arrows), left hilar and subcarinal (short arrows) adenopathy, consistent with disease relapse.

Figure 4. Progressive Radiation Fibrosis. 19-year-old woman diagnosed with Stage IIA nodular sclerosing Hodgkin disease was treated with chemotherapy and 2550 cGy modified mantle irradiation. One year after completing therapy, she developed disease relapse treated with intensive chemotherapy, autologous stem cell rescue, and radiation therapy to the lower cervical spine and porta hepatis. At diagnosis, the posteroanterior chest

radiograph (A) showed right paratracheal adenopathy and bilateral superior mediastinal widening, which improved with therapy. By 3 years later, posteroanterior chest radiograph (B) demonstrated straightening of the left mediastinum and early cephalad retraction of the left hilum. At 11 years, posteroanterior chest radiograph (C) showed progression of cephalad retraction of the left hilum and coarsening of post-radiation scarring. Imaging findings paralleled the patient’s decreasing pulmonary function, ultimately leading to her demise.

A

C B A

D E F

C B



myeloid leukemia.24 Other reported risk factors include black race and the presence of trisomy 21.25

The most common cardiac event reported is congestive heart failure.26 The hallmark of anthracycline cardiotoxicity is reduced thickness and mass of the left ventricular wall.27 Though symptomatic cardiac compromise is infrequent22,23, a recent study reported a 12.6% incidence of such events in patients treated with both anthracyclines and cardiac irradiation, 7.3% incidence with anthracyclines alone, and 4.0% incidence after cardiac irradiation with a median patient age of 27 years at the time of the events26 (Fig. 5). Cardiotoxic effects of therapy may not manifest until adulthood or during times of stress, such as pregnancy or physical exertion.22

A recent investigation of 62 adolescent survivors of childhood cancer (mean age 14.6 years at the time of study) who received anthracyclines as part of their oncotherapy found that gadolinium-enhanced cardiac MR detected and quantified both left and right ventricular dysfunction in 61% and 27%, respectively.28

Breast Hypoplasia

Breast hypoplasia or aplasia is a well-known late effect following irradiation to the chest during childhood (Fig. 6). Radiation-induced underdevelopment of the breast has been reported in a variety of pathologies for which irradiation has been used, including cutaneous hemangiomas of the chest29, mediastinal lymphadenopathy30, Wilm tumor31, 32, and neuroblastoma.32 Radiation effects on developing human breast tissue is dose dependent30, 33 and may occur with doses of <500 cGy.34 Clinical changes associated with radiation-induced breast underdevelopment include the presence of dyschromasia and telengiectasias on the affected breast, as well as overall asymmetric breast development with the irradiated breast being smaller and irregular in size compared to the non-irradiated breast.33 Reported histopathological findings of irradiated hypoplastic breasts include extensive fibrosis, loss of breast lobules, and significant shrinkage of the ducts.33 Patients affected by breast hypoplasia can also experience significant psychological distress due to the undesirable cosmetic effects of asynchronous breast growth.33

It is important to recognize the association of breast cancer arising as a result of irradiation that included

Figure 5. Anthracycline-Induced Cardiomyopathy. 12-year-old patient diagnosed with nodular sclerosing Hodgkin disease and received multiagent chemotherapy that included anthracycline. Pathologic examination revealed Grade 2 of 3 anthracycline cardiac toxicity. Posteroanterior chest radiograph obtained about 1 year after completion of therapy demonstrates cardiomegaly, bilateral pleural effusions, and pulmonary vascular congestion indicative of congestive heart failure.

Figure 6. Breast Hypoplasia. 49-year-old woman diagnosed with Wilm tumor at 5 years of age and received 1200 cGy whole lung irradiation for pulmonary metastases, as well as 1200cGy abdominal radiation therapy for primary disease and hepatic metastases. Posteroanterior (A) and lateral (B) chest radiographs demonstrate hypoplasia of both breasts. The anteroposterior diameter of the chest is narrow from radiation-induced rib dysplasia.

A B



hypoplasia of bones exposed to radiation therapy, demineralization associated with chemotherapy and/or radiation therapy, growth aberrations related to radiation therapy, and altered vertebral height when radiation therapy is compounded by the effects of chemotherapy.36 Similarly, chemotherapy can directly affect growing bones.36,37 Growing bone is most susceptible to the effects of radiation during the two periods of most rapid growth: during the first 6 years of life and during puberty.38,39 Radiation injury is most likely related to injury of chondroblasts with inhibition of cartilaginous cells and is seen with single doses of 200 to 2000 cGy.5,40 Thus, the adverse impact of treatment – whether chemotherapy, radiation therapy, or in combination – on the developing skeletal structures varies with patient age, as well as the type, distribution, and intensity of therapy at the time of treatment.36, 39

Scoliosis

Impaired vertebral growth can occur with doses of 1000 to 2000 cGy41,42 and can lead to short stature38, altered vertebral body configuration38,42, and contribute to the development of scoliosis40,43,44 and/or kyphosis (Figs. 7 and 8).44 Probert and Parker reported changes in developing vertebral bodies when exposed to radiation doses of greater than 2000 rads.38 Asymmetric exposure of the vertebral bodies may contribute to the development of scoliosis.40,43,44

In addition to therapeutic irradiation, chest wall resection may result in scoliosis. In children, post-surgical scoliosis is progressive and related to the number of posterior ribs resected.45

Clavicular Growth

Merchant, et al. investigated the effect of asymmetric exposure of the clavicles to 1500 cGy as administered with hemi-mini-mantle irradiation for unilateral Hodgkin disease of the neck or supraclavicular region. The clavicles which were fully exposed to radiation therapy grew 0.5 cm less overall compared to those only partially exposed (p=0.007), regardless of the patient’s age at the time of therapy (median age, 13.3 years; range, 5.1 to 18.9 years)

Figure 7. Chest Wall Deformity And Scoliosis. At the age of 6 years, this boy was diagnosed with Ewing sarcoma family of tumors of the right chest wall. He received multiagent chemotherapy, surgical resection, and 504 cGy external beam irradiation. Over the course of 7 years, he developed significant scoliosis. Axial chest CT image at the time of diagnosis (A) shows the soft tissue mass with foci of increased attenuation arising from the right lateral chest wall. Posteroanterior chest radiograph obtained 2 years after completion of therapy (B) shows chest wall deformity due to resection of several right thoracic ribs and pulmonary scarring. Note the absence of a visible scoliosis. Scoliosis series obtained 7 years after therapy completion due to the presence of a “thoracic hump” (C) demonstrates a 52 degree mid-thoracic convex right rotoscoliosis.

C B

A

breast tissue.35 After chest irradiation, the standardized incidence ratio for developing secondary breast cancer was 24.7 (95%CI 18.3-31.0), as opposed to 4.8 (95%CI 2.9 - 7.4) for those who received no chest irradiation.35 Thus, education of these patients regarding health risks associated with chest irradiation should be prompted by recognition of this finding upon verification of prior therapy.

Skeletal Sequelae

Radiation-induced changes of bone have been recognized for decades, and any bone exposed to the radiation field can be affected. Therapy inflicted during the developmental stages of the skeleton can result in



(Fig. 9). Further, the effect on clavicular growth was more pronounced in the younger-aged patients (mean age, 9.9 years) compared to those who were older (mean age, 16.4 years; p=0.036).46 Thus, as with prior reports, the effects of radiation therapy on bone are influenced by patient age, therapeutic dose, and extent of tissues exposed.40

Radiation-Induced Exostosis

Osteochondromas are the most common benign tumor of bone to occur following radiation therapy (Fig. 10).47 They manifest as a late effect of total body or local irradiation and have also been reported as a long-term sequela of hematopoietic stem cell transplantation (HSCT).48,49 The median age of presentation and latency for osteochondromas

following HSCT is 13.3 and 8.9 years, respectively.49, 50 Among the risk factors investigated as contributing to their development following HSCT, only total body irradiation and a young age at time of TBI and or HSCT have been consistently shown to significantly affect the risk of developing osteochondromas.49,51

The prevalence of osteochondromas is approximately 3% in the general population with the majority presenting as solitary osteochondromas unless in the setting of hereditary multiple exostosis.52 Among survivors of HSCT, approximately 1% develop osteochondromas. Unlike the general population, only a slight majority of long-term survivors of HSCT develop solitary osteochondromas.49,51 In pediatric patients who undergo irradiation, damage to the epiphyseal plate causes a portion of the epiphyseal cartilage to migrate to the metaphyseal regions

Figure 8. Rib Dysplasia. 49-year-old woman diagnosed with non-Hodgkin lymphoma at 9 years of age was treated with mediastinal radiation therapy and multiagent chemotherapy. Posteroanterior (A) and lateral (B) chest radiographs demonstrate linear pulmonary scarring with mild cephalad retraction of the hila (arrows) and a mild levoconvex mid-thoracic scoliosis (apex of the curve indicated by the arrowhead). The striking chest wall deformity with depression of the anterior chest wall (B) resulted from radiation-induced rib dysplasia. Similarly, note the asymmetric size of the breasts (right smaller than left) and smaller volume of the right hemithorax compared to the left (A). The lateral view also readily demonstrates demineralization of the thoracic vertebral bodies. Initial posteroanterior ches t radiograph at the time of diagnosis (C) shows extensive mediastinal, paratracheal, and right hilar adenopathy coupled with a large right pleural effusion.

Figure 9. Asymmetric Clavicular Growth. 15-year-old boy was diagnosed with Stage IA Hodgkin disease of his right neck. In addition to multiagent chemotherapy, treatment included right hemi-mantle irradiation of 1500 cGy. Axial CT image of the neck at the time of diagnosis (A) shows prominent lymphadenopathy. Posteroanterior chest radiograph obtained 15 years after completion of treatment (B) demonstrates asymmetric clavicular growth with the right clavicle measuring 2 cm shorter than the left.

C B A

B

A



other osseous lesions due to the contrast of high T2 and low T1 signal intensity of the cartilaginous cap.52

Demineralization

Survivors of childhood cancer are at risk for deficits in bone mineral density which may lead to earlier onset and more severe osteoporosis and related fractures.53 Attention to the integrity of bone mineralization in the thoracic spine of childhood cancer survivors is important. Occasionally, compression fractures may be the first indication of such a deficit in survivors of childhood cancer. Though the best studied pediatric cancer population has been children treated for acute lymphoblastic leukemia, such deficits are associated with a variety of pediatric malignancies, as well as with bone marrow transplantation.54,55

Deficits in bone mineralization arise from a multitude of risk factors and include genetic predisposition54, lifestyle factors (such as suboptimal nutrition)53,54, inadequate weight-bearing exercise53,54, treatment with osteotoxic chemotherapeutic agents (particularly glucocorticoids but also associated with ifosfamide and methotrexate)37,53,54,56, endocrinopathies37,53,54, and radiation therapy whether localized to the thoracic spine or gonads53, or cranial irradiation.37,53

causing the formation of osteochondromas.

Osteochondromas that occur as a result of irradiation are radiographically indistinguishable from those that occur from other etiologies. Osteochondromas most commonly localize to the metaphysis of long bones, particularly the femur and proximal tibia, with involvement of flat bones being less common.49 Clinically, osteochondromas present as painless slow-growing masses that cause local distortion of tissue. Depending on their proximity to neurovascular structures, osteochondromas can present with paresthesias or loss of peripheral pulse in the affected limb.52 In addition to the above presentations, a minority of long-term survivors of HSCT are diagnosed with osteochondromas incidentally through the course of routine radiographic or clinical examination.49

Radiographically, the appearance of osteochondromas can be described as cartilage capped protruding osseous lesions that have cortical and medullary contiguity with the parent bone. The neck of an osteochondromas can either be wide or narrow, giving the appearance of either a sessile or pedunculated lesion, respectively.47 Osteochondromas can be easily recognized using radiographs. However, more complex lesions, such as those that involve the spine or shoulder, can be better resolved with computed tomography.52 Magnetic resonance imaging can accurately distinguish osteochondromas from

Figure 10. Radiation-Induced Exostosis. A 7-year-old girl returned 4 years after undergoing bone marrow transplantation for chronic myelogenous leukemia because of a newly found “lump” in her right anterior chest. The preparative regimen for her bone marrow transplantation included total body irradiation. Posteroanterior chest radiograph (A) was obtained, demonstrating expansion of the right anterior seventh rib (arrow). Axial limited chest CT (B) was performed through the rib for characterization of the abnormality shown on the chest radiograph and shows the typical appearance of an exostosis (skin marker).

B A



Osteonecrosis

Children undergoing therapy for childhood cancer are at risk for osteonecrosis when treatment includes high dose glucocorticoids, bone marrow transplantation, and/or local radiation (Fig. 11).57 The reported prevalence of osteonecrosis in these survivors varies with the modality used to detect the toxicity (MR being the most sensitive modality), whether or not a report was based upon patients having symptoms, age at the time of diagnosis of the primary disease, and type of treatment.58,59 In contrast to the general population, osteonecrosis in survivors of childhood cancer occurs as a multijoint toxicity in 60% of those in whom it develops. As reported by the Childhood Cancer Survivor Study, the most frequent joints involved are the hips (72%), shoulders (24%) and knees (21%).58

Summary

The rapidly growing population of survivors of childhood cancer underscores the need for recognizing potential sequelae of both the primary disease and associated therapies, to include knowledge of risk factors for complications. While numerous reports are available regarding second malignant neoplasms in this population, only in the more recent past have investigations and understanding of adverse toxicities manifesting after completion of therapy been undertaken. It is with the hope of enhancing care of survivors of childhood cancer that this review of the more common chest manifestations has been developed. Though not meant to be all-inclusive, this work serves as a starting point to enhance the acumen of imaging healthcare providers, and thus, improve the care of these patients.

Acknowledgement

The authors would like to thank Ms. Sandra Gaither for manuscript preparation.

Disclosure

Supported in part by grant P30 CA-21765 from the National Institutes of Health, a Center of Excellence grant from the State of Tennessee, the Le Bonheur Foundation (Memphis TN), and the American Lebanese Syrian Associated Charities (ALSAC).

Figure 11. Osteonecrosis. 20-year-old woman diagnosed with B-cell non-Hodgkin lymphoma at 16 years of age experienced multiple relapses of the disease. She was treated with multiagent chemotherapy that included high dose glucocorticoids. The posteroanterior chest radiograph showed changes of osteonecrosis of the left humeral head. Dedicated radiographs of the shoulders confirmed the advanced osteonecrotic changes of both humeral heads with crescent signs, collapse of the articular surfaces, and intermixed areas of sclerosis and cystic changes.



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23. Kremer LC, van Dalen EC, Offringa M, et al. Frequency and risk factors of anthracycline-induced clinical heart failure in children: a systematic review. Ann Oncol 2002:13:503-512.

24. Orgel E, Zung L, Ji L, et al. Early cardiac outcomes following contemporary treatment for childhood acute myeloid leukemia: a North American perspective. Pediatr Blood Cancer 2013:60:1528-1533.

25. Krischer JP, Epstein S, Cuthbertson DD, et al. Clinical cardiotoxicity following anthracycline treatment for childhood cancer: the Pediatric Oncology Group experience. J Clin Oncol 1997:15:1544-1552.

26. van der Pal HJ, van Dalen EC, van DE, et al. High risk of symptomatic cardiac events in childhood cancer survivors. J Clin Oncol 2012:30:1429-1437.

27. Lipshultz SE. Exposure to anthracyclines during childhood causes cardiac injury. Semin Oncol 2006:33:S8-14.

28. Ylanen K, Poutanen T, Savikurki-Heikkila P, et al. Cardiac magnetic resonance imaging in the evaluation of the late effects of anthracyclines among long-term survivors of childhood cancer. J Am Coll Cardiol 2013:61:1539-1547.

29. Braun-Falco O, Schultze U, Meinhof W, et al. Contact radiotherapy of cutaneous hemangiomas: therapeutic effects and radiation sequelae in 818 patients. Arch Dermatol Res 1975:253:237-247.

30. Kolar J, Bek V, Vrabec R. Hypoplasia of the growing breast after contact-x-ray therapy for cutaneous angiomas. Arch Dermatol 1967:96:427-430.

31. Macklis RM, Oltikar A, Sallan SE. Wilms' tumor patients with pulmonary metastases. Int J Radiat Oncol Biol Phys 1991:21:1187-1193.

32. Pinter AB, Hock A, Kajtar P, et al. Long-term follow-up of cancer in neonates and infants: a national survey of 142 patients. Pediatr Surg Int 2003:19:233-239.

33. Weidman AI, Zimany A, Kopf AW. Underdevelopment of the human breast after radiotherapy. Arch Dermatol 1966:93:708-710.

34. Furst CJ, Lundell M, Ahlback SO, et al. Breast hypoplasia following irradiation of the female breast in infancy and early childhood. Acta Oncol 1989:28:519-523.

35. Kenney LB, Yasui Y, Inskip PD, et al. Breast cancer after childhood cancer: a report from the Childhood Cancer Survivor Study. Ann Intern Med 2004:141:590-597.

36. Papadakis V, Tan C, Heller G, et al. Growth and final height after treatment for childhood Hodgkin disease. J Pediatr Hematol Oncol 1996:18:272-276.

37. van Leeuwen BL, Kamps WA, Jansen HW, et al. The effect of chemotherapy on the growing skeleton. Cancer Treat Rev 2000:26:363-376.

38. Probert JC, Parker BR. The effects of radiation therapy on bone growth. Radiology 1975:114:155-162.



39. Dorr W, Kallfels S, Herrmann T. Late bone and soft tissue sequelae of childhood radiotherapy. Relevance of treatment age and radiation dose in 146 children treated between 1970 and 1997. Strahlenther Onkol 2013:189:529-534.

40. Dawson WB. Growth impairment following radiotherapy in childhood. Clin Radiol 1968:19:241-256.

41. Mitchell MJ, Logan PM. Radiation-induced changes in bone. Radiographics 1998:18:1125-1136.

42. Neuhauser EB, Wittenborg MH, Berman CZ, et al. Irradiation effects of roentgen therapy on the growing spine. Radiology 1952:59:637-650.

43. Parker RG, Berry HC. Late effects of therapeutic irradiation on the skeleton and bone marrow. Cancer 1976:37:1162-1171.

44. Makipernaa A, Heikkila JT, Merikanto J, et al. Spinal deformity induced by radiotherapy for solid tumours in childhood: a long-term follow up study. Eur J Pediatr 1993:152:197-200.

45. DeRosa GP. Progressive scoliosis following chest wall resection in children. Spine (Phila Pa 1976 ) 1985:10:618-622.

46. Merchant TE, Nguyen L, Nguyen D, et al. Differential attenuation of clavicle growth after asymmetric mantle radiotherapy. Int J Radiat Oncol Biol Phys 2004:59:556-561.

47. Murphey MD, Choi JJ, Kransdorf MJ, et al. Imaging of osteochondroma: variants and complications with radiologic-pathologic correlation. Radiographics 2000:20:1407-1434.

48. Harper GD, cks-Mireaux C, Leiper AD. Total body irradiation-induced osteochondromata. J Pediatr Orthop 1998:18:356-358.

49. Faraci M, Bagnasco F, Corti P, et al. Osteochondroma after hematopoietic stem cell transplantation in childhood. An Italian study on behalf of the AIEOP-HSCT group. Biol Blood Marrow Transplant 2009:15:1271-1276.

50. Bordigoni P, Turello R, Clement L, et al. Osteochondroma after pediatric hematopoietic stem cell transplantation: report of eight cases. Bone Marrow Transplant 2002:29:611-614.

51. Danner-Koptik K, Kletzel M, Dilley KJ. Exostoses as a long-term sequela after pediatric hematopoietic progenitor cell transplantation: potential causes and increase risk of secondary malignancies from Ann & Robert H. Lurie Children's Hospital of Chicago. Biol Blood Marrow Transplant 2013:19:1267-1270.

52. Kitsoulis P, Galani V, Stefanaki K, et al. Osteochondromas: review of the clinical, radiological and pathological features. In Vivo 2008:22:633-646.

53. Kang MJ, Lim JS. Bone mineral density deficits in childhood cancer survivors: Pathophysiology, prevalence, screening, and management. Korean J Pediatr 2013:56:60-67.

54. Wasilewski-Masker K, Kaste SC, Hudson MM, et al. Bone mineral density deficits in survivors of childhood cancer: long-term follow-up guidelines and review of the literature. Pediatrics 2008:121:e705-e713.

55. Kaste SC, Shidler TJ, Tong X, et al. Bone mineral density and osteonecrosis in survivors of childhood allogeneic bone marrow transplantation. Bone Marrow Transplant 2004:33:435-441.

56. Wilson CL, Ness KK. Bone Mineral Density Deficits and Fractures in Survivors of Childhood Cancer. Curr Osteoporos Rep 2013.

57. Kadan-Lottick NS, Dinu I, Wasilewski-Masker K, et al. Osteonecrosis in adult survivors of childhood cancer: a report from the childhood cancer survivor study. J Clin Oncol 2008:26:3038-3045.

58. Diller L, Chow EJ, Gurney JG, et al. Chronic disease in the Childhood Cancer Survivor Study cohort: a review of published findings. J Clin Oncol 2009:27:2339-2355.

59. Kaste SC, Karimova EJ, Neel MD. Osteonecrosis in children after therapy for malignancy. AJR Am J Roentgenol 2011:196:1011-1018.


Chest X-Ray, Folio

Introduction

The chest x-ray (CXR) remains one of the most commonly requested imaging studies, yet is one of the most complex and least understood, particularly the intensive care unit (ICU) bedside examination. In addition to deciphering numerous lines, tubes, lung and pleural findings of the AP (anterior-posterior) radiograph, critical care providers look to radiologists’ reports to summarize any pertinent changes in underlying pathological processes. This article will provide an overview of the bedside chest radiograph in the ICU setting, as well as a guide to effective reporting for the radiologist.

While computed tomography (CT) has added tremendous value in chest imaging in ICU patients, the CXR remains the mainstay in ICU imaging. Compared to CT scans, the CXR can be obtained more readily and is associated with less radiation; thus, CXRs can be performed serially for temporal comparison. Ultrasound is becoming more commonplace and can often be complementary to CXR, CT, and physiologic parameters.1

This article presents an overview of common CXR findings in the ICU setting with example reporting, in the hope of increasing awareness of accepted report terminology. It will also touch on traditional views, new techniques/approaches to bedside chest imaging, and technological advances that may improve diagnostic accuracy on CXR and negate the need for CT in some conditions.2

Topic points include positions of lines and tubes, abnormal collections of fluid and air, and common causes of pulmonary opacities. Radiologists should keep in mind that ICU physicians want to know findings that may alter management, those which are potentially life-threatening, as well as pertinent temporal changes.

Approach to the Bedside Chest X-Ray

The recommended approach to CXR interpretation is to first identify abnormal findings, including their location and distribution, and then further define patterns to help classify and categorize. This represents the body of the report. Based upon this information and correlation with any pertinent history, radiologists generate a differential diagnosis, or conclusion; that is, the impression section of the report.

For example, the report body and impression of a CXR describing a consolidation in a patient with cough, fever, and elevated white blood cell count may look like this:

Findings: A focal patchy opacity is noted in the right upper lung field with air-bronchograms.

Impression: Consolidation on right, consistent with pneumonia

It is important to have a systematic approach to CXR interpretation, especially when reviewing complex studies, such as the case shown in Fig. 1. One method uses a mnemonic-based search pattern consisting of the ABCDEs twice. The acronym includes the following: Airway (including an endotracheal [ET] tube, when applicable), Aorta (contours, edges, central lines), Breathing (lungs and pleura), Bones (quick review since this often does not significantly change in the ICU), Circulation (pulmonary vessels), Cardiac (silhouette), Diaphragm (free air, costophrenic angles), Deformity (post-operative, positioning considerations), Soft tissues (chest wall), Shoulders (periphery of projection). Other search patterns include starting in the midline and working one’s way outward or vice versa. The key point is to have a systematic search pattern which includes all aspects of the CXR and ensuring that the pattern is followed on each and every examination. This will help avoid becoming overwhelmed, especially when there are a multitude of findings.

Interpretive Approach and Reporting the Intensive Care Bedside Chest X-Ray


Radiology and Imaging Sciences, National Institutes of Health, Bethesda, MD


Chest X-Ray, Folio

Figure 1. Example of a Potentially Perplexing Case Simplified Through a Systematic Approach and Routine Reporting. Starting with the ET tube, the tip is easily seen at the inferior medial clavicles within 5cm from the carina. Although the NG tube tip is not seen, the sideport is within the stomach; therefore, there is no need to say the tip is not seen. Next, describe the chest tubes and the Swan-Ganz catheter with its tip in right PA. Then move on to the tube effects, such as the subcutaneous emphysema, surgical clips, and extracardiac lucency. In evaluating the hemithoracies, the diaphragmatic silhouette is obscured, especially on the left due to a pleural effusion. Pulmonary opacities within the left hemithorax result from a pleural effusion with underlying parenchymal consolidation versus atelectasis. The cardiac silhouette and aortic contour are enlarged and show lucency on the left representing a pneumomediastinum. Finally, evaluate the extrathoracic regions of the film, including the upper abdomen, soft tissues, and bony structures.

Reports should be predictable and consistent for critical care providers to quickly understand the meaning; for example, some radiologists report on lines and tubes first in the body, keeping that order in the impression. This allows ICU staff and other providers to know where to look for specific information in reports. Standard reporting terminology and formats for chest CT have been proposed, and the Radiologic Society of North America (RSNA) has existing and developing report templates in a variety of formats.3 The RadLex initiative, implemented by RSNA, has led to standardized terms and reporting that may be useful in thoracic imaging.4,5 One group of researchers developed a structured report for the chest x-ray with standardized terminology.6 Although there is no national or international standard, there seems to be a trend in this direction.

Support Devices: Lines and tubes

The ICU generates many requests for support device placement on CXR, especially serial examinations in patients with multiple lines and tubes. The American College of Radiology (ACR) appropriateness criteria provides guidelines for imaging in the setting of line and tube placement.7 The literature supports obtaining a CXR immediately following placement of endotracheal, enteric (especially feeding tubes), and chest tubes; however, it does not support daily CXRs in the absence of a change in clinical condition or suspected line or tube migration.8-10

A comprehensive review of lines and tubes is beyond the scope of this article. However, it is important to know which types of lines and tubes have been placed, along with their optimal locations and potential complications of malpositioning. Figs. 2, 3,

Figure 2. Incorrect Positioning of an Endotracheal Tube. A CT scout image (A) shows an ET tube located within the left mainstem bronchus. Portable chest radiograph following repositioning of the ET tube (B) demonstrates correct positioning within the trachea with residual right lower lobe atelectasis from prior malpositioning; the region of atelectasis resolved on subsequent films (not shown). A B


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and 4 demonstrate examples of correct and incorrect positioning of endotracheal tubes and central venous catheters. Chest tube positioning is discussed in the section covering pathology of the pleural space.

Positioning, Technique Ideas and Technical

Advances

The portable CXR is often inconsistent and sometimes limited due to variable patient positioning (rotation, tilt, angle of inclination, etc.). For example, it can be difficult to evaluate pleural effusions on serial

examinations when technologists have different degrees of inclination and thresholds for placing the “Upright,” “Erect,” or “Semierect” markers on the cassette. Rotation is often accentuated in bedside imaging compared to standard PA projections performed in the Radiology Department, making changes on serial exams more difficult to assess. Overlying material, such as the external component of tubes and lines, also limit visualization and evaluation of underlying structures.

New technologies to improve CXR interpretation are available or in design and include dual energy, temporal subtraction, tomosynthesis, and decision support.11 Also available is line and tube visualization software, which improves conspicuity of various support devices (Fig. 5).12,13 Some centers are using portable CT in the ICU, which has been found to be advantageous due to minimizing the need for patient transport (especially with many support devices) and obtaining more rapid assessments with superior spatial resolution.14

Pleural Fluid, Air, and Loculations

Pleural effusions are common in ICU patients. It is important to distinguish effusions from other pathologic processes, as well as to assess for changes over time on serial examinations. Since fluid is dependent when not loculated or otherwise bound, optimal positioning in as upright a position as possible is paramount. Inconsistent positioning over time often gives false impressions of changes in severity and has variable effects on masking of underlying conditions, such as pneumonia or atelectasis. Technologists will often indicate patient positioning with use of arrows or

Figure 3. Malpositioning of Central Venous Catheters. Portable chest radiograph flowing placement of a right jugular central line (A) shows an abnormal cephalad course of the catheter extending into the neck. Portable chest radiograph following placement of a left subclavian central line in a different patient (B) reveals the catheter coursing into a variant left superior vena cava.

Figure 4. Positioning of Multiple Central Lines. Frontal chest radiograph reveals placement of bilateral peripherally-inserted central venous catheters (PICC lines), as well as a right internal jugular (IJ) central venous catheter (CVC). The tip of the right IJ CVC is optimally located within the distal superior vena cava. The left PICC line tip projects over the right atrium (arrows).

A B


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markers stating “Upright;” however, there is poor agreement or consistency as to when to use such indications. For example, defining a threshold angle of 60 degrees before an examination is to be considered “Upright.” The angle of inclination also affects evaluation for pneumothoraces or free intra-abdominal air.

The use of decubitus projections can be extremely valuable in assessing the mobility and possibly the drainability of pleural fluid, often negating the need for CT (Fig. 6). One should keep in mind, however, that with the many support devices and critical nature of the patient’s underlying medical condition, decubitus positioning in the ICU is often difficult and in some cases not possible. The decubitus view to order is the

side of the effusion or what technologists often refer to as “side down, side seen.” This means that a right-sided effusion should be evaluated with a right side down decubitus projection. This is opposite of the abdominal decubitus projection when looking for free-air (“side up, side seen”) where a left lateral decubitus projection detects free air at the liver margin. Although this appears intuitive, it is important to be clear with the terminology when recommending, ordering, performing, or interpreting decubitus examinations.

Empyemas represent localized infectious collections within the pleural space and are not uncommon in the ICU setting. Differentiation from simple pleural effusions is a common and important question of ICU

Figure 5. Application of the Line and Tube Visualization Software. In this patient who underwent right forequarter amputation from a scapular sarcoma, standard (A) and post-processed (B) CXR images were obtained. The post-processed image (B) more readily identifies the malpositioned left PICC line within the right brachiocephalic vein. There are also postoperative features to the lungs bilaterally with resultant volume loss to left lower lung field. Note a prototype inclination marker in the upper left portion of the image with demonstrates an inclination angle of 60 degrees.

Figure 6. How the Decubitus Projection Can Determine Mobility of Pleural Effusions. Frontal (A) and lateral (B) chest radiographs demonstrate a moderate-sized right pleural effusion with suspected peripheral loculations. The right-side down decubitus view (C) verifies free mobility of the pleural fluid without evidence of loculations, thus negating the need for a CT examination.

A B

A B C


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lower lung field often indicates the presence of a hydropneumothorax. Treatment of pneumothoraces often depends upon the size and pneumothorax and clinical status of the patient. Often times, placement of a chest tube is necessary.

Chest tubes can be malpositioned in a manner where bedside radiography alone is not adequate for evaluation.17 In this setting, CT is often necessary to evaluate for a malpositioned tube, typically when an abnormal course is identified on CXR or the tube is not draining properly. Common findings associated with malpositioning include visualization of the tube within a pulmonary fissure (Fig. 10) or in a superficial location with the sideports outside of the chest cavity. Placement within the pulmonary parenchyma or the

Figure 7. Empyemas. Frontal chest radiograph (A) reveals peripheral opacities along the lateral margins of the thoracic cavities, some of which have irregular borders. The size and extent of the collections were resulting in cardiac tamponade. Coronal reformatted CT image (B) better depicts the loculated collections which were subsequently drained but recurred.

staff. However, the distinction cannot be made on CXR alone. Common findings include loculated, non-mobile collections of pleural fluid (Fig. 7). A relatively specific finding for empyemas includes air-fluid levels that are disparate in size/length when comparing the frontal and lateral projections.15 This supports a non-spherical shape and is helpful in distinguishing empyemas from simple effusions or pulmonary abscesses.16

Most parenchymal abscesses or cavities are spherical in shape, resulting in air-fluid levels of similar size/length on all projections (Fig. 8). Although there are findings suggestive of empyemas on CXR, recommending a CT and potentially image-guided drainage is often in order.

Visualization of air-fluid levels in the pleural space is a useful finding in the setting of subtle pneumothoraces (Fig. 9). A dependent fluid level in the

A B

Figure 8. Lung Abscess. Frontal (A) and lateral (B) chest radiographs show a lung cavity with air-fluid level in the superior segment of the right lower lobe (right upper lung field) that has the same size and configuration on both the PA and lateral views, confirming a spherical shape. Biopsy revealed an aspergilloma in this patient with Job’s syndrome.

A B


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chest wall is less common.

Pulmonary/Lung Opacities

Pulmonary opacities are commonly seen in the ICU setting. Distinguishing between air space disease and

atelectasis, especially on hypoinflated portable CXR, is a common dilemma for radiologists. When air space opacities are identified, differential conditions include pneumonia, pulmonary edema, acute respiratory distress syndrome (ARDS), and pulmonary hemorrhage.

Atelectasis often mimics air space disease on CXR,

Figure 9. Air-fluid Level in the Pleural Space Indicative of a Hydropneumothorax. Frontal chest radiograph (A) demonstrates an air-fluid level within the inferior right hemithorax (thick arrows). Magnified view of the right upper thoracic cavity (B) reveals a subtle pneumothorax (thin arrows).

Figure 10. Malpositioned Chest Tube. Frontal chest radiograph (A) shows bilateral chest tubes with persistent pneumothoraces. The chest tube on the right was not draining properly. Para coronal/axial (B) and sagittal reformatted (C) CT images demonstrate an interfissural course of the right-sided chest tube.

A

A B

B C A

Figure 11. Pneumonia. Frontal chest radiograph (A) demonstrates a focal rounded consolidation, likely within the lateral right middle lobe due to the lack of obscuration of the diaphragmatic border. Coronal reformatted (B) and axial (C) CT images

confirm the middle lobe location and best depict the central air bronchograms in this patient with fever and X-linked agammaglobulinemia

(XLA), which is the underlying cause of the lower lobe bronchiectasis noted on the CT examination.


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pleural effusions.

Acute respiratory distress syndrome (ARDS) often occurs in the setting of shock or inhalation toxicity and results in fluid accumulation within the lung parenchyma. The air space disease may appear similar to that of pulmonary edema; however, it is not typically associated with cardiomegaly or pleural effusions. The air space disease also tends to occur along the lung periphery.18 Chronically, ARDS may result in pulmonary fibrosis.

Pulmonary hemorrhage may be focal, especially in the setting of trauma, or diffuse secondary to an underlying systemic or autoimmune disease process. Chest x-rays demonstrate multifocal air space opacities, which may be ground glass, consolidated, well-defined, or diffuse (Fig. 13). Cavitation is not uncommon.19

Reporting/Terminology

Findings in the body of the report should support the conclusions in the impression. A finding that includes consolidation, for example, should have an impression which includes a portion of the well-known

since it often presents as a focal opacity with or without air bronchograms. A key distinguishing feature is volume loss within the affected lobe, which may be subtle but is a useful discriminator.

The imaging pattern of infectious pneumonia is dependent upon the causative agent. Bacterial infections present with lobar air space disease, which may be localized or multi-focal (Fig. 11). Parapneumonic effusions or empyemas may be seen. Atypical infections, such as viral or Mycoplasma, tend to be interstitial but may occasionally be lobar as well. Nosocomial infections are more diffuse and aggressive with a higher prevalence in patients who are immunosuppressed. Cavitation is common and the morbidity and mortality is significantly higher than community-acquired pneumonia.

Left-sided congestive heart failure demonstrates a predictable sequence of findings on CXR (Fig. 12). Initially, there is enlargement of the cardiac silhouette with cephalization of pulmonary blood flow. As the degree of heart failure progresses, interstitial edema is noted with prominent interstitial markings along the periphery of the lung fields (Kerley B lines). Finally, edema extends into the pulmonary parenchyma and pleural space, resulting in air space opacities and

Figure 12.

Congestive Heart Failure/Pulmonary Edema. Sequential frontal chest radiographs in a patient with progressive heart failure (A, B, and C) show an initial normal examination (A) with subsequent development of cardiomegaly, cephalization of pulmonary vasculature, and increased peripheral interstitial markings – referred to as Kerley B lines (B). Air space disease and pleural effusions are common and best depicted on images B and C. The relative increased lung volumes on image C are the result of interval intubation; enteric tubes and a right IJ CVC were also placed in this patient (C) and are appropriately positioned. A coronal reformatted image (D) nicely shows the peripheral Kerley lines, as well air space disease within the right lower lobe.

A B

C D


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differential diagnosis of water, pus, blood, protein, and cells based upon the clinical history. If there is a new finding of a focal opacity and the critical care team is looking for infection, then pneumonia is most likely. If the opacity is diffuse, then fluid or blood (DAH) may be added to the list of differentials.

There are unique considerations in CXR terminology with regards to 2-dimensional representation of 3-dimensional structures. For example, there is considerable overlap and variability of lung lobes; hence the use of the term lung “fields,” which is commonly used and appropriate. Also, if a central line tip appears low in the superior vena cava (SVC), positioning and projection could mean that the tip is actually in right atrium; therefore, the broader phrase “overlying the cavoatrial junction” may be useful.

ICU staff, like radiologists, are busy and want concise information at their fingertips. The radiologist should avoid extraneous information and be

consistent and predictable. If the tip of the enteric tube is not seen but the sideport is visible, state the location of the sideport; there is no need to state that the tip is not seen in such cases.

Although residents and fellows are often taught not to use the term “infiltrate,” it may provide flexibility for both the radiologist and the ordering provider. For example, if one commits to “consolidation” or “fluid,” this may minimize options for the clinician. Keeping the differential (impression) broader allows providers to apply the clinical information to their management. However, there is a fine line between keeping differentials broad and being noncommittal or “hedging.”

Having an organized search pattern is essential in evaluating the entire film. It also helps prevent “satisfaction of search” where obvious abnormalities

Figure 13. Diffuse Alveolar Hemorrhage. Frontal chest radiograph in a patient with known Kaposi Sarcoma involving the lungs (A) demonstrates multifocal interstitial and air space pulmonary opacities, as well as a left-sided pneumothorax. As the patient’s condition continued to deteriorate, subsequent imaging (B) shows extensive, diffuse pulmonary opacification. The support lines and tubes are appropriately positioned. Autopsy revealed diffuse alveolar hemorrhage.

Figure 14. Unsuspected Finding on CXR. A frontal radiograph of the chest and abdomen for line and tube placement (A) reveals an unusual bowel gas pattern compatible with pneumotosis intestinalis, which was confirmed on CT (B). The right-sided PICC line is in the SVC; the feeding tube tip is not seen, however, it courses well into the duodenum.


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are noted initially and more subtle findings are overlooked.20 Fig. 14 shows an unsuspected case of pneumotosis intestinalis picked-up on a CXR for line and tube placement.

Interaction With Intensive Care Team; The

Report is Just the Beginning; ICU Rounds, Process

Although the radiology report represents the final product of a particular diagnostic imaging study, it may also represent the beginning of a diagnostic and procedural dialogue with ordering providers. A continuous feedback and understanding of clinicians’ needs provides insight that is otherwise not gained if radiologists remain in isolation. Breaking the misguided and stereotypical perceptions of radiologists keeping to themselves in a dark room will improve communication chains with ordering providers and help guide the work-up and care for the most critically-ill patients.

Summary

The chest x-ray remains one of the most common, important, and complex examinations in the ICU setting. Given the multitude of pathologies and support devices often encountered, it is critical that radiologists develop and follow a logical search pattern to help define the underlying abnormalities, evaluate all aspects of the film, and avoid “satisfaction of search.” Correlating findings with the patient’s clinical status will aid in providing a useful list of differentials. Most importantly, continuous communication with ordering providers will allow radiologists to help guide

1. Silva S, Biendel C, Ruiz J, et al. Usefulness of cardiothoracic chest ultrasound in the management of acute respiratory failure in critical care practice. Chest. 2013;144(3):859-65.

2. Rubinowitz AN, Siegel MD, Tocino I. Thoracic imaging in the ICU. Crit Care Clin 2007;23(3):539-73.

3. Radiologic Society of North America (RSNA) radiology reporting initiative. Chest Radiography. http://www.radreport.org/specialty/ch, accessed Sep 2013.

4. RadLex, Radiology Society of North America (RSNA). Available at http://www.radlex.com, accessed Aug 2013.

5. Marwede D, Schulz T, Kahn T. Indexing thoracic CT reports using a preliminary version of a standardized radiological lexicon (RadLex). J Digit Imaging 2008;21(4):363-70.

6. Hasegawa Y, Matsumura Y, Mihara N, et al. Development of a system that generates structured reports for chest x-ray radiography. Methods Inf Med 2010;49(4):360-70.

7. ACR Appropriateness Criteria; http://www.acr.org/~/media/ACR/Documents/AppCriteria/Diagnostic/RoutineChestRadiographsInICUPatients.pdf, accessed July 2013.

8. Hejblum G, Chalumeau-Lemoine L, Ioos V, et al. Comparison of routine and on-demand prescription of chest radiographs in mechanically ventilated adults: a multicentre, cluster-randomised, two-period crossover study. Lancet 2009; 374:1687-1693.

9. Graat ME, Choi G, Wolthuis EK, et al. The clinical value of daily routine chest radiographs in a mixed medical-surgical intensive care unit is low. Crit Care 2006; 10(1):R11.

10. Krivopal M, Shlobin OA, Schwartzstein RM. Utility of daily routine portable chest radiographs in mechanically ventilated patients in the medical ICU. Chest 2003; 123(5):1607-1614.

11. Jaeger S, Karargyris A, Candemir S, et al. Automatic screening for tuberculosis in chest radiographs: a survey. Quant Imaging Med Surg 2013;3(2):89-99.

12. Folio L. Chest Imaging; An algorithmic approach to learning. New York: Springer, 2012, 136-37.

13. Foos DH, Yankelevitz DF, Wang X, et al. Improved visualization of tubes and lines in portable intensive care unit radiographs: a study comparing a new approach to the standard approach. Clin Imaging 2011; 35(5):346–352.

14. Teichgräber UK, Pinkernelle J, Jürgensen JS, et al. Portable computed tomography performed on the intensive care unit. Intensive Care Med 2003;29(3):491-5.

15. Bouros D (ed.). Pleural Disease, 2nd ed. New York: Informa, 2010, 35.

16. Porcel JM, Light RW. Diagnostic approach to pleural effusion in adults. Am Fam Physician 2006;73(7):1211-1220.

17. Lim KE, Tai SC, Chan CY, et al. Diagnosis of malpositioned chest tubes after emergency tube thoracostomy: is computed tomography more accurate than chest radiograph? Clin Imaging 2005;29(6):401-5.

18. Arsani A, Kaewlai R, Digumarthy S, et al. Urgent findings on portable chest radiography: what the radiologist should know – self-assessment module. Am J Roentgenol 2011; 196: WS37-46.

19. Primack SL, Miller RR, Müller NL. Diffuse pulmonary hemorrhage: clinical, pathologic, and imaging features. Am J Roentgenol 1995; 164: 295-300.

The views expressed in this material are those of the author, and do not reflect the official policy or position of the U.S. Government or NIH.

the work-up and management of the most critically-ill patients.

References


Case Report, Crum

Cavitary Lung Mass in a Febrile Child

Rachel Pevsner Crum, D.O., Ricardo Restrepo, M.D., Nolan Altman, M.D.

Department of Radiology, Miami Children’s Hospital, Miami, FL

Case Presentation

A 13-year-old boy with asthma, gastroesophageal reflux (GERD), multiple food allergies, and history of 2 uncomplicated right middle lobe pneumonias within the last year presented to the emergency room with persistent cough and fever (max 102˚F) for 10 days, despite macrolide antibiotic treatment. A chest radiograph was performed in the emergency, followed by an esophagram/upper GI and CT examinations after admission (Fig).

Figure. Chest radiograph on initial presentation (A) shows a large right upper lobe mass-like opacification with an air-fluid level. Also noted

is a dilated esophagus (arrows). Esophagram performed 2 days later (B) shows diffuse, moderate dilatation of the esophagus and typical

findings of achalasia with a “bird’s beak” appearance of distal esophagus (arrow) and persistent air-fluid level in the upright position.

Despite IV antibiotic treatment, the patient did not improve clinically. Increasing size of the abscess on serial radiographs (not shown) was

worrisome. Chest CT for further evaluation (C) shows enlargement of the right upper lobe consolidation with thick, irregular walls and an

internal air-fluid level. The region of consolidation forms acute angles with the chest wall. Ultrasound-guided percutaneous drainage was

performed; procedural chest radiograph following catheter placement and contrast injection (D) reveals confirmation of proper catheter

placement. The infectious collection was successfully drained. Follow-up chest radiograph 8 weeks later showed resolution of the region of

consolidation with a small residual linear opacity (not shown).

C

B A

D


Case Report, Crum

Key Clinical Finding

Recurrent pneumonia

Key Imaging Findings

Cavitary mass with internal air-fluid level

Differential Diagnoses

Lung abscess

Empyema

Necrotizing pneumonia

Discussion

Although uncommon, complications from pneumonia in children do occur, and recent literature has suggested that they are increasing in prevalence.1 Complications of pneumonia include parapneumonic effusions, empyemas, lung abscesses, necrotizing pneumonia (multiple small abscesses), and empyema neccessitatis. These complications can lead to extended hospital admission and increased morbidity.1 Children usually recover completely without significant sequelae, unlike adults who often have underlying lung disease or co-morbidities.2 Although surgical intervention is often required to treat adults with these same complications due to high associated mortality (20%), children often need only conservative medical management.2,3

Ultrasound is invaluable for evaluation of the pediatric chest, as it involves no ionizing radiation, can be performed bedside, and allows excellent evaluation of simple or complex parapneumonic effusions and abscesses. Ultrasound should be used as first-line confirmation of a pleural effusion, as well as to guide treatment and need for percutaneous drainage, as it can readily distinguish between fluid, consolidations, and loculations.2 Ultrasound detects thin septae, fibrin strands, internal debris, and loculations in complex effusions, which are usually not evident by CT. CT should be reserved for complicated cases with worsening respiratory function or immunocompromised patients.2

For parapneumonic effusions and abscesses which are expanding or compromising respiratory function,

percutaneous drainage should be considered. Ultrasound guidance is preferred, as it allows for real-time localization of collections or abscesses. Direct visualization under ultrasound is advantageous for catheter insertion and manipulation through septae or thick loculations that can interfere with drainage. In children, CT should not be used routinely; CT-guided drainage should be avoided, when possible, due to the potential risks of ionizing radiation in the pediatric population.2 Adjunctive tissue plasminogen activator (tPA) can be administered via a percutaneous catheter to promote drainage of an abscess by lysing fibrin strands.4 At our institution, we routinely use tPA for drainage of loculated effusions and empyemas with good results, although use of tPA is controversial in the literature. One major complication of percutaneous drainage is the formation of a bronchopleural fistula; however, these may also occur directly from the complicated pneumonia alone. Tissue plasminogen activator is contraindicated if a bronchopleural fistula is present. Other major complications of percutaneous drainage include pneumothorax and hemorrhage.

Pulmonary Abscess.

Pulmonary abscesses can be classified as primary or secondary. Primary pulmonary abscesses in a child are usually a complication of pneumonia or aspiration.5 Secondary pulmonary abscesses can be caused by underlying lung disease or pulmonary abnormality, either congenital or acquired. Secondary abscesses can also be seen in patients at risk of aspiration, such as those with neurodevelopmental abnormalities (seizures, muscular dystrophy) or esophageal abnormalities (achalasia, tracheoesophageal fistula, strictures).6 Underlying pulmonary disorders, such as cystic fibrosis or congenital lung malformation, are also implicated as causes of recurrent pneumonia and pulmonary abscesses.6

Radiographs often show a large cavitary mass with thick walls; air-fluid levels may be seen. CT may not be necessary on a routine basis, as radiographs may be sufficient for the diagnosis. Contrast-enhanced CT may be useful for delineation and extent of disease but should only be performed for worsening respiratory symptoms. On CT, pulmonary abscesses are usually round with thick walls and irregular luminal


Case Report, Crum

surfaces. Vessels and bronchi terminate abruptly at the abscess edge, and the walls of the abscess form acute angles with the chest wall.7 On ultrasound, abscesses are seen as a thick-walled collections containing echogenic pus and debris. Internal septations and bright echogenic foci with dirty shadowing from intraluminal air may be seen.

Lung abscesses in children often resolve with medical treatment alone. Usually, at least a 3-week course of intravenous antibiotics is needed with coverage for anaerobic organisms, which are most commonly implicated in pulmonary abscesses.8,9 However, in some cases, the patient may require intervention with ultrasound-guided percutaneous drainage. Abscess drainage is indicated if the patient has persistent fever, sepsis, or worsening respiratory symptoms which are not responding to medical treatment alone.2 Other indications include an enlarging abscess collection or imminent rupture into a bronchus. Percutaneous ultrasound-guided drainage of a recalcitrant pulmonary abscess is safe and effective, avoids surgery, and helps to shorten the clinical course of the illness.5

Empyema.

Empyemas form as a complication of pneumonia and are characterized as complex collections of pus within the pleural space. Inflammation of the pleura leads to increased vascular permeability and fibrin production, resulting in pleural adhesions which can form a thick rind.3 Blockage of lymphatic drainage leads to increasing fluid accumulation, further compressing and compromising the adjacent lung parenchyma.3 Empyema formation evolves in 3 stages: 1) an exudative phase with inflammation and simple effusion of low cellular count; 2) a fibrinopurulent phase in which fibrin covers the pleura and forms thin septae and loculations; and 3) an organizing phase with formation of a thick fibrous capsule which prevents lung re-expansion.3

On radiographs, empyemas appear as loculated effusions with convex borders or consolidated lung. On CT, empyemas are often lentiform in shape, compress vessels and bronchi, and form obtuse margins with the chest wall.7 Uniform thickening of the visceral and parietal pleura form the “split pleural” sign previously described in the literature.7 Pleural enhancement is usually present and greatest along the

visceral pleural. Ultrasound is important, as it can distinguish fluid which is not readily defined on chest radiographs. Ultrasound of an empyema defines pleural thickening, loculations (which may have a honeycombed appearance), fibrous strands, and septae in the pleural space.

Most empyemas can be treated conservatively with antibiotics and chest tube drainage.2 At our institution, adjunctive tPA is used when draining empyemas. Video-assisted thoracoscopic surgery is reserved for severe cases which do not respond to conservative management. Within the current literature, there is still no clear consensus on surgical treatment in children.1-3

Necrotizing Pneumonia.

Necrotizing pneumonia or cavitary necrosis is a severe complication of pneumonia with destruction of the lung parenchyma and gangrenous necrotizing changes; there may be formation of multiple small abscesses. Necrosis develops as a result of ischemia caused by inflammation with occlusion of capillary vessels.6 Although the illness is severe, children usually recover fully without the need for surgical intervention or severe sequelae, contrary to what is typically seen in adults.6

On chest radiographs, necrotizing pneumonia appears as a large consolidation which may or may not contain small lucencies or cavities. CT is more sensitive than radiographs for evaluation of cavitation.6 Unlike pulmonary abscesses, necrotizing pneumonia on CT demonstrates loss of the normal lung architecture, decreased parenchymal enhancement, and absence of a thick wall. On ultrasound, consolidated lung will have multiple small cystic and hypoechoic areas with decreased or only mild peripheral color flow.


Case Report, Crum

Diagnosis

Pulmonary abscess secondary to occult aspiration from underlying esophageal achalasia.

Summary

In summary, children with recurrent pneumonia should receive follow-up imaging to document resolution of the infectious process and exclude an underlying pathologic process or mass. In our patient, the underlying cause of recurrent pneumonia - and ultimately abscess formation - was occult aspiration due to primary achalasia. Although our patient had been treated clinically in the past for gastroesophageal reflux, an upper GI was not preformed until an observant radiologist recommended the study for a dilated esophagus noted on chest radiographs.

Pulmonary abscesses in children are commonly related to pneumonia or aspiration. Children usually have an excellent prognosis with conservative medical management and no significant long-term sequelae. Percutaneous ultrasound-guided drainage should be considered if clinical symptoms do not improve, the abscess enlarges, or there is impending rupture into a bronchus. First-line ultrasound should be considered to distinguish between complex and simple parapneumonic pleural effusions, as it is effective in delineating loculations and septations.

References

1. Cohen E, Weinstein M, Fisman DN. Cost-effectiveness of competing strategies for treatment of pediatric empyema. Pediatrics 2008; 121:e1250-57.

2. I M Balfour-Lynn, E Abrahamson, G Cohen, et al. BTS guidelines for the management of pleural infection in children. Thorax 2005; 60: i1-21.

3. Calder A, Owens CM. Imaging of parapneumonic pleural effusions and empyema in children. Pediatr Radiol 2009; 39:527-537.

4. Grevais DA, Levis DA, Hahn PF, et al. Adjunctive Intrapleurral Tissue Plasminogen Activator Administered via Chest tubes Placed with Imaging Guidance: Effectiveness and Risk for Hemorrhage. Radiology 2008; 246:956-963.

5. Alsubie H, Fitzgerald DA. Lung Abscess in Children. Journal of pediatric infectious diseases 2009; 4:27-35.

6. Donnelly LF, Klosterman LA. Cavitary Necrosis Complicating Pneumonia in Children: Sequential Findings on Chest Radiography. AJR 1998; 171:253-256.

7. Stark DD, Federle MP, Goodman PC, Podrasky AE, Webb WR. Differentiating lung abscess and empyema: radiography and computed tomography. Am J Roentgenol 1983;141(1):163-167.

8. Emanuel B, Shulman ST. Lung Abscess in infants & Children. Clin Pediatr 1995 34:2-6.

9. Bartlett JG. Anaerobic bacterial infections of the lung and pleural space. Clin Infect Dis 1993; 16:S248–255.


Case Report, Concepcion et al.

Pulmonary Vascular Anomaly

Nathan David P. Concepcion, M.D., Bernard F. Laya, D.O., Ana Maria Saulog, M.D.

Institute of Radiology, St. Luke’s Medical Center, Quezon City and Global City, Philippines

Case Presentation

A 32-year-old man presented with a two-year history of chronic cough and episodes of hemoptysis. He had been previously managed as having pulmonary tuberculosis. A chest CT was performed at another institution, which revealed a vascular malformation. CT angiography of the pulmonary arteries and aorta (Fig.) was advised and subsequently performed at our center.

Figure. Coronal reformatted images (A and B) show a

large arterial branch emanating from the descending

thoracic aorta (A) supplying the left lower lobe, as well

as a prominent pulmonary vein normally draining into

the left atrium (LA). Axial image in lung window (C)

shows the abnormal vessels with hyperemia in the left

lower lobe. No consolidation, soft tissue mass, or cyst

is noted. 3-D reconstruction seen from the posterior

view (D) shows the large systemic branch from the

descending thoracic aorta (long arrow) and a

hypoplastic pulmonary arterial supply (short arrow) to

the left lower lobe.

C

A

LA

B A

D



Key Clinical Finding

Chronic cough with hemoptysis


Pulmonary vascular anomaly

Systemic arterial supply to the left lower lobe with prominent pulmonary venous drainage


Pulmonary arteriovenous malformation

Pulmonary varix

Pulmonary sequestration

Pulmonary pseudosequestration

Discussion

Congenital bronchopulmonary foregut anomalies may involve the lung parenchyma, airways, and/or vascular arterial supply and venous drainage.1,2 These are included in a spectrum, which ranges from abnormal lung parenchyma with normal vasculature to abnormal vasculature with normal lung parenchyma. In between are lesions with mixed parenchymal and vascular abnormalities.3,4,5

Although chest radiographs play a role in the incidental detection and initial imaging evaluation for such lung lesions, 5 CT is very useful in confirming the presence of a lesion, determining its extent, defining

associated abnormalities,1 and as pre-operative evaluation for surgical cases. 5 3-D and multiplanar reformations can be particularly helpful in delineating abnormalities of the bronchi and arterial and venous vasculature.1

Pulmonary Arteriovenous Malformation.

Pulmonary arteriovenous malformations (AVMs) usually present with dyspnea, hemoptysis, cyanosis, or clubbing; they may also be asymptomatic and found incidentally. These lesions are caused by abnormal communication between the pulmonary arteries and veins and occur most frequently in the lower lobes.1,2,5 CT may demonstrate more complex appearances, such

as a plexiform mass of dilated vascular channels or with dilated, tortuous direct communication between an anomalous feeding artery and draining vein (nidus). AVMs may be solitary or multiple. Multiple lesions are often associated with hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome.1,5 An AVM is excluded in our patient because of the presence of a systemic arterial supply to the left lower lobe and the lack of a definite direct communication between the pulmonary artery and vein.

Pulmonary Varix.

Pulmonary varix refers to an enlargement of a segment of a pulmonary vein without an enlarged feeding artery or nidus. This is typically seen near the left atrium with contiguity with the pulmonary vein. Varices may be congenital or acquired. Patients are usually asymptomatic and generally not treated, but may also present with hemoptysis; hence, surgery may be required.5 Although the left inferior pulmonary vein is prominent in our patient, the presence of a large systemic arterial supply makes this diagnosis unlikely.

Pulmonary Sequestration.

Pulmonary sequestration is characterized by dysplastic, nonfunctioning lung parenchyma that does not communicate with the tracheobronchial tree and has an anomalous systemic arterial supply,1,2,3,4,5 usually from the thoracic or abdominal aorta; arterial supply from the celiac, splenic, intercostal, subclavian, or even coronary arteries is less common.3,4 A sequestration may appear as a persistent opacity or mass. It may be associated with congenital pulmonary airway malformation (CPAM), in which case air may be present within the lesion. Lesions may also contain air when infected. The most common location is within the left lower lobe.1,2,4 Sequestrations can be intralobar (within visceral pleura and venous drainage via the inferior pulmonary vein) or extralobar (separate pleural covering with venous drainage usually via systemic veins, typically the azygous vein and less commonly via the portal, left subclavian, or internal mammary veins).1,2,3,4,5 The imaging findings in our patient are very similar to a pulmonary sequestration, except that the involved lung only shows hyperemia with a normal tracheobronchial tree.



Pulmonary Pseudosequestration.

Pseudosequestration is within the sequestration spectrum and is characterized by lung parenchyma that is perfused by a systemic artery but maintains a normal tracheobronchial tree. The pulmonary artery is often rudimentary or hypoplastic with poor arborization.6 Although the cause of the systemic arterial supply is unknown, it is thought that persistence of an embryonic connection between the aorta and the pulmonary parenchyma leads to the anomaly.7

According to Yamanaka and colleagues,8 patients may range from 0 to 68 years of age and are predominantly male. Pseudosequestration is often left-sided and supplied by a branch of the descending thoracic aorta. The pulmonary veins drain normally into the left atrium. Most patients are asymptomatic; when symptomatic, hemoptysis, exertional dyspnea, and congestive heart failure from left heart overload are the most common presentations.8 A cardiac (continuous or systolic) murmur is the most common clinical manifestation in children.7,8

Based upon the above-mentioned characteristics, our patient has pulmonary pseudosequestration in the left lower lobe.

Diagnosis

Pulmonary pseudosequestration

Summary

With the advances in CT having multi-detector technology, the evaluation and diagnosis of congenital bronchopulmonary foregut malformations is greatly enhanced. Thorough and careful assessment of the airway, lung parenchyma, esophagus, arteries, and veins should be systematically analyzed in order to arrive at the correct diagnosis. The treatment plan is dependent in the proper identification of the pulmonary and systemic vessels.

In our 32-year-old patient who presented with a two-year history of chronic cough and hemoptysis, CT findings in the left lower lobe of a predominantly systemic arterial supply from the descending thoracic aorta, a small pulmonary arterial supply, a prominent left inferior pulmonary vein draining into the left atrium, and a normal tracheobronchial tree leads to the diagnosis of pulmonary pseudosequestration.

References

1. Daltro P, Bradley LF, Donnelly LF, et al. CT of Congenital Lung Lesions in Pediatric Patients. AJR 2004; 183: 1497-1506.

2. Daltro P, Werner H, Gasparetto TD, et al. Congenital Chest Malformations: A Multimodality Approach with Emphasis on Fetal MR Imaging. RadioGraphics 2010; 30: 385-395.

3. Biyyam DR, Chapman T, Ferguson MR, et al. Congenital Lung Abnormalities: Embryologic Features, Prenatal Diagnosis, and Postnatal Radiologic-Pathologic Correlation. RadioGraphics 2010; 30: 1721-1738.

4. Newman B. Congenital bronchopulmonary foregut malformations: concepts and controversies. Pediatr Radiol 2006; 36: 773–791.

5. Lee EY, Boiselle PM, Cleveland RH. Multidetector CT Evaluation of Congenital Lung Anomalies. Radiology 2008; 247: 632-648.

6. Singh AS, Subbain SK, Subramanian KG, et al. Pseudosequestration of the left lung. Tex Heart Inst J 2007; 34 (2): 195-198.

7. Do KH, Goo JM, Im JG, et al. Systemic Arterial Supply to the Lungs in Adults: Spiral CT Findings. RadioGraphics 2001; 21: 387-402.

8. Yamanaka A, Hirai T, Fujimoto T, et al. Anomalous systemic arterial supply to normal basal segments of the left lower lobe. Ann Thorac Surg 1999; 68: 332-338.


Case Report, Takla et al.

Interstitial Lung Disease

Shereef Takla, B.S.a, Aaron M. Betts, M.D.b

a Uniformed Services University of the Health Sciences, Bethesda, MD b Department of Radiology, University of Cincinnati Medical Center, Cincinnati, OH

Case Presentation

A 76-year-old woman with a history of heart failure presented with 3 days of non-productive cough and increased dyspnea both at rest and with exertion. The patient had been admitted for community-acquired pneumonia 6 months earlier and has required supplemental home oxygen since that illness. She denied prior history of smoking or significant occupational/environmental pulmonary exposures. On clinical examination, she was afebrile with an oxygen saturation of 93% on room air. Pulmonary auscultation revealed mild respiratory crackles at the lung bases. A high resolution CT of the chest was performed (Figs. 1-3) .

Figure. Axial high-resolution computed tomography (CT) images through the chest (A and B) show septal thickening with a

subpleural distribution and traction bronchiectasis. Fibrotic changes with honeycombing are noted at the posterior lung bases

(B). Coronal reformatted CT image (C) demonstrates the basilar and subpleural distribution of the findings seen above.

Mosaic ground glass attenuation is also noted .

C

B A



Key Clinical Findings

Increased dyspnea with non-productive cough

Bibasilar inspiratory crackles


Interstitial lung disease with a peripheral basilar distribution


Usual interstitial pneumonia

Non-specific interstitial pneumonia

Interstitial lung disease associated with connective tissue disease

Asbestosis

Discussion

Interstitial lung disease (ILD) encompasses a broad category of pulmonary diseases affecting the interstitium of the lung. Progressive dyspnea and cough are common presenting symptoms. The clinical assessment of patients with suspected ILD includes a thorough history, physical examination, and pulmonary function testing. The radiologic evaluation includes chest radiographs and high-resolution CT. The information obtained from clinical and imaging evaluations may often yield a leading diagnosis without the need for conformational surgical lung biopsy.

Progressive dyspnea, non-productive cough, and restrictive pattern on pulmonary function testing raise clinical suspicion for an interstitial process. The radiologic findings may confirm the presence of an interstitial process, and the specific findings and distribution may further narrow the differential diagnosis. In the context of high-resolution CT showing septal thickening with basilar and subpleural distribution, honeycombing, and traction bronchiectasis, the primary differential diagnosis includes usual interstitial pneumonia, interstitial lung disease associated with connective tissue disease, and asbestosis. A final diagnosis is often not possible by

high-resolution CT alone. However, correlation of the imaging appearance with patient’s medical history, occupational/exposure history, and progression over time can often yield a final diagnosis.

Usual Interstitial Pneumonia/Idiopathic Pulmonary Fibrosis.

Idiopathic interstitial pneumonias are primarily classified by histopathologic patterns and criteria. These patterns correlate with fairly characteristic findings on high resolution CT imaging of the chest. Among the idiopathic interstitial pneumonias, usual interstitial pneumonia (UIP) is the most common histologic and imaging pattern. Idiopathic pulmonary fibrosis (IPF) is the prototypical and most common entity that corresponds to the morphologic pattern of UIP.

Patients with UIP/IPF are usually 50 years or older at the time of diagnosis. A history of smoking is associated with increased risk of IPF. Patients often do not respond to treatment with corticosteroids, resulting in a relatively poor prognosis. Patients with UIP/IPF have a median survival ranging from 2 to 4 years after initial diagnosis.1,2

On chest radiographs, UIP/IPF may appear normal or demonstrate decreased lung volumes with reticular markings in an apicobasilar distribution with more advanced disease. High-resolution CT imaging shows reticular opacities with a basilar and peripheral (subpleural) predominance, honeycombing, and traction bronchiectasis. Ground glass opacities may also be seen.1,2

Non-Specific Interstitial Pneumonia.

In the context of the morphologic pattern of UIP, non-specific interstitial pneumonia (NSIP) should be considered. While the characteristic imaging findings of NSIP are somewhat different from UIP, there is a considerable overlap between the two conditions. NSIP shows a similar pattern of subpleural reticular opacities with traction bronchiectasis. However, NSIP tends to lack the apicobasilar gradient and honeycombing. Ground glass opacities are a more prominent feature of NSIP compared to UIP. Clinically, patients with NSIP tend to be slightly younger than patients with UIP (age 40-50).



The most important clinical distinction between UIP and NSIP is prognosis. The histologic pattern of cellular NSIP (predominantly inflammatory without fibrosis) has a survival rate of nearly 100%, and the histologic pattern of fibrotic NSIP is associated with a 5-year survival rate of 45-90%. Compared to UIP, NSIP also shows a favorable response to treatment with corticosteroids and cytotoxic agents.1-3

Connective Tissue Disease Associated Interstitial Lung Disease.

Connective tissue diseases are a group of inflammatory autoimmune-mediated processes that may affect multiple organ systems, including the lung parenchyma and chest cavity. Rheumatoid arthritis and progressive systemic sclerosis are two of the more common connective tissue diseases that may result in interstitial lung disease with reticular opacities in a basilar distribution. The interstitial lung disease that develops with these entities may show a histologic pattern of UIP or NSIP, with UIP being more common in rheumatoid arthritis, and NSIP more common in progressive systemic sclerosis.

The prevalence of interstitial lung disease in rheumatoid arthritis is variable, ranging from 5 to 40%. Interstitial lung disease is usually a late complication of the disease. Other common thoracic manifestations of rheumatoid arthritis include pleural thickening or pleural effusion. Rarely, cavitary necrobiotic rheumatoid nodules may be seen.

Approximately 80% of patients with progressive systemic sclerosis will develop interstitial lung disease, and up to 97% of patients with progressive systemic sclerosis will have esophageal involvement of the disease, leading to esophageal dysmotility. On imaging, the esophageal involvement manifests as a patulous and fluid-filled esophagus. The coexistence of these common manifestations is highly suggestive of interstitial lung disease associated with progressive systemic sclerosis.4,5

Asbestosis.

Asbestos is a non-combustible and durable silicate mineral that has been commercially developed for many purposes. The most common commercial applications include insulation material and brake pads/linings. The two main classifications of asbestos

fibers are serpentine and amphiboles. As the name implies, the serpentine fibers are curly and flexibile, while the amphiboles are straight, needle-shaped fibers. While both forms may lead to asbestos-related lung disease, the amphiboles are considered more toxic. Exposure to asbestos fibers by inhalation can lead to various manifestations of asbestos-related lung disease, including pleural effusion, pleural plaques (with or without calcification), diffuse pleural thickening, and/or malignant mesothelioma. Patients with asbestos exposure are also at increased risk of primary bronchogenic carcinoma.

Asbestosis is a form of asbestos-related lung disease that leads to interstitial fibrosis. Asbestosis is clinically and histologically similar to idiopathic pulmonary fibrosis. On high-resolution CT imaging, asbestosis will show subpleural septal thickening and traction bronchiectasis in a similar distribution as seen with UIP/IPF; honeycombing is seen in more advanced cases.6 Concomitant asbestos-related pleural disease may be seen in 75-83% of patient with asbestosis. However, in the absence of pleural abnormalities, asbestosis and idiopathic pulmonary fibrosis cannot be differentiated by imaging alone.7



Diagnosis

Usual interstitial pneumonia/idiopathic pulmonary fibrosis

Summary

High-resolution CT is an important component in the evaluation of interstitial lung disease. When used in conjunction with a thorough history, physical examination, and pulmonary function testing, high-resolution CT imaging may eliminate the need for surgical lung biopsy. Knowledge of subtle differences in the imaging of various interstitial lung diseases may help narrow the differential diagnosis. However, there is significant overlap in the imaging appearance of various interstitial lung diseases, and a final diagnosis by imaging alone is not always possible. Rather, the high-resolution CT findings must often be interpreted in the context of patients medical, occupation, and exposure history.

References

1. Mueller-Mang C, Grosse C, Schmid K, et al. What every radiologist should know about idiopathic interstitial pneumonias. Radiographics 2007;27(3):595-615.

2. Wittram C, Mark EJ, McLoud TC. CT-histologic correlation of the ATS/ERS 2002 classification of idiopathic interstitial pneumonias. Radiographics 2003;23(5):1057-1071.

3. Kligerman SJ, Groshong S, Brown KK, et al. Nonspecific interstitial pneumonia: radiologic, clinical, and pathologic considerations. Radiographics 2009;29(1):73-87.

4. Capobianco J, Grimberg A, Thompson BM, et al. Thoracic manifestations of collagen vascular diseases. Radiographics 2012;32(1):33-50.

5. Kim EA, Lee KS, Johkoh T, et al. Interstitial lung diseases associated with collagen vascular diseases: radiologic and histopathologic findings. Radiographics 2002;22 Spec No:S151-165.

6. Roach HD, Davies GJ, Attanoos R, et al. Asbestos: when the dust settles an imaging review of asbestos-related disease. RadioGraphics 2002;22 Spec No:S167-184.

7. Akira M, Yamamoto S, Inoue Y, et al. High-resolution CT of asbestosis and idiopathic pulmonary fibrosis. Am J Roentgenol 2003;181(1):163-169.

The views expressed in this material are those of the author, and do not reflect the official policy or position of the U.S. Government, the Department of Defense, or the Department of the Army.


Case Report, Joshi et al.

Posterior Mediastinal Mass

Anagha Joshi, M.D., DMRE, Chintan Trivedi, M.D., DNB, Ashank Bansal, MBBS

Lokmanya Tilak Municipal Medical College & Lokmanya Tilak Municipal General Hospital, Sion, Mumbai, India

Case Presentation

A 57-year-old woman presented with epigastric pain and cough for a period of 15 days, as well as a history of significant weight loss of 12 kgs in past 2 months. The patient had no significant past medical history. A chest x-ray was performed (Fig. 1), which prompted further work-up, consisting of a contrast-enhanced CT (Fig. 2) MRI (not shown), and PET-CT (Fig. 3). Frontal chest radiograph done as a part of the routine work up, revealed soft tissue opacity in the retrocardiac region, with the left heart border seen separate from the lesion. Lateral radiograph confirmed the posterior location of the mediastinal lesion.

Figure 1. Frontal radiograph (A) reveals a

soft tissue opacity in the retrocardiac region

with the left heart border seen separate

from the lesion (black arrow). Lateral

radiograph (B) confirms a posterior

mediastinal location. The adjacent vertebral

bodies and neural foramina appear normal.

Figure 2. Post-contrast axial MIP CT image

shows a heterogeneously enhancing mass in

the posterior mediastinum engulfing the

descending thoracic aorta, which shows

multiple contrast-filled outpouchings. The fat

plane with the liver is maintained, and the

adjacent vertebral body does not appear to

be involved. There is displacement of the

esophagus and IVC.

Figure 3. Fused PET-CT image in the axial

plane reveals intense uptake by the

posterior mediastinal mass (SUV 7.3).

A B



Key Imaging Finding

Posterior mediastinal mass


Neurogenic Tumors / Peripheral Nerve Sheath Tumors

Foregut Cysts

Lymphoma

Aortic aneurysm

Esophageal neoplasms

Sarcoma

Discussion

The posterior mediastinum is bounded anteriorly by the pericardium and great vessels, posteriorly by the prevertebral fascia, and laterally by the pleura.1 Its contents include the aorta, esophagus, azygous and hemiazgous vessels, neural structures, and lymph nodes. By convention, the paravertebral space is also included in the posterior mediastinum. Posterior mediastinal masses can arise from any of these structures. Morphological characteristics, enhancement patterns, and relation to surrounding organs as studied on imaging help in determining the organ of origin. Correlation with the clinical profile and histopathology are essential in arriving at the final diagnosis. These studies also play an important role in staging of the disease.

Neurogenic Tumors.

Neurogenic tumors, to include nerve sheath and sympathetic ganglion tumors, represent the most common posterior mediastinal masses. Most lesions, especially if benign, are asymptomatic. Nerve sheath tumors, such as schwannoma and neurofibroma, are most often seen in patients around 20-30 years of age. Frontal and lateral radiographs reveal widening of the neural foramina with splaying of ribs, which can be confirmed on CT. These lesions demonstrate heterogeneous contrast enhancement on CT and appear hypointense on T1 and hyperintense on T2. MRI may show intraspinal extension, which is

characteristic. Necrosis, hemorrhage, and heterogeneous enhancement are more often seen with malignant nerve sheath tumors. Sympathetic ganglion tumors, such as ganglioneuromas, are typically seen in the first decade of life, and are vertically oriented along the lateral aspect of vertebrae, and are less common.2

Foregut Cysts.

Mediastinal foregut cysts result from embryologic aberrations with anomalous budding of the primitive foregut. The spectrum of anomalies includes bronchogenic cysts, esophageal duplication cysts, and neuroentric cysts. Bronchogenic cysts are most commonly located in the carinal region, while esophageal duplication cysts are most often located along the esophagus in the lower mediastinum. Neuroentric cysts communicate with the meninges and are usually associated with vertebral anomalies. Foregut cysts usually do not cause symptoms and have similar imaging features.

Frontal radiographs typically reveal sharply marginated areas of increased opacity. CT reveals well-defined fluid density lesions, often with a thin enhancing wall. Occasionally, increased protein content will result in increased attenuation.1 There is no infiltration or invasion of adjacent structures and no solid tissue enhancement within the lesion. On MRI, foregut cysts appear as well-defined lesions which are hypointense on T1 and hyperintense on T2 weighted images. MR imaging is useful in determining the cystic nature of foregut lesions with an atypical appearance or increased attenuation on CT, since cysts will typically have T2 bright signal intensity, regardless of the nature of the cyst contents.

Lymphoma.

Lymphoma presents as a soft tissue mass with widening of mediastinum, which is often revealed on conventional radiographs. An anterior or middle mediastinal location is more common than posterior. CT demonstrates a lobulated soft tissue density mass with heterogeneous enhancement; regions of calcification may be seen post-treatment but are rare in patients who have not undergone treatment. The margins often conform to surrounding structures. The appearance of lymphoma on MRI varies based upon



the type of lymphoma and whether or not the patient has undergone treatment.3

Aortic Aneurysm.

Patients with descending aortic aneurysms are usually asymptomatic. Frontal radiographs reveal a posterior mediastinal mass with the aortic shadow not seen separately from the lesion. Curvilinear calcification may be seen at the periphery of the lesion. CT and MRA will show contrast enhancement in the arterial phase. Partially thrombosed aneurysms show regions of non-enhancing clot with areas of hemorrhage.

Esophageal Neoplasms.

Patients with esophageal neoplasms generally present with dysphagia to solid food and weight loss. Imaging findings often lag clinical presentation; therefore, radiographs may be normal initially. When large, esophageal tumors present as a posterior mediastinal soft tissue mass. CT shows eccentric or circumferential esophageal wall thickening with dilated proximal fluid and debris-filled esophageal lumen. Exophytic components may show heterogeneous enhancement. Invasion of local structures is common due to lack of a serosa.1 MRI provides little advantage over CT.

Sarcoma.

Sarcomas are rare in the mediastinum and present as posterior mediastinal masses, which may appear ill- or well-defined on radiographs. Rib erosions may be seen. CT shows a solid mass lesion, often with infiltrative margins and heterogeneous enhancement. MRI will show heterogeneous but predominantly T1 hypointense and T2 hyperintense signal intensity with foci of hemorrhage and necrosis. Neovascularity may be present. It is uncommon for sarcomas to invade the aorta and cause aneurysm formation. No specific imaging findings are known to differentiate the various subtypes of sarcomas. Histopathology is essential for knowing the type of sarcoma. PET imaging helps in grading and staging of the tumor.

Diagnosis

Sarcoma

Summary

Posterior mediastinal masses are usually asymptomatic and are best diagnosed by cross sectional imaging. In this case, imaging findings were of a mass lesion with heterogeneous and delayed enhancement with erosion and aneurysm formation of the descending aorta, thereby favoring a neoplastic etiology. The tumor did not involve the esophagus or vertebral bodies, and there was no intraspinal extension. Sarcoma, therefore, was the most likely diagnosis despite its rareity. A CT-guided biopsy revealed that this was a rare case of pleomorphic undifferentiated sarcoma, formerly referred to as malignant fibrous histiocytomas,4,5 with secondary involvement of the aorta. To our knowledge, only 13 cases of pleomorphic sarcoma involving the posterior mediastinum have been described in literature.6 Hence, if the imaging findings don’t fit in any of the commonly known posterior mediastinal masses, a differential of sarcoma should be kept in mind.

References

1. Kawashima A, Fishman EK, Kuhlman JE, et al. CT of posterior mediastinal masses, RadioGraphics 1991;11:1045-1067

2. Nakazono T, White CS, Yamasaki F, et al. MRI findings of mediastinal neurogenic tumors. Am J Roentgenol 2011;197:W643-52.

3. Juanpere S, Cañete N, Ortuño P, et al. A diagnostic approach to the mediastinal massesA diagnostic approach to the mediastinal masses Insights Imaging 2013;4(1):29-52.

4. Fletcher CDM, Unni KK, Mertens F, eds. World Health Organization Classification of Tumors: Pathology and Genetics of Tumours of Soft Tissue and Bone. Lyon, France, IARC Press, 2002.

5. Fletcher CDM. Pleomorphic malignant fibrous histiocytoma: fact or fiction? A critical reappraisal based on 159 tumors diagnosed as pleomorphic sarcoma. Am J Surg Pathol 1992;16(3):213-28.

6. Hernandez A, Gill, FI, Aventura E, et al. Mediastinal pleomorphic sarcoma in an immunodeficient patient: case report and review of the literature. Journal of the Louisiana State Medical Society 2012; 164(1): 21.


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Bernard F. Laya, D.O.a,b, and Regina C. Nava, M.D.b

aInstitute of Radiology, St. Luke’s Medical Center, Quezon City, Philippines

bInstitute of Radiology, St. Luke’s Medical Center Global City, Taguig, Philippines

Pulmonary Lymphangioleiomyomatosis.

This chest radiograph of a 27-year-old woman presenting with severe difficulty of breathing (A) appears grossly unremarkable. A high resolution chest CT scan was obtained (B), which reveals variably-sized cysts throughout the lung parenchyma with thickened interlobular septae, compatible with lymphangioleioyomatosis (LAM). Based upon these findings, an abdominal CT scan was performed (C), revealing a large, heterogeneous right renal mass with predominantly fatty attenuation. A smaller lesion with similar imaging characteristics is seen in the left kidney. Brain CT scan (not shown) demonstrated small subependymal calcifications. Overall constellation of findings is compatible with Tuberous Sclerosis.

Pulmonary LAM is a rare disease affecting mostly women of child-bearing age. It also occurs in some patients with Tuberous Sclerosis. It is characterized by disorderly proliferation of smooth muscle throughout the lungs, causing destruction of lung tissue and leading to abnormal cyst formation. Dyspnea and pneumothorax are the two most common presenting symptoms. LAM is a slowly progressive condition with a poor prognosis. Treatment is difficult and is primarily supportive.

C

B

A


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Ali Yikilmaz, M.D.

Istanbul Medeniyet University, Goztepe Research and Training Hospital, Department of Radiology, Istanbul, Turkey

Hydatid Cyst of the Lung.

A 12-year-old girl presented with cough and fever. PA chest X-ray shows a large air filled cyst in the left lung base (A). Contrast enhanced axial CT image (B) demonstrates a round cyst with air-fluid level and detached-floating germinative membranes (asterisk), which are typical for hydatid disease.

Echinococcosis or hydatid disease is a parasitosis caused by infestation with Echinococcus granulosus (dog tapeworm). Although most children with pulmonary involvement by hydatid disease are asymptomatic, they may occasionally present with fever, shortness of breath, cough, and/or chest pain, which is usually a sign of cyst rupture. Diagnosis of hydatid disease depends on the combination of imaging findings and serology tests that use antigens specific for the organism.

The radiological findings are characterized by single or multiple (~25%), round or oval-shaped, cystic nodules or masses (1-20 cm in diameter) with well-defined walls, surrounded by normal lung parenchyma. Other findings include an air-crescent sign when a cyst communicates with a bronchus or the “water-lily sign” when a cyst membrane floats in residual fluid after the rupture of cyst. The water-lily sign is considered to be highly specific or pathognomonic, especially in endemic areas.

B

A