INTERACTIVE CASE DISCUSSIONS Medical Clerkship Department of Radiological Sciences
Mar 22, 2016
INTERACTIVE CASE DISCUSSIONS
Medical ClerkshipDepartment of Radiological Sciences
CASE 1
HISTORY OF PRESENT ILLNESS
PHYSICAL EXAM
INATION
(+) cough (+) difficulty of breathing (-) fever
Persistence.
VS HR 120/80 HR 96 RR 28 T 36.4°C in respiratory distress, supraclavicular,
intercostal and subcostal retractions symmetric chest expansion, BS left lower
lung, (+) coarse crackles & rhonchi, L
1 wk PTC
Consult.
30/F CC: cough
CHEST X-RAY AP SUPINE LEFT LAT DECUBITUS
CLERK’S GUIDE: Discuss first the basics of a normal chest x-ray.
CC: Cough action of the body takes to get rid of
substances that are irritating the air passages
occurs when mechanical or chemical afferent nerves get irritated and trigger a chain of events
Air in lungs is forced out under high pressure.
Analysis Cough
› Acute < 3weeks› Persistent >3weeks› Chronic >8weeks
› Acute cough Infectious Non infectious
Acute CoughAcute Cough – signs and symptoms
Infectious Non infectiousFever, chills, body aches, sore
throat vomiting, headache, sinus pressure, runny nose, night sweats, and postnasal drip.
sputum, or phlegm,
exposure to certain chemicals or irritants in the environment,
coughs that may improve with inhalers or allergy medications
Indications for a Chest X-rayFor patient with acute cough Abnormal vital signs Chest examination suggestive of
pneumonia
Patient: RR 28 › in respiratory distress, supraclavicular,
intercostal and subcostal retractions› symmetric chest expansion, BS left lower
lung, (+) coarse crackles & rhonchi, L
AP supine if px can’t assume upright position,
though can’t critically evaluate the size of the
heart because of hypoventilation, diaphragmatic elevation pushing the base of the heart upwards.
Lateral Decubitus position px lies on right or left side; the beam
traverses the body in horizontal position
px w/pleural effusion, pneumothorax – presence of fluid gravitates to dependent portions
demonstrate fluid levels in cavities
Normal Chest X-ray
Chest anatomy: Evaluation Ribs
› Anterior ribs obliquely placed wider intercostals
spaces› Posterior ribs
horizontally placed narrower intercostals
spaces› Intercostal Spaces
Chest anatomy: Evaluation Diaphragm: right and left
› middle segment partially obscured
› Normal level 10th post rib / 5th ant rib right higher than the left
(liver)› dome-shaped
Costophrenic angle / sinus and Cardiophrenic angle› Sharp, well defined and
not blunted
Chest anatomy: Evaluation Trachea and
mediastinum› radioluscent: means it
has an air› bifurcates at T5
(carina) into right and left bronchus
› normal: midline› right bronchus: shorter
and more vertical› left bronchus: longer
and more horizontal
Chest anatomy: Evaluation Hila, bronchovascular
markings› pulmonary artery and vein› bronchial artery and vein› bronchus› lymph nodes
Normal: › left hilum higher than the
right› pulmonary artery crosses
above the left and below the right bronchus
› size of hilum varies depending on pulmonary blood flow
Chest anatomy: Evaluation Lungs
› Radiolucent Inner, middle, outer zones
› Inner zone: from sternoclavicular joint draw a vertical line following contour of the chest, big blood vessels are located
› middle zone: medium blood vessels are located
› outer zone: junction of the clavicle and 1st rib draw a vertical line; small blood vessels are located
Chest anatomy: Evaluation Upper, middle, lower
lung fields› landmarks: 2nd and
4th anterior ribs› upper lung field:
further subdivided by the clavicle into supraclavicular (apex) and infraclavicular
› significance: for localization of the lesions
Chest anatomy: Evaluation Lobar anatomy
› right lobe major fissure: divides lower lobe from upper
and middle minor fissure: divides upper and middle
› left lobe for upper and lower lobes only
Chest anatomy: Evaluation Heart shadow
› Superior mediastinum draw a line from the sternal
angle to the 4th vertebra› Anterior mediastinum
bounded by posterior surface of the sternum and anterior surface of the heart
› Posterior mediastinum bounded by posterior part
of the heart and anterior spinal muscle
A
S
P
Chest anatomy: Evaluation Size
› Cardiothoracic ratio› Easiest gross determination› Compare size of the heart with the
thorax› Normal 2:1› Get the widest transverse
diameter of the heart compare with the widestinternal transverse diameter of the thorax
Shape› Variable› neonate: globular
Chest anatomy: Evaluation Right border
› Superior vena cava› Right atrium› Inferior vena cava
Chest anatomy: Evaluation Right border
› Superior vena cava› Right atrium› Inferior vena cava
Left border› Aortic knob› Main pulmonary trunk› Left ventricle
Lateral View
Left atriumLeft ventricleRight ventricle
AORTA
Main Pulmonary Artery
trachea
RC
RS
Patients Chest X-ray
CHEST X-RAY AP SUPINE LEFT LAT DECUBITUS
CLERK’S GUIDE: Discuss first the basics of a normal chest x-ray.
Patient’s chest xray Obscured diagphragmatic sulci at the
left Narrow intercostal space No shifting of the mediastinal
structures Cardiac shadow not appreciated
Hyperluscency of the right lung Homogenous opacification of the left
lung
Radiographic Differentials Consolidation Atelectasis Pleural effusion Mass lesions
Mass Consolidation
Pleural effusion Atelectasis
Duration Chronic Sub acute to chronic
Sub acute to chronic Acute to sub acute
A-abdomen and thorax, costophrenc and cardiophrenic sulci, diaphragm
May be affected depending on the location of the mass
Blunted/ normal
Blunting of costrophrenic sulcus, nor visualization of hemidiaphragm, due to presence of fluid
Hemidiaphragm may be affected depending on the size of atelectasis
T-thoracic cage
normal Normal +/- widenend interspaces on affected side
Narrowed interspaces on affected side with compensatory widening on opposite side
M-mediastinum
+/- shifting depends on the size and location
Normal +/- shifting contralaterally
+/- shifting ipsilaterally
LL- Lung comparison
Solitary , calcificied, ildefined, spiculations, irreguar, cavitations, hilar enlargement, effusions
Air bronchogram
Homogenous opacification with a lateral upward curve(meniscus sign)Lat decubitus view- free fluid within the pleural space +layering oon the dependent part
Homogenous opacification of affected side
Atelectasis means “lack of stretch” refers to collapse or loss of lung
volume 2 types: Obstructive or Non obstructive
Atelectasis Obstructive
› blockage of an airway › Air retained distal to the occlusion is then
resorbed from nonventilated alveoli› affected regions become totally airless
Non obstructive› caused by loss of contact between the parietal
and visceral pleurae, parenchymal compression, loss of surfactant, or replacement of lung tissue by scarring or infiltrative disease.
Direct signs › displacement of fissures › increased opacification of the airless lobe.
Indirect signs › displacement of hilar structures, › cardiomediastinal shift toward the side of
collapse, › narrowing of ipsilateral intercostal spaces, › elevation of the ipsilateral hemidiaphragm,
compensatory hyperinflation and hyperlucency of the remaining aerated parts of the lung, and
› obscuring of structures adjacent to the collapsed lung, such as the diaphragm, heart, or pulmonary vessels.
ROLE OF MAGNETIC RESONANCE IMAGING
can distinguish between obstructive and nonobstructive atelectasis
Obstructive atelectasis › displays high signal intensity on T2-weighted images due
to proton-rich mucus accumulation. Nonobstructive atelectasis
› low signal intensity on T1 and T2 weighted spin-echo images, since the residual alveolar gas has a low proton concentration, and magnetic susceptibility effects between alveolar walls lead to a decrease in signal.
The use of MRI in diagnosing atelectasis is still experimental, and more experience needs to be accrued
Treatment Continuous positive airway pressure
(CPAP) Fiberoptic bronchoscopy for the
extraction of secretions Mucolytic therapy
NORMAL CHEST X RAY