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Chest X-ray Evaluation of Cardiac Chest X-ray Evaluation of Cardiac PatientsPatients

Dr Awadhesh Kumar Sharma,

Wilhelm Conrad Roentgen (1845 - 1923)Wilhelm Conrad Roentgen (1845 - 1923)

"I did not think I investigated...It seemed "I did not think I investigated...It seemed at first at first

a new kind of invisible light. It was clearlya new kind of invisible light. It was clearly

something new something something new something unrecorded...There is unrecorded...There is

much to do, and I am busy, very busy"much to do, and I am busy, very busy"

Wilhelm Conrad Röntgen Wilhelm Conrad Röntgen

(First observer of X-rays made on 8 Nov (First observer of X-rays made on 8 Nov 1895)1895)

INTRODUCTIONINTRODUCTION The discovery of X-rays by W.C.Roentgen,the The discovery of X-rays by W.C.Roentgen,the

german physicist on November 8,1895 ,was a german physicist on November 8,1895 ,was a crucially important landmark in the advancement crucially important landmark in the advancement of medical knowledge.of medical knowledge.

The cardiopulmonary images help us to understand The cardiopulmonary images help us to understand the anatomy, physiology and pathophysiology of the anatomy, physiology and pathophysiology of the heart and blood vessels because of the excellent the heart and blood vessels because of the excellent contrast between the lungs filled with air and the contrast between the lungs filled with air and the opaque silhouette of the heart and vessels filled opaque silhouette of the heart and vessels filled with blood.with blood.

With careful evaluation, it yields a large amount of anatomic and With careful evaluation, it yields a large amount of anatomic and physiologic information, but it is difficult and sometimes even physiologic information, but it is difficult and sometimes even impossible to extract the information that it contains. impossible to extract the information that it contains.

The major variables that determine what can be learned from the The major variables that determine what can be learned from the chest x-ray include the technical factors (miliamperage [mA], kilo chest x-ray include the technical factors (miliamperage [mA], kilo voltage [kV], exposure duration) used in obtaining the radiographs, voltage [kV], exposure duration) used in obtaining the radiographs, patient specific factors (e.g., body habitus, age, physiologic status, patient specific factors (e.g., body habitus, age, physiologic status, ability to stand and to take and hold a deep breath), and the training, ability to stand and to take and hold a deep breath), and the training, experience, and focus of the interpreter. experience, and focus of the interpreter.

The aims of my todays seminar are to review how chest radiographs The aims of my todays seminar are to review how chest radiographs are obtained, present a basic approach to their interpretation, and are obtained, present a basic approach to their interpretation, and discuss and illustrate common and characteristic findings relevant to discuss and illustrate common and characteristic findings relevant to cardiovascular disease in adults.cardiovascular disease in adults.

Technical ConsiderationsTechnical Considerations

The usual chest radiograph consists of a frontal and a lateral The usual chest radiograph consists of a frontal and a lateral view. The frontal view is a postero anterior (PA) view, with view. The frontal view is a postero anterior (PA) view, with the patient standing with the chest toward the recording the patient standing with the chest toward the recording medium and the back to the x-ray tube. The lateral view is also medium and the back to the x-ray tube. The lateral view is also taken with the patient standing, with the left side toward the taken with the patient standing, with the left side toward the film. film.

For both, the x-ray tube is positioned at a distance of 6 feet For both, the x-ray tube is positioned at a distance of 6 feet from the film. This is termed a 6-foot SID (source-image from the film. This is termed a 6-foot SID (source-image distance). distance).

At 6 feet distance the focal length of X-rays gives maximum At 6 feet distance the focal length of X-rays gives maximum resolution with less irradiation. The beam is near parallel resolution with less irradiation. The beam is near parallel without divergence and distortions.without divergence and distortions.

X-rays are blocked from the film or other recording medium to X-rays are blocked from the film or other recording medium to varying degrees by various structures, leading to shades of varying degrees by various structures, leading to shades of gray that allow discrimination between the heart, which is gray that allow discrimination between the heart, which is fluid-filled and relatively impervious to x-rays, and the air-fluid-filled and relatively impervious to x-rays, and the air-filled lung parenchyma, which blocks few x-rays. filled lung parenchyma, which blocks few x-rays.

The exposure that the patient receives is a function of the The exposure that the patient receives is a function of the strength and duration of the current applied to the x-ray tube strength and duration of the current applied to the x-ray tube (or, more precisely and accurately, of the number, strength and (or, more precisely and accurately, of the number, strength and duration of the x-ray photons produced—the mA, kV, and duration of the x-ray photons produced—the mA, kV, and milliseconds), size of the focal spot, distance from the tube to milliseconds), size of the focal spot, distance from the tube to the patient, and degree to which the x-rays are blocked and the patient, and degree to which the x-rays are blocked and scattered within the patient.scattered within the patient.

Most patient exposure is not a result of the x-rays that Most patient exposure is not a result of the x-rays that penetrate, but rather those that interact with tissues and are penetrate, but rather those that interact with tissues and are slowed and changed, and in the process deposit residual energy slowed and changed, and in the process deposit residual energy in tissue. This process is what is broadly referred to as scatter. in tissue. This process is what is broadly referred to as scatter.

Patients who are very thin will require an inherently lower x-Patients who are very thin will require an inherently lower x-ray dose to achieve diagnostically satisfactory deposition of x-ray dose to achieve diagnostically satisfactory deposition of x-ray photons on an imaging medium, and will have less energy ray photons on an imaging medium, and will have less energy deposition within the body. In patients who are obese, a higher deposition within the body. In patients who are obese, a higher x-ray dose will be necessary to penetrate the patient and x-ray dose will be necessary to penetrate the patient and produce a diagnostic exposure. The increased soft tissue in produce a diagnostic exposure. The increased soft tissue in these patients also causes more dispersion of the x-ray beam these patients also causes more dispersion of the x-ray beam and results in a higher dose. and results in a higher dose.

There are several additional practical considerations that relate There are several additional practical considerations that relate to the physics of chest radiographs. The standard chest to the physics of chest radiographs. The standard chest radiograph is obtained with deep inspiration and the patient radiograph is obtained with deep inspiration and the patient facing the film. If patients are unable to stand, chest radiographs facing the film. If patients are unable to stand, chest radiographs are generally obtained with the patient's chest toward the tube are generally obtained with the patient's chest toward the tube and the back toward the film, the antero-posterior (AP) position. and the back toward the film, the antero-posterior (AP) position.

With the standard PA view, the heart appears smaller and its With the standard PA view, the heart appears smaller and its size and contour are more accurately depicted than on an AP size and contour are more accurately depicted than on an AP view, because the heart is closer to the recording medium. view, because the heart is closer to the recording medium.

With AP views, as with portable films, there is resultant greater With AP views, as with portable films, there is resultant greater divergence of x-rays because the heart lies relatively anteriorly divergence of x-rays because the heart lies relatively anteriorly (and so is farther from the film) .(and so is farther from the film) .

X-ray film is close to the heart in PA view,hence further magnification is avoided.In AP view ,the film is X-ray film is close to the heart in PA view,hence further magnification is avoided.In AP view ,the film is over the posterior chest and away from the heart,resulting in 5-10% magnification of heart shadow hence over the posterior chest and away from the heart,resulting in 5-10% magnification of heart shadow hence

apparent cardiomegaly.apparent cardiomegaly.

X-ray chest PA view if taken in X-ray chest PA view if taken in expiration, gives a false impression of expiration, gives a false impression of cardiomegaly, widening of aorta and cardiomegaly, widening of aorta and prominent pulmonary arteries .This is the prominent pulmonary arteries .This is the importance of taking X-ray chest held in importance of taking X-ray chest held in deep inspiration- the criteria for it is deep inspiration- the criteria for it is being able to see ten posterior ribs and/or being able to see ten posterior ribs and/or six anterior ribs.six anterior ribs.

X-ray chest PA X-ray chest PA view showing view showing effects of effects of expiration. expiration. There is pseudo There is pseudo cardiomegaly cardiomegaly and aorta and aorta becomes becomes prominent.prominent.

Properly exposed chest film Properly exposed chest film PA view held in inspirationPA view held in inspiration

Portable radiographsPortable radiographs

Portable radiographs are invariably taken as AP Portable radiographs are invariably taken as AP views and the SID is less than 6 feet, of necessity, views and the SID is less than 6 feet, of necessity, because of the nature of the portable x-ray machine because of the nature of the portable x-ray machine and also because of the usual position of the patient, and also because of the usual position of the patient, sitting or lying in a bed. Most portable x-ray units do sitting or lying in a bed. Most portable x-ray units do not have generators sufficiently strong to be able to not have generators sufficiently strong to be able to produce x-rays that will penetrate a patient produce x-rays that will penetrate a patient adequately and expose the film from 6 feet. Space adequately and expose the film from 6 feet. Space constraints and the patient's position are additional constraints and the patient's position are additional hurdles. hurdles.

For all these reasons, the inherent resolution is poorer with For all these reasons, the inherent resolution is poorer with portable radiographs, making them less accurate and useful. Also portable radiographs, making them less accurate and useful. Also because of the lower available energy with portable x-ray units because of the lower available energy with portable x-ray units and the longer exposure time necessary to compensate, radiation and the longer exposure time necessary to compensate, radiation exposure to the patient is greater than with a standard PA film. exposure to the patient is greater than with a standard PA film.

Portable films are most useful for answering relatively simple Portable films are most useful for answering relatively simple mechanical questions, such as whether the pacemaker or mechanical questions, such as whether the pacemaker or automated implantable cardioverter-defibrillator (ICD) is automated implantable cardioverter-defibrillator (ICD) is properly positioned , whether the endotracheal tube is in the properly positioned , whether the endotracheal tube is in the correct location, and whether the mediastinum is midline. They correct location, and whether the mediastinum is midline. They are generally not good at providing physiologic or complex are generally not good at providing physiologic or complex anatomic information.anatomic information.

Portable X-ray machinePortable X-ray machine

Image Recording and Radiation Image Recording and Radiation ExposureExposure

Until the turn of the last century, all chest radiographs Until the turn of the last century, all chest radiographs were recorded on high-resolution x-ray film. With were recorded on high-resolution x-ray film. With optimal technique and a cooperative patient who can optimal technique and a cooperative patient who can hold a deep inspiration, the result is a study that hold a deep inspiration, the result is a study that clearly and accurately depicts very small structures, clearly and accurately depicts very small structures, such as the contour of small pulmonary arteries. such as the contour of small pulmonary arteries.

This has changed as the digital age has come to This has changed as the digital age has come to imaging. With the advent of digital radiography imaging. With the advent of digital radiography (DR), a filmless form of radiography, chest (DR), a filmless form of radiography, chest radiographs are increasingly stored on digital media. radiographs are increasingly stored on digital media.

DR, is the direct recording of images by digital DR, is the direct recording of images by digital means, without analog-to-digital conversion. The means, without analog-to-digital conversion. The most common is flat plate technology for reasons of most common is flat plate technology for reasons of resolution, usefulness and, in the long term, cost. It resolution, usefulness and, in the long term, cost. It involves the use of an image-sensing plate that involves the use of an image-sensing plate that directly converts the incident photons into a digital directly converts the incident photons into a digital signal.signal.

DR is truly “filmless”; and the classic chest DR is truly “filmless”; and the classic chest radiograph relies on film that is exposed and radiograph relies on film that is exposed and developed.developed.

Radiation HazardsRadiation Hazards The radiation exposure to the patient should always be kept in mind The radiation exposure to the patient should always be kept in mind

when any x-ray study is ordered or performed. The complexity of when any x-ray study is ordered or performed. The complexity of diagnostic radiation in the general population limits obtaining clear diagnostic radiation in the general population limits obtaining clear answers. However, a real concern is that ionizing radiation at answers. However, a real concern is that ionizing radiation at cumulative diagnostic doses may be teratogenic and may, over cumulative diagnostic doses may be teratogenic and may, over decades, cause cancers. decades, cause cancers.

The radiation necessary for PA and lateral chest films is usually The radiation necessary for PA and lateral chest films is usually minimal in terms of radiation effects, in both the dose of a single minimal in terms of radiation effects, in both the dose of a single study (generally <1 mSv) and the cumulative dose of repeated chest study (generally <1 mSv) and the cumulative dose of repeated chest x-rays. x-rays.

In pregnant women and children, radiation exposure is always a In pregnant women and children, radiation exposure is always a concern because of the long latency period for radiation-induced concern because of the long latency period for radiation-induced cancer.cancer.

The contribution from conventional imaging procedures, The contribution from conventional imaging procedures, such as chest x-rays, is small, but the precise relationships such as chest x-rays, is small, but the precise relationships between individual exposures and cumulative effect are not between individual exposures and cumulative effect are not known. known.

Despite this, and despite the lack of clarity of the relationship Despite this, and despite the lack of clarity of the relationship between diagnostic level radiation and cancer, it is always between diagnostic level radiation and cancer, it is always wise to limit the amount of radiation as much as possible. wise to limit the amount of radiation as much as possible. Consequently, each chest film should be ordered with care. Consequently, each chest film should be ordered with care.

Whether the dose is actually decreased with digital imaging Whether the dose is actually decreased with digital imaging remains an open question, because digital systems continue remains an open question, because digital systems continue to evolve rapidly.to evolve rapidly.

Normal Chest RadiographNormal Chest Radiograph Interpreting standard PA and lateral chest radiographs is a daunting task. The Interpreting standard PA and lateral chest radiographs is a daunting task. The

amount of information present is huge, and there are countless relevant variables. amount of information present is huge, and there are countless relevant variables. It is imperative to have a systematic and standardized approach, based first on an It is imperative to have a systematic and standardized approach, based first on an assessment of anatomy, then of physiology, and finally of pathology. assessment of anatomy, then of physiology, and finally of pathology.

Any approach must be based on an understanding of what is normal and must Any approach must be based on an understanding of what is normal and must include an evaluation of the soft tissues, bones and joints, pleura, lungs and include an evaluation of the soft tissues, bones and joints, pleura, lungs and major airways, pulmonary vascularity, mediastinum and its contents, and heart major airways, pulmonary vascularity, mediastinum and its contents, and heart and its chambers specifically, as well as the areas seen below the diaphragm and and its chambers specifically, as well as the areas seen below the diaphragm and above the thorax. above the thorax.

In the standard PA chest study, the overall heart diameter is normally less than In the standard PA chest study, the overall heart diameter is normally less than half the transverse diameter of the thorax . The heart overlies the thoracic spine, half the transverse diameter of the thorax . The heart overlies the thoracic spine, roughly 75% to the left of the spine and 25% to the right. The mediastinum is roughly 75% to the left of the spine and 25% to the right. The mediastinum is narrow superiorly, and normally the descending aorta can be defined from the narrow superiorly, and normally the descending aorta can be defined from the arch to the dome of the diaphragm, on the left. The pulmonary hila are seen arch to the dome of the diaphragm, on the left. The pulmonary hila are seen below the aortic arch, slightly higher on the left than the right. below the aortic arch, slightly higher on the left than the right.

Normal chest X-rayNormal chest X-ray

On the lateral film , the left main pulmonary artery can be seen coursing On the lateral film , the left main pulmonary artery can be seen coursing superiorly and posteriorly compared with the right. On both frontal and superiorly and posteriorly compared with the right. On both frontal and lateral views, the ascending aorta (aortic root) is normally obscured by the lateral views, the ascending aorta (aortic root) is normally obscured by the main pulmonary artery and both atria. The location of the pulmonary main pulmonary artery and both atria. The location of the pulmonary outflow tract is usually clear on the lateral film.outflow tract is usually clear on the lateral film.

On the normal chest film, it is not usually possible to define individual On the normal chest film, it is not usually possible to define individual cardiac chambers. It is imperative, however, to know their normal position cardiac chambers. It is imperative, however, to know their normal position and to examine the film to determine whether the size and location of each and to examine the film to determine whether the size and location of each chamber and the great vessels are within the normal range.chamber and the great vessels are within the normal range.

On the PA view, the right contour of the mediastinum contains the right On the PA view, the right contour of the mediastinum contains the right atrium and the ascending aorta and superior vena cava (SVC). If the azygous atrium and the ascending aorta and superior vena cava (SVC). If the azygous vein is enlarged, secondary to right heart failure or SVC obstruction , it may vein is enlarged, secondary to right heart failure or SVC obstruction , it may also be visible. The right ventricle, as is clear from cross-sectional imaging , also be visible. The right ventricle, as is clear from cross-sectional imaging , is located partially overlying the left ventricle on both frontal and lateral is located partially overlying the left ventricle on both frontal and lateral views.views.

The left atrium is located just inferior to the left pulmonary hilum. In The left atrium is located just inferior to the left pulmonary hilum. In normal individuals, there is a concavity at this level, which is the location normal individuals, there is a concavity at this level, which is the location of the left atrial appendage. The atrium constitutes the upper portion of the of the left atrial appendage. The atrium constitutes the upper portion of the posterior contour of the heart on the lateral film but cannot normally be posterior contour of the heart on the lateral film but cannot normally be differentiated from the left ventricle.differentiated from the left ventricle.

The left ventricle constitutes the prominent, rounded apex of the heart on The left ventricle constitutes the prominent, rounded apex of the heart on the frontal view and the sloping inferior portion of the mediastinum on the the frontal view and the sloping inferior portion of the mediastinum on the lateral view .lateral view .

The apex is often not clearly delineated for a reason related to x-ray The apex is often not clearly delineated for a reason related to x-ray attenuation. The heart is distinguishable from the lungs because it contains attenuation. The heart is distinguishable from the lungs because it contains water density blood rather than air. Because blood attenuates x-rays to a water density blood rather than air. Because blood attenuates x-rays to a greater extent than air, the heart appears relatively white (although less so greater extent than air, the heart appears relatively white (although less so than calcium-containing bones) and the lungs relatively black (less so than than calcium-containing bones) and the lungs relatively black (less so than the edges of the film, where there is only air and no interposed tissue). the edges of the film, where there is only air and no interposed tissue).

Chest X-ray PA view: Normal. Structures Chest X-ray PA view: Normal. Structures forming right and left borders of the heartforming right and left borders of the heart

Structures forming anterior and posterior Structures forming anterior and posterior borders of the heartborders of the heart

Chest X-ray PA viewChest X-ray PA view

A fat pad of varying thickness surrounds the apex of the heart . Fat has a density A fat pad of varying thickness surrounds the apex of the heart . Fat has a density greater than that of air and marginally less than that of blood. As it covers the greater than that of air and marginally less than that of blood. As it covers the ventricular apex, the fat pad is relatively thick and dense. As it thins out toward the ventricular apex, the fat pad is relatively thick and dense. As it thins out toward the left lateral chest wall, it is progressively less dense; hence, the hazy, poorly left lateral chest wall, it is progressively less dense; hence, the hazy, poorly marginated appearance of the apex. Similarly, a fat pad may be seen on the lateral marginated appearance of the apex. Similarly, a fat pad may be seen on the lateral chest film as a wedge-shaped density overlying the anterior aspect of the left chest film as a wedge-shaped density overlying the anterior aspect of the left ventricle.ventricle.

The pericardial sac cannot normally be defined . The borders of the cardiac silhouette The pericardial sac cannot normally be defined . The borders of the cardiac silhouette are normally moderately but not completely sharp in contour. Even though the are normally moderately but not completely sharp in contour. Even though the exposure time for a chest x-ray is very short (less than 100 milliseconds), there is exposure time for a chest x-ray is very short (less than 100 milliseconds), there is usually sufficient cardiac motion to cause minor haziness of the silhouette. If a usually sufficient cardiac motion to cause minor haziness of the silhouette. If a portion of the heart border does not move, as in the case of a left ventricular portion of the heart border does not move, as in the case of a left ventricular aneurysm, the border may be unusually sharp .aneurysm, the border may be unusually sharp .

The aortic arch, however, is usually visible, as the aorta courses posteriorly and is The aortic arch, however, is usually visible, as the aorta courses posteriorly and is surrounded by air. Most of the descending aorta is also visible. The position and the surrounded by air. Most of the descending aorta is also visible. The position and the size of each can be easily evaluated using the frontal and lateral views.size of each can be easily evaluated using the frontal and lateral views.

Lungs and Pulmonary VasculatureLungs and Pulmonary Vasculature

Lung size varies as a function of inspiratory effort, age, body habitus, Lung size varies as a function of inspiratory effort, age, body habitus, water content, and intrinsic pathologic processes. For example, because water content, and intrinsic pathologic processes. For example, because lung distensibility decreases with age, the lungs normally appear subtly but lung distensibility decreases with age, the lungs normally appear subtly but progressively smaller as patients age, even with maximal inspiratory effort. progressively smaller as patients age, even with maximal inspiratory effort. As lung size decreases, the heart appears relatively slightly larger, although As lung size decreases, the heart appears relatively slightly larger, although in adults the heart does not exceed half the transverse diameter of the chest in adults the heart does not exceed half the transverse diameter of the chest in a good-quality PA film unless there is true cardiomegaly.in a good-quality PA film unless there is true cardiomegaly.

Also, with increasing left ventricular dysfunction, interstitial fluid in the Also, with increasing left ventricular dysfunction, interstitial fluid in the lungs increases and lung compliance, and therefore expansion as seen on a lungs increases and lung compliance, and therefore expansion as seen on a chest x-ray, decreases. With the presence of chronic obstructive pulmonary chest x-ray, decreases. With the presence of chronic obstructive pulmonary disease, with or without bullae, the lungs appear larger and blacker, the disease, with or without bullae, the lungs appear larger and blacker, the diaphragms may appear flattened, and the relative heart size, even in the diaphragms may appear flattened, and the relative heart size, even in the presence of heart failure, decreases. The heart often appears small or presence of heart failure, decreases. The heart often appears small or normal in size, even in the presence of cardiac dysfunction .normal in size, even in the presence of cardiac dysfunction .

Barrel shaped Barrel shaped chest in a chest in a patient with patient with emphysemaemphysema

In normal subjects, pulmonary vascularity has a predictable pattern. Pulmonary In normal subjects, pulmonary vascularity has a predictable pattern. Pulmonary arteries are usually easily visible centrally in the hila and progressively less so arteries are usually easily visible centrally in the hila and progressively less so more peripherally. Centrally, the main right and left pulmonary arteries are more peripherally. Centrally, the main right and left pulmonary arteries are difficult to quantify unless they are grossly enlarged, because they lie within the difficult to quantify unless they are grossly enlarged, because they lie within the mediastinum .mediastinum .

If the lung is thought of in three zones, the major arteries are central; the clearly If the lung is thought of in three zones, the major arteries are central; the clearly distinguishable midsized pulmonary arteries (third and fourth order branches) are distinguishable midsized pulmonary arteries (third and fourth order branches) are in the middle zone, and the small arteries and arterioles that are normally below in the middle zone, and the small arteries and arterioles that are normally below the limit of resolution are in the outer zone. the limit of resolution are in the outer zone.

The visible small and midsized arteries (midzone) have sharp, clearly definable The visible small and midsized arteries (midzone) have sharp, clearly definable margins. As noted, this is because of the sharp border between water density and margins. As noted, this is because of the sharp border between water density and air density structures. In the standard, standing frontal (PA) chest film, the arteries air density structures. In the standard, standing frontal (PA) chest film, the arteries in the lower zone are larger than those in the upper zone, at an equal distance in the lower zone are larger than those in the upper zone, at an equal distance from the hila. This is because of the effect of gravity on the normal, low-pressure from the hila. This is because of the effect of gravity on the normal, low-pressure lung circulation. That is, gravity leads to slightly greater intravascular volume at lung circulation. That is, gravity leads to slightly greater intravascular volume at the lung bases than in the upper zones. the lung bases than in the upper zones.

This effect of gravity on the distribution of This effect of gravity on the distribution of normal intravascular lung volume is reflected in normal intravascular lung volume is reflected in a normal perfusion lung scan. Because the a normal perfusion lung scan. Because the radionuclide is generally administered with the radionuclide is generally administered with the patient supine, there is a greater concentration patient supine, there is a greater concentration posteriorly than anteriorly, as confirmed in the posteriorly than anteriorly, as confirmed in the count rates. If the patient is sitting or standing count rates. If the patient is sitting or standing when the radionuclide is injected, the count rate when the radionuclide is injected, the count rate is greater at the lung base than at the apices.is greater at the lung base than at the apices.

Evaluating the Chest Radiograph in Evaluating the Chest Radiograph in Heart DiseaseHeart Disease

There is no single best way to read a chest film. A systematic approach to There is no single best way to read a chest film. A systematic approach to the evaluation of a chest radiograph is imperative to distinguish normal the evaluation of a chest radiograph is imperative to distinguish normal from abnormal and to define the underlying pathology and from abnormal and to define the underlying pathology and pathophysiology.pathophysiology.

The first step is to define which type of film is being evaluated—PA and The first step is to define which type of film is being evaluated—PA and lateral, PA alone, or AP view (either portable or one obtained in the AP lateral, PA alone, or AP view (either portable or one obtained in the AP view because the patient is unable to stand). view because the patient is unable to stand).

The next step is to determine whether prior films are available for The next step is to determine whether prior films are available for comparison. Many abnormalities are put into appropriate perspective by comparison. Many abnormalities are put into appropriate perspective by determining whether they are new. Common examples are a prominent determining whether they are new. Common examples are a prominent aortic arch, visible major fissure related to prior inflammatory process, or aortic arch, visible major fissure related to prior inflammatory process, or widened superior mediastinum related to aortic ectasia , substernal thyroid, widened superior mediastinum related to aortic ectasia , substernal thyroid, or enlarged azygous vein .or enlarged azygous vein .

Any system should incorporate a routine that includes a deliberate attempt to Any system should incorporate a routine that includes a deliberate attempt to look at areas that are easily ignored. These include the thoracic spine, neck look at areas that are easily ignored. These include the thoracic spine, neck (for masses and tracheal position), costophrenic angles, lung apices, (for masses and tracheal position), costophrenic angles, lung apices, retrocardiac space, and retrosternal space. Looking at these areas enables retrocardiac space, and retrosternal space. Looking at these areas enables definition of mediastinal position and cardiac and aortic situs and the definition of mediastinal position and cardiac and aortic situs and the presence of pleural effusions, scarring, or diaphragmatic elevation.presence of pleural effusions, scarring, or diaphragmatic elevation.

It is logical to evaluate the lung fields next. This should involve a careful It is logical to evaluate the lung fields next. This should involve a careful search for infiltrates or masses, even when the primary concern is search for infiltrates or masses, even when the primary concern is cardiovascular abnormalities. The logic is that many people with coronary cardiovascular abnormalities. The logic is that many people with coronary artery disease have a history of tobacco abuse and are thus at increased risk artery disease have a history of tobacco abuse and are thus at increased risk for lung malignancies.for lung malignancies.

Cardiovascular disease states cause various and complex changes in the Cardiovascular disease states cause various and complex changes in the appearance of the chest radiograph. The overall size of the cardiac silhouette, appearance of the chest radiograph. The overall size of the cardiac silhouette, its position, and the location of the ascending and descending aorta must be its position, and the location of the ascending and descending aorta must be specifically evaluated. specifically evaluated.

Cervical rib on the right sideCervical rib on the right side

Dextrocardia and a right descending aorta are rare, particularly Dextrocardia and a right descending aorta are rare, particularly in adults, but are easy to check for and are important to in adults, but are easy to check for and are important to recognize because of their association with congenital cardiac recognize because of their association with congenital cardiac and abdominal situs abnormalities. It is also important to look and abdominal situs abnormalities. It is also important to look at the site and position of the stomach. This information can be at the site and position of the stomach. This information can be used to differentiate between a high diaphragm and a pleural used to differentiate between a high diaphragm and a pleural effusion .effusion .

Cardiomegaly, accurately judged by the heart diameter Cardiomegaly, accurately judged by the heart diameter exceeding half the diameter of the thorax on a PA film, is a exceeding half the diameter of the thorax on a PA film, is a common but nonspecific finding.It is probably most often seen common but nonspecific finding.It is probably most often seen as a result of ischemic cardiomyopathy following one or more as a result of ischemic cardiomyopathy following one or more myocardial infarctions.myocardial infarctions.

CARDIOMEGALY IN X-RAY CHEST(PA VIEW)CARDIOMEGALY IN X-RAY CHEST(PA VIEW)

Trans cardiac diameter is Trans cardiac diameter is measured as follows-measured as follows-

Mark a mid-vertical line along Mark a mid-vertical line along the spinous process.the spinous process.

Draw a horizontal line from the Draw a horizontal line from the vertical line to the maximum vertical line to the maximum convexity in the right cardiac convexity in the right cardiac border.border.

Draw another horizontal line Draw another horizontal line from the vertical line to the from the vertical line to the maximum convexity in the left maximum convexity in the left cardiac bordercardiac border

Line A+B=Transcardiac diameterLine A+B=Transcardiac diameter Transthoracic diameter Transthoracic diameter at the at the level of inner border of ninth rib.level of inner border of ninth rib.

Cardiothoracic ratio=TCD/TTDCardiothoracic ratio=TCD/TTD Normally cardiothoracic ratio is 33%-50%(0.33-Normally cardiothoracic ratio is 33%-50%(0.33-

0.50).0.50). Any increase in transcardiac diameter more then Any increase in transcardiac diameter more then

2 cm,is significant if earlier X-rays are available 2 cm,is significant if earlier X-rays are available for comparison.for comparison.

In old age and emphysema, transcardiac In old age and emphysema, transcardiac diameter of 15 cm or more is taken as diameter of 15 cm or more is taken as cardiomegaly irrespective of CT ratio.cardiomegaly irrespective of CT ratio.

Assessment of pulmonary Assessment of pulmonary vasculaturevasculature

Evaluation of the pulmonary vascular pattern is difficult and imprecise but very Evaluation of the pulmonary vascular pattern is difficult and imprecise but very important. As noted, the pattern varies with the patient's position (erect versus important. As noted, the pattern varies with the patient's position (erect versus supine) and is altered substantially by underlying pulmonary disease. It is best to supine) and is altered substantially by underlying pulmonary disease. It is best to define pulmonary vascularity by looking at the middle zone of the lungs (i.e., the define pulmonary vascularity by looking at the middle zone of the lungs (i.e., the third of the lungs between the hilar region and peripheral region laterally) and third of the lungs between the hilar region and peripheral region laterally) and comparing a region in the upper portion of the lungs with a region in the lower comparing a region in the upper portion of the lungs with a region in the lower portion, at equal distances from the hilum.portion, at equal distances from the hilum.

Vessels should be larger in the lower lung but sharply marginated in the upper and Vessels should be larger in the lower lung but sharply marginated in the upper and lower zones. In normal individuals, the vessels taper and bifurcate and are lower zones. In normal individuals, the vessels taper and bifurcate and are difficult to define in the outer third of the lung. They normally become too small difficult to define in the outer third of the lung. They normally become too small to be seen near the pleurato be seen near the pleura

Two distinct patterns of abnormality are recognizable. When pulmonary arterial Two distinct patterns of abnormality are recognizable. When pulmonary arterial flow is increased, as in patients with a high-output state (e.g., pregnancy, severe flow is increased, as in patients with a high-output state (e.g., pregnancy, severe anemia as in sickle cell disease, hyperthyroidism) or left-to-right shunt, the anemia as in sickle cell disease, hyperthyroidism) or left-to-right shunt, the pulmonary vessels are seen more prominently than usual in the periphery of the pulmonary vessels are seen more prominently than usual in the periphery of the lung. lung.

They are uniformly enlarged and can be traced almost to the pleura, but They are uniformly enlarged and can be traced almost to the pleura, but their margins remain clear. In contrast, in patients with elevated pulmonary their margins remain clear. In contrast, in patients with elevated pulmonary venous pressure, the vessel borders become hazy, the lower zone vessels venous pressure, the vessel borders become hazy, the lower zone vessels constrict and the upper zone vessels enlarge, and vessels become visible constrict and the upper zone vessels enlarge, and vessels become visible farther toward the pleura, in the outer third of the lungs farther toward the pleura, in the outer third of the lungs

Larry Elliots grading of Pulmonary Venous Larry Elliots grading of Pulmonary Venous HypertensionHypertension

Grade-1 Grade-1 pulmonary venous pulmonary venous hypertension-hypertension-

The upper lobe The upper lobe veins becomes veins becomes more prominent more prominent than the lower than the lower lobe veins-lobe veins-cephalisationcephalisation

Grade-2 pulmonary venous Grade-2 pulmonary venous hypertension-hypertension-

Kerleys lines Kerleys lines are due to are due to interlobular septal thickening interlobular septal thickening due to lymphatic and venous due to lymphatic and venous drainage.drainage.

Kerleys A linesKerleys A lines-Horizontal linear -Horizontal linear shadows towards the hilum.shadows towards the hilum.

Kerleys B linesKerleys B lines-Horizontal and -Horizontal and linear shadows towards the linear shadows towards the costophrenic angle.costophrenic angle.

Kerleys C linesKerleys C lines-Crisscross -Crisscross between A and B.between A and B.

Chest X-ray PA view of 40 Chest X-ray PA view of 40 year old male with grade-II year old male with grade-II pulmonary venous pulmonary venous hypertension-hypertension-

Top panel shows typical Top panel shows typical features of pulmonary features of pulmonary venous hypertension with venous hypertension with Kerley's lines and Kerley's lines and interstitial oedema.interstitial oedema.

Bottom panel shows X-Bottom panel shows X-rays of the same patient 4 rays of the same patient 4 hours after treatment with hours after treatment with diuretics.diuretics.

Grade –III Grade –III pulmonary venous pulmonary venous hypertensionhypertensionAlveolar edema, Alveolar edema, manifesting as manifesting as bilateral diffuse patchy bilateral diffuse patchy cotton wool opacities cotton wool opacities in the lung in the lung parenchyma.parenchyma.

Grade IV Grade IV pulmonary pulmonary venous venous hypertensionhypertension

-results in bilateral -results in bilateral miliary mottling -miliary mottling -hemosiderosishemosiderosis

-calcification-calcification

-irreversible-irreversible

Assessment of cardiac chambersAssessment of cardiac chambers

Right AtriumRight Atrium

Right atrial enlargement is essentially never isolated Right atrial enlargement is essentially never isolated except in the presence of congenital tricuspid atresia except in the presence of congenital tricuspid atresia or Ebstein anomaly. Both are rarely encountered, or Ebstein anomaly. Both are rarely encountered, even in the pediatric age group. even in the pediatric age group.

The right atrium may dilate in the presence of The right atrium may dilate in the presence of pulmonary hypertension or tricuspid regurgitation, pulmonary hypertension or tricuspid regurgitation, but right ventricular dilation usually predominates but right ventricular dilation usually predominates and prevents definition of the atrium. and prevents definition of the atrium.

The right atrial contour blends with that of the SVC, The right atrial contour blends with that of the SVC, right main pulmonary artery, and right ventricle. right main pulmonary artery, and right ventricle.

Radiological features S/O Right Radiological features S/O Right atrial enlargement in PA viewatrial enlargement in PA view

Right cardiac border becomes more convex and Right cardiac border becomes more convex and elongated. It forms more then 50% of right cardiac elongated. It forms more then 50% of right cardiac border.border.

Distance from mid-vertical line to the maximum Distance from mid-vertical line to the maximum convexity in the right border is more then 5cm in convexity in the right border is more then 5cm in adults and more then 4cm in children which results in adults and more then 4cm in children which results in cardiomegaly.cardiomegaly.

Right atrial border extends beyond three intercostal Right atrial border extends beyond three intercostal spaces.spaces.

Dilation of superior vena cava.Dilation of superior vena cava.

Right atrial enlargement in LAO Right atrial enlargement in LAO viewview

Normally in LAO view, upper half of anterior Normally in LAO view, upper half of anterior cardiac border is formed by right atrium and cardiac border is formed by right atrium and lower half by right ventricle.lower half by right ventricle.

When right atrium enlarges the upper anterior When right atrium enlarges the upper anterior cardiac border becomes squared giving a box cardiac border becomes squared giving a box like appearance.like appearance.

LAO is the best view to visualise right atrial LAO is the best view to visualise right atrial enlargement.enlargement.

Right atrial Right atrial enlargement in a enlargement in a patient with patient with rheumatic mitral rheumatic mitral stenosis. There is stenosis. There is left atrial left atrial enlargement and enlargement and mitralisation too, mitralisation too, of heartof heart..

Right VentricleRight Ventricle The classic signs of right ventricular enlargement are a boot-shaped heart The classic signs of right ventricular enlargement are a boot-shaped heart

and filling in of the retrosternal air space.The former is caused by and filling in of the retrosternal air space.The former is caused by transverse displacement of the apex of the right ventricle as it dilates. In transverse displacement of the apex of the right ventricle as it dilates. In adults, it is rare for the right ventricle to dilate without left ventricular adults, it is rare for the right ventricle to dilate without left ventricular dilation, so this boot shape is not often obvious. It is most commonly seen dilation, so this boot shape is not often obvious. It is most commonly seen as an isolated finding in congenital heart disease, typically in tetralogy of as an isolated finding in congenital heart disease, typically in tetralogy of Fallot. As the right ventricle dilates, it expands superiorly as well as Fallot. As the right ventricle dilates, it expands superiorly as well as laterally and posteriorly, explaining the well-marginated increase in laterally and posteriorly, explaining the well-marginated increase in density in the retrosternal airspace.density in the retrosternal airspace.

The classic teaching is that in a lateral chest radiograph in normal patients, The classic teaching is that in a lateral chest radiograph in normal patients, the soft tissue density is confined to less than one third of the distance from the soft tissue density is confined to less than one third of the distance from the suprasternal notch to the tip of the xephoid. If the soft tissue fills in by the suprasternal notch to the tip of the xephoid. If the soft tissue fills in by more than one third, in the absence of other explanations, it is a reliable more than one third, in the absence of other explanations, it is a reliable indication of right ventricular enlargement. indication of right ventricular enlargement.

Right ventricular Right ventricular enlargementenlargement

PA viewPA view--Rounded Rounded and elevated apex and elevated apex from the left dome from the left dome of the diaphragmof the diaphragm

Right lateral view-Right lateral view-Obliteration of Obliteration of retrosternal spaceretrosternal space

Chest radiographs of a 59-year-old woman with a history of rheumatic heart disease and Chest radiographs of a 59-year-old woman with a history of rheumatic heart disease and mitral stenosis. a, PA view demonstrates enlarged cardiac silhouette, with suggestion of a mitral stenosis. a, PA view demonstrates enlarged cardiac silhouette, with suggestion of a double density seen through the heart (left atrial enlargement), prominent convexity of the double density seen through the heart (left atrial enlargement), prominent convexity of the left atrial appendage (small arrow), and slightly elevated cardiac apex (large arrow), left atrial appendage (small arrow), and slightly elevated cardiac apex (large arrow), suggestive of right ventricular (rather than left ventricular) enlargement. there is significant suggestive of right ventricular (rather than left ventricular) enlargement. there is significant elevation of the pulmonary venous pressures. elevation of the pulmonary venous pressures. B, The lateral view confirms marked right ventricular (arrow) and left atrial (small arrows) B, The lateral view confirms marked right ventricular (arrow) and left atrial (small arrows) enlargement. note filling in of the retrosternal airspace. la = left atrium; lv = left ventricle.enlargement. note filling in of the retrosternal airspace. la = left atrium; lv = left ventricle.

Left AtriumLeft Atrium Several classic signs define left atrial enlargement-Several classic signs define left atrial enlargement- The first is dilation of the left atrial appendage, seen as a focal convexity The first is dilation of the left atrial appendage, seen as a focal convexity

where there is normally a concavity between the left main pulmonary where there is normally a concavity between the left main pulmonary artery and left border of the left ventricle on the frontal view .artery and left border of the left ventricle on the frontal view .

Second, because of its location, as the left atrium enlarges, it elevates the Second, because of its location, as the left atrium enlarges, it elevates the left main stem bronchus. In so doing, it widens the angle of the left main stem bronchus. In so doing, it widens the angle of the carina,normal being 45-75 degrees.carina,normal being 45-75 degrees.

Third, with marked left atrial enlargement, a double density can be seen on Third, with marked left atrial enlargement, a double density can be seen on the frontal view because the left atrium projects laterally toward the right the frontal view because the left atrium projects laterally toward the right and posteriorly, and the discrete outline of the blood-filled left atrium is and posteriorly, and the discrete outline of the blood-filled left atrium is surrounded by air-filled lung . surrounded by air-filled lung .

Finally, on the lateral film, left atrial enlargement appears as a focal, Finally, on the lateral film, left atrial enlargement appears as a focal, posteriorly directed bulge .posteriorly directed bulge .

Chest X-ray PA view Chest X-ray PA view of two patients with of two patients with

varying degree of left varying degree of left atrial enlargement in atrial enlargement in

rheumatic mitral rheumatic mitral stenosisstenosis

Left VentricleLeft Ventricle Left ventricular enlargement is characterized by a prominent, downwardly directed Left ventricular enlargement is characterized by a prominent, downwardly directed

contour of the apex, as distinguished from the transverse displacement seen with contour of the apex, as distinguished from the transverse displacement seen with right ventricular enlargement.right ventricular enlargement.

On the PA film, the overall cardiac contour is also usually enlarged, although this On the PA film, the overall cardiac contour is also usually enlarged, although this is a nonspecific finding. is a nonspecific finding.

It may also be seen inferiorly, pushing the gastric bubble . Such left ventricular It may also be seen inferiorly, pushing the gastric bubble . Such left ventricular enlargement is an illustration of findings that lie outside the usual confines of the enlargement is an illustration of findings that lie outside the usual confines of the chest and another example of the value of looking at the entire chest radiograph. chest and another example of the value of looking at the entire chest radiograph. Focal left ventricular enlargement in adults is most commonly seen in the presence Focal left ventricular enlargement in adults is most commonly seen in the presence of aortic insufficiency (with aortic root dilation; or mitral regurgitation (with left of aortic insufficiency (with aortic root dilation; or mitral regurgitation (with left atrial dilation.atrial dilation.

In contrast, because aortic stenosis is characterized by left ventricular hypertrophy In contrast, because aortic stenosis is characterized by left ventricular hypertrophy rather than dilation, the left ventricle is dilated on the chest film only when aortic rather than dilation, the left ventricle is dilated on the chest film only when aortic stenosis is accompanied by left ventricular failure.stenosis is accompanied by left ventricular failure.

Chest radiographs of a 63-year-old man with chronic aortic regurgitation. A, PA view shows downward Chest radiographs of a 63-year-old man with chronic aortic regurgitation. A, PA view shows downward displacement of the apex (arrow), suggestive of left ventricular enlargement. There is prominence and displacement of the apex (arrow), suggestive of left ventricular enlargement. There is prominence and

enlargement of the ascending aorta, creating a convex right border of the mediastinum. B, Lateral view enlargement of the ascending aorta, creating a convex right border of the mediastinum. B, Lateral view shows prominent left ventricular enlargement (arrowheads). The aortic root is markedly enlarged in the shows prominent left ventricular enlargement (arrowheads). The aortic root is markedly enlarged in the

retrosternal airspace but is separate from the sternum (in contrast to findings in right ventricular retrosternal airspace but is separate from the sternum (in contrast to findings in right ventricular enlargement).enlargement).

Assessment of great vessels Assessment of great vessels

Pulmonary ArteriesPulmonary Arteries

The main pulmonary artery can appear abnormal in many clinical settings. The main pulmonary artery can appear abnormal in many clinical settings. In the presence of pulmonic stenosis, the main pulmonary artery and left In the presence of pulmonic stenosis, the main pulmonary artery and left pulmonary artery dilate . This dilation is thought to be caused by the jet pulmonary artery dilate . This dilation is thought to be caused by the jet effect on the vessel wall of the blood flow through the stenotic valve, effect on the vessel wall of the blood flow through the stenotic valve, coupled with the anatomy. That is, the main pulmonary artery continues coupled with the anatomy. That is, the main pulmonary artery continues straight into the left main pulmonary artery but the right comes off at a straight into the left main pulmonary artery but the right comes off at a fairly sharp angle and is not generally affected by the jet from the stenotic fairly sharp angle and is not generally affected by the jet from the stenotic valve. This enlargement can be seen with a prominent left hilum on the valve. This enlargement can be seen with a prominent left hilum on the frontal view and a prominent pulmonary outflow tract on the lateral view.frontal view and a prominent pulmonary outflow tract on the lateral view.

It is important to remember that the pulmonic valve lies more superiorly in It is important to remember that the pulmonic valve lies more superiorly in the outflow tract and more anteriorly than the aortic valve .the outflow tract and more anteriorly than the aortic valve .

Chest radiographs of a 56-year-old asymptomatic woman with Chest radiographs of a 56-year-old asymptomatic woman with incidentally discovered pulmonic stenosis. A, PA view shows marked incidentally discovered pulmonic stenosis. A, PA view shows marked

enlargement of the main pulmonary trunk extending into the left main enlargement of the main pulmonary trunk extending into the left main pulmonary artery (arrow). B, Lateral view confirms prominence of the pulmonary artery (arrow). B, Lateral view confirms prominence of the

pulmonary outflow tract and main and left pulmonary arteries (arrows). pulmonary outflow tract and main and left pulmonary arteries (arrows).

AortaAorta The most commonly seen abnormality of the aorta is dilation, and The most commonly seen abnormality of the aorta is dilation, and

the way the aorta dilates is a function of the underlying pathology . the way the aorta dilates is a function of the underlying pathology . It is often possible to define the pathology by a combination of the It is often possible to define the pathology by a combination of the pattern of dilation and associated cardiac abnormalities.pattern of dilation and associated cardiac abnormalities.

On the frontal chest radiograph, aortic dilation appears as a On the frontal chest radiograph, aortic dilation appears as a prominence to the right of the middle mediastinum . There is also a prominence to the right of the middle mediastinum . There is also a prominence in the anterior mediastinum on the lateral view, behind prominence in the anterior mediastinum on the lateral view, behind and superior to the pulmonary outflow tract.and superior to the pulmonary outflow tract.

Dilation of the aortic root is seen in the presence of aortic valve Dilation of the aortic root is seen in the presence of aortic valve disease (both stenosis and regurgitation) but more frequently has disease (both stenosis and regurgitation) but more frequently has other causes, such as long-term, poorly controlled systemic other causes, such as long-term, poorly controlled systemic hypertension or generalized atherosclerosis with ectasia.hypertension or generalized atherosclerosis with ectasia.

Chest radiographs of a 65-year-old woman with severe aortic stenosis. A, Frontal Chest radiographs of a 65-year-old woman with severe aortic stenosis. A, Frontal view shows a prominent aortic root, to the right of the midline (arrowheads). Note view shows a prominent aortic root, to the right of the midline (arrowheads). Note absence of cardiomegaly and presence of normal pulmonary vascular pattern. B, absence of cardiomegaly and presence of normal pulmonary vascular pattern. B,

Lateral view demonstrates calcification of the aortic valve leaflets (arrows), Lateral view demonstrates calcification of the aortic valve leaflets (arrows), suggestive of a bicuspid valve. There is a prominent, mildly dilated aortic root suggestive of a bicuspid valve. There is a prominent, mildly dilated aortic root

(arrowheads). (arrowheads).

Pleura and PericardiumPleura and Pericardium The pleura and pericardium also require systematic evaluation. The The pleura and pericardium also require systematic evaluation. The

pericardium is rarely distinctly definable on plain films of the chest.There are pericardium is rarely distinctly definable on plain films of the chest.There are two situations, however, in which it can be seen; in the presence of a large two situations, however, in which it can be seen; in the presence of a large pericardial effusion, the visceral and parietal pericardium separate. Because pericardial effusion, the visceral and parietal pericardium separate. Because there is a fat pad associated with each, it is sometimes possible to make out there is a fat pad associated with each, it is sometimes possible to make out two parallel lucent lines (i.e., fat) on the lateral film, usually in the area of the two parallel lucent lines (i.e., fat) on the lateral film, usually in the area of the cardiac apex, with density (fluid) between them. CMRI, echocardiography, cardiac apex, with density (fluid) between them. CMRI, echocardiography, and CT, however, are all far more reliable for defining a pericardial effusion and CT, however, are all far more reliable for defining a pericardial effusion

Nonetheless, if the cardiac silhouette is enlarged on the chest radiograph, it is Nonetheless, if the cardiac silhouette is enlarged on the chest radiograph, it is important to look for specific explanations. Although cardiac dilation and important to look for specific explanations. Although cardiac dilation and valvular disease are more common causes, the presence of an unsuspected valvular disease are more common causes, the presence of an unsuspected effusion is worth considering. Typically, the cardiac silhouette has a water effusion is worth considering. Typically, the cardiac silhouette has a water bottle shape in the presence of a pericardial effusion, but this shape is not in bottle shape in the presence of a pericardial effusion, but this shape is not in itself diagnostic.itself diagnostic.

Pericardial effusionPericardial effusion

CardiomegalyCardiomegaly Cardio phrenic angles Cardio phrenic angles

become more and more become more and more acute.acute.

Narrow vascular pedicleNarrow vascular pedicle Marked change in Marked change in

cardiac silhouette in cardiac silhouette in decubitus position is decubitus position is very diagnostic.very diagnostic.

Pleural and pericardial calcification Pleural and pericardial calcification

Pleural and pericardial calcification can occur, but are often not obvious . Pleural and pericardial calcification can occur, but are often not obvious . Pericardial calcification is associated with a history of pericarditis. Pericardial calcification is associated with a history of pericarditis. Although there are multiple causes, tuberculosis and various viruses are the Although there are multiple causes, tuberculosis and various viruses are the most common. Such calcification is usually thin and linear and follows the most common. Such calcification is usually thin and linear and follows the contour of the pericardium. Because the calcification is thin, it is often seen contour of the pericardium. Because the calcification is thin, it is often seen only on one view.only on one view.

Myocardial calcification secondary to a large myocardial infarction with Myocardial calcification secondary to a large myocardial infarction with transmural necrosis is rare but can generally be distinguished from transmural necrosis is rare but can generally be distinguished from pericardial calcification. It tends to appear thicker, more focal, and less pericardial calcification. It tends to appear thicker, more focal, and less consistent with the outer contour of the heart. consistent with the outer contour of the heart.

Pleural calcification is easily distinguishable from pericardial calcification Pleural calcification is easily distinguishable from pericardial calcification and is essentially pathognomonic for asbestos exposure. It is associated and is essentially pathognomonic for asbestos exposure. It is associated with a high risk of malignant mesothelioma but is not diagnostic of this with a high risk of malignant mesothelioma but is not diagnostic of this type of tumor.type of tumor.

Chest radiographs of a 45-year-old man with calcific pericarditis. Chest radiographs of a 45-year-old man with calcific pericarditis. A, PA view is essentially normal. B, Lateral view demonstrates A, PA view is essentially normal. B, Lateral view demonstrates

thin, irregular calcification of pericardium around the left thin, irregular calcification of pericardium around the left ventricular contour. ventricular contour.

Chest radiograph showing marked pericardial calcification in a Chest radiograph showing marked pericardial calcification in a

patient with constrictive pericarditis.patient with constrictive pericarditis.

Cardiac valves calcificationCardiac valves calcification

Calcified cardiac valvesCalcified cardiac valves

Chest PA viewChest PA view

Aortic valve will be at the level of Aortic valve will be at the level of T6-T7 overlying the midline area. T6-T7 overlying the midline area. Mitral valve will be at T8 level away Mitral valve will be at T8 level away from the midline in the paravertebral from the midline in the paravertebral region.region.

Lateral viewLateral view

Aortic calcification is above an Aortic calcification is above an imaginary line from left bronchus to imaginary line from left bronchus to RV apex and mitral calcification is RV apex and mitral calcification is below the line.below the line.

Specific clinical situationSpecific clinical situation

Rheumatic valvular heart Rheumatic valvular heart diseasesdiseases

Rheumatic Mitral StenosisRheumatic Mitral Stenosis X-ray chest PA viewX-ray chest PA view The typical mitralisation.The typical mitralisation. Less prominent aortic knuckle.Less prominent aortic knuckle. Obliteration of pulmonary bay due to prominent main Obliteration of pulmonary bay due to prominent main

and left pulmonary arteries.and left pulmonary arteries. Prominent left atrial appendage.Prominent left atrial appendage. Straightening of convex contour of left ventricular Straightening of convex contour of left ventricular

border due to hypoplasia and hypovolumia.border due to hypoplasia and hypovolumia.

Top panel Top panel shows shows mitralisation.mitralisation.

Bottom panel Bottom panel shows shows gross enlargement of gross enlargement of main pulmonary main pulmonary artery, left atria and artery, left atria and left atrial appendage left atrial appendage dilation and right dilation and right ventricular ventricular enlargement.enlargement.

Mitral stenosisMitral stenosis

Mitral regurgitationMitral regurgitation

Left atrial Left atrial enlargementenlargement

Left Left ventricular ventricular enlargementenlargement

Right atrial Right atrial enlargementenlargement

MS+MRMS+MR

Aortic valvular Aortic valvular stenosisstenosis

Left Left ventricular ventricular hypertrophy hypertrophy and left and left ventricular ventricular dilationdilation

Aortic valvular Aortic valvular regurgitationregurgitation

Left Left ventricular ventricular dilationdilation

Left atrial Left atrial enlargementenlargement

Prosthetic valvesProsthetic valves

Congenital heart diseases-AcyanoticCongenital heart diseases-Acyanotic

Without a shuntWithout a shunt Pulmonary valvular stenosisPulmonary valvular stenosis The radiological features are-The radiological features are- Pulmonary oligaemiaPulmonary oligaemia Post-stenotic dilatation of main pulmonary Post-stenotic dilatation of main pulmonary

arteryartery Right ventricular enlargementRight ventricular enlargement Right atrial enlargrmentRight atrial enlargrment

Valvular pulmonary stenosisValvular pulmonary stenosis

Primary pulmonary Primary pulmonary hypertensionhypertension

X-ray chest PA viewX-ray chest PA view Moderate to marked enlargement of main Moderate to marked enlargement of main

pulmonary artery and its proximal branches.pulmonary artery and its proximal branches. Peripheral pulmonary arteries are diminished Peripheral pulmonary arteries are diminished

and pruned resulting in clear peripheral lung and pruned resulting in clear peripheral lung fields.fields.

Absence of pulmonary venous hypertension.Absence of pulmonary venous hypertension. Small and inconspicuous ascending aortaSmall and inconspicuous ascending aorta Right ventricular and right atrial enlargementRight ventricular and right atrial enlargement Absent left atrial enlargementAbsent left atrial enlargement

Primary pulmonary hypertensionPrimary pulmonary hypertension

Congenital heart diseases-AcyanoticCongenital heart diseases-Acyanotic

With a shuntWith a shunt Shunt at atrial levelShunt at atrial level Shunt at ventricular levelShunt at ventricular level Shunt at aorto pulmonary levelShunt at aorto pulmonary level Pulmonary plethora is common in all left to Pulmonary plethora is common in all left to

right shunts.right shunts.

Atrial septal defectAtrial septal defect Ostium secundum ASDOstium secundum ASD Enlargement of RV,RA and LA.Enlargement of RV,RA and LA. Left ventricle is hypovolaemic and hypoplastic.Left ventricle is hypovolaemic and hypoplastic. Right pulmonary artery is more prominent than left Right pulmonary artery is more prominent than left

pulmonary artery giving the radiological sign of pulmonary artery giving the radiological sign of jug-handle appearance.jug-handle appearance.

Ostium primum ASDOstium primum ASD

Left ventricular enlargement in addition to the Left ventricular enlargement in addition to the radiological features of OS –ASD.radiological features of OS –ASD.

Ostium secundum ASDOstium secundum ASD

Ostium primum ASDOstium primum ASD

VSDVSD

All four chambers are All four chambers are involved.involved.

The ascending aorta is The ascending aorta is inconspicuous.inconspicuous.

Both pulmonary arteries Both pulmonary arteries are equally prominent.are equally prominent.

Patent Ductus ArteriosusPatent Ductus Arteriosus

All the four chambers are All the four chambers are involved.involved.

Prominent ascending aorta.Prominent ascending aorta. There may be speck of There may be speck of

calcium when PDA is calcium when PDA is calcified.It is comma shaped calcified.It is comma shaped between aortic knuckle and between aortic knuckle and main pulmonary artery and main pulmonary artery and is known as is known as Cap of Zin.Cap of Zin.

Both pulmonary arteries are Both pulmonary arteries are equally dilated.equally dilated.

Congenital cyanotic heart diseasesCongenital cyanotic heart diseases

Increased pulmonary Increased pulmonary arterial blood flowarterial blood flow

Complete transposition Complete transposition of great arteries(d-TGA)of great arteries(d-TGA)

Absent thymic shadowAbsent thymic shadow Narrow vascular pedicleNarrow vascular pedicle Increased CT ratio with Increased CT ratio with

egg lying on its side egg lying on its side appearanceappearance

Pulmonary plethoraPulmonary plethora

Truncus ArteriosusTruncus Arteriosus

All four chambers All four chambers are dilated with are dilated with pulmonary pulmonary plethora.plethora.

In one – third of In one – third of cases right aortic cases right aortic arch is present.arch is present.

TAPVCTAPVC Supracardiac type is the Supracardiac type is the

commonest and will have a commonest and will have a distinctive distinctive figure of 8 or figure of 8 or snowman silhouette or snowman silhouette or cottage loafcottage loaf.The upper .The upper portion of figure of 8 is portion of figure of 8 is formed by the dilated left formed by the dilated left vertical vein and right vertical vein and right superior vena cava.The superior vena cava.The lower portion consists of lower portion consists of dilated right atrium and dilated right atrium and right ventricle.right ventricle.

Decreased pulmonary arterial blood flowDecreased pulmonary arterial blood flow

Tetralogy of FallotTetralogy of Fallot No cardiomegalyNo cardiomegaly Uplifted apex-boot shaped or Uplifted apex-boot shaped or

coeur en sabot appearancecoeur en sabot appearance Pulmonary oligaemiaPulmonary oligaemia Dilated ascending aorta with right Dilated ascending aorta with right

aortic arch in 25% of casesaortic arch in 25% of cases Bilateral reticular formation due Bilateral reticular formation due

to bronchopulmonary collateralsto bronchopulmonary collaterals Unilateral rib notching after BT Unilateral rib notching after BT

shuntshunt

Ebstein anomaly of the tricuspid valveEbstein anomaly of the tricuspid valve

Cardiomegaly with Cardiomegaly with dilated right atrium and dilated right atrium and right ventricular right ventricular infundibulum accounts infundibulum accounts for the box like for the box like silhouette with normal silhouette with normal or decreased pulmonary or decreased pulmonary blood flow,resembling blood flow,resembling pericardial effusion.pericardial effusion.

Coarction of aortaCoarction of aorta Three sign on chest X-rayThree sign on chest X-ray E sign or reverse 3 sign in barium E sign or reverse 3 sign in barium

swallowswallow Rib notching of 3Rib notching of 3rdrd to 8 to 8thth posterior posterior

ribs along its lower border usually ribs along its lower border usually after the age of 9 yearsafter the age of 9 years

Cardiac malpositionCardiac malpositionSitus solitus Situs inversus totalisSitus solitus Situs inversus totalis

Implantable Devices and Other Postsurgical Implantable Devices and Other Postsurgical FindingsFindings

A final important and broad area concerns the chest radiograph following A final important and broad area concerns the chest radiograph following surgery or other procedures. In these situations, it is crucial to recognize surgery or other procedures. In these situations, it is crucial to recognize devices that have been implanted and changes that may occur. Among the devices that have been implanted and changes that may occur. Among the most common are various valve prostheses, pacemakers and ICDs, intra-most common are various valve prostheses, pacemakers and ICDs, intra-aortic counterpulsation balloons , and ventricular assist devices . There are aortic counterpulsation balloons , and ventricular assist devices . There are also clear changes that occur after surgery, such as the presence of clips on also clear changes that occur after surgery, such as the presence of clips on the side branches of saphenous veins used for coronary artery bypass grafting the side branches of saphenous veins used for coronary artery bypass grafting and retrosternal blurring and effusions and retrosternal blurring and effusions

Some of these findings may be temporary, such as lines and tubes associated Some of these findings may be temporary, such as lines and tubes associated with surgery and effusions. Pacemakers and ICDs present specific questions . with surgery and effusions. Pacemakers and ICDs present specific questions . The first is whether the leads are intact and the second is the position of the The first is whether the leads are intact and the second is the position of the tips. Although course and tip position are generally confirmed tips. Although course and tip position are generally confirmed fluoroscopically at the time of placement, malposition can occur. If there are fluoroscopically at the time of placement, malposition can occur. If there are two leads, the tips should generally be in the anterolateral wall of the right two leads, the tips should generally be in the anterolateral wall of the right atrium and apex of the right ventricle. atrium and apex of the right ventricle.

If the leads are not positioned in this way, the reasons If the leads are not positioned in this way, the reasons should be carefully determined. That is, are they should be carefully determined. That is, are they positioned because of error or anatomic variants (e.g., positioned because of error or anatomic variants (e.g., a persistent left SVC that empties into the coronary a persistent left SVC that empties into the coronary sinus and then the right atrium or because the lead sinus and then the right atrium or because the lead belongs in the coronary sinus. Additionally, the belongs in the coronary sinus. Additionally, the position of the wires and of valve prostheses can help position of the wires and of valve prostheses can help in the definition of specific chamber enlargement in the definition of specific chamber enlargement

AV sequential AV sequential pacemaker in right infra pacemaker in right infra clavicular subcutaneous clavicular subcutaneous pocket. J shaped atrial pocket. J shaped atrial lead is seen in right lead is seen in right atrial appendage.Tip of atrial appendage.Tip of ventricular lead is in ventricular lead is in right ventricular apex.right ventricular apex.

Biventricular Biventricular pacing. Atrial lead pacing. Atrial lead is in right atrium; is in right atrium; right ventricular right ventricular lead is in RV apex, lead is in RV apex, left ventricular lead left ventricular lead is introduced is introduced through coronary through coronary sinus to pace left sinus to pace left ventricular ventricular epicardium.epicardium.

ConclusionConclusion Chest radiographs provide a wealth of physiologic and anatomic Chest radiographs provide a wealth of physiologic and anatomic

information. As such, they play a central role in the evaluation and information. As such, they play a central role in the evaluation and management of patients with a wide variety of cardiovascular and other management of patients with a wide variety of cardiovascular and other disorders. disorders.

The radiation dose inherent in obtaining x-rays should always be The radiation dose inherent in obtaining x-rays should always be considered. considered.

Portable chest films should be used as infrequently as possible because the Portable chest films should be used as infrequently as possible because the information they provide is limited and may even be misleading (e.g., in information they provide is limited and may even be misleading (e.g., in defining cardiomegaly or in ruling out a pneumothorax or effusion). defining cardiomegaly or in ruling out a pneumothorax or effusion).

Standard 6-foot frontal and lateral chest x-rays, on the other hand, are Standard 6-foot frontal and lateral chest x-rays, on the other hand, are almost always of value. Whether recorded conventionally or digitally, if almost always of value. Whether recorded conventionally or digitally, if they are evaluated carefully using a systematic approach and, whenever they are evaluated carefully using a systematic approach and, whenever possible, compared with prior chest radiographs, it is hard to overstate their possible, compared with prior chest radiographs, it is hard to overstate their importance.importance.