2. Wilhelm Conrad Roentgen (1845 - 1923)
"I did not think I investigated...It seemed at first
a new kind of invisible light. It was clearly
something new something unrecorded...There is
much to do, and I am busy, very busy"
Wilhelm Conrad Röntgen
(First observer of X-rays made on 8 Nov 1895)
3. INTRODUCTION
The discovery of X-rays by W.C.Roentgen,the
german physicist on November 8,1895 ,was a
crucially important landmark in the
advancement of medical knowledge.
The cardiopulmonary images help us to
understand the anatomy, physiology and
pathophysiology of the heart and blood vessels
because of the excellent contrast between the
lungs filled with air and the opaque silhouette
of the heart and vessels filled with blood.
4. With careful evaluation, it yields a large amount of anatomic
and physiologic information, but it is difficult and sometimes
even impossible to extract the information that it contains.
The major variables that determine what can be learned from
the chest x-ray include the technical factors (miliamperage
[mA], kilo voltage [kV], exposure duration) used in obtaining
the radiographs, patient specific factors (e.g., body habitus,
age, physiologic status, ability to stand and to take and hold a
deep breath), and the training, experience, and focus of the
interpreter.
The aims of my todays seminar are to review how chest
radiographs are obtained, present a basic approach to their
interpretation, and discuss and illustrate common and
characteristic findings relevant to cardiovascular disease in
adults.
5. Technical Considerations
The usual chest radiograph consists of a frontal and a lateral
view. The frontal view is a postero anterior (PA) view, with
the patient standing with the chest toward the recording
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
film.
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
distance).
At 6 feet distance the focal length of X-rays gives maximum
resolution with less irradiation. The beam is near parallel
without divergence and distortions.
6. X-rays are blocked from the film or other recording medium to
varying degrees by various structures, leading to shades of
gray that allow discrimination between the heart, which is
fluid-filled and relatively impervious to x-rays, and the air-
filled lung parenchyma, which blocks few x-rays.
The exposure that the patient receives is a function of the
strength and duration of the current applied to the x-ray tube
(or, more precisely and accurately, of the number, strength and
duration of the x-ray photons produced—the mA, kV, and
milliseconds), size of the focal spot, distance from the tube to
the patient, and degree to which the x-rays are blocked and
scattered within the patient.
7. Most patient exposure is not a result of the x-rays that
penetrate, but rather those that interact with tissues and are
slowed and changed, and in the process deposit residual
energy in tissue. This process is what is broadly referred to as
scatter.
Patients who are very thin will require an inherently lower x-
ray dose to achieve diagnostically satisfactory deposition of x-
ray photons on an imaging medium, and will have less energy
deposition within the body. In patients who are obese, a higher
x-ray dose will be necessary to penetrate the patient and
produce a diagnostic exposure. The increased soft tissue in
these patients also causes more dispersion of the x-ray beam
and results in a higher dose.
8. There are several additional practical considerations that relate
to the physics of chest radiographs. The standard chest
radiograph is obtained with deep inspiration and the patient
facing the film. If patients are unable to stand, chest
radiographs are generally obtained with the patient's chest
toward the tube and the back toward the film, the antero-
posterior (AP) position.
With the standard PA view, the heart appears smaller and its
size and contour are more accurately depicted than on an AP
view, because the heart is closer to the recording medium.
With AP views, as with portable films, there is resultant
greater divergence of x-rays because the heart lies relatively
anteriorly (and so is farther from the film) .
9. 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
apparent cardiomegaly.
10. X-ray chest PA view if taken in
expiration, gives a false impression of
cardiomegaly, widening of aorta and
prominent pulmonary arteries .This is the
importance of taking X-ray chest held in
deep inspiration- the criteria for it is
being able to see ten posterior ribs and/or
six anterior ribs.
11. X-ray chest PA view
showing effects of
expiration. There is
pseudo cardiomegaly
and aorta becomes
prominent.
13. Portable radiographs
Portable radiographs are invariably taken as AP
views and the SID is less than 6 feet, of necessity,
because of the nature of the portable x-ray machine
and also because of the usual position of the patient,
sitting or lying in a bed. Most portable x-ray units do
not have generators sufficiently strong to be able to
produce x-rays that will penetrate a patient
adequately and expose the film from 6 feet. Space
constraints and the patient's position are additional
hurdles.
14. For all these reasons, the inherent resolution is poorer with
portable radiographs, making them less accurate and useful.
Also because of the lower available energy with portable x-ray
units and the longer exposure time necessary to compensate,
radiation exposure to the patient is greater than with a standard
PA film.
Portable films are most useful for answering relatively simple
mechanical questions, such as whether the pacemaker or
automated implantable cardioverter-defibrillator (ICD) is
properly positioned , whether the endotracheal tube is in the
correct location, and whether the mediastinum is midline.
They are generally not good at providing physiologic or
complex anatomic information.
16. Image Recording and Radiation
Exposure
Until the turn of the last century, all chest radiographs
were recorded on high-resolution x-ray film. With
optimal technique and a cooperative patient who can
hold a deep inspiration, the result is a study that
clearly and accurately depicts very small structures,
such as the contour of small pulmonary arteries.
This has changed as the digital age has come to
imaging. With the advent of digital radiography
(DR), a filmless form of radiography, chest
radiographs are increasingly stored on digital media.
17. DR, is the direct recording of images by digital
means, without analog-to-digital conversion. The
most common is flat plate technology for reasons of
resolution, usefulness and, in the long term, cost. It
involves the use of an image-sensing plate that
directly converts the incident photons into a digital
signal.
DR is truly “filmless”; and the classic chest
radiograph relies on film that is exposed and
developed.
18. Radiation Hazards
The radiation exposure to the patient should always be kept in
mind when any x-ray study is ordered or performed. The
complexity of diagnostic radiation in the general population
limits obtaining clear answers. However, a real concern is that
ionizing radiation at cumulative diagnostic doses may be
teratogenic and may, over decades, cause cancers.
The radiation necessary for PA and lateral chest films is
usually minimal in terms of radiation effects, in both the dose
of a single study (generally <1 mSv) and the cumulative dose
of repeated chest x-rays.
In pregnant women and children, radiation exposure is always
a concern because of the long latency period for radiation-
induced cancer.
19. The contribution from conventional imaging
procedures, such as chest x-rays, is small, but the
precise relationships between individual exposures
and cumulative effect are not known.
Despite this, and despite the lack of clarity of the
relationship between diagnostic level radiation and
cancer, it is always wise to limit the amount of
radiation as much as possible. Consequently, each
chest film should be ordered with care.
Whether the dose is actually decreased with digital
imaging remains an open question, because digital
systems continue to evolve rapidly.
20. Normal Chest Radiograph
Interpreting standard PA and lateral chest radiographs is a daunting task.
The 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 assessment of anatomy, then of physiology, and finally of
pathology.
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 major airways, pulmonary vascularity, mediastinum and its
contents, and heart and its chambers specifically, as well as the areas seen
below the diaphragm and above the thorax.
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, 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 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.
22. On the lateral film , the left main pulmonary artery can be seen coursing
superiorly and posteriorly compared with the right. On both frontal and
lateral views, the ascending aorta (aortic root) is normally obscured by the
main pulmonary artery and both atria. The location of the pulmonary
outflow tract is usually clear on the lateral film.
On the normal chest film, it is not usually possible to define individual
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
chamber and the great vessels are within the normal range.
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 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 , is located partially overlying the left ventricle on
both frontal and lateral views.
23. 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
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
differentiated from the left ventricle.
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
lateral view .
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
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
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).
24. Chest X-ray PA view: Normal. Structures
forming right and left borders of the heart
25. Chest X-ray PA view
Structures forming anterior and posterior
borders of the heart
26. 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 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 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 ventricle.
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 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 portion of the heart border does not move, as
in the case of a left ventricular aneurysm, the border may be unusually
sharp .
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 size of each can be easily evaluated using the frontal and
lateral views.
27.
28. Lungs and Pulmonary Vasculature
Lung size varies as a function of inspiratory effort, age, body habitus,
water content, and intrinsic pathologic processes. For example, because
lung distensibility decreases with age, the lungs normally appear subtly but
progressively smaller as patients age, even with maximal inspiratory effort.
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 a good-quality PA film unless there is true cardiomegaly.
Also, with increasing left ventricular dysfunction, interstitial fluid in the
lungs increases and lung compliance, and therefore expansion as seen on a
chest x-ray, decreases. With the presence of chronic obstructive pulmonary
disease, with or without bullae, the lungs appear larger and blacker, the
diaphragms may appear flattened, and the relative heart size, even in the
presence of heart failure, decreases. The heart often appears small or
normal in size, even in the presence of cardiac dysfunction .
30. In normal subjects, pulmonary vascularity has a predictable pattern.
Pulmonary arteries are usually easily visible centrally in the hila and
progressively less so more peripherally. Centrally, the main right and left
pulmonary arteries are difficult to quantify unless they are grossly
enlarged, because they lie within the mediastinum .
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 in the middle zone, and the small arteries and arterioles that
are normally below the limit of resolution are in the outer zone.
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 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 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 the lung bases than in the
upper zones.
31. This effect of gravity on the distribution of
normal intravascular lung volume is reflected
in a normal perfusion lung scan. Because the
radionuclide is generally administered with the
patient supine, there is a greater concentration
posteriorly than anteriorly, as confirmed in the
count rates. If the patient is sitting or standing
when the radionuclide is injected, the count
rate is greater at the lung base than at the
apices.
32. Evaluating the Chest Radiograph in
Heart Disease
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
from abnormal and to define the underlying pathology and
pathophysiology.
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
view because the patient is unable to stand).
The next step is to determine whether prior films are available for
comparison. Many abnormalities are put into appropriate perspective by
determining whether they are new. Common examples are a prominent
aortic arch, visible major fissure related to prior inflammatory process, or
widened superior mediastinum related to aortic ectasia , substernal thyroid,
or enlarged azygous vein .
33. 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 (for masses and tracheal position), costophrenic angles, lung apices,
retrocardiac space, and retrosternal space. Looking at these areas enables
definition of mediastinal position and cardiac and aortic situs and the
presence of pleural effusions, scarring, or diaphragmatic elevation.
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
cardiovascular abnormalities. The logic is that many people with coronary
artery disease have a history of tobacco abuse and are thus at increased risk
for lung malignancies.
Cardiovascular disease states cause various and complex changes in the
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 specifically evaluated.
35. Dextrocardia and a right descending aorta are rare, particularly
in adults, but are easy to check for and are important to
recognize because of their association with congenital cardiac
and abdominal situs abnormalities. It is also important to look
at the site and position of the stomach. This information can be
used to differentiate between a high diaphragm and a pleural
effusion .
Cardiomegaly, accurately judged by the heart diameter
exceeding half the diameter of the thorax on a PA film, is a
common but nonspecific finding.It is probably most often seen
as a result of ischemic cardiomyopathy following one or more
myocardial infarctions.
36. CARDIOMEGALY IN X-RAY CHEST(PA VIEW)
Trans cardiac diameter is
measured as follows-
Mark a mid-vertical line
along the spinous process.
Draw a horizontal line from
the vertical line to the maximum
convexity in the right cardiac
border.
Draw another horizontal line
from the vertical line to the
maximum convexity in the left
cardiac border
Line A+B=Transcardiac
diameter
Transthoracic diameter at the
level of inner border of ninth rib.
37. Cardiothoracic ratio=TCD/TTD
Normally cardiothoracic ratio is 33%-
50%(0.33-0.50).
Any increase in transcardiac diameter more
then 2 cm,is significant if earlier X-rays are
available for comparison.
In old age and emphysema, transcardiac
diameter of 15 cm or more is taken as
cardiomegaly irrespective of CT ratio.
39. 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 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 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 portion, at equal distances from the
hilum.
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 difficult to define in the outer third of the lung. They
normally become too small to be seen near the pleura
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 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 lung.
40. They are uniformly enlarged and can be traced almost to the pleura, but
their margins remain clear. In contrast, in patients with elevated pulmonary
venous pressure, the vessel borders become hazy, the lower zone vessels
constrict and the upper zone vessels enlarge, and vessels become visible
farther toward the pleura, in the outer third of the lungs
43. Grade-2 pulmonary venous
hypertension-
Kerleys lines are due to
interlobular septal thickening
due to lymphatic and venous
drainage.
Kerleys A lines-Horizontal
linear shadows towards the
hilum.
Kerleys B lines-Horizontal and
linear shadows towards the
costophrenic angle.
Kerleys C lines-Crisscross
between A and B.
44. Chest X-ray PA view of 40
year old male with grade-II
pulmonary venous
hypertension-
Top panel shows typical
features of pulmonary
venous hypertension with
Kerley's lines and
interstitial oedema.
Bottom panel shows X-
rays of the same patient 4
hours after treatment with
diuretics.
48. Right Atrium
Right atrial enlargement is essentially never isolated
except in the presence of congenital tricuspid atresia
or Ebstein anomaly. Both are rarely encountered,
even in the pediatric age group.
The right atrium may dilate in the presence of
pulmonary hypertension or tricuspid regurgitation,
but right ventricular dilation usually predominates
and prevents definition of the atrium.
The right atrial contour blends with that of the SVC,
right main pulmonary artery, and right ventricle.
49. Radiological features S/O Right
atrial enlargement in PA view
Right cardiac border becomes more convex and
elongated. It forms more then 50% of right cardiac
border.
Distance from mid-vertical line to the maximum
convexity in the right border is more then 5cm in
adults and more then 4cm in children which results in
cardiomegaly.
Right atrial border extends beyond three intercostal
spaces.
Dilation of superior vena cava.
50. Right atrial enlargement in LAO
view
Normally in LAO view, upper half of anterior
cardiac border is formed by right atrium and
lower half by right ventricle.
When right atrium enlarges the upper anterior
cardiac border becomes squared giving a box
like appearance.
LAO is the best view to visualise right atrial
enlargement.
51.
52. Right atrial
enlargement in a
patient with
rheumatic mitral
stenosis. There is
left atrial
enlargement and
mitralisation too,
of heart.
53. Right Ventricle
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
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
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
Fallot. As the right ventricle dilates, it expands superiorly as well as
laterally and posteriorly, explaining the well-marginated increase in density
in the retrosternal airspace.
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 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
indication of right ventricular enlargement.
55. 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
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),
suggestive of right ventricular (rather than left ventricular) enlargement. there is significant
elevation of the pulmonary venous pressures.
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.
56. Left Atrium
Several classic signs define left atrial enlargement-
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
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
left main stem bronchus. In so doing, it widens the angle of the
carina,normal being 45-75 degrees.
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
and posteriorly, and the discrete outline of the blood-filled left atrium is
surrounded by air-filled lung .
Finally, on the lateral film, left atrial enlargement appears as a focal,
posteriorly directed bulge .
57.
58. Chest X-ray PA view
of two patients with
varying degree of left
atrial enlargement in
rheumatic mitral
stenosis
59. Left Ventricle
Left ventricular enlargement is characterized by a prominent, downwardly directed
contour of the apex, as distinguished from the transverse displacement seen with
right ventricular enlargement.
On the PA film, the overall cardiac contour is also usually enlarged, although this
is a nonspecific finding.
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
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
of aortic insufficiency (with aortic root dilation; or mitral regurgitation (with left
atrial dilation.
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
stenosis is accompanied by left ventricular failure.
60.
61. 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
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
retrosternal airspace but is separate from the sternum (in contrast to findings in right ventricular
enlargement).
63. Pulmonary Arteries
The main pulmonary artery can appear abnormal in many clinical settings.
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
effect on the vessel wall of the blood flow through the stenotic valve,
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
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
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
the outflow tract and more anteriorly than the aortic valve .
64. Chest radiographs of a 56-year-old asymptomatic woman with
incidentally discovered pulmonic stenosis. A, PA view shows marked
enlargement of the main pulmonary trunk extending into the left main
pulmonary artery (arrow). B, Lateral view confirms prominence of the
pulmonary outflow tract and main and left pulmonary arteries (arrows).
65. Aorta
The most commonly seen abnormality of the aorta is dilation,
and 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 pattern of dilation and associated cardiac
abnormalities.
On the frontal chest radiograph, aortic dilation appears as a
prominence to the right of the middle mediastinum . There is
also a prominence in the anterior mediastinum on the lateral
view, behind and superior to the pulmonary outflow tract.
Dilation of the aortic root is seen in the presence of aortic
valve disease (both stenosis and regurgitation) but more
frequently has other causes, such as long-term, poorly
controlled systemic hypertension or generalized
atherosclerosis with ectasia.
66. 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
absence of cardiomegaly and presence of normal pulmonary vascular pattern. B,
Lateral view demonstrates calcification of the aortic valve leaflets (arrows),
suggestive of a bicuspid valve. There is a prominent, mildly dilated aortic root
(arrowheads).
67. Pleura and Pericardium
The pleura and pericardium also require systematic evaluation. The
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 pericardial effusion, the visceral and parietal pericardium separate.
Because 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 cardiac apex, with density (fluid) between them. CMRI,
echocardiography, 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 important to look for specific explanations. Although cardiac dilation
and valvular disease are more common causes, the presence of an
unsuspected 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 itself diagnostic.
68. Pericardial effusion
Cardiomegaly
Cardio phrenic angles
become more and more
acute.
Narrow vascular pedicle
Marked change in
cardiac silhouette in
decubitus position is
very diagnostic.
69. Pleural and pericardial calcification
Pleural and pericardial calcification can occur, but are often not obvious .
Pericardial calcification is associated with a history of pericarditis.
Although there are multiple causes, tuberculosis and various viruses are 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
only on one view.
Myocardial calcification secondary to a large myocardial infarction with
transmural necrosis is rare but can generally be distinguished from
pericardial calcification. It tends to appear thicker, more focal, and less
consistent with the outer contour of the heart.
Pleural calcification is easily distinguishable from pericardial calcification
and is essentially pathognomonic for asbestos exposure. It is associated
with a high risk of malignant mesothelioma but is not diagnostic of this
type of tumor.
70. Chest radiographs of a 45-year-old man with calcific pericarditis.
A, PA view is essentially normal. B, Lateral view demonstrates
thin, irregular calcification of pericardium around the left
ventricular contour.
71. Chest radiograph showing marked pericardial calcification in a
patient with constrictive pericarditis.
72. Cardiac valves calcification
Calcified cardiac valves
Chest PA view
Aortic valve will be at the level of
T6-T7 overlying the midline area.
Mitral valve will be at T8 level away
from the midline in the paravertebral
region.
Lateral view
Aortic calcification is above an
imaginary line from left bronchus to
RV apex and mitral calcification is
below the line.
74. Rheumatic valvular heart diseases
Rheumatic Mitral Stenosis
X-ray chest PA view
The typical mitralisation.
Less prominent aortic knuckle.
Obliteration of pulmonary bay due to prominent main
and left pulmonary arteries.
Prominent left atrial appendage.
Straightening of convex contour of left ventricular
border due to hypoplasia and hypovolumia.
75. Top panel shows
mitralisation.
Bottom panel
shows gross
enlargement of
main pulmonary
artery, left atria and
left atrial
appendage dilation
and right
ventricular
enlargement.
82. Congenital heart diseases-Acyanotic
Without a shunt
Pulmonary valvular stenosis
The radiological features are-
Pulmonary oligaemia
Post-stenotic dilatation of main pulmonary
artery
Right ventricular enlargement
Right atrial enlargrment
84. Primary pulmonary
hypertension
X-ray chest PA view
Moderate to marked enlargement of main
pulmonary artery and its proximal branches.
Peripheral pulmonary arteries are diminished
and pruned resulting in clear peripheral lung
fields.
Absence of pulmonary venous hypertension.
Small and inconspicuous ascending aorta
Right ventricular and right atrial enlargement
Absent left atrial enlargement
86. Congenital heart diseases-Acyanotic
With a shunt
Shunt at atrial level
Shunt at ventricular level
Shunt at aorto pulmonary level
Pulmonary plethora is common in all left to
right shunts.
87. Atrial septal defect
Ostium secundum ASD
Enlargement of RV,RA and LA.
Left ventricle is hypovolaemic and
hypoplastic.
Right pulmonary artery is more prominent
than left pulmonary artery giving the
radiological sign of jug-handle appearance.
Ostium primum ASD
Left ventricular enlargement in addition to the
radiological features of OS –ASD.
90. VSD
All four chambers are
involved.
The ascending aorta is
inconspicuous.
Both pulmonary arteries
are equally prominent.
91. Patent Ductus Arteriosus
All the four chambers are
involved.
Prominent ascending aorta.
There may be speck of
calcium when PDA is
calcified.It is comma shaped
between aortic knuckle and
main pulmonary artery and
is known as Cap of Zin.
Both pulmonary arteries are
equally dilated.
92. Congenital cyanotic heart diseases
Increased pulmonary
arterial blood flow
Complete transposition
of great arteries(d-TGA)
Absent thymic shadow
Narrow vascular pedicle
Increased CT ratio with
egg lying on its side
appearance
Pulmonary plethora
93. Truncus Arteriosus
All four chambers are
dilated with pulmonary
plethora.
In one – third of cases
right aortic arch is
present.
94. TAPVC
Supracardiac type is the
commonest and will
have a distinctive figure
of 8 or snowman
silhouette or cottage
loaf.The upper portion
of figure of 8 is formed
by the dilated left
vertical vein and right
superior vena cava.The
lower portion consists
of dilated right atrium
and right ventricle.
95. Decreased pulmonary arterial blood flow
Tetralogy of Fallot
No cardiomegaly
Uplifted apex-boot shaped or
coeur en sabot appearance
Pulmonary oligaemia
Dilated ascending aorta with right
aortic arch in 25% of cases
Bilateral reticular formation due
to bronchopulmonary collaterals
Unilateral rib notching after BT
shunt
96. Ebstein anomaly of the tricuspid valve
Cardiomegaly with
dilated right atrium and
right ventricular
infundibulum accounts
for the box like
silhouette with normal
or decreased pulmonary
blood flow,resembling
pericardial effusion.
97. Coarction of aorta
Three sign on chest X-ray
E sign or reverse 3 sign in barium
swallow
Rib notching of 3rd to 8th posterior
ribs along its lower border usually
after the age of 9 years
99. Implantable Devices and Other Postsurgical
Findings
A final important and broad area concerns the chest radiograph following
surgery or other procedures. In these situations, it is crucial to recognize
devices that have been implanted and changes that may occur. Among the
most common are various valve prostheses, pacemakers and ICDs, intra-
aortic counterpulsation balloons , and ventricular assist devices . There are
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 and retrosternal blurring and effusions
Some of these findings may be temporary, such as lines and tubes
associated 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 tips. Although course and tip position are generally
confirmed 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 atrium and apex of the right ventricle.
100. If the leads are not positioned in this way, the reasons
should be carefully determined. That is, are they
positioned because of error or anatomic variants (e.g.,
a persistent left SVC that empties into the coronary
sinus and then the right atrium or because the lead
belongs in the coronary sinus. Additionally, the
position of the wires and of valve prostheses can help
in the definition of specific chamber enlargement
101. AV sequential
pacemaker in right infra
clavicular subcutaneous
pocket. J shaped atrial
lead is seen in right
atrial appendage.Tip of
ventricular lead is in
right ventricular apex.
102. Biventricular pacing.
Atrial lead is in right
atrium; right ventricular
lead is in RV apex, left
ventricular lead is
introduced through
coronary sinus to pace
left ventricular
epicardium.
103. Conclusion
Chest radiographs provide a wealth of physiologic and anatomic
information. As such, they play a central role in the evaluation and
management of patients with a wide variety of cardiovascular and other
disorders.
The radiation dose inherent in obtaining x-rays should always be
considered.
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
defining cardiomegaly or in ruling out a pneumothorax or effusion).
Standard 6-foot frontal and lateral chest x-rays, on the other hand, are
almost always of value. Whether recorded conventionally or digitally, if
they are evaluated carefully using a systematic approach and, whenever
possible, compared with prior chest radiographs, it is hard to overstate their
importance.