X-ray picture of heart diseases: typical variants

Chest X-ray remains a basic examination for shortness of breath, chest pain, cough, suspected pulmonary congestion, and cardiovascular complications, as a single image evaluates the lungs, pleura, mediastinum, and overall cardiac contour. This method is particularly useful as a rapid "complication screening" when it is necessary to differentiate cardiac from pulmonary causes of symptoms and identify associated findings. [1]

However, radiography rarely answers the fundamental cardiological question of "why the heart works this way." It reveals the consequences: chamber enlargement, venous congestion, pulmonary edema, pleural effusion, calcifications, and certain contours of large vessels. For this reason, modern algorithms view radiography as a supportive method rather than a "diagnosis based on an image." [2]

Clinically, sensitivity is important to remember. Updates on acute heart failure emphasize that chest radiography may not detect pulmonary congestion early on, and the European Society of Cardiology guidelines describe its role in the emergency department more cautiously than previously. This does not negate the usefulness of chest radiography, but it does explain why lung ultrasound and echocardiography are increasingly being used to supplement the examination. [3]

The practical conclusion is simple: radiography provides better answers to questions such as "is there pulmonary edema?", "is there pleural effusion?", "does it look like pericardial effusion?", and "is there significant cardiomegaly" than questions about the exact cause of the valve defect or the degree of ischemia. Therefore, a competent interpretation is always based on clinical findings and the results of a cardiac ultrasound. [4]

Table 1. What radiography shows well and where its limits are

Task	What can be seen on an x-ray?	What is usually required for confirmation?
Pulmonary congestion and edema	venous congestion, interstitial and alveolar edema, effusions	ultrasound examination of the lungs, echocardiography, laboratory markers
Suspected enlargement of the heart	increase in cardiothoracic index, change in contours	echocardiography, magnetic resonance imaging of the heart
Suspected pericardial effusion	"water bottle" for large effusions	echocardiography as the main method
Gross signs of valve defects	indirect signs of chamber overload, stagnation	echocardiography for anatomy and severity
Congenital defects	characteristic configuration of the heart and vascular pattern in the lungs	echocardiography, computed tomography, magnetic resonance imaging

[5]

How to read a scan systematically: technique and checklist of signs

The quality of the image determines the interpretation. The cardiothoracic index is more accurately assessed using a posteroanterior projection with adequate inspiration, as the anterior-posterior translational projection and the prone position often "enlarge" the heart and can mimic cardiomegaly. [6]

A cardiothoracic index above 0.5 is usually considered elevated, but it is a guideline, not a diagnosis. The result is influenced by projection, body type, inspiratory volume, kyphoscoliosis, the amount of pericardial adipose tissue, and sometimes chest wall characteristics. Therefore, it is more appropriate to use the index as a "signal for clarification" rather than as a standalone criterion for heart failure. [7]

A convenient reading checklist begins with the external environment: projection, rotation, inspiration, and exposure. Then the following are assessed: 1) overall cardiac size; 2) cardiac arches and suspected chamber enlargement; 3) aorta and pulmonary arch; 4) pulmonary vascular pattern; 5) interstitial congestion; 6) alveolar infiltrates; 7) pleural effusions; 8) associated lung and bone findings. [8]

A separate assessment block is the signs of pulmonary venous hypertension and edema. Classic stages include redistribution of blood flow to the upper lobes, interstitial edema with thickening of the interlobular septa and peribronchial "muff-shaped" thickening, and then alveolar edema with "butterfly wings" in the hilar regions. [9]

It's important to recognize the "pitfalls." In patients with severe emphysema, the heart may appear relatively small due to hyperinflation of the lungs, while in patients with obesity and a high diaphragm, the cardiac shadow may appear larger. Rapid clinical changes, such as sudden dyspnea, require dynamic assessment and confirmation with more accurate methods, rather than attempting to "guess" a diagnosis from a single image. [10]

Table 2. Mini algorithm for interpreting radiographs in case of suspected cardiac pathology

Step	What to look at	Typical tips
1	Projection and Quality	portable anterior-posterior projection often overestimates the size of the heart
2	Cardiothoracic index	above 0.5 indicates an increase, but requires context
3	Contours of the heart	Which arcs are "bulging" and what does this mean?
4	Pulmonary vessels	redistribution of blood flow, venous dilation, arterial oligo- or hypervascularization
5	Interstitium and alveoli	Kerley lines, peribronchial thickening, butterfly wings
6	Pleura	small effusions often support the diagnosis of congestive decompensation

[11]

Table 3. X-ray signs of pulmonary congestion and edema

Sign	What does it look like?	What does it most often indicate?
Redistribution of blood flow	the vessels of the upper lobes appear more pronounced	increased pressure in the pulmonary veins
Curley Type B Lines	short horizontal lines at the costophrenic sinuses	interstitial edema, thickening of the septa
Peribronchial thickening	"couplings" around the bronchi, blurring of the roots	interstitial congestion
Alveolar edema	bilateral hilar infiltrates	acute deterioration of hemodynamics
Pleural effusion	dullness of sinuses, meniscus	congestion, sometimes accompanied by inflammation

[12]

Heart failure, ischemia, and myocardial infarction: what does an X-ray show?

In chronic heart failure, chest radiography often reveals a combination of an enlarged heart and signs of pulmonary venous hypertension, especially in the presence of prior heart attacks, cardiomyopathy, or significant valvular disease. However, a normal chest radiograph does not rule out early decompensation, so clinical guidelines emphasize the value of a combined approach with ultrasound and echocardiography. [13]

In acute decompensation, the key task of radiography is to confirm pulmonary edema and assess effusions. Kerley type B lines have high specificity but not the highest sensitivity, so their absence does not guarantee the absence of congestion. This is one reason why lung ultrasound is often more sensitive to congestion. [14]

Coronary artery disease and acute myocardial infarction are diagnosed not by radiography, but by clinical examination, electrocardiography, and biomarkers, with imaging chosen based on indications. Radiography is often needed to assess complications and alternative causes of deterioration: pulmonary edema, pleural effusions, sometimes signs of aneurysm, as well as concomitant pneumonia or pneumothorax, which may change the treatment strategy.

A separate situation is post-infarction aneurysm and intracardiac thrombi. A localized bulge is sometimes visible on an X-ray, but this is more accurately assessed by echocardiography and cardiac magnetic resonance imaging, which show wall thinning, impaired contractility, and the presence of a thrombus. In modern practice, an X-ray is merely a "reason to suspect" and refer for further investigation.

Table 4. Typical X-ray patterns in cardiac decompensation

Scenario	In the picture most often	Which clarifies the reason
Acute heart failure	interstitial or alveolar edema, effusions, sometimes enlargement of the heart	echocardiography, lung ultrasound, laboratory markers
Cardiogenic pulmonary edema	bilateral hilar infiltrates, Kerley lines, effusions	echocardiography, valve and contractility assessment
Chronic volume overload	cardiomegaly, signs of venous hypertension	echocardiography for structure and function
Pressure overload, pulmonary hypertension	dilation of the pulmonary artery, changes in vascular pattern	echocardiography, computed tomography as indicated

[17]

Valve defects: mitral and aortic "prints" on radiographs

In valvular defects, radiography reveals the indirect consequences of chamber and pulmonary circulation overload, but does not measure the severity of the defect. Therefore, echocardiography remains the key method, while computed tomography is used to clarify calcification and anatomy before intervention, which is emphasized in current guidelines for valvular defects. [18]

Mitral valve insufficiency most often results in enlargement of the left atrium and left ventricle, and with increasing pulmonary hypertension, signs of right-sided congestion and pulmonary venous congestion. On imaging, this may manifest as increased pulmonary vascularity, effusions, and altered cardiac contours, but definitive confirmation requires echocardiography with assessment of regurgitation.

Mitral stenosis is classically associated with left atrial enlargement and signs of pulmonary venous hypertension. Radiographic findings include a "straightening" of the left cardiac contour due to the left atrial appendage, a double contour, dilation of the pulmonary artery, and sometimes valve calcifications. These signs are well-known, but they vary in severity and are not a substitute for ultrasound assessment of valve area and pressure. [20]

Aortic defects most often manifest as left ventricular overload: in stenosis, this results in poststenotic dilation of the ascending aorta and calcification of the leaflets; in insufficiency, this results in left ventricular enlargement and dilation of the ascending aorta. Radiography helps visualize calcification and the general type of remodeling, but does not determine the indications for intervention, which are currently based on echocardiography, symptoms, and remodeling parameters.

Table 5. Valve defects and the most typical X-ray signs

Vice	What is most often seen on an x-ray?	Frequent "confirming" steps
Mitral valve insufficiency	enlargement of the left atrium and left ventricle, pulmonary congestion during decompensation	echocardiography with Doppler assessment
Mitral valve stenosis	signs of left atrial enlargement, pulmonary hypertension, sometimes calcification	echocardiography, assessment of pulmonary pressure
Aortic valve stenosis	calcifications of the valves, poststenotic dilation of the aorta, signs of left ventricular overload	echocardiography, computed tomography of calcification as indicated
Aortic valve insufficiency	enlargement of the left ventricle, dilation of the ascending aorta	echocardiography, assessment of the aorta and ejection fraction

[22]

Congenital defects: vascular patterns and "recognizable" configurations

In congenital malformations, radiography can provide useful clues regarding cardiac configuration and pulmonary vascular patterns, especially over time. However, the guidelines emphasize that echocardiography remains the first-line method, with radiography being a complementary tool to help monitor changes in cardiac size and pulmonary blood flow. [23]

Left-to-right shunt defects typically exhibit signs of increased pulmonary blood flow: increased vascularity, often dilation of the right pulmonary arteries and the pulmonary artery. This may be seen in atrial septal defects, ventricular septal defects, and patent ductus arteriosus, but the precise anatomy and hemodynamic significance are determined by echocardiography and, if necessary, magnetic resonance imaging. [24]

Defects with limited blood flow to the pulmonary circulation or with significant right-to-left shunting are characterized by reduced pulmonary vascularity. A classic example is tetralogy of Fallot, where a "boot" can form due to right ventricular hypertrophy. However, even here, radiography serves more as a guide, and key decisions are based on echocardiography and 3D imaging. [25]

There are also "rare" recognizable signs, such as the "scimitar" sign with anomalous venous drainage of the right lung, dextrocardia, and mirror-image disposition of organs. In such situations, radiography is often the first sign, followed by computed tomography or magnetic resonance imaging for precise vascular mapping before treatment.

Table 6. Congenital defects: what the vascular pattern of the lungs suggests

Hemodynamic type	Pulmonary pattern on a radiograph	Examples of vices	What is confirmed?
Left-right reset	increased vascularization	atrial septal defect, ventricular septal defect, patent ductus arteriosus	echocardiography, magnetic resonance imaging
Restriction of blood flow to the lungs	decreased vascularization	tetralogy of Fallot, severe pulmonary artery stenosis	echocardiography, computed tomography
Mixed variants and complex anatomy	non-uniform pattern	complex combined defects	magnetic resonance imaging, computed tomography

[27]

Pericarditis and pericardial effusion: where radiography is helpful and where it is misleading

In acute pericarditis, radiographs are often normal, especially if there is no effusion or it is small. However, with prolonged pericarditis, thickening and calcification of the pericardium may lead to the appearance of dense calcifications along the cardiac contour, and deformation of the cardiac shadow may support the suspicion of a constrictive process. [28]

Pericardial effusion on radiography most often appears as an enlarged, more "spherical" cardiac shadow, while the classic "water bottle" configuration typically corresponds to larger effusions. Importantly, cardiac tamponade cannot be confirmed from a single image, nor can the hemodynamic significance of the effusion be reliably assessed; therefore, echocardiography is required if clinical suspicion exists. [29]

A useful practical tip: with effusion, relatively "clear" lung fields without significant venous congestion are often preserved, whereas with true cardiomegaly due to heart failure, there are more often signs of pulmonary venous hypertension. However, this rule is not absolute, especially in patients with combined pathology, so the final decision always rests with echocardiography. [30]

Modern multimodal pericardial imaging is based on echocardiography as the initial step, with computed tomography and magnetic resonance imaging used to assess pericardial thickening, inflammation, tumor lesions, and complex situations. This approach is reflected in guidelines for pericardial diseases, where radiography is considered an adjunctive modality. [31]

Table 7. Pericardium: what is visible on the radiograph and what to do next

Situation	Possible X-ray finding	The next step
Acute chest pain, suspected pericarditis	the picture may be normal	echocardiography to rule out effusion and complications
Suspected large effusion	enlarged "globular" shadow of the heart	Echocardiography urgently if there are signs of tamponade
Suspected constriction	pericardial calcifications, contour deformation	echocardiography, then computed tomography or magnetic resonance imaging
Vague cardiomegaly	increased cardiothoracic index without clear cause	echocardiography, assessment of projection and clinical features

[32]