Summary
Chest x-ray (CXR) is one of the most commonly performed imaging studies in clinical practice. CXR is a quick, noninvasive, and relatively low-radiation method to evaluate conditions and monitor procedures related to the heart and main vessels, lungs, airways, bones, and soft tissues of the thorax. Verification of patient and study data, view, and technical quality is essential before interpreting a CXR. Radiological interpretation should be performed using a systematic approach (e.g., the ABCDEFGHI mnemonic) to minimize errors while also integrating clinical findings to formulate a diagnostic impression.
General information on x-ray technology is found in “Radiography.”
Indications
CXRs are used in the evaluation of several conditions and to monitor various procedures, including: [1][2]
- Clinical findings that require further assessment, e.g.:
- Respiratory (e.g., dyspnea, pathological breath sounds)
- Cardiovascular (e.g., chest pain, heart murmur)
- Gastroesophageal (e.g., hiatal hernia)
- Patients with polytrauma, chest trauma
- Critical care patients (e.g., upon admission, to monitor for complications)
- Chronic conditions (e.g., to monitor neoplasms, COPD)
- Postprocedural patients: to confirm the position of tubes and devices, e.g., endotracheal or nasogastric tube placement, cardiac implantable electronic devices (CIEDs)
A routine CXR upon admission is not required if patients do not have cardiothoracic symptoms or conditions. [1]
Contraindications
There are no absolute contraindications to performing a CXR. Radiation exposure is a common concern.
- The radiation dose of a single CXR has not been associated with an increase in negative health outcomes. [3][4]
- Always follow the ALARA principle and radiation safety protocols when performing a CXR.
-
Pregnancy and fetal radiation exposure
- The fetal radiation dose of a two-view CXR is classified as very low. [1][5]
- There is no evidence of increased fetal risks or pregnancy loss with typical CXR doses. [5][6]
Consider the clinical indication carefully before exposing a patient to even small doses of radiation.
We list the most important contraindications. The selection is not exhaustive.
Technical background
Patient and study data [2][7][8]
Verify the following:
- Patient's name and date of birth
- Date and type of study
Views [2][7][8]
- Posteroanterior (PA) view
- Patient position: standing with the chest as close to the x-ray detector as possible
- Preferred view: provides the most accurate visualization of chest structures
- Anteroposterior (AP) view
- Patient position: sitting or lying, with the x-ray detector under the back
- Alternative to PA view for patients who cannot stand (e.g., intubated patients, patients in the ICU)
- The cardiac silhouette and other mediastinal structures appear magnified.
-
Lateral view
- Patient position: standing with the left side as close to the x-ray detector as possible
- Complement to the PA view: used to visualize the retrosternal and retrocardiac spaces
-
Lateral decubitus view
- Patient position: lying with the side of interest down, arms raised overhead; x-ray detector behind the back
- Used to detect, e.g., small pleural effusion, pneumothorax
Technical quality [2][7][8]
Assess the following aspects of a CXR to ensure good technical quality :
- Penetration: The vertebral bodies should be visible through the heart shadow.
- Inspiration: At least 6 anterior and/or 10 posterior ribs should be visible. [7][8]
- Rotation: The distance between the medial end of the clavicles and the spinous process should be the same on both sides.
The study may need to be repeated if the data is incorrect or the quality is inadequate.
The x-ray beam enters from the front of the body, passing through it to the back. As the human heart is located ventrally, it is further away from the x-ray detector in an anteriorposterior view (compared to posterioranterior). As a result, on the x-ray, the heart seems enlarged and its borders appear indistinct.
© AMBOSS
X-ray chest (PA view) of an adult female patient
The lung volumes are normal. No abnormal pulmonary parenchymal opacities are seen. The cardiac silhouette appears normal. The costophrenic sulci are sharp, with no evidence of effusion. No concerning skeletal lesions are identified.
Ak: aortic knob; blue overlay: examples of pedicles; dashed lines: medial end of clavicles; green overlay: ribs (1-6); LPA: left pulmonary artery; MPA: main pulmonary artery; red overlay: examples of spinous processes; RPA: right pulmonary artery; Sc: scapula; St: stomach; white outline: example of vertebral body
Source: “Normal posteroanterior (PA) chest radiograph (X-ray)” by Mikael Häggström, Wikimedia Commons, licensed under CC0 1.0. Modifications: two images have been combined. Coypright info above applies to PA image. Source title of lateral image: Normal lateral chest radiograph (X-ray). Source link of right image: https://commons.wikimedia.org/wiki/ File:Normal_lateral_chest_radiograph_(X-ray).jpg. License type, author of source and source designation identical for both images. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
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Interpretation/findings
General principles [2][7][8]
- Verify patient and study data, view, and adequate technical quality of the study.
- Review the image from cranial to caudal and medial to lateral to ensure a comprehensive assessment and minimize errors.
- Utilize a systematic approach to CXR interpretation (e.g., the ABCDEFGHI approach).
- Assess for CXR emergency findings.
Obtain previous chest x-rays for comparison when available.
Do not delay treatment for expert interpretation of imaging studies if an emergency is clinically suspected.
ABCDEFGHI approach
- Airway
- Bones and soft tissue
- Cardiovascular
- Diaphragm
- Edges and effusions
- Fields
- Gastric bubble
- Hardware
- Impression
Always verify the view (e.g., AP or PA) and patient position (e.g., standing or supine) when interpreting a chest x-ray.
Airway
-
Trachea: Trace down and identify deviations and/or narrowing.
- There may be a slight, normal deviation to the right caused by the aortic knob.
- Tracheal deviation can occur toward an affected lung field (e.g., lobar collapse, pulmonary fibrosis ) or away from it (e.g., tension pneumothorax ).
-
Main bronchi: Identify the carina.
- Should be a well-defined, midline angle
- Identify deviations, deformities, surrounding masses, and dilation (e.g., tumors, bronchiectasis ).
Bones and soft tissue
-
Bones: Trace the clavicles, posterior and anterior rib arches, scapulae, and vertebrae.
- Should appear radiopaque with smooth and continuous edges without any irregularities or disruptions
- Changes in density (e.g., areas of ↑ radiolucency) are seen in osteolytic lesions.
- Disruptions of the bony cortex are seen in fractures.
- Examine and compare the intercostal spaces: Widened intercostal spaces and horizontal ribs are signs of pulmonary hyperinflation.
-
Soft tissue
- Should appear homogeneous without any abnormal masses or irregularities
- Confirm symmetric mammary shadows.
- Evaluate for areas of increased radiopacity (e.g., cutaneous calcification) or radiolucency (e.g., subcutaneous emphysema ).
Posterior ribs appear more horizontal than anterior ribs on CXR.
Cardiovascular
- The mediastinum is visualized as a radiopaque area with well-defined contours in the center of the CXR.
- Loss of pulmonary volume (e.g., due to lobectomy, pneumonectomy, or atelectasis ) can cause a shift to the affected side.
- A tension pneumothorax or a large pleural effusion can cause a contralateral shift.
- Trace the border between the aorta, trachea, and heart.
- The aortic arch should appear as a smooth, rounded prominence on the left side of the mediastinum.
- Abnormal aortic contour can be seen in, e.g., age-related aortic ectasia, aneurysmal dilatation, and dissection.
- Calculate the cardiothoracic ratio ; increases can be due to cardiomegaly or pericardial effusion.
- Trace the right and left heart contours and assess its components; request a lateral view if necessary.
- The right atrium forms the right heart border; the left ventricle forms the left heart border.
- Heart contours should be well-defined.
- Poorly-defined heart contours can be caused by multiple conditions, e.g., pleural effusion, pneumonia, pericardial effusion, lymphadenopathy.
- Mediastinal widening can be caused by multiple conditions, e.g., mediastinal masses, aortic aneurysm, aortic dissection.
Diaphragm
- Trace both hemidiaphragms from the costophrenic angle to the vertebrae.
- The right hemidiaphragm should be slightly higher than the left. [7][8]
- Assess for diaphragmatic elevations (e.g., in atelectasis, phrenic nerve injury , hepatomegaly) or depressions (e.g., in tension pneumothorax , hyperinflation due to COPD ).
- Subdiaphragmatic free gas may be observed in pneumoperitoneum.
Edges and effusions
- Trace the lung borders and identify the cardiophrenic and costophrenic angles.
-
Pleura and pleural spaces are not typically visible unless affected by a disease. [8]
- Imaging findings in pneumothorax include the deep sulcus sign and a visible visceral pleura.
- CXR findings in pleural effusion consist of a radiopaque area of variable size and conformation depending on the etiology and amount of fluid.
- Pleural thickening can be visualized as areas of increased radiopacity, e.g., in mesothelioma.
A hemothorax is indistinguishable from a pleural effusion on CXR.
Fields
Compare the lung fields by assessing the following aspects:
-
Lung volume: 6 anterior and/or 10 posterior ribs should be visible. [7][8]
- Increased lung volume may be observed, e.g., in pulmonary hyperinflation in COPD.
- Decreased lung volume may be observed, e.g., in interstitial lung disease, myasthenia gravis, obesity, and ascites.
-
Lung density: should be relatively uniform across both lungs
- Compare the right and left lung fields to assess for changes in density, e.g.:
- Abrupt radiolucency in pneumothorax
- Bilateral reticular, nodular, or linear opacities in interstitial lung disease
- Bilateral diffuse opacities with or without Kerley B lines in pulmonary edema
- Assess the upper, middle, and lower zones of each lung to identify focal changes in density, e.g.:
- Pulmonary consolidation
- Air bronchogram
- Bronchiectasis
- Solitary pulmonary nodules (< 3 cm) or masses (≥ 3 cm) [2][8]
- Compare the right and left lung fields to assess for changes in density, e.g.:
-
Lung hila
- Visualized as two triangular areas superior to the cardiac silhouette [2][8]
- Compare the right and left hila to assess for changes in hilar size (e.g., hilar lymphadenopathy in sarcoidosis or lymphoma ) and density (e.g., calcifications from granulomatous diseases including histoplasmosis and tuberculosis).
-
Lung markings
- Pulmonary vessels are easily visualized in the hilar areas and lower lung zones, becoming smaller and less visible toward the periphery and upper lung zones.
- Increased lung markings in the upper lung zones are often observed in pulmonary edema and pulmonary hypertension.
- Reduced lung markings are a feature of pneumothorax.
Gastric bubble and hardware
- The gastric bubble is frequently visible under the left hemidiaphragm.
- Confirm correct positioning of hardware (e.g., tubes, catheters, CIEDs).
Impression
- Gain an overall diagnostic impression by performing a clinical interpretation:
- Combine all relevant radiological findings.
- Incorporate clinical findings.
- Compare past CXRs if available.
- Initiate immediate treatment for CXR emergency diagnoses.
A systematic approach to CXR interpretation reduces errors and omissions.
CXR emergency findings [2][7][8]
| CXR findings suggestive of thoracic emergencies | |
|---|---|
| Finding | Emergency diagnosis |
| Tracheal or mediastinal deviation |
|
| Multiple rib fractures |
|
| Increased cardiothoracic ratio |
|
| Mediastinal widening |
|
| Westermark sign and/or Hampton hump |
|
| Hemidiaphragmatic depression |
|
| Abrupt radiolucency and ↓ lung markings | |
| Subdiaphragmatic free gas |
|
| Bilateral diffuse opacities, Kerley B lines, and ↑ lung markings |
|
Other common abnormal chest x-ray findings
- CXR findings in pneumonia
- CXR findings in pleural effusion
- CXR findings in atelectasis
- CXR findings in foreign body aspiration
- CXR findings in cardiogenic pulmonary edema
- CXR findings in noncardiogenic pulmonary edema
- CXR findings in COPD
X-ray chest (PA view)
The lung volumes are normal. No abnormal pulmonary parenchymal opacities are seen. The cardiac silhouette size is normal. The costophrenic sulci are sharp, without evidence of effusion. No concerning skeletal abnormalities are identified.
1: trachea; 2: right main bronchus; 3: left main bronchus; 4: right upper lobe bronchus; 5: right lower lobe bronchus; 6: left upper lobe bronchus; 7: left lower lobe bronchus
AK: aortic knuckle; RPA: right pulmonary artery; LPA: left pulmonary artery
Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.
X-ray chest (PA view) of a patient with ankylosing spondylitis
Opacification of the upper right lung (green overlay) is accompanied by ipsilateral hilar elevation and tracheal deviation (arrow) indicating volume loss. There is also linear atelectasis or scarring (arrowhead) in the right lower lobe and blunting of the right lateral costophrenic sulcus (yellow line) from pleural thickening.
Chronic apical parenchymal opacification from fibrosis is an uncommon extraarticular complication of ankylosing spondylitis. It is important to distinguish it clinically and radiographically from active diseases, such as tuberculosis and lung cancer.
H: hilum; red lines: tracheal wall
Source: “Figure 1, in: Rapidly Progressive Pulmonary Apical Fibrosis and Parenchymal Destruction in a Patient with Ankylosing Spondylitis” by Hasan Ulusoy, Nazmiye Tibel Tuna, Aslı Tanrivermis Sayit, Hindawi, licensed under CC BY 4.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
Chest x-ray (PA view) of a patient without a history of trauma
A large left pneumothorax (blue overlay) is seen, with an absence of lung markings peripheral to the collapsed lung (yellow overlay). Contralateral shift of the mediastinum (indicated by arrows) has resulted in a prominent right heart border (white line), and there is slight widening of the left lateral costophrenic angle (angle marker). These findings are consistent with tension pneumothorax. Incidentally noted is a mild rotatory curvature of the upper thoracic spine.
The absence of thoracic trauma suggests a spontaneous pneumothorax.
Dashed white line: visceral pleural line; green overlay: spinous process; red overlay: vertebral pedicles
Source: “Spontanpneumothorax” by Hellerhoff, Wikimedia Commons, licensed under CC BY-SA 3.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
X-ray chest (PA view; right lung) and CT (coronal plane; lung window; right lung) of a patient with bronchiectasis
The right lung is diffusely abnormal. Numerous parallel lines (tram track sign; examples indicated by arrows and green lines) representing thickened bronchial walls demarcate lucent air within dilated bronchi. Some thick-walled bronchi are alternatively imaged in cross-section and are visible as circles with lucent centers (examples indicated by red overlay).
Source: “Chest imaging using signs, symbols, and naturalistic images: a practical guide for radiologists and non-radiologists” by Alessandra Chiarenza, Luca Esposto Ultimo, Daniele Falsaperla, Mario Travali, Pietro Valerio Foti, Sebastiano Emanuele Torrisi, Matteo Schisano, Letizia Antonella Mauro, Gianluca Sambataro, Antonio Basile, Carlo Vancheri & Stefano Palmucci, Insights Imaging, licensed under CC BY 4.0. Modifications: image cropped, letter removed. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
X-ray chest (PA view) of a patient with polytrauma from a motor vehicle collision
A displaced fracture (green overlay) of the mid-shaft of the right clavicle is accompanied by fractures of the third and fourth ribs (red overlay). Subtle buckling of the cortex of the first rib also suggests a fracture (arrowheads). A first rib fracture is a marker of severity in polytrauma, frequently associated with severe organ injury.
Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.
Chest x-ray (PA view)
Large lung volumes (green outline and arrows) are accompanied by intercostal space widening (examples indicated by red arrows) and diaphragmatic flattening, indicating hyperinflation.
Source: © IMPP
Chest x-ray (PA view)
Vague opacification of the lower hemithoraces is the result of mammary shadows (dashed lines). Pulmonary vessels are well-seen; there is no evidence of pulmonary consolidation. Additionally, the costophrenic angles (red overlay) are clear, without blunting to indicate pleural effusion.
Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.
Chest x-ray (PA view) after a fall
Linear lucencies (examples indicated by green overlay) throughout the soft tissues of the thoracic wall indicate subcutaneous emphysema. Additional air along fibers of the pectoralis major muscles (examples indicated by blue overlay) creates a pattern similar to the branching veins of a ginkgo leaf (ginkgo leaf sign). Mediastinal emphysema (examples indicated by red overlay) is also seen, for example, air is seen along the thoracic aorta and left side of the trachea. The lung volumes are large and the cardiac silhouette size is normal.
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
X-ray chest (left; AP view) and CT chest (right; axial plane; lung window) of patient with small cell carcinoma
A central mass (black arrowheads) projects over the left hilum on the chest radiograph. It is accompanied by partial opacification of the left lung resulting from left upper lobe collapse, with ipsilateral mediastinal shift. The right lung shows compensatory hyperinflation. The margin of the left hemidiaphragm remains sharply demarcated. A small pneumothorax (white arrowheads) is visible in the right hemithorax and a right chest tube (red overlay) is in place. A lucent stripe (blue overlay) outlining the aortic knob and proximal descending thoracic aorta (luftsichel sign) is due to interposition of a hyperinflated superior segment of the left lower lobe between the collapsed left upper lobe and the aorta.
CT shows the left upper lobe collapse (LULC) distal to a central mass, which produces a convexity along the medial aspect of the distorted major fissure (Golden S sign; yellow line). The aerated superior segment of the left upper lobe (white arrow) outlines the proximal descending aorta and is responsible for the luftsichel sign seen on the chest radiograph. Additional findings on the CT include a small amount of peripheral atelectasis (green overlay) in the left lower lobe and a small right pneumothorax (yellow overlay).
AA: ascending aorta; Black arrow: right central catheter; C: carina; DA: descending aorta; SS: superior segment left lower lobe
Source: “Fig 1, In: Medical Image of the Week: Infected Emphysematous Bulla | Main | January 2017 Imaging Case of the Month” by Gabe L, Snyder L, The Southwest Journal of Pulmonary, Critical Care & Sleep, licensed under CC BY-SA 4.0. Modifications: Removed arrows. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 4.0.
X-ray chest (PA view)
A large right tension pneumothorax is accompanied by lung collapse. When compared to the left hemithorax, no lung markings are seen in the right hemithorax beyond the margin of the collapsed right lung (green overlay). Signs of tension seen here include contralateral shift of mediastinal structures and depression of the right hemidiaphragm (indicated by red lines and arrow). Another sign that may be seen in tension pneumothorax is ipsilateral intercostal space widening.
An unrelated finding on this radiograph is slight curvature of the upper to midthoracic spine, convex to the left.
Black line and arrows: shift of mediastinal pleura; white line and arrows: shift of cardiomediastinal silhouette
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
X-ray chest (PA view) of a malignant pleural effusion in a patient with lung cancer
Complete opacification of the left hemithorax (green overlay) is accompanied by mediastinal shift to the contralateral right side (indicated by blue and red lines and arrows). This shift confirms that a space-occupying process, rather than volume loss, is the primary cause of the opacification.
The absence of air in the distal left main bronchus reflects bronchial obstruction and correlates with the patient's clinical history of bronchogenic carcinoma.
T: trachea; Green outline: trachea and main bronchi
Source: © IMPP
X-ray chest (PA view)
The lung volumes are normal. No abnormal pulmonary parenchymal opacities are seen. The cardiac silhouette (outlined in white), pulmonary hila (example indicated by green overlay), and superior mediastinum are normal in size and configuration. The lateral costophrenic sulci (outlined in green) are sharp, with no evidence of effusion. No concerning skeletal lesions are identified.
LV: left ventricle; RV: right ventricle; RA: right atrium; PT: pulmonary trunk (white arrow); AK: aortic knob; Trachea: red overlay, Breast shadow: white dotted outline
Source: © IMPP
X-ray chest (PA view) of a patient with a history of aneurysmal dilatation of the thoracic aorta
The mediastinum is widened, with the descending thoracic aorta (white line) extending further to the left than is normal (normal course estimated by white dashed line). The margin of the ascending aorta also extends to the right to a greater degree than normal (white line). Widening of the mediastinum on a chest radiograph as a result of an abnormal aortic contour can be seen in several settings, among them age-related aortic ectasia, aneurysmal dilatation, and dissection. Further imaging (e.g., computed tomography) may be required.
A fine curvilinear structure (azygos fissure) courses inferiorly in the medial right apex, terminating at an opaque, tear-shaped structure, which represents the azygos vein (green overlay). The finding is a normal anatomical variant formed by displacement of the azygos vein during fetal development. An azygos fissure is comprised of two layers of parietal pleura and two layers of visceral pleura. Lung medial to the fissure is called an azygos lobe.
AK: aortic knob
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image. Further notes: edit: bottom text removed: (Sup. Inst.)
Chest x-ray (PA view)
The cardiothoracic ratio (CTR) is used to aid in the detection of cardiac silhouette enlargement on a PA radiograph. The maximum transverse diameter of the cardiac silhouette is divided by the maximum transverse diameter (inner-inner edges of ribs or pleura) of the thorax.
A value > 0.50 may be considered an indicator of cardiac silhouette enlargement. The CTR is influenced by several factors, including dilatation of cardiac chambers, rotation of the heart, phase of respiration, posture, and measurement error.
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
X-ray chest (PA view) of a patient with peripartum cardiomyopathy
There is marked generalized enlargement of the cardiac silhouette, which correlated with biventricular enlargement on subsequent echocardiography.
Cardiothoracic ratio (CTR) is calculated as the maximum transverse diameter of the cardiac silhouette divided by the maximum transverse diameter of the thorax on a posteroanterior (PA) chest radiograph. A CTR >0.50 is usually considered cardiac silhouette enlargement, although a larger CTR can be seen in certain normal situations (e.g., expiratory radiograph, prominent fat pad).
Source: “Fig. 1, in: An unusual case of peripartum cardiomyopathy manifesting with multiple thrombo-embolic phenomena, Figure 1” by Uzoma N Ibebuogu, John W Thornton & Guy L Reed, Thrombosis Journal, licensed under CC BY 2.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
Chest X-ray (PA view) of a patient with a history of pericarditis and clinical findings of tamponade
The cardiac silhouette is enlarged (globular water bottle-shape; enlargement highlighted by green-hatched overlay) due to pericardial effusion.
Source: “28-01-Perikarderguss Perimyokarditis pa” by Hellerhoff, Wikimedia Commons, licensed under CC BY-SA 3.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
X-ray chest (left: PA view; right: lateral view) of an adult female patient
The lung volumes are normal. No abnormal pulmonary parenchymal opacities are seen. The cardiac silhouette size and shape are normal. The costophrenic sulci are sharp, with no evidence of effusion. No concerning skeletal lesions are identified.
On the lateral radiograph (right), the patient's upper arms (black dashed lines) obscure the retrosternal space. Furthermore, the lower thorax is slightly rotated with the left side anterior; note the stomach bubble (S) under the left hemidiaphragm and the projection of the left posterior costophrenic sulcus (dashed yellow line) anterior to the right (dashed blue line).
A: aorta
PT: pulmonary trunk
LA: left atrium
S: stomach
SVC: superior vena cava
IVC: inferior vena cava
Dashed white lines: margins of superior and inferior vena cavae
White line: aortopulmonary reflection (aortic-pulmonary reflection)
Yellow overlay: right atrium
Green overlay: right ventricle
Red overlay: left ventricle
Blue overlay: left atrium
Blue incomplete circle: left main to left upper lobe bronchus continuum
Dashed green line: posterior wall of bronchus intermedius
Green line: posterior wall of left main bronchus
Red line: top of left pulmonary artery
Blue line: aortic arch
Yellow lines: edges of scapulae
Source: “Normal posteroanterior (PA) chest radiograph (X-ray)” by Mikael Häggström, Wikimedia Commons, licensed under CC0 1.0. Modifications: two images have been combined. Coypright info above applies to PA image. Source title of lateral image: Normal lateral chest radiograph (X-ray). Source link of right image: https://commons.wikimedia.org/wiki/ File:Normal_lateral_chest_radiograph_(X-ray).jpg. License type, author of source and source designation identical for both images. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
X-ray chest (PA view) of an adult female patient
The lung volumes are normal. No abnormal pulmonary parenchymal opacities are seen. The cardiac silhouette, superior mediastinum, and pulmonary hila (outlined by green curved lines) are normal in size and configuration. The lateral costophrenic sulci (red lines) are sharp, with no evidence of effusion. No concerning skeletal lesions are identified.
Green arrow: aortopulmonary window (aortic-pulmonic window)
Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.
X-ray chest (lateral view)
The patient is slightly rotated. Edges of the soft tissue of both arms project over the retrosternal space (red overlay). The right hilar vasculature (RHV) is visible and the left pulmonary artery (LPA) is seen arching over the left upper lobe continuum (LULC; yellow circle), which is the region of transition between the left main bronchus and left upper lobe bronchus. The posterior wall of the left main bronchus (indicated by yellow line) can be identified as can the posterior wall of the bronchus intermedius (indicated by red line) on the right, projecting through the LULC. A central venous catheter (indicated by blue line) can also be seen.
RVOT: right ventricular outflow tract; RV: right ventricle; LA: left atrium; LV: left ventricle; IVC: inferior vena cava; green overlay: retrocardiac space; T: trachea
Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.
X-ray chest (PA view)
Costophrenic angles (also called costodiaphragmatic angles or sulci) are located at the reflections between the diaphragmatic and costal pleurae. On a PA or AP radiograph, normal lateral costophrenic angles typically appear distinct and pointed (green arrows and outlines). Posterior costophrenic angles are best seen on a lateral radiograph. Costophrenic angles may appear blunted or obliterated by adjacent pleural or parenchymal lung disease.
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
X-ray chest (PA view)
Two discrete masses are visible in the right lung (green overlay). The hila are enlarged and lobulated, suggesting bilateral lymphadenopathy (red overlay). There is atelectasis (yellow overlay) adjacent to elevation of the left hemidiaphragm (white line) suspicious for phrenic nerve paralysis. Gaseous dilatation of bowel (B) is also seen in the left upper quadrant, and the mediastinum is slightly shifted to the right (indicated by arrows).
Blue overlay (top right corner): hardware left humerus
Source: © IMPP Further notes: Illustration added to overlay, source: "Fig. 7, in: Surgical Approaches to Supradiaphragmatic Segment of IVC and Right Atrium through Abdominal Cavity during Intravenous Tumor Thrombus Removal" by Dmytro Shchukin, Vladimir Lesovoy, Igor Garagatiy, Gennadiy Khareba, Redouane Hsain; Advances in Urology, licensed under CC BY 3.0.
X-ray chest (lateral view)
There is elevation of the left hemidiaphragm (dashed line) with adjacent atelectasis (yellow overlay) of lung parenchyma and underlying dilated bowel (B).
Blue overlay: hardware left humerus; solid line: right hemidiaphragm
Source: © IMPP
X-ray chest (PA view)
Free intraperitoneal gas (green overlay) is visible under both the right and left hemidiaphragms.
Source: “34-01-Freie Luft nach LH-OP” by Hellerhoff, Wikimedia Commons, licensed under CC BY-SA 3.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
X-ray chest (AP view; supine)
A pneumothorax is visible in the left pleural space. The air has displaced the visceral pleura medially (arrowheads), portions of which are seen as a thin white curvilinear opacity. Pleural air has reduced the density of the lower left hemithorax compared to the right and has widened the left lateral costophrenic angle (deep sulcus sign, red overlay).
Pneumothorax collects anteriorly and basally within the nondependent pleural space when a patient is positioned supine. Air located laterally can abnormally deepen the lateral costophrenic angle. The deep sulcus sign is sometimes the only finding of pneumothorax in a supine patient.
Blue overlay: endotracheal tube; green overlay: atelectasis; yellow overlay: left internal jugular line
Source: “Pneumothorax im liegen” by Braegel, Wikimedia Commons, licensed under CC BY-SA 3.0. Modifications: Removed tag. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
Chest x-ray (right lateral view)
A pneumothorax is visible in the upper thoracic cavity as a hyperlucent area devoid of lung markings (green overlay). The right lung has collapsed and appears hyperlucent (the white dashed line marks the visible border of the collapsed lung).
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
X-ray chest (PA view) of a patient with tamoxifen-induced acute eosinophilic pneumonia
Peribronchial thickening (examples circled in yellow) and linear parenchymal opacities (examples indicated by white lines) are evidence of interstitial lung disease. A small pleural effusion (red line) projects through the right hemidiaphragm and blunts the right lateral costophrenic sulcus. A normal costophrenic sulcus is typically seen as an acutely angled junction between the costal and diaphragmatic pleural reflections (white dashed line).
Right chest wall staples (examples indicated by black overlays) and breast asymmetry (green outline) are the result of a recent mastectomy and reconstruction.
Source: “Fig. 1, In: Tamoxifen-induced acute eosinophilic pneumonia in a breast cancer patient” by Eiyoung Kwon, Mijin Kim, Eunhye Choi, Youngsam Park, Cheolseung Kim, International Journal of Surgery Case Reports, licensed under CC BY 4.0. Modifications: image cropped. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
X-ray chest (PA view)
There is marked opacification (green overlay) of the middle and lower left hemithorax from pleural effusion and passive atelectasis of the adjacent lung. No gastric air bubble is seen projecting over the lower left hemithorax to suggest marked elevation of the left hemidiaphragm from a large amount of atelectasis, but concave upper lateral borders, or menisci (white dashed lines), help confirm the presence of effusion extending to the mid thorax.
The margins of the cardiac silhouette and left hemidiaphragm are obscured. Additionally, the cardiac silhouette is shifted slightly to the right (indicated by blue line and arrow) and the left bronchial tree is slightly elevated (indicated by black lines and arrow).
In the right hemithorax, a small meniscus from effusion is seen laterally (indicated by red line). Additionally, increased opacification projects through the right hemidiaphragm indicating effusion in the posterior sulcus (red overlay).
Source: “Effusionhalf” by James Heilman, MD, Wikimedia Commons, licensed under CC BY-SA 3.0. Modifications: removed circle. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
X-ray chest (PA view)
Near complete opacification of the left hemithorax (green overlay) is accompanied by marked contralateral mediastinal shift (indicated by arrows) indicating a space-occupying process. The margin of the left hemidiaphragm is obscured (normal position indicated by black dashed line). A small amount of lung in the left apex remains aerated (red overlay), although it is encompassed by pleural disease, part of which demonstrates a lobulated appearance (indicated by white line).
Further workup revealed adenocarcinoma metastatic to the pleura, with nodular pleural thickening and effusion.
White dashed outline: tracheobronchial tree
Source: “Pleural effusion - Left lung” by Drs. Y Rosen & R Pillappa, Flickr, licensed under CC BY-SA 2.0. Modifications: cropped. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 2.0.
X-ray chest (PA view) of a patient with malignant mesothelioma
Marked opacification of the middle and lower left hemithorax (green overlay) is accompanied by menisci that indicate the presence of a pleural effusion. There is no appreciable ipsilateral or contralateral mediastinal shift. Non-dependent pleural thickening at the left apex (red overlay) is more conspicuous on the lateral radiograph.
A meniscus from a small right pleural effusion (yellow overlay) is also visible.
Source: © IMPP
X-ray chest (lateral view) of a patient with malignant mesothelioma
Opacification of the middle and lower left hemithorax is accompanied by a meniscus that indicates the presence of a pleural effusion (green overlay). Also visible is pleural thickening (red overlay) encompassing the upper left hemithorax.
Source: © IMPP
Chest x-ray (PA view)
The pulmonary lobes are seen overlapping each other. The major portions of the lower lobes lie dorsally (green overlay), extending up to the 4th–6th rib (green line with arrowheads). The right lung has a middle lobe (white dashed line; white overlay superimposed on green) that lies ventrally, overlapping the right lower lobe. The major portions of the upper lobes (red overlay) lie ventrally. The lingula is the tongue-shaped projection of the left upper lobe (white overlay superimposed on red).
This is the typical appearance of a normal chest x-ray.
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
X-ray chest (PA view) of a patient with a history of emphysema
The lungs are hyperlucent, with diaphragmatic flattening (indicated by dashed lines and arrows) and widening of the costophrenic sulci (indicated by white lines). The findings are consistent with air trapping.
An additional finding is asymmetry of the lung apices with slightly increased opacification in the left apex (red overlay) compared to the right. The chronicity cannot be determined from this single study, and the differential for chronic causes includes both scar and malignancy. A second small indeterminate opacity projects in the lower left lung (green overlay).
Source: © IMPP
X-ray chest (PA view)
A thin white line represents the visceral pleura of the left lung (dotted line). No lung markings are seen peripheral to the visceral pleura (green overlay).
The appearance is consistent with a left pneumothorax. There is no evidence of contralateral mediastinal shift, diaphragmatic depression, or ipsilateral intercostal space widening to suggest tension pneumothorax.
© AMBOSS
X-ray chest (posteroanterior view) of a patient with chronic progressive shortness of breath
Coarse reticular opacities (examples indicated by blue circles) in both lungs show a basal predominant distribution. The cardiac silhouette is enlarged and midline sternotomy wires (example of sternal wire indicated by black outline) and surgical clips (red lines) are evidence of prior coronary artery bypass grafting; however, there are no supportive findings for cardiogenic pulmonary edema, such as Kerley lines or pleural effusions.
CT was subsequently performed and showed peripheral honeycombing diagnostic of a usual-interstitial-pneumonia pattern. The patient was diagnosed with idiopathic pulmonary fibrosis (green overlay).
Source: “Fig. 1.7a, in: Chapter 1, A Systematic Approach to Chest Radiographic Analysis” by Klein J, L. Rosado-de-Christenson, M, Diseases of the Chest, Breast, Heart and Vessels 2019-2022: Diagnostic and Interventional Imaging, licensed under CC BY 4.0. Modifications: image cropped. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
X-ray chest (AP view)
The cardiac silhouette is enlarged (hatched green overlay) and the perihilar air space opacities (green overlay) have a bat wing, or butterfly, configuration. Linear interstitial opacities representing Kerley A lines (orange dashed lines) radiate from the hila to the apices and Kerley B lines (white dashed lines) are seen in the lateral mid zones. The costophrenic angles are blunted (arrows) from bilateral pleural effusions.
These features are characteristically seen in cardiogenic pulmonary edema.
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
X-ray chest (PA and lateral views) of a patient with pneumonia
There is heterogeneous right upper lobe consolidation (green overlay) with air bronchograms (examples of bronchial walls indicated by white lines). The major (white dashed line) and minor fissures (red dashed lines) are elevated from normal position as a result of accompanying atelectasis. No hilar enlargement or pleural effusion is seen.
The differential diagnosis for airspace consolidation considers the radiographic appearance, associated findings (e.g., lymphadenopathy, pleural effusion), and patient history and symptoms. Pneumonia, hemorrhage, edema, tumor, and protein can all present as consolidation on a chest radiograph.
Green line: aortic arch margin; LL: lower lobe; ML: middle lobe; UL: upper lobe
Source: © IMPP
X-ray chest (PA view) of a patient with bronchogenic carcinoma
A solitary nodule (red overlay) with an irregular margin is visible in the periphery of the upper left lung. An additional soft-tissue opacity peripheral to the nodule along the ribs may represent adjacent pleural thickening (green overlay).
The differential diagnosis for a solitary pulmonary nodule includes neoplastic (malignant and benign), inflammatory, and congenital conditions.
Source: “Thorax pa peripheres Bronchialcarcinom li OF markiert” by Lange123, Wikimedia Commons, licensed under CC BY-SA 3.0. Modifications: removed marking. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
X-ray chest (PA view) of a patient with bronchogenic carcinoma
A mass in the paramediastinal left upper lobe (green overlay) is accompanied by lymphadenopathy, as indicated by enlargement and convexity of the left hilum (indicated by white line). A left 7th rib fracture (red outlines) with adjacent soft tissue density (edge indicated by yellow line) could be pathologic; the intact bordering cortex raises the alternative possibility of a traumatic fracture with hematoma formation.
Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.
Chest x-ray (PA view)
The pulmonary hila (demarcated by white lines) contain the central bronchi, lymph nodes, lymphatics, nerves, pulmonary arteries and veins, and bronchial arteries and veins. The normal right and left hila project between the T5 and T7 vertebrae at the medial aspect of each lung on a well-positioned PA radiograph. The left hilum normally projects 1-2 cm above the right hilum primarily because the left pulmonary artery (LPA) is slightly higher than the right pulmonary artery.
Evaluation of the hila for pathology should include assessment of size, shape, density, position, and change compared to prior radiographs.
RDPA: right descending pulmonary artery
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
Chest x-ray (PA view) of a patient with sarcoidosis
The pulmonary hila (green overlay) are enlarged and lobulated. Additionally, the right superior mediastinum (red overlay) is widened and dense. A normal thin right paratracheal stripe is not seen.
Relatively symmetric bilateral hilar and right paratracheal lymph node enlargement on a chest radiograph in sarcoidosis is termed the “1-2-3 sign” or “Garland triad.” Examples of other causes of hilar and mediastinal lymphadenopathy include lymphoma, metastatic disease, granulomatous infections, and inorganic dust disease.
Our great thanks to Dr. Kissig (Center for Diagnostic and Interventional Radiology, Hedwigshöhe, St. Hedwig, Berlin, and St. Josefs Hospital, Potsdam) for kindly providing this image.
Chest x-ray (AP view)
Hilar and left pulmonary nodular shadows are visible (green overlay). There is a discrete widening of the superior mediastinum with a masked aortic arch (hatched green overlay).
These findings are consistent with malignant lymphoma with mediastinal, hilar, and pulmonary involvement.
Source: © IMPP
X-ray chest (PA view) of an adult female patient
On a PA radiograph, the pulmonary arteries and veins are the primary structures visible at the hila, with the arteries responsible for the majority of the hilar shadow. The normal left hilum (LH) appears higher than the right hilum (RH). Peripheral vascularity is normally symmetrical from side to side when comparing corresponding upper, middle, and lower zones of the lungs (indicated by lines).
Normal pulmonary vascular structures gradually taper toward the periphery of each lung and are more prominent in the lower lungs than in the upper lungs in the upright position (examples indicated by zoom-boxes). Vascularity in the lower left lung sometimes appears reduced compared to the right lung due to the overlying cardiac silhouette.
Our great thanks to PD Dr. M. Jergas (Center for Diagnostic and Interventional Radiology, St. Elizabeth Hospital, Cologne) for kindly providing this image.
X-ray chest (PA view) of a patient in the third trimester of pregnancy with peripartum cardiomyopathy
The cardiac silhouette is enlarged and upper lobe vessels are prominent (redistribution of flow; examples indicated by arrows). Bilateral interstitial and airspace edema is predominantly perihilar in distribution and produces a classic bat wing, or butterfly, appearance (green outlines). Pulmonary vessel margins are obscured (perihilar haze) and thickened interlobular septae (Kerley lines) are conspicuous. The diaphragms appear dense due to the presence of pleural effusions.
Green arrowhead: example of Kerley A; red arrowheads: example of Kerley B
Source: “Fig. 1b, in: Bromocriptine use for sudden peripartum cardiomyopathy in a patient with preeclampsia: a case report.” by Hakata, S., Umegaki, T., Soeda, T. et al., JA Clin Rep, licensed under CC BY 4.0. Modifications: Original image cropped. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
X-ray chest (PA view)
The cardiac silhouette is enlarged. The central right and left pulmonary arteries are also enlarged, with rapid tapering of peripheral branches (vascular pruning; indicated by arrowhead). The left pulmonary artery is seen through a prominent convexity along the left mediastinum, which corresponds to an enlarged main pulmonary artery.
Black arrow: margin of right atrium; LDPA: left descending pulmonary artery; RDPA: right descending pulmonary artery
Source: “Fig 1, In: Pulmonary Hypertension in Chronic Lung Diseases: What Role Do Radiologists Play?” by Valentini A, Franchi P, Cicchetti G et al., MDPI, licensed under CC BY 4.0. Modifications: Image cropped, with dashed line, arrow, and arrowhead also removed.. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
X-ray chest (AP view; cropped radiograph)
The distal endotracheal tube (green outline) is visible over the T3 vertebral body.
An endotracheal tube should terminate 3–7 cm proximal to the carina (indicated by arrow) when the head and neck are in neutral position or over T2–T4 when the carina is not visible; tracking the main bronchi centrally can often help locate the carina.
An endotracheal tube will move in the caudal direction with the neck in flexion (“nose down, goes down”) and in the cephalic direction with the neck in extension. Projection of the anterior mandible over the lower cervical spine is typically an indicator of flexion.
Dashed outline: trachea and central bronchi; red outline: endotracheal tube cuff; 1–4: ribs
Source: “ET tube: Good Position” by James Heilman, MD, Wikipedia, licensed under CC BY-SA 4.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 4.0.
X-ray chest (AP view; supine)
A nasogastric tube courses through the esophagus and terminates in the stomach in the left upper quadrant (green line). A left chest tube is in place (red line), and pulmonary vessels are lacking in the left apex where a pneumothorax is present (green circle). A right central line terminates in the region of the right atrium (blue line). The left hemidiaphragm is obscured by atelectasis and effusion. A skin fold projects lateral to the left hilum (dashed line). A left axillary stent is present (yellow overlay).
Source: “Fig 5, In: Using Video-Assisted Laryngoscope (GlideScope®) to Insert a Nasogastric Tube and Prevent Pneumothorax From Incorrectly Inserted Nasogastric Tubes” by AlHafidh OZ, Enriquez D, Quist J, Schmidt F, Cureus, licensed under CC BY 4.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above (© AMBOSS).
X-ray chest (PA view)
A single-chamber pacemaker is visible, with the pulse generator (G) on the upper right chest wall and a single lead wire (green dashed line) in the right ventricle.
Additional radiographic findings include mild cardiac silhouette enlargement, aortic tortuosity, and thoracic spine curvature with degenerative changes.
Source: “VVI Schrittmacher THWZ” by Th. Zimmermann, Wikimedia Commons, licensed under CC BY-SA 3.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
X-ray chest (PA view)
A large pneumothorax (green overlay) has resulted in collapse of the right lung along the mediastinum (edge marked by white dashed line). No bronchovascular markings are seen in the right hemithorax. Additionally, the mediastinum has shifted to the contralateral left side (blue line and arrows), the right hemidiaphragm is depressed (red line and arrow), and the right intercostal spaces are widened (example indicated by white arrows).
These findings are characteristic of tension pneumothorax.
Source: © IMPP
X-ray chest (AP view; supine) of patient with a history of trauma
Multiple right rib fractures (red lines) are present, some of which show marked displacement. There is extensive subcutaneous emphysema (examples indicated by arrowheads). The right lung is diffusely opaque (green overlay), likely reflective of pulmonary contusion in view of the trauma history.
White overlay: ribs
Source: “Pulmonary contusion” by Karim, Wikimedia Foundation, licensed under CC BY-SA 3.0. The supplementary image with overlays of relevant areas was adapted from the image mentioned above and licensed under CC BY-SA 3.0.
X-ray chest (PA view) of a patient with lupus pericarditis
The cardiac silhouette is enlarged and demonstrates a globular, or water bottle, configuration due to pericardial effusion (green hatched overlay).
Source: © IMPP
X-ray chest (PA view) of a patient with pleuritic chest pain
A peripheral opacity (Hampton hump; green overlay) obscures the adjacent margin of the right hemidiaphragm. A Hampton hump is subpleural and is caused by pulmonary hemorrhage or infarction. The appearance is often wedge-shaped; however, it can alternatively be dome-shaped, if the apex is spared as a result of collateral bronchial arterial blood flow.
The differential diagnosis includes pneumonia and malignancy. Of note, the greater distance between the spinous processes and the medial edge of the clavicle on the right compared to the left indicates that the patient is rotated slightly to the right. The distances will be nearly equal when a patient is not rotated, whereas widening will be seen on the side to which a patient is rotated.
Dashed lines: margins of medial clavicles; White line and ellipses: spinous processes
Source: © IMPP
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External Resources
References
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