A systematic approach to reading PA/AP and lateral chest radiographs for radiology residents, from technical adequacy to the impression.
RadPhrases Editorial Team5 min read
A systematic approach to reading PA/AP and lateral chest radiographs for radiology residents, from technical adequacy to the impression.
Scope This content is intended for the general assessment of adult PA/AP and, when available, lateral chest radiographs. Pediatric cases, intensive care device checks, trauma series, and disease-specific follow-up examinations require additional protocols.
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Chest radiography may appear quick to interpret; however, following the same sequence in every examination is essential to avoid missing a small pneumothorax, a retrocardiac opacity, or a malpositioned tube. A systematic sequence reduces the risk of error and makes reporting language more consistent.
This checklist is not a diagnostic algorithm. It is a practical framework for reviewing the entire image and confirming that the report answers the clinical question.
1. Before starting the examination
Clarify the request, technique, and comparison information before focusing on the image.
☐ Read the clinical question. Symptoms, trauma, suspected infection, device assessment, or follow-up purpose will change the focus of the report.
☐ Identify the projection. PA, AP, supine, or portable acquisition can affect the interpretation of findings such as cardiac size and pleural air.
☐ Is a lateral image available? When present, assess it together with the frontal radiograph and recheck the retrosternal and retrocardiac regions in particular.
☐ Open the prior examination. Whenever possible, compare with the same modality to distinguish new, changing, and stable findings.
☐ Confirm image coverage. The apices, costophrenic angles, and the entire thorax should be included in the field of view.
2. Technical quality: the RIPE approach
☐ Rotation. Compare the distances between the medial clavicular heads and the spinous processes. Marked rotation may mislead assessment of the mediastinum and hila.
☐ Inspiration. Poor inspiration may exaggerate basal linear opacities and the cardiac silhouette. Assess the diaphragmatic level together with the posterior ribs.
☐ Penetration/exposure. Are the thoracic vertebrae visible through the cardiac silhouette? Overpenetration or underpenetration may conceal small opacities.
☐ Additional technical issues. Note potential mimics such as motion, hair or clothing artifacts, external objects, and skin folds.
☐ Report technical limitations. If a limited examination prevents assessment of an important region, state this explicitly.
3. Tubes, catheters, and devices
☐ Endotracheal or tracheostomy tube. Assess the tip level, mainstem bronchial intubation, or high positioning, and consider the effect of head position.
☐ Enteric tube. Check its course through the esophagus, whether it crosses the diaphragm, and the position of the tip and side port.
☐ Central venous catheter and port. Assess the catheter course and tip position, as well as kinking, discontinuity, and associated pneumothorax.
☐ Thoracic drain. Confirm that the side holes lie within the thorax, check for drain kinking, and assess residual pleural air or fluid.
☐ Pacemaker/ICD and other devices. Review the generator, lead integrity, lead tips, and any new complications.
4. Airway, mediastinum, and hila
☐ Trachea. Is it midline? Is there narrowing or significant deviation? Distinguish true deviation from rotation.
☐ Mediastinum. Assess width, contour, new fullness, and air. Remember that portable AP radiographs may cause apparent widening.
☐ Hila. Compare size, density, and symmetry; try to distinguish vascular prominence from a mass or lymphadenopathy.
☐ Aortic contour. Note visible findings such as tortuosity, ectasia, or a new contour change in the clinical context.
5. Heart and pulmonary vasculature
☐ Cardiomediastinal silhouette. Assess cardiac size and contours while accounting for projection and adequacy of inspiration.
☐ Pulmonary vasculature. Is there abnormal central or peripheral vascular distribution, redistribution, or overt congestion?
☐ Associated features of edema. Assess perihilar or basal opacities, septal lines, and pleural fluid together.
☐ Pericardial or cardiac devices. When present, compare position and appearance with prior images.
6. Lung parenchyma and airways
☐ Review both lungs zone by zone. Follow the same sequence from the apices to the bases and from the periphery inward.
☐ Focal opacity. Describe location, distribution, margins, and associated volume loss; answer the clinical question without forcing a single diagnosis.
☐ Suspected nodule or mass. Check visibility on both projections, presence on prior studies, and possible external shadows.
☐ Atelectasis/volume loss. Look for displacement of fissures, hila, or diaphragm and signs of compensatory hyperinflation.
☐ Diffuse interstitial/alveolar pattern. State the distribution and symmetry; exclude the effects of technical limitation and low lung volume.
☐ Retrocardiac and paraspinal regions. Use the lateral radiograph particularly to assess the left lower lobe and posterior bases.
7. Pleura, diaphragm, and subdiaphragmatic region
☐ Pneumothorax. Assess the apices and lateral pleural surfaces; on supine radiographs, look for the deep sulcus sign.
☐ Pleural fluid. Check the costophrenic angles, a meniscus, and the possibility of loculation.
☐ Pleural thickening/calcification. Record its location and any change from prior examinations.
☐ Diaphragms. Assess height, contour, elevation, and clues to subpulmonic fluid.
☐ Below the diaphragm. Review beneath both hemidiaphragms for free air and visible upper abdominal findings.
8. Bones and soft tissues
☐ Ribs, clavicles, scapulae, and vertebrae. Review for acute fracture, destruction, or marked deformity.
☐ Shoulder girdles. Compare the humeral heads and joints included in the field of view.
☐ Soft tissues. Check for subcutaneous emphysema, postoperative change, breast shadows, and asymmetry.
9. Building the impression
Place the most important finding that directly answers the clinical question first.
For an indeterminate finding, separate the observation, possible interpretation, and any recommendation.
Clearly compare new and clinically important changes with the prior examination.
When there is no acute abnormality, state this simply without ignoring technical limitations.
If findings require urgent action, do not rely on the report alone; follow the institution's critical results communication process.
Communication of critical findings
Do not forget communication beyond the report New or enlarging pneumothorax, substantially malpositioned tubes or catheters, findings suggesting tension physiology, free subdiaphragmatic air, or other emergencies require timely, documented communication according to the local critical results policy.
10. Commonly overlooked areas
Apices and regions behind the clavicles
Retrocardiac left lower lobe
Both costophrenic angles
Subdiaphragmatic regions
Catheter and tube tips
Ribs and shoulder girdle
Subcutaneous emphysema
Small but new changes compared with the prior radiograph
11. Example report framework
INDICATION: [Clinical question / symptom / reason for follow-up] TECHNIQUE: [PA/AP] chest radiograph. [Lateral image available/not available]. [State any technical limitation]. COMPARISON: Compared with the examination dated [date] / No comparison available. FINDINGS: - Cardiomediastinal silhouette: [...] - Lung parenchyma and pulmonary vasculature: [...] - Pleural spaces: [...] - Tubes/catheters/devices: [...] - Bones and soft tissues: [...] IMPRESSION: 1. [Primary finding that answers the clinical question.] 2. [Additional important finding / interval change, if present.]
References
ACR Practice Parameter for Communication of Diagnostic Imaging Findings, Revised 2025. Report components and principles for nonroutine/urgent communication. Source (opens in a new tab)
ACR-SPR-STR Practice Parameter for the Performance of Chest Radiography, Revised 2022. Performance, documentation, and quality principles for chest radiography. Source (opens in a new tab)
ACR-AAPM-SIIM-SPR Practice Parameter for Digital Radiography. Image quality and practice framework for digital radiography. Source (opens in a new tab)
Clinical use note
This content is educational and is not patient-specific medical advice. Every phrase, template, classification result, and recommendation must be verified and adapted by a physician using the complete examination, clinical context, current guidelines, and institutional protocol.
Turn the checklist into a report template
Use this sequence as an editable RadPhrases template and verify it against the images in every case.
