CXR (chest x-ray)
Formal Definition
CXR — chest X-ray, a fundamental radiographic imaging study using low-dose ionizing radiation (typically 0.1–0.2 mSv for PA/lateral) to evaluate the thoracic contents: lungs, pleural surfaces, mediastinum, heart size, thoracic vasculature, ribs and other bony structures, and chest tubes/catheters if present; the most commonly ordered imaging study in inpatient and emergency settings, used to evaluate dyspnea, chest pain, cough, fever, suspected pneumonia, pleural effusion, pneumothorax, pulmonary edema, cardiomegaly, and to confirm positioning of tubes and lines.
How It's Used on the Ward
"CXR" or "chest film" — the most common imaging study ordered in hospitals; portable CXR for inpatients too unstable to go to radiology (single AP view at bedside), PA + lateral in radiology department for ambulatory patients; "wet read" — preliminary read while waiting for radiologist; "official read" — radiologist's final report.
Example
""76-year-old with chronic HF, presenting with dyspnea and orthopnea. Exam: bilateral crackles at bases, JVD, 3+ pitting edema to knees. Portable CXR ordered at bedside: 'Diffuse bilateral airspace opacities, predominance in the lower lobes, blunting of costophrenic angles bilaterally suggesting small pleural effusions, mildly enlarged cardiac silhouette. Tip of central venous catheter in the SVC. ET tube tip 4 cm above carina.' Findings consistent with cardiogenic pulmonary edema superimposed on CHF. Diuresed with IV furosemide, symptom improvement.""
Clinical Context
View options: PA (posteroanterior, beam enters back, exit through front — better detail, ambulatory patients); AP (anteroposterior, beam enters front — portable inpatients, magnification of anterior structures); lateral (L, perpendicular to PA — helps localize findings). Patient population considerations: pregnant patients (lower dose acceptable but typically still routine ordering is appropriate), children under 2 (routine CXR not indicated for uncomplicated bronchiolitis or asthma; over-ordering has been a quality concern). Systematic CXR review (ABCDE approach): A — Airway (trachea midline, ET tube position). B — Bones (ribs, clavicles, scapulae, spine). C — Cardiac silhouette (size <50% thoracic diameter on PA, normal ~9–12 cm width; boot-shaped in CHF; globular for effusion). D — Diaphragm (costophrenic angles sharp; flat in COPD; silhouetted in effusion). E — Everything else (lung fields, mediastinum, hila, soft tissues, lines/tubes). Common findings: cardiomegaly, pulmonary edema, pleural effusion (meniscus sign), pneumothorax (absent lung markings, visceral pleural line), consolidation/pneumonia (air bronchograms, lobar distribution), atelectasis (volume loss, opacity, mediastinal shift toward), pneumomediastinum, rib fractures. Contrast: CT chest — higher resolution, cross-sectional, indicated for further characterization when CXR equivocal.