1. Image quality
   • Confirm patient details, date, and view: PA vs AP, erect vs supine.
   • Rotation: medial clavicular heads should be roughly equidistant from the spinous processes.
   • Inspiration: about 5-6 anterior ribs or 9-10 posterior ribs visible above the diaphragm.
   • Penetration: thoracic vertebrae should be just visible through the heart.
2. A - Airway
   • Trachea central.
   • Carina visible, usually near T4-T5.
   • Main bronchi and hila not widened or displaced.
3. B - Breathing: lungs and pleura
   • Both lungs equally expanded and symmetrically lucent.
   • Normal vascular markings: more prominent at the lower zones and tapering toward the periphery.
   • No focal opacity, collapse, mass, interstitial marking increase, or hyperinflation.
   • No pleural line, effusion, or costophrenic-angle blunting.
4. C - Cardiomediastinal silhouette
   • Cardiac silhouette not enlarged. On a good PA film, cardiothoracic ratio should be less than 50%.
   • Normal left cardiac border: aortic arch, pulmonary artery, left atrial appendage, left ventricle.
   • Normal right cardiac border: superior vena cava and right atrium.
   • Mediastinum not widened; aortic contour normal for age.
5. D - Diaphragm
   • Right hemidiaphragm is usually slightly higher than the left.
   • Both domes smoothly outlined.
   • Sharp right and left costophrenic angles.
   • Gastric air bubble usually under the left hemidiaphragm.
   • No free subdiaphragmatic air.
6. E - Everything else
   • Ribs, clavicles, scapulae, spine, and shoulders: no fracture or destructive lesion.
   • Soft tissues: no subcutaneous emphysema or abnormal mass.
   • Check apices, hila, behind the heart, and below both diaphragms, which are frequent blind spots.
   • If lines, tubes, or devices are present, check their position.

PA chest radiograph: Cardiomediastinal silhouette is within normal limits. Lungs are clear without focal consolidation, pleural effusion, or pneumothorax. No acute osseous abnormality.