Basic Sciences Relevant to Radiology (Anatomy, Physiology, Pathology)
Core concepts
This domain tests cross-sectional anatomy and the physiology that explains imaging appearances. Know the mediastinal compartments and their contents, the segmental anatomy of the lung, the lobes and fissures, and the hilar relationships. Understand abdominal anatomy: the peritoneal spaces, retroperitoneum, and the vascular supply of the gut (SMA/SMA territory, watershed areas). Learn the physiology of body fluid compartments and how they affect attenuation and enhancement. Understand the pathology principles behind common patterns: inflammation (edema, increased water), infarction, neoplastic growth, and fibrosis. Correlate gross pathology with imaging: consolidation (airspace filling), ground-glass (partial alveolar filling), and interstitial patterns. Know the lymphatic drainage pathways relevant to staging, and the anatomy of the cranial nerves and skull base foramina.
Traps
Questions test spatial relationships: what lies anterior/posterior to a structure, and which compartment a lesion occupies. Distinguish the true and false vocal cords, the parapharyngeal versus retropharyngeal spaces, and the segments of the liver (Couinaud). Do not confuse the arterial territories of the colon (watershed at splenic flexure and rectosigmoid). Remember that the right adrenal sits above the kidney, the left is more medial.
Rule of thumb
When localizing a lesion, describe it by compartment first, then by organ of origin. Compartment-based reasoning narrows the differential dramatically on cross-sectional questions.