Lessons
Short lessons built on real scans and primary sources. New lessons are added as each video is published.
CT windows: one scan, many pictures
Why the same CT slice can look completely different: Hounsfield units, the limited greys of a screen, and why scans are read in more than one window.
Early ischaemic signs on unenhanced CT
The subtle signs of an early middle cerebral artery infarct on a plain head CT: the insular ribbon, the lentiform nucleus and the grey-white border.
Pulmonary embolism on CT: the filling defect
How a pulmonary embolus looks on CT pulmonary angiography, how acute and chronic clot differ, and why a poor study should say what it could not assess.
The India ink artefact on opposed-phase MRI
Why thin black lines outline organs on opposed-phase MRI, why they vanish in phase, and what the line means at the edge of a mass.
Ultrasound-guided thyroid fine-needle aspiration
How the needle looks under ultrasound during thyroid FNA, what a study comparing needle sizes found, and the six Bethesda reporting categories.