CT SCAN(BRAIN)
Dr. Sumit Kr. GhoshAsst. Professor
Department of MedicineMedical College & Hospital, Kolkata
COMPUTED TOMOGRAPHY
Godfrey Hounsfield
Hounsfield unit / number
-1000Black Air
+ 1000WhiteBone
0
Water
HYPODENSE ISODENSE HYPERDENSE
Black White
1. Air (air sinuses)
Brain parenchyma 1. Bone
2. CSF (ventricles/ sulci/cisterns)
2. Calcification ( Choroid plexus, pineal gland, basal ganglia, granuloma , tumour)
3. Fat (retro-orbital) 3. Heomarrhage
4. Infarct 4. Blood vessels
5. Edema 5. Ring –enhancing lesion
Hypo/hyper -intensityHypo/hyper-echoic
Conventional : thik slice : 7-10 mmHRCT : thinner slice : 1-2 mm