False about Diffusion-weighted MRI :: (A) High apparent Diffusion Coefficient, (B) Based on brownian motion, (C) Detects cytotoxic edema before a vasogenic edema develops, (D) High cellularity tumours can be detected
Answer is A. Diffusion-weighted imaging (DWI) Based on Brownian motion of water molecules within a voxel of tissue. When there is Diffusion Restriction-MRI gives a bright signal on DWI images and has low apparent Diffusion Coefficient(ADC value). DW-MRI detects Cytotoxic edema before a Vasogenic edema develops. Lesions showing Diffusion Restriction Infarct(Acute Infarct)- IOC Abscess Medulloblastoma & Other High Cellularity Tumours . Epidermoid Cyst