<prompt> Imaging tool of choice for GD?DWI MRI with ADC mapsHMPAO SPECTMR SpectroscopyPET  <response>: Ans ACreutzfeldt-Jacob disease is a spongiform encephalopathy caused by prions. On MRI T2 hyperintensity in basal ganglia, thalamus Hockey stick sign, cortex and white matter with persistent diffusion restriction in considered most sensitive sign. On PET scan there can be hypometabolsim in affected area however it is less sensitive 