This 69-year-old male presents with visual deficit. The finding on CT is a left occipital stroke. In what vascular territory is it distributed? Would the MRI be positive? More specifically, would a FLAIR MRI be positive? What about a diffusion MRI?


The location of the stroke is the left posterior cerebral artery territory. FLAIR MRI would never be normal when CT is positive. It is inordinately more sensitive and positive in the first 24 hours after a stroke. The diffusion MRI is positive even earlier than the FLAIR, as early as three hours.
ProScan Pearl: To find blood in a stroke on MRI, consider blood-sensitive sequences like BSI (Hitachi), SWI (GE), SWAN (Siemens) or Venous BOLD (Philips). Blood in a small stroke may “hide” or obscure diffusion imaging findings – pseudonormality. For more neuro case review, head to MRI Online.