Fig 2. Patient 1. A, Quantitative CBF map generated from the ASL sequence shows significant hyperperfusion (arrow) within the cortex of the right cerebral hemisphere corresponding to the signal intensity abnormalities on the conventional MR imaging sequences. Region of interest placed over the frontal gray matter shows a mean CBF in the right hemisphere of 128.9 compared with the left frontal hemisphere mean CBF of 56.6 mL/100 g tissue/min. B, Quantitative CBF map obtained 6 days after the initial examination shows resolution of the hyperperfusion within the cortex of the right frontal and parietal lobes. Mean gray matter CBF in the right and left frontal lobe decreased to 57.7 and 61.6 mL/100 g tissue/min, respectively.