BBB PS map of all 7 patients at months 0 and 6. The yellow circle represents highest BBB PS product region in the 7 patients with iTTP (1.80 ml/min/100 g, at right parietal lobe). There is intense blue color in that region. For the same patient, the red and blue arrows represent a significant change between month 0 and 6 PS products (1.72-0.73 ml/min/100 g at the left frontal lobe). Please see supplemental Figure 1 for comparison of PS product images. Patient 4 had chronic ischemic changes on the CT images. Patient 5 had persistent low ADAMTS13 activities < 1% with inhibitor level > 94 U/mL, consistent with iTTP.