MR perfusion studies of brain for patients with unilateral carotid stenosis or occlusion: Evaluation of maps of "time to peak" and "percentage of baseline at peak"

Maps of "time to peak" (TTP) and "percentage of baseline at peak" (PBP) wer e compared with maps of conventional brain perfusion parameters, namely, me an transit time (MTT) and relative cerebral blood volume (rCBV). We perform ed MR perfusion studies in 11 patients. All of them had occlusion or high-g rade stenosis of the unilateral carotid artery. Three areas of old infarct, 4 areas of new infarct, and 10 areas of brain without infarct were evaluat ed specifically. In all these cases, the TTP maps appeared similar to the M TT maps. They showed increases, normal values, or decreases at the same tim e in all areas evaluated. Most areas of abnormally decreased CBV had increa sed signal in PBP maps. In conclusion, the TTP map provided the same qualit ative information as MTT. PBP seemed correlated inversely to CBV and was le ss sensitive in demonstrating abnormality.