Ge X, et al. - Through a prospective study of 429 patients with symptomatic intracranial arterial stenosis who underwent conventional brain MR imaging, 3D-TOF-MRA, and brain CTP, the experts examined the correlation between fractional flow and cerebral perfusion changes among subjects with symptomatic MCA stenosis. A total of 91 patients with unilateral M1 segment stenosis of the MCA and a stenosis degree of 50%∼99% were involved in the study. An important fractional flow threshold value at 0.90 was exhibited by the receiver operating characteristic curve. Subjects with a fractional flow of ≤0.90 were independently correlated with cerebral hypoperfusion downstream from the stenosis site. Hence, for ascertaining the cerebral hypoperfusion in subjects with symptomatic MCA stenosis, fractional flow measured on 3D-TOF-MRA could serve as a noninvasive and practical tool.