Cerebral hemodynamic impairment: assessment with resting-state functional MR imaging.
OBJECTIVE
To test the feasibility of noninvasive global assessment of cerebral hemodynamic impairment with use of resting-state blood oxygenation level-dependent functional magnetic resonance (MR) imaging.


METHODS
In this institutional review board-approved study, five patients with chronic hypoperfusion without neurologic impairment and six patients with acute stroke underwent 10-minute resting-state functional MR imaging and dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging, which was considered the standard of reference. All patients gave informed consent. The temporal shift of low-frequency signal fluctuations in each voxel compared with the averaged whole brain or global mean signal at resting-state functional MR imaging and the delay in time to peak at dynamic susceptibility-weighted contrast-enhanced perfusion imaging were computed with voxel-wise analysis. The similarity of the temporal delay maps obtained with resting-state functional MR imaging and perfusion data, as well as the stability of the resting-state functional MR imaging measurement, were evaluated with the Dice similarity coefficient (DSC) and the two-tailed t test (random-effect analysis).


RESULTS
The brain tissue with normal perfusion at dynamic susceptibility-weighted contrast-enhanced imaging showed no delay to global mean signal at resting-state functional MR imaging, whereas areas of abnormal perfusion with delayed time to peak (3.4 seconds ± 2.1) showed a delay at resting-state functional MR imaging that was similar to the time to peak at dynamic susceptibility-weighted contrast-enhanced perfusion imaging, both in spatial coverage (mean DSC, 0.57 ± 0.16) and tendency (t = 5.1, P < .001). Resting-state functional MR imaging measurements were highly stable (mean DSC, 0.83 ± 0.12).


CONCLUSIONS
Resting-state functional MR imaging temporal-shift analysis can noninvasively demonstrate the extent and degree of perfusion delay in patients with hypoperfusion both with and without neurologic deficit.
From the Departments of Radiology (S.A., A.K., K.O.) and Neurosurgery (N.S.), Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.
Shiori
S
Amemiya
Akira
A
Kunimatsu
Nobuhito
N
Saito
Kuni
K
Ohtomo
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001927:Brain Diseases / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003287:Contrast Media; D005240:Feasibility Studies; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020521:Stroke / Q000503:physiopathology*; D013997:Time Factors
D003287:Contrast Media