Usefulness of magnetic resonance-derived quantitative measurements of cerebral blood flow and volume in prediction of infarct growth in hyperacute stroke.
OBJECTIVE
The identification of the tissue at risk for infarction remains challenging in stroke patients. In this study, we evaluated the value of quantitative cerebral blood flow (CBF) and cerebral blood volume (CBV) measurements in the prediction of infarct growth in hyperacute stroke.


METHODS
Fluid-attenuated inversion recovery (FLAIR), diffusion-weighted (DW), and gradient-echo echo-planar perfusion-weighted (PW) sequences were obtained in 66 patients within 6 hours of stroke onset; ischemia was confirmed on follow-up FLAIR images. We delineated the following: (1) the initial infarct on DW images, (2) the area of hemodynamic disturbance on mean transit time (MTT) maps, and (3) the final infarct on follow-up FLAIR images. MTT, CBF, and CBV were calculated in the following areas: area of initial infarct (INF), area of infarct growth (IGR, final minus initial infarct), the hemodynamically disturbed area that remained viable (OLI, hemodynamic disturbance minus final infarct), and all contralateral mirror regions.


RESULTS
Compared with mirror regions, the MTT in abnormal areas was always prolonged. The respective mean+/-SD CBF and CBV values were as follows: for INF, 28+/-16 mL/min per 100 g and 6.9+/-2.7%; for IGR, 36+/-20 mL/min per 100 g and 8.9+/-3.1%; for OLI, 50+/-17 mL/min per 100 g and 11.2+/-3%; and for mirror regions, 64+/-23 mL/min per 100 g and 8.7+/-2.5%. The CBV and CBF values were significantly different between all abnormal areas (except for the CBF between INF and IGR). In the area of DW/PW mismatch, a combined CBF or CBV threshold of 35 or 8.2, respectively, predicted evolution to infarction with a sensitivity of 81% and a specificity of 76%.


CONCLUSIONS
Quantitative measurements of CBF and CBV in hyperacute stroke may help to predict infarct growth and to select the subjects who will benefit from thrombolysis.
Grandin
C B
CB
Department of Medical Imaging, Cliniques Universitaires St. Luc, Université Catholique de Louvain, Brussels, Belgium. grandin@rdgn.ucl.ac.be
Duprez
T P
TP
Smith
A M
AM
Mataigne
F
F
Peeters
A
A
Oppenheim
C
C
Cosnard
G
G
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D001810:Blood Volume; D001921:Brain / Q000098:blood supply / Q000473:pathology / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D018450:Disease Progression; D017352:Echo-Planar Imaging; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity; D020521:Stroke / Q000175:diagnosis* / Q000503:physiopathology*