Predictive value of MR 3D-TOF angiography and T2 fast-FLAIR sequence to detect hemodynamic disturbance at the hyper acute phase of stroke

Goal: To define during the hyperacute phase of stroke the value of 3D-TOF M R angiography (MRA) and T2 fast-FLAIR sequence for predicting the volume of tissue presenting a hemodynamic disturbance. Material and method: Thirty-five cases of hyperacute stroke located in foll owing territories: middle cerebral artery (MCA) (n = 29), anterior choroida l artery (AChoA) (n = 5) and watershed (n = 1) were retrospectively reviewe d. The vascular abnormalities defined on MRA (vessel stenosis or occlusion) or FLAIR sequence (vessel hyperintensity) were classified into 3 groups: n ormal (I), distal abnormalities (II), abnormalities of the the entire arter ial territory (III). These results were compared with the volume of tissue showing a prolonged mean transit time (MTT) determined on relative MTT maps calculated from bolus tracking MR perfusion images. Results: The abnormal volume measured on the MTT map was significantly corr elated to the results of the MRA and FLAIR sequence. In the 12 cases of gro up III defined on the MRA (abnormality from M1), the volume of hemodynamic disturbance was always higher than 100 ml. For the MCA territory, it was no t possible to predict the presence of a hemodynamic disturbance in any of t he 3 groups defined on the FLAIR sequence and in the groups I and II define d on the MRA. For the AChoA territory, a hemodynamic disturbance was never observed in groups I and II defined either on MRA or FLAIR sequence. Conclusion: When there was no flow within the M1 segment on the MRA, there was always a hemodynamic disturbance larger than 100 ml on the MTT map. In the case of AChoA ischemic lesion, when no vascular abnormality was observe d on the MRA or FLAIR images, the MTT map was always normal.