Correlation of Asymmetry Indices Measured by Arterial Spin-Labeling MR Imaging and SPECT in Patients with Crossed Cerebellar Diaschisis

Abstract

BACKGROUND AND PURPOSE:Crossed cerebellar diaschisis, not only a secondary result of supratentorial infarction but also an indicator of clinical outcomes, has frequently been reported on PET and SPECT but has been rarely described with arterial spin-labeling MR imaging. The purpose of this study was to determine the ability of arterial spin-labeling MR imaging to evaluate crossed cerebellar diaschisis compared with that of SPECT. To our knowledge, this is the first study to validate arterial spin-labeling in crossed cerebellar diaschisis by using SPECT as a reference standard.

Detection of crossed cerebellar diaschisis in hyperacute ischemic stroke using arterial spin-labeled MR imaging

“…A major strength of this study was the use of an ASL method that had been previously validated against SPECT for CCD detection [21]. This feature strengthens the impact of our findings, as any data acquired using a non-validated ASL method would not represent valuable results for CCD due to unknown performance in the posterior circulation.…”

“…Two radiologists with 7 and 27 years of experience in neuroradiology who were blinded to CCD status and stroke location evaluated the cerebellum from bottom to top [21]. The signal intensity of the affected cerebellum was assigned one of the following 3 grades: grade I, in which the affected cerebellum was isointense to the unaffected cerebellum; grade II, in which the affected cerebellum was slightly hypointense to the unaffected cerebellum; and grade III, in which the affected cerebellum was markedly hypointense to the unaffected cerebellum (Fig 1).…”

“…The signal intensity of the affected cerebellum was assigned one of the following 3 grades: grade I, in which the affected cerebellum was isointense to the unaffected cerebellum; grade II, in which the affected cerebellum was slightly hypointense to the unaffected cerebellum; and grade III, in which the affected cerebellum was markedly hypointense to the unaffected cerebellum (Fig 1). A grade of II or III was considered a positive CCD diagnosis [21]. For the CCD-positive group, the laterality of the cerebellar hypoperfusion was checked whether it was contralateral to the supratentorial stroke or not.…”

“…To assess inter-observer agreement for the presence of CCD in the qualitative analysis, the kappa statistic was used [21]. κ values of < 0.20, 0.21–0.40, 0.41–0.60, 0.61–0.80, and > 0.81 indicated poor, fair, moderate, good and excellent agreement, respectively.…”

“…In addition, we previously reported that the asymmetric index (AI) of CCD obtained using ASL was significantly correlated with the AI obtained using SPECT, suggesting that ASL could be used as a noninvasive alternative to SPECT for evaluating CCD [21]. Therefore, in the previous study, ASL was validated both against a gold-standard perfusion method (i.e., SPECT) and for its ability to detect CCD.…”