Arterial Spin-Labeling MRI Can Identify the Presence and Intensity of Collateral Perfusion in Patients With Moyamoya Disease

Abstract

Background and Purpose Determining the presence and adequacy of collateral blood flow is important in cerebrovascular disease. Therefore, we explored whether a noninvasive imaging modality, arterial spin labeling (ASL) MRI, could be used to detect the presence and intensity of collateral flow using digital subtraction angiography (DSA) and stable xenon CT cerebral blood flow as gold standards for collaterals and cerebral blood flow, respectively. Methods ASL and DSA were obtained within 4 days of each other in 18 patients with Moyamoya disease. Two neurointerventionalists scored DSA images using a collateral grading scale in regions of interest corresponding to ASPECTS methodology. Two neuroradiologists similarly scored ASL images based on the presence of arterial transit artifact. Agreement of ASL and DSA consensus scores was determined, including kappa statistics. In 15 patients, additional quantitative xenon CT cerebral blood flow measurements were performed and compared with collateral grades. Results The agreement between ASL and DSA consensus readings was moderate to strong, with a weighted kappa value of 0.58 (95% confidence interval, 0.52–0.64), but there was better agreement between readers for ASL compared with DSA. Sensitivity and specificity for identifying collaterals with ASL were 0.83 (95% confidence interval, 0.77–0.88) and 0.82 (95% confidence interval, 0.76–0.87), respectively. Xenon CT cerebral blood flow increased with increasing DSA and ASL collateral grade (P<0.05). Conclusions ASL can noninvasively predict the presence and intensity of collateral flow in patients with Moyamoya disease using DSA as a gold standard. Further study of other cerebrovascular diseases, including acute ischemic stroke, is warranted.

Cerebral Blood Flow Improvement after Indirect Revascularization for Pediatric Moyamoya Disease: A Statistical Analysis of Arterial Spin-Labeling MRI

“…In this study, ASL sensitivity and specificity were 0.83 and 0.82, respectively. 5 Further studies, mainly from Ja- In the present study, quantitative analysis of CBF in the frontal lobe showed postoperative improvement in the Moyamoya hemispheres and not in the healthy hemispheres. However, selection of an ROI introduces some bias because it depends on the observer's choice and limits the spatial sampling of the cerebral cortex.…”

“…4 Recently, to avoid radiation exposure, arterial spin-labeling (ASL) MR imaging has been successfully developed to quantify CBF alterations in different stroke conditions, including MM. 5,6 This MR imaging has the advantage of being noninvasive because it uses water protons as an endogenous tracer to measure CBF, rather than intravenous injection of a contrast agent, which may be a concern in the pediatric population. Because children under-going an operation for MM need repeated quantification of their CBF before and after surgery, ASL MR imaging may be of particular interest, and statistical approaches, as described with statistical parametric analysis (SPM) of ASL MR imaging in cognitive series, may allow intraindividual and group analysis of CBF comparisons before and after the operation.…”

Clinical Significance of Discrepancy between Arterial Spin Labeling Images and Contrast-enhanced Images in the Diagnosis of Brain Tumors

“…In ASL, hyperintensity results from tissue hyperperfusion and intravessel signals. 13 In T 1 -weighted CE images, on the other hand, the enhancement effect is caused by disruption of the blood-brain barrier (BBB) and vascular structures. Therefore, the distributions of areas of hyperintensity on ASL and contrast enhancement could be different.…”

Hemodynamic Alterations in Vertebrobasilar Large Artery Disease Assessed by Arterial Spin-Labeling MR Imaging

“…4 Another ATT acquisition approach is to perform multiple inflow ASL with a lower spatial resolution acquisition that requires fewer averages to estimate ATT. 26 We characterized the relationship between CBF and ATT and found a significant trend among patients.…”

“…This approach is justified for healthy patients but might be problematic in cerebrovascular diseases where arterial flow is atypical or delayed, as in the case of ischemic scenarios. 2,4 Recent work illustrates the value of multiple inflow ASL to extract both CBF and ATT information [5][6][7] The current study focused on symptomatic VB circulation. In contrast to carotid circulation, the impact of stenotic disease on brain perfusion in VB circulation has not been reported in the literature thus far.…”