Acceleration-selective Arterial Spin-labeling MR Angiography Used to Visualize Distal Cerebral Arteries and Collateral Vessels in Moyamoya Disease

Abstract

Purpose To evaluate and compare the performance of acceleration-selective arterial spin labeling (AccASL) magnetic resonance (MR) angiography in the visualization of cerebral arteries and collateral vessels in patients with Moyamoya disease with that of time-of-flight (TOF) MR angiography, with digital subtraction angiography (DSA) as the reference standard. Materials and Methods Thirty-six cerebral hemispheres from 22 patients with Moyamoya disease underwent TOF and AccASL MR angiography and DSA. Qualitative evaluations included imaging of the terminal internal carotid artery (ICA), distal middle cerebral arteries (MCAs), Moyamoya vessels, and leptomeningeal anastomosis (LMA) collaterals with reference to DSA. Quantitative evaluations included assessment of contrast-to-noise ratio (CNR) and number of vessels in MCA branches. The linear mixed-effect model was used to compare the two methods. Results Mean scores for qualitative evaluation were significantly higher with AccASL angiography than with TOF angiography for imaging distal MCAs (3.9 ± 0.3 [standard deviation] vs 2.9 ± 1.1; P < .001), Moyamoya vessels (3.6 ± 0.6 vs 2.7 ± 0.9, P < .001), and LMA collaterals (3.8 ± 0.6 vs 1.8 ± 0.7, P < .001). Scores for steno-occlusive degree around the terminal ICAs were better with TOF angiography than with AccASL angiography (2.6 ± 0.5 vs 2.4 ± 0.6, P = .023). CNRs in the M4 segment were significantly higher with AccASL angiography (11.9 ± 12.9, P < .001) than with TOF angiography (4.1 ± 7.9). The number of vessels was significantly higher with AccASL angiography (18.3 ± 5.0, P < .001) than with TOF angiography (8.9 ± 4.9). The increase in the number of vessels from TOF angiography to AccASL angiography was greater in patients with severe ICA steno-occlusion (late ICA stage group, 11.4 ± 4.5; early ICA stage group, 6.8 ± 4.0; P = .007) and well-developed leptomeningeal anastomosis (mildly developed LMA group, 7.1 ± 4.3; well-developed LMA group, 11.3 ± 4.5; P = .011). Conclusion AccASL MR angiography enables better visualization of distal cerebral arteries and collateral vessels in patients with Moyamoya disease than does TOF MR angiography, while TOF MR angiography enables better visualization of stenosis of proximal arteries. Both methods work in a mutually beneficial manner in the assessment of cerebral arteries. RSNA, 2017 Online supplemental material is available for this article.

Validation of Zero TE–MRA in the Characterization of Cerebrovascular Diseases: A Feasibility Study

“…However, there are known major limitations to the use of TOF-MRA for the delineation of cerebrovascular disorders, such as pseudoocclusions, 15 the inaccurate detection of aneurysms 16 and the nidus and draining veins in AVMs, 17 and collateral vessels in Moyamoya disease. 18 The resultant signal losses are mainly due to saturation secondary to slow flow or phase-dispersion effects caused by turbulent flow, 19 which account for the overestimation or inaccuracy of TOF-MRA observed in our study. In contrast to TOF-MRA, zTE-MRA showed some encouraging characteristics as a nonenhanced MRA approach.…”

Angiographic study of the transdural collaterals at the anterior cranial fossa in patients with Moyamoya disease

“…Due to the ischemic state in anterior circulation, collateral circulation always forms in patients with MMD 17 . According to their origin, the collaterals of MMD can be classified as moyamoya vessels, leptomeningeal anastomosis from the posterior circulation, and TDCs 18 . In MMD, moyamoya-like vessels mainly locate at the basal ganglia and thalamus, anterior cranial fossa, and cerebral convexity 19 .…”

Robust visualization of middle cerebral artery main trunk by enhanced acceleration‐selective arterial spin labeling (eAccASL) for intracranial MRA

“…Togao et al mentioned that contrast-to-noise ratios (CNRs) of the MCA segments for AccASL were lower in proximal segments (M1 and M2) compared with those obtained for TOF. 4 In that report, steno-occlusive sites around the terminal internal carotid arteries were better visualized with TOF than with AccASL. We hypothesize that one of the causes of this problem is spin dispersion in the MCA main trunk and resulting flow voids occurring during the T2 preparation pulse in the control module.…”

“…However, AccASL has some limitations in visualizing the main trunk of the middle cerebral artery (MCA). Togao et al mentioned that contrast‐to‐noise ratios (CNRs) of the MCA segments for AccASL were lower in proximal segments (M1 and M2) compared with those obtained for TOF . In that report, steno‐occlusive sites around the terminal internal carotid arteries were better visualized with TOF than with AccASL.…”