Contrecoup Injury-Induced Middle Meningeal Arteriovenous Fistula Detected by Time-of-Flight Magnetic Resonance Angiography and Magnetic Resonance Arterial Spin Labeling: Case Report and Review of the Literature

Introduction: Recently, four-dimensional magnetic resonance angiography without contrast enhancement using arterial spin labeling (ASL-4D MRA) has become available to visualize the intracranial arteries. However, few reports are available about the efficacy of ASL-4D MRA in moyamoya disease (MMD). Hypothesis: We hypothesized that postoperative hemodynamic changes in MMD patients could be evaluated using ASL-4D MRA. Methods: This study included 26 hemispheres of 21 patients who underwent combined direct and indirect revascularization for MMD. ASL-4D MRA was serially performed before and after surgery. We assessed the time phases where signals of the arteries were detected on ASL-4D MRA in order to analyze perioperative changes in cerebral hemodynamics. Results: The signals of the anastomosed arteries on ASL-4D MRA were detected and disappeared at significantly earlier time phase after surgery than before. This change in acute period was moderated in chronic period after surgery. Postoperative hyperperfusion was observed in 12 of 26 hemispheres within 7 days after surgery. The signals of the arteries were detected significantly earlier in hemispheres with hyperperfusion than those without. In cases with hyperperfusion, ASL-4D MRA demonstrated high intensity of peripheral middle cerebral artery (MCA) around anastomosed region in early time phase (Figure). This “early hyperintensity of MCA” was observed in all cases with hyperperfusion and corresponded to the timing of the occurrence of hyperperfusion. Furthermore, this hyperperfusion-specific sign could not be detected by routine TOF MRA. Conclusions: Noninvasive ASL-4D MRA successfully evaluated perioperative dynamic changes of cerebral blood flow and the effect of surgical revascularization in MMD. This next generation modality could also visualize cerebral hemodynamics in cases with postoperative hyperperfusion and would be quite useful for appropriate postoperative management.

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Arterial Spin Labeling Imaging of a Giant Aneurysm Leading to Subarachnoid Hemorrhage following Cerebral Infarction

Case Reports in Neurology ◽

10.1159/000487587 ◽

2018 ◽

Vol 10 (1) ◽

pp. 66-71 ◽

Cited By ~ 1

Author(s):

Tatsuya Ueno ◽

Tatsuya Sasaki ◽

Masatoshi Iwamura ◽

Tomoya Kon ◽

Jin-ichi Nunomura ◽

...

Keyword(s):

Subarachnoid Hemorrhage ◽

Magnetic Resonance ◽

Magnetic Resonance Angiography ◽

Cerebral Infarction ◽

Arterial Spin Labeling ◽

Giant Aneurysm ◽

Spin Labeling ◽

Left Internal Carotid Artery ◽

Hyperintense Signal ◽

Aneurysm Thrombosis

An 83-year-old Japanese man was admitted with dysarthria and right hemiparesis. He had had a large intracranial aneurysm on the left internal carotid artery 5 years before admission and had been followed up under conservative treatment. On admission, diffusion-weighted imaging revealed a hyperintense signal on the left anterior choroidal artery territory. Time-of-flight magnetic resonance angiography demonstrated poor visibility of the middle and anterior cerebral arteries and the inferior giant aneurysm, suggesting distal emboli from aneurysm thrombosis or a reduction of blood outflow due to aneurysm thrombosis. Arterial spin labeling (ASL) signal increased in the giant aneurysm, suggesting blood stagnation within the aneurysmal sac, and decreased in the left hemisphere. We diagnosed cerebral infarction due to aneurysm thrombosis, and started antithrombotic therapy. On day 2, he suddenly died of subarachnoid hemorrhage due to rupturing of the giant aneurysm. When thrombosis occurs in a giant aneurysm, increasing ASL signal within the aneurysm and decreasing ASL signal with poor visibility on magnetic resonance angiography in the same arterial territory may indicate the danger of impending rupture of the giant aneurysm.

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