Artikel
Ventricular microaneurysms in Moyamoya angiopathy visualized with 7 Tesla magnetic resonance angiography
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Veröffentlicht: | 8. Juni 2016 |
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Objective: The pathophysiological role of hemodynamic stress to peripheral vessels in Moyamoya angiopathy and formation of microaneurysms remains unclear. The purpose of this in-vivo 7 Tesla magnetic resonance angiography (MRA) study was to investigate microaneurysms in collateral Moyamoya vessels.
Method: In addition to a standard clinical workup with 3 Tesla MRA and selective digital subtraction angiography (DSA), 10 patients with Moyamoya angiopathy were prospectively recruited in a 7 Tesla time-of-flight (TOF) MRA feasibility study between October 2011 and November 2012. These data were recently re-evaluated to screen for presence of microaneurysms in collateral Moyamoya vessels. All patients underwent TOF MRA acquired with 0.22 × 0.22 × 0.41 mm3 resolution utilizing a 7 Tesla whole-body MR system equipped with a 32-channel head coil. Images were analyzed by two experienced vascular neurosurgeons in consensus reading using multiplanar three-dimensional image reconstructions as well as maximum intensity projections to investigate the vascular microanatomy.
Results: There were no signs of acute hemorrhage or bleeding remnants in any patient. Collateral vessels in the ventricles branching from posterior choroidal arteries were present in 8 of 10 patients. Neither conventional 3 Tesla MRA nor DSA detected microaneurysms in these collateral Moyamoya vessels. Out of ten patients with moyamoya angiopathy 4 microaneuryms were delineated by 7 Tesla MRA. The mean diameter of these microaneurysms arising from tiny collateral vessels were 0.80 mm (range 0.56 - 0.96 mm) and 0.87 mm (range 0.79 - 1.07 mm), respectively. In one case with follow-up scans 6 months after direct extracranial-intracranial bypass surgery the microaneurysm disappeared.
Conclusions: In the presented cases of Moyamoya angiopathy, 7 Tesla MRA could detect ventricular microaneurysms in collateral vessels, which may be a key pathophysiological finding due to hemodynamic stress.