Postoperative Evaluation of Moyamoya Disease with Perfusion-Weighted MR Imaging: Initial Experience
Seung-Koo Leea,b,
Dong Ik Kima,b,
Eun-Kee Jeonga,b,
Si-Yeon Kima,b,
Sang Heum Kima,b,
Yon Kwon Ina,b,
Dong-Seok Kimc and
Joong-Uhn Choic
a Department of Diagnostic Radiology, BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
b Research Institute of Radiological Science, BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
c Department of Neurosurgery, BK21 Project for Medical Science, Yonsei University College of Medicine, Seoul, Korea
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FIG 1. Regions of interest (MCA, PCA, and BG) are drawn on a TTP map. On the rCBV maps (not shown), the relative signal intensity ratios of the MCA and the BG to the PCA territory were obtained, whereas on the TTP maps the time differences in the MCA and BG were calculated and compared with that of the PCA territory.
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FIG 2. 9-year-old boy with moyamoya disease.
A, Anteroposterior angiogram of the right ICA shows an occlusion of the supraclinoid portion, with development of multiple basal collateral vessels (moyamoya vessels).
B, Left ICA angiogram depicts mild changes of the luminal caliber in the left MCA, but with preserved patency. Left ACA shows severe narrowing.
C, Technetium-99m ethyl cysteinate dimer SPECT scan (left scan) reveals decreased perfusion in both hemispheres, more prominent on the right side. After the acetazolamide (Diamox) injection (right scan), there is no evidence of a significant perfusion reduction.
D, Perfusion MR images show delayed TTP in the right hemisphere before EDAS (arrows in left TTP map) and a signal intensity reduction after EDAS (arrows in right TTP map), which means a restoration of rapid flow at the surgical site. Note, rCBV maps show nothing significant.
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FIG 3. A and B, Graphs show changes in the rCBV ratios to the posterior circulation of the MCA territory (A) and the basal ganglia (B). The rCBV can be increased or decreased before (Preop) and after (Postop) surgery, which cannot characterize the rCBV patterns of moyamoya disease.
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FIG 4. A and B, Graphs show changes in the TTP delay to the posterior circulation of the MCA territory (A) and basal ganglia (B). Note the markedly increased TTP in the MCA territory, with a significant reduction after surgery (Postop). There were no specific changes in the TTP values in the basal ganglia.
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FIG 5. 7-year-old boy with moyamoya disease.
A, Preoperative left carotid angiogram shows an occlusion of the supraclinoid ICA with basal collateral vessels. No transdural collateral vessels from the superficial temporal or middle meningeal arteries are seen.
B, Vertebral artery angiogram shows prominent leptomeningeal collateral vessels supplying the bilateral hemispheres.
C, Serial perfusion-weighted MR images (rCBV, top row; TTP, bottom row) were obtained because the patient underwent bilateral EDAS procedures with a 1-month interval. One-month follow-up perfusion MR image shows a mild reduction in the TTP delay (arrow in middle TTP map), which means neovascularization is beginning to develop. The last perfusion MR image (right TTP map) shows near-complete normalization of the TTP in the left hemisphere (solid arrow) and a partial TTP shortening on the right side (open arrow).
D and E, Postoperative 7-month follow-up left ECA angiograms show successful neovascularization from the middle meningeal and superficial temporal arteries.
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