Whole-Brain CT Perfusion and CT Angiography Assessment of Moyamoya Disease before and after Surgical Revascularization: Preliminary Study with 256-Slice CT

BACKGROUND/AIMS: The 256-slice CT enables the entire brain to be scanned in a single examination. We evaluated the application of 256-slice whole-brain CT perfusion (CTP) in determining graft patency as well as investigating cerebral hemodynamic changes in Moyamoya disease before and after surgical revascularization. METHODS: Thirty-nine cases of Moyamoya disease were evaluated before and after surgical revascularization with 256-slice CT. Whole-brain perfusion images and dynamic 3D CT angiographic images generated from perfusion source data were obtained in all patients. Cerebral blood flow (CBF), cerebral blood volume (CBV), time to peak (TTP) and mean transit time (MTT) of one hemisphere in the region of middle cerebral artery (MCA) distribution and contralateral mirroring areas were measured. Relative CTP values (rCBF, rCBV, rTTP, rMTT) were also obtained. Differences in pre- and post- operation perfusion CT values were assessed with paired t test or matched-pairs signed-ranks test. RESULTS: Preoperative CBF, MTT and TTP of potential surgical side were significantly different from those of contralateral side (P<0.01 for all). All graft patencies were displayed using the 3D-CTA images. Postoperative CBF, rCBF and rCBV values of surgical side in the region of MCA were significantly higher than those before operation (P<0.01 for all). Postoperative MTT, TTP, rMTT and rTTP values of the surgical side in the region of MCA were significantly lower than those before operation (P<0.05 for all). CONCLUSION: The 256-slice whole-brain CTP can be used to evaluate cerebral hemodynamic changes in Moyamoya disease before and after surgery and the 3D-CTA is useful for assessing the abnormalities of intracranial arteries and graft patencies.