Treatment of symptomatic cerebral artery stenosis and occlusion with Xenon CT guided cerebral revascularization / 中国脑血管病杂志

Objective To investigate the roles of Xenon-CT cerebral blood flow perfusion imaging in cerebral revascularization before surgery and efficacy evaluation.Methods The clinical data of 15 patients with symptomatic cerebral artery stenosis/occlusion of anterior circulation were analyzed retrospectively.Eight patients were treated with endovascular stenting,1 was treated with internal carotid endarterectomy,and 6 were treated with superficial temporal artery-middle cerebral artery bypass grafting.The regional cerebral blood flow (rCBF) detected by Xenon CT within 2 weeks before and after procedure and the modified Ranking scale (mRS) scores at 6 months after procedure were compared.Results (1) The mean rCBF value of 12 patients with abnormal blood perfusion of target vessels before procedure was 30±10 ml/(100 g·min) and that was 32±14 ml/(100 g·min) after procedure.Compared with before procedure,the difference was statistically significant (P0.05).(2) The postoperative mRS score was decreased in 8 cases and stable in 7 cases.Compared with before procedure,there were significant differences in mRS scores after procedure in 15 cases (P<0.05).During the follow-up period,none of the patients had new neurological impairment.Conclusion Revascularization can improve the presence of hemodynamic disorders in patients with symptomatic anterior circulation cerebral artery stenosis or occlusion of the target blood vessels in the distal local cerebral perfusion and neurological deficit symptoms.The patients with abnormal perfusion of preoperative Xenon-CT cerebral blood flow perfusion imaging may be more beneficial than those with normal perfusion.

Computer-Aided Classification of Visual Ventilation Patterns in Patients with Chronic Obstructive Pulmonary Disease at Two-Phase Xenon-Enhanced CT

OBJECTIVE: To evaluate the technical feasibility, performance, and interobserver agreement of a computer-aided classification (CAC) system for regional ventilation at two-phase xenon-enhanced CT in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Thirty-eight patients with COPD underwent two-phase xenon ventilation CT with resulting wash-in (WI) and wash-out (WO) xenon images. The regional ventilation in structural abnormalities was visually categorized into four patterns by consensus of two experienced radiologists who compared the xenon attenuation of structural abnormalities with that of adjacent normal parenchyma in the WI and WO images, and it served as the reference. Two series of image datasets of structural abnormalities were randomly extracted for optimization and validation. The proportion of agreement on a per-lesion basis and receiver operating characteristics on a per-pixel basis between CAC and reference were analyzed for optimization. Thereafter, six readers independently categorized the regional ventilation in structural abnormalities in the validation set without and with a CAC map. Interobserver agreement was also compared between assessments without and with CAC maps using multirater kappa statistics. RESULTS: Computer-aided classification maps were successfully generated in 31 patients (81.5%). The proportion of agreement and the average area under the curve of optimized CAC maps were 94% (75/80) and 0.994, respectively. Multirater kappa value was improved from moderate (kappa = 0.59; 95% confidence interval [CI], 0.56-0.62) at the initial assessment to excellent (kappa = 0.82; 95% CI, 0.79-0.85) with the CAC map. CONCLUSION: Our proposed CAC system demonstrated the potential for regional ventilation pattern analysis and enhanced interobserver agreement on visual classification of regional ventilation.

Postoperative Cerebral Blood Flow Evaluation by Stable Xenon Computed Tomography in Patients with a Ruptured Intracranial Aneurysm

In cerebrovascular disease, the measurement of cerebral blood flow(CBF) is an important indicator of a patient's clinical status, treatment and prognosis. The main advantage of Stable Xenon CT is that it noninvasively provides three-dimensional, high resolution, quantitative local cerebral blood flow information coupled to anatomic exposition. Using this modality, we measured postoperative CBF in 50 patients with subarachnoid hemorrhage from a ruptured intracranial aneurysm. The results were as follows : 1) There was a negative relationship between age and CBF. 2) Among postoperative disability patients, global and regional CBF were markedly diminished. 3) CBF on the ipsilateral side of a craniotomy site was markedly lower than on the contralateral side. Xenon CT is a very useful method for the evaluation of postoperative CBF in intracranial aneurysm patients.