双低剂量320排 CT 全脑灌注技术在急性期脑缺血中的应用价值

目的：探讨采用“双低剂量”320排 CT 全脑灌注成像联合 CTA 在急性脑缺血中的可行性及实用价值。方法采用“双低方案”对40例拟诊为急性脑缺血患者行320排 CT 全脑灌注成像联合 CTA 一站式检查。利用软件包处理得到 CTA、4D-CTA、4D-perfusion、Fusion 图像,40例患者均经3.0T MR 行 DWI 作为对照。分析评价 CTA 图像质量、血管狭窄程度及缺血病变位置。结果有脑动脉狭窄或闭塞的患者33例,其中8例经 DSA 证实。CTA 质量达优率为82.5%。CT 灌注成像(CTP)发现297处灌注异常区,其中202处病灶 DWI 证实为脑梗死区,95处 DWI 未见异常：49处 CTP 表现为延迟时间(DLY)、达峰时间(TTP)升高,脑血流量(CBF)、脑血容量(CBV)轻度降低；21处 DLY、TTP 升高,CBF、CBV 正常；25处 DLY、TTP 升高,CBF、CBV 轻度升高。结论“双低剂量”320排 CT 脑灌注联合 CTA 是具有可行性和实用性的,可以准确观察颅内血管形态结构及脑组织梗死前期缺血的状态。

The application of 320-slice CT with dual-low-dose in whole brain perfusion imaging in detection of acute cerebral ischemia

Objective To investigate the feasibility and value of CT perfusion imaging in combination of CTA 320-slice CT with dual-low-dose in detection of acute cerebral ischemia.Methods Forty patients with acute stroke underwent perfusion imaging and CTA using a single scan with 320-slice CT with dual-low-dose schedule.CTA,4D-CTA,4D-perfusion imaging and fusion images were generated at a post-processing workstation.All patients also underwent a 3.0T magnetic resonance imaging with DWI for a comparison.Quality of the images,degree of vascular stenosis,and location of ischemic lesions were evaluated.Results The vascu-lar stenosis or occlusion was found in 33 patients,8 of whom were confirmed by the DSA.The ratio of better images of CTA was 82.5%.CTP showed 297 lesions with abnormal perfusion.202 lesions were confirmed as infarct by DWI,while 95 ones were nor-mal on DWI but with increased DLY and TTP and slightly decreased CBF and CBV in 49,increased DLY and TTP and normal CBF and CBV in 21,and increased DLY and TTP and slightly increased CBF and CBV in 25.Conclusion CT perfusion in combination with CTA by 320-slice CT with dual-low-dose is feasible and useful to observe accurately the vascular structures and the ischemic status of the whole brain at early stage.