Waaijer Annet, van Leeuwen Maarten S, van Osch Matthias J P, van der Worp Bart H, Moll Frans L, Lo Rob T H, Mali Willem P T M, Prokop Mathias
Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, Utrecht, The Netherlands.
Radiology. 2007 Nov;245(2):541-8. doi: 10.1148/radiol.2451061493. Epub 2007 Sep 11.
To prospectively evaluate changes in brain perfusion computed tomographic (CT) parameters after revascularization of unilateral symptomatic carotid artery stenosis and to determine whether pretreatment perfusion CT parameters can be used to predict changes in cerebral hemodynamics after treatment.
This study was medical ethics committee approved, and written informed consent was obtained from all patients. Thirty-six patients (23 men, 13 women; mean age, 67 years) with unilateral symptomatic carotid artery stenosis underwent multi-detector row perfusion CT before and after revascularization. Mean transit time (MTT), cerebral blood volume (CBV), and cerebral blood flow (CBF) were calculated, and relative values based on the comparison between symptomatic and asymptomatic hemispheres-specifically, relative CBV, relative CBF, and difference in MTT-were derived. The absolute and relative perfusion values before treatment were assessed and compared with posttreatment values. These analyses were performed for the group as a whole by using the t test and after subdividing patients into three tertiles according to the difference in MTT by using the Wilcoxon signed rank test.
Among the absolute perfusion values, only the MTT in the symptomatic hemisphere improved significantly after treatment (P < .01). All relative values (difference in MTT, relative CBV, and relative CBF) changed significantly after treatment (P < .05). When the patients were subdivided into three tertiles according to difference in MTT, no significant change in any relative perfusion value could be demonstrated in the lowest tertile, only the difference in MTT improved significantly (P = .004) in the middle tertile, and all relative perfusion values changed significantly (P = .002) in the highest tertile.
Compared with relative CT perfusion values based on interhemispheric comparison, absolute perfusion CT values are less suited for demonstrating changes in cerebral perfusion after revascularization in patients with unilateral symptomatic carotid artery stenosis.
前瞻性评估单侧症状性颈动脉狭窄血运重建后脑灌注计算机断层扫描（CT）参数的变化，并确定治疗前灌注CT参数是否可用于预测治疗后脑血流动力学的变化。
本研究经医学伦理委员会批准，并获得所有患者的书面知情同意。36例（23例男性，13例女性；平均年龄67岁）单侧症状性颈动脉狭窄患者在血运重建前后接受了多排探测器灌注CT检查。计算平均通过时间（MTT）、脑血容量（CBV）和脑血流量（CBF），并得出基于症状性和无症状性半球比较的相对值，即相对CBV、相对CBF和MTT差值。评估治疗前的绝对和相对灌注值，并与治疗后的值进行比较。通过t检验对整个组进行这些分析，并在根据MTT差值将患者分为三个三分位数后，使用Wilcoxon符号秩检验进行分析。
在绝对灌注值中，仅治疗后症状性半球的MTT有显著改善（P <.01）。所有相对值（MTT差值、相对CBV和相对CBF）在治疗后均有显著变化（P <.05）。当根据MTT差值将患者分为三个三分位数时，最低三分位数中任何相对灌注值均无显著变化，中间三分位数中仅MTT差值有显著改善（P =.004），最高三分位数中所有相对灌注值均有显著变化（P =.002）。
与基于半球间比较的相对CT灌注值相比，绝对灌注CT值不太适合用于证明单侧症状性颈动脉狭窄患者血运重建后脑灌注的变化。
