Department of Neurology, Chang Gung Memorial Hospital at Chiayi, Chang-Gung University College of Medicine, Tao-Yuan, Taiwan.
PLoS One. 2013 Jul 16;8(7):e69085. doi: 10.1371/journal.pone.0069085. Print 2013.
The aim of this study was to evaluate whether arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) can reliably quantify perfusion deficit as compared to dynamic susceptibility contrast (DSC) perfusion MRI.
Thirty-nine patients with acute ischemic stroke in the anterior circulation territory were recruited. All underwent ASL and DSC MRI perfusion scans within 30 hours after stroke onset and 31 patients underwent follow-up MRI scans. ASL cerebral blood flow (CBF) and DSC time to maximum (T(max)) maps were used to calculate the perfusion defects. The ASL CBF lesion volume was compared to the DSC Tmax lesion volume by Pearson's correlation coefficient and likewise the ASL CBF and DSC T(max) lesion volumes were compared to the final infarct sizes respectively. A repeated measures analysis of variance and least significant difference post hoc test was used to compare the mean lesion volumes among ASL CBF, DSC T(max) >4-6 s and final infarct.
Mean patient age was 72.6 years. The average time from stroke onset to MRI was 13.9 hours. The ASL lesion volume showed significant correlation with the DSC lesion volume for T(max) >4, 5 and 6 s (r = 0.81, 0.82 and 0.80; p<0.001). However, the mean lesion volume of ASL (50.1 ml) was significantly larger than those for T(max) >5 s (29.2 ml, p<0.01) and T(max) >6 s (21.8 ml, p<0.001), while the mean lesion volumes for T(max) >5 or 6 s were close to mean final infarct size.
Quantitative measurement of ASL perfusion is well correlated with DSC perfusion. However, ASL perfusion may overestimate the perfusion defects and therefore further refinement of the true penumbra threshold and improved ASL technique are necessary before applying ASL in therapeutic trials.
本研究旨在评估动脉自旋标记（ASL）灌注磁共振成像（MRI）与动态对比增强（DSC）灌注 MRI 相比是否能可靠地定量评估灌注不足。
共招募 39 例前循环区急性缺血性脑卒中患者。所有患者均在发病后 30 小时内接受 ASL 和 DSC 灌注 MRI 扫描，其中 31 例患者接受了随访 MRI 扫描。ASL 脑血流量（CBF）和 DSC 达峰时间（Tmax）图用于计算灌注缺损。采用 Pearson 相关系数比较 ASL CBF 病变体积与 DSC Tmax 病变体积，同时比较 ASL CBF 和 DSC Tmax 病变体积与最终梗死体积。采用重复测量方差分析和最小显著差异事后检验比较 ASL CBF、DSC Tmax >4-6 s 和最终梗死的平均病变体积。
患者平均年龄为 72.6 岁。从发病到 MRI 的平均时间为 13.9 小时。ASL 病变体积与 DSC 病变体积 Tmax >4、5 和 6 s 均呈显著相关（r = 0.81、0.82 和 0.80；p<0.001）。然而，ASL 的平均病变体积（50.1 ml）明显大于 Tmax >5 s（29.2 ml，p<0.01）和 Tmax >6 s（21.8 ml，p<0.001），而 Tmax >5 或 6 s 的平均病变体积接近最终梗死体积。
ASL 灌注的定量测量与 DSC 灌注具有良好的相关性。然而，ASL 灌注可能会高估灌注不足，因此在将 ASL 应用于治疗试验之前，需要进一步细化真正的半影阈值并改进 ASL 技术。
