Bockhorst K H, Smith J M, Smith M I, Bradley D P, Houston G C, Carpenter T A, Hall L D, Papadakis N G, Parsons A A, Huang C L, James M F
Herchel Smith Laboratory for Medicinal Chemistry, University of Cambridge School of Clinical Medicine, Cambridge, CB2 2PZ, United Kingdom.
J Magn Reson Imaging. 2000 Nov;12(5):722-33. doi: 10.1002/1522-2586(200011)12:5<722::aid-jmri9>3.0.co;2-a.
Cortical spreading depression (CSD) in the gyrencephalic cat brain was detected with diffusion-weighted echoplanar (DWEP) magnetic resonance imaging (4-8/min for 1-2 hours) using a horizontal imaging plane through the suprasylvian (SG) and marginal gyri. A t-statistic mapping technique allowed a quantitative characterization of the passage of events through single-image pixels (0.15 mm(2)), thus providing a resolution unavailable to previous studies in which time-dependent changes instead were derived from averaging data over relatively large ROIs. Using the enhanced analysis, CSD events initiated by KCl could be quantified for the first time as primary or secondary according to their spatial and temporal features. Primary events covered 26.2 +/- 9.9 mm(2)of cortical surface (mean +/- SD, n = 7 experiments) and propagated rapidly (3.5 +/- 0.65 mm * min(-1)) with a hemispherical geometry. In contrast, the subsequent secondary events were multiple, spatially restricted (covering 7.6 +/- 4.6 mm(2), P < 0.005), slower in propagation (2.6 +/- 0.41 mm * min(-1), P < 0.012), and often confined to the originating gyrus (26 out of 59 events). However, both event types were associated with significantly reduced apparent diffusion coefficients (ADCs; from 800 to approximately 660 x 10(-6) mm(2)* s(-1), P < 0.05) that were similar for both primary (21 +/- 5.1%) and secondary waves (18 +/- 7. 7%) and that had similar durations (full width at half-maximal height: 86 +/- 17 vs. 79 +/- 20 seconds, respectively). These findings associate CSD for the first time with two categories of ADC disturbance that are similar in amplitude and duration but that differ in spatial extent, velocity, and extensiveness of spread.
使用水平成像平面，通过颞上回（SG）和缘回，利用扩散加权回波平面（DWEP）磁共振成像（4 - 8次/分钟，持续1 - 2小时）检测脑回状猫脑的皮质扩散性抑制（CSD）。t统计映射技术能够对事件通过单图像像素（0.15平方毫米）的过程进行定量表征，从而提供了以往研究中所没有的分辨率，以往研究中与时间相关的变化是通过对相对较大的感兴趣区域（ROI）的数据进行平均得出的。利用这种增强分析，首次可以根据氯化钾引发的CSD事件的时空特征，将其量化为原发性或继发性。原发性事件覆盖皮质表面26.2±9.9平方毫米（平均值±标准差，n = 7次实验），并以半球形几何形状快速传播（3.5±0.65毫米·分钟⁻¹）。相比之下，随后的继发性事件是多个，空间上受限（覆盖7.6±4.6平方毫米，P < 0.005），传播较慢（2.6±0.41毫米·分钟⁻¹，P < 0.012），并且通常局限于起源的脑回（59个事件中有26个）。然而，两种事件类型均与表观扩散系数（ADC）显著降低相关（从800降至约660×10⁻⁶平方毫米·秒⁻¹，P < 0.05），原发性波（21±5.1%）和继发性波（18±7.7%）的降低相似，且持续时间相似（半高宽：分别为86±17秒和79±20秒）。这些发现首次将CSD与两类ADC干扰联系起来，这两类干扰在幅度和持续时间上相似，但在空间范围、速度和传播范围上有所不同。
