Moen Kent Gøran, Vik Anne, Olsen Alexander, Skandsen Toril, Håberg Asta Kristine, Evensen Kari Anne I, Eikenes Live
Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway.
Department of Medical Imaging, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway.
J Neurosci Res. 2016 Jul;94(7):623-35. doi: 10.1002/jnr.23728. Epub 2016 Mar 6.
This prospective study of traumatic brain injury (TBI) patients investigates fractional anisotropy (FA) from chronic diffusion tensor imaging (DTI) in areas corresponding to persistent and transient traumatic axonal injury (TAI) lesions detected in clinical MRI from the early phase. Thirty-eight patients (mean 24.7 [range 13-63] years of age) with moderate-to-severe TBI and 42 age- and sex-matched healthy controls were included. Patients underwent 1.5-T clinical MRI in the early phase (median 7 days), including fluid-attenuated inversion recovery (FLAIR) and T2* gradient echo (T2GRE) sequences. TAI lesions from the early phase were characterized as nonhemorrhagic or microhemorrhagic. In the chronic phase (median 3 years), patients and controls were imaged at 3 T with FLAIR, T2GRE, T1, and DTI sequences. TAI lesions were classified as transient or persistent. The FLAIR/T2GRE images from the early phase were linearly registered to the FA images from the chronic phase and lesions manually segmented on the FA-registered FLAIR/T2GRE images. For regions of interest (ROIs) from both nonhemorrhagic and microhemorrhagic lesion, we found a significant linear trend of lower mean FA from ROIs in healthy controls to ROIs in patients without either nonhemorrhagic or microhemorrhagic lesions and further to transient and finally persistent lesion ROIs (P < 0.001). Histogram analyses showed lower FA in persistent compared with transient nonhemorrhagic lesion ROIs (P < 0.001), but this was not found in microhemorrhagic lesion ROIs (P = 0.08-0.55). The demonstrated linear trend of lower FA values from healthy controls to persistent lesion ROIs was found in both nonhemorrhagic and microhemorrhagic lesions and indicates a gradual increasing disruption of the microstructure. Lower FA values in persistent compared with transient lesions were found only in nonhemorrhagic lesions. Thus, clinical MRI techniques are able to depict important aspects of white matter pathology across the stages of TBI. © 2016 Wiley Periodicals, Inc.
这项针对创伤性脑损伤（TBI）患者的前瞻性研究，调查了慢性扩散张量成像（DTI）在与早期临床MRI检测到的持续性和短暂性创伤性轴索损伤（TAI）病变相对应区域的分数各向异性（FA）。纳入了38例中重度TBI患者（平均年龄24.7岁[范围13 - 63岁]）和42例年龄及性别匹配的健康对照者。患者在早期（中位时间7天）接受了1.5-T临床MRI检查，包括液体衰减反转恢复（FLAIR）和T2梯度回波（T2GRE）序列。早期的TAI病变被表征为非出血性或微出血性。在慢性期（中位时间3年），患者和对照者接受了3 T的FLAIR、T2GRE、T1和DTI序列成像。TAI病变被分类为短暂性或持续性。将早期的FLAIR/T2GRE图像线性配准到慢性期的FA图像上，并在FA配准的FLAIR/T2*GRE图像上手动分割病变。对于非出血性和微出血性病变的感兴趣区域（ROI），我们发现从健康对照者的ROI到既无非出血性也无微出血性病变患者的ROI，再到短暂性病变ROI以及最终的持续性病变ROI，平均FA存在显著的线性下降趋势（P < 0.001）。直方图分析显示，持续性非出血性病变ROI的FA低于短暂性非出血性病变ROI（P < 0.001），但在微出血性病变ROI中未发现此差异（P = 0.08 - 0.55）。在非出血性和微出血性病变中均发现了从健康对照者到持续性病变ROI的FA值下降的线性趋势，这表明微观结构的破坏逐渐增加。仅在非出血性病变中发现持续性病变的FA值低于短暂性病变。因此，临床MRI技术能够描绘TBI各阶段白质病理的重要方面。© 2016威利期刊公司
