School of Health Sciences, Faculty of Health and Medicine, University of Newcastle, Callaghan, NSW 2308, Australia; Hunter Medical Research Institute, Newcastle, Australia.
Hunter Medical Research Institute, Newcastle, Australia.
Magn Reson Imaging. 2020 Dec;74:21-30. doi: 10.1016/j.mri.2020.09.001. Epub 2020 Sep 6.
To evaluate the performance of novel spiral MRSI and tissue segmentation pipeline of the brain, to investigate neurometabolic changes in normal-appearing white matter (NAWM) and white matter lesions (WML) of stable relapsing remitting multiple sclerosis (RRMS) compared to healthy controls (HCs).
Spiral 3D MRSI using LASER-GOIA-W [16,4] was undertaken on 16 RRMS patients and 9 HCs, to acquire MRSI data from a large volume of interest (VOI) 320 cm and analyzed using LCModel. MRSI data and voxel tissue segmentation were compared between the two cohorts using t-tests. Support vector machine (SVM) was used to classify tissue types and assessed by accuracy, sensitivity and specificity.
Compared to HCs, RRMS demonstrated a statistically significant reduction in all mean brain tissues and increase in CSF volume. Within VOI, WM decreased (-10%) and CSF increased (41%) in RRMS compared to HCs (p < 0.001). MRSI revealed that total creatine (tCr) ratios of N-acetylaspartate and glutamate+glutamine in WML were significantly lower than NAWM-MS (-9%, -8%) and HCs (-14%, -10%), respectively. Myo-inositol/tCr in WML was significantly higher than NAWM-MS (14%) and HCs (10%). SVM of MRSI yielded accuracy, sensitivity and specificity of 86%, 95%, and 70%, respectively for HCs vs WML, which were higher than HC vs NAWM and WML vs NAWM models.
This study demonstrates the benefit of MRSI in evaluating MS neurometabolic changes in NAWM. SVM of MRSI data in the MS brain may be suited for clinical monitoring and progression of MS patients. Longitudinal MRSI studies are warranted.
评估新型螺旋 MRSI 及脑组织结构分割技术的性能，比较稳定复发缓解型多发性硬化症（RRMS）患者正常表现的白质（NAWM）和白质病变（WML）与健康对照（HC）之间的神经代谢变化。
采用 LASER-GOIA-W [16,4] 进行螺旋 3D MRSI，共纳入 16 名 RRMS 患者和 9 名 HC，对大感兴趣区（VOI）320 cm 采集 MRSI 数据，并用 LCModel 进行分析。使用 t 检验比较两组 MRSI 数据和体素组织分割结果。使用支持向量机（SVM）对组织类型进行分类，并评估其准确性、敏感性和特异性。
与 HC 相比，RRMS 患者全脑各组织的平均水平显著降低，CSF 容积增加。在 VOI 内，RRMS 患者 WM 减少（-10%），CSF 增加（41%），与 HC 相比差异具有统计学意义（p<0.001）。MRSI 显示，WML 中的 N-乙酰天冬氨酸和谷氨酸+谷氨酰胺的总肌酸（tCr）比值明显低于 NAWM-MS（-9%，-8%）和 HC（-14%，-10%）。WML 中的肌醇/tCr 明显高于 NAWM-MS（14%）和 HC（10%）。MRSI 的 SVM 对 HC 与 WML 的分类准确率、敏感性和特异性分别为 86%、95%和 70%，优于 HC 与 NAWM 和 WML 与 NAWM 模型。
本研究表明 MRSI 可用于评估 MS 患者 NAWM 的神经代谢变化。MS 脑 MRSI 数据的 SVM 可能适用于 MS 患者的临床监测和疾病进展。需要进行纵向 MRSI 研究。
