Radiology, University of British Columbia, Vancouver, Canada.
Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada.
J Neurol. 2017 Nov;264(11):2205-2214. doi: 10.1007/s00415-017-8609-6. Epub 2017 Sep 11.
Prolonged spin-spin relaxation times in tumour tissue have been observed since some of the earliest nuclear magnetic resonance investigations of the brain. Over the last three decades, numerous studies have sought to characterize tumour morphology and malignancy using quantitative assessment of T relaxation times, although attempts to categorize and differentiate tumours have had limited success. However, previous work must be interpreted with caution as relaxation data were typically acquired using a variety of multiple echo sequences with a range of echoes and T decay curves and were frequently fit with monoexponential analysis. We defined the distribution of T components in three different human brain tumours (glioblastoma, oligodendroglioma, meningioma) using a multi-echo sequence with a greater number of echoes and a longer acquisition window than previously used (48 echoes, data collection out to 1120 ms) with no a priori assumptions about the number of exponential components contributing to the T decay. T relaxation times were increased in tumour tissue and each tumour showed a distinct T distribution profile. Tumours have complex and unique compartmentalization characteristics. Quantitative assessment of T relaxation in brain cancer may be useful in evaluating different grades of brain tumours on the basis of their T distribution profile, and has the potential to be a non-invasive diagnostic tool which may also be useful in monitoring therapy. Further study with a larger sample size and varying grades of tumours is warranted.
自早期对大脑的核磁共振研究以来，人们就已经观察到肿瘤组织中的自旋-自旋弛豫时间延长。在过去的三十年中，许多研究试图通过定量评估 T 弛豫时间来描述肿瘤的形态和恶性程度，尽管对肿瘤进行分类和区分的尝试取得的成果有限。但是，由于以前的研究通常使用多种回波序列来获取弛豫数据，这些序列具有不同的回波数和 T 衰减曲线，并且经常使用单指数分析进行拟合，因此必须谨慎解释弛豫数据。我们使用一种多回波序列来定义三种不同的人脑肿瘤（胶质母细胞瘤、少突胶质细胞瘤、脑膜瘤）中的 T 分量分布，该序列的回波数比以前使用的序列（48 个回波，数据采集时间最长可达 1120 毫秒）多，并且没有关于贡献 T 衰减的指数分量数的先验假设。肿瘤组织中的 T 弛豫时间增加，并且每种肿瘤都显示出独特的 T 分布特征。肿瘤具有复杂而独特的分区化特征。对脑癌 T 弛豫的定量评估可能有助于根据其 T 分布特征评估不同等级的脑肿瘤，并且有可能成为一种非侵入性诊断工具，也可能有助于监测治疗。需要进一步进行更大样本量和不同肿瘤分级的研究。
