Laule Cornelia, Vavasour Irene M, Kolind Shannon H, Traboulsee Anthony L, Moore G R Wayne, Li David K B, Mackay Alex L
Department of Radiology, University of British Columbia Hospital Room M10 Purdy Pavilion/ECU, 2221 Wesbrook Mall, Vancouver BC V6T 2B5, Canada.
J Neurol. 2007 Nov;254(11):1579-87. doi: 10.1007/s00415-007-0595-7. Epub 2007 Sep 4.
Multi-echo T(2) measurements are invaluable in studying brain pathology in multiple sclerosis (MS). In addition to information about myelin water and total water content, the T(2) distribution has the potential to detect additional water reservoirs arising from other sources such as inflammation or edema. The purpose of this study was to better define the T(2) distribution in MS lesions and normal appearing white matter (NAWM) with particular emphasis on the characterisation of longer T(2) components. Magnetisation transfer (MT), T(1) and 48-echo T(2) relaxation data were acquired in 20 MS subjects and regions of interest were drawn in lesions and NAWM. Twenty-seven out of 107 lesions exhibited signal with a markedly prolonged T(2) (200-800 ms). Lesions with a Long-T(2) signal also exhibited a longer geometric mean T(2) (GMT(2)), increased water content (WC), higher T(1), reduced magnetisation transfer ratio (MTR) and decreased myelin water fraction (MWF) than lesions without a Long-T(2) signal. Those subjects with Long-T(2) lesions had a significantly longer disease duration than subjects without this lesion subtype. A strong correlation was observed between T(1) and Long-T(2) fraction, while a slightly weaker relationship was found for GMT(2), MTR and MWF with Long-T(2) fraction. A potential source of the Long-T(2) signal is an increase in extracellular water. This study supports the usefulness of increasing the data acquisition window of the multi-echo T(2) relaxation sequence to better characterise the T(2) decay in MS.
多回波T(2)测量在研究多发性硬化症（MS）的脑病理学方面具有极高价值。除了有关髓鞘水和总含水量的信息外，T(2)分布还有潜力检测出由炎症或水肿等其他来源产生的额外水源。本研究的目的是更好地定义MS病变和正常外观白质（NAWM）中的T(2)分布，特别强调对较长T(2)成分的特征描述。在20名MS受试者中采集了磁化传递（MT）、T(1)和48回波T(2)弛豫数据，并在病变和NAWM中绘制了感兴趣区域。107个病变中有27个表现出T(2)明显延长（200 - 800毫秒）的信号。与没有长T(2)信号的病变相比，具有长T(2)信号的病变还表现出更长的几何平均T(2)（GMT(2)）、增加的含水量（WC）、更高的T(1)、降低的磁化传递率（MTR）和降低的髓鞘水分数（MWF）。那些有长T(2)病变的受试者的病程明显长于没有这种病变亚型的受试者。观察到T(1)与长T(2)分数之间有很强的相关性，而对于GMT(2)、MTR和MWF与长T(2)分数之间的关系则稍弱。长T(2)信号的一个潜在来源是细胞外水的增加。本研究支持增加多回波T(2)弛豫序列的数据采集窗口以更好地表征MS中T(2)衰减的有用性。
