Parry A, Clare S, Jenkinson M, Smith S, Palace J, Matthews P M
Centre for Functional Magnetic Resonance Imaging of the Brain, The John Radcliffe Hospital, Headington, Oxford, OX3 9DU, UK.
J Neurol. 2002 Sep;249(9):1279-86. doi: 10.1007/s00415-002-0837-7.
Previous studies have established the clinical relevance of hypointense lesions ("black holes") on T1-weighted MRI as a surrogate marker for pathological change [36]. In contrast to measuring the volume of "black holes", the direct measurement of T1 values allows an objective assessment of the changes contributing to hypointensity both in the focal lesions and in the normal appearing white matter (NAWM). The aims of this study were first, to determine the relationship between T1 values in the NAWM and in discrete lesions, second, to test the relationship between white matter T1 changes and measures of disability and third, to determine whether pathology leading to T1 change occurred in thalamic grey matter of patients with multiple sclerosis. 24 patients with clinically definite multiple sclerosis (13 with relapsing-remitting multiple sclerosis and 11 with secondary progressive multiple sclerosis) and 11 controls participated. White matter T1 histograms and mean T1 values for the thalamus were generated from whole brain T1 relaxation time maps measured using a novel echo-planar imaging based MRI sequence at 3Tesla. Tissue segmentation based on T2- and T1-weighted images allowed independent study of changes in lesions and NAWM. White matter T1 histograms from the patient group showed a reduced peak height and a shift towards higher T1 values (p = 0.028) relative to controls. The mean thalamic T1 was greater for secondary progressive patients than for healthy controls (p = 0.03). Mean white matter T1 values correlated significantly with disability (r = 0.48, p = 0.02). The mean T1 value in the T1-hypointense lesions correlated strongly with the mean T1 value in the NAWM (r = 0.80, p < 0.001). No significant relationship was found between mean white matter T1 value and cerebral volume (r = -0.23, p = 0.31). The T1 measurements extend previous observations suggesting that changes in the NAWM occur in parallel with pathology in lesions of MS. T1 measurements of either the total or NAWM therefore may provide a potentially observer- and scanner- independent marker of pathology relevant to disability in MS.
先前的研究已证实，T1加权磁共振成像（MRI）上的低信号病变（“黑洞”）作为病理变化的替代标志物具有临床相关性[36]。与测量“黑洞”的体积不同，直接测量T1值能够客观评估局灶性病变和正常白质（NAWM）中导致低信号的变化。本研究的目的：一是确定NAWM和离散病变中T1值之间的关系；二是检验白质T1变化与残疾程度测量指标之间的关系；三是确定导致T1变化的病理改变是否发生在多发性硬化症患者的丘脑灰质中。24例临床确诊的多发性硬化症患者（13例复发缓解型多发性硬化症患者和11例继发进展型多发性硬化症患者）和11名对照者参与了研究。利用基于回波平面成像的新型MRI序列在3特斯拉磁场下测量全脑T1弛豫时间图，生成丘脑的白质T1直方图和平均T1值。基于T2加权和T1加权图像进行组织分割，从而能够独立研究病变和NAWM中的变化。与对照组相比，患者组的白质T1直方图显示峰值降低且向更高T1值偏移（p = 0.028）。继发进展型患者的丘脑平均T1值高于健康对照组（p = 0.03）。白质平均T1值与残疾程度显著相关（r = 0.48，p = 0.02）。T1低信号病变中的平均T1值与NAWM中的平均T1值密切相关（r = 0.80，p < 0.001）。未发现白质平均T1值与脑容量之间存在显著关系（r = -0.23，p = 0.31）。T1测量扩展了先前的观察结果，表明NAWM中的变化与MS病变中的病理改变同时发生。因此，对全脑或NAWM进行T1测量可能提供一种潜在的、与观察者和扫描仪无关的、与MS残疾相关的病理标志物。
