Department of Child Neurology, VU University Medical Center, Amsterdam, the Netherlands.
AJNR Am J Neuroradiol. 2011 Mar;32(3):481-9. doi: 10.3174/ajnr.A2327. Epub 2011 Jan 27.
Quantitative MR imaging techniques may improve the pathologic specificity of MR imaging regarding white matter abnormalities. Our purposes were to determine whether ADC, FA, MTR, and MRS metabolites correlate with the degree of white matter damage in patients with X-ALD; whether differences in ADC, FA, and MTR observed in vivo are retained in fresh and formalin-fixed postmortem brain tissue; and whether the differences predict histopathology.
MRS metabolites, MTR, ADC, and FA, were determined in 7 patients with X-ALD in 3 white matter areas (NAWM, active demyelination, and complete demyelination) and were compared with values obtained in 14 controls. MTR, ADC, and FA were assessed in postmortem brains from 15 patients with X-ALD and 5 controls. Values were correlated with the degree of astrogliosis and density of myelin, axons, and cells. Equations to estimate histopathology from MR imaging parameters were calculated by linear regression analysis.
MRS showed increased mIns, Lac, and Cho and decreased tNAA in living patients with X-ALD; the values depended on the degree of demyelination. MTR, ADC, and FA values were different in postmortem than in vivo white matter, but differences related to degrees of white matter damage were retained. ADC was high and FA and MTR were low in abnormal white matter. Correlations between histopathologic findings and MR imaging parameters were strong. A combination of ADC and FA predicted pathologic parameters best.
Changes in quantitative MR imaging parameters, present in living patients and related to the severity of white matter pathology, are retained in postmortem brain tissue. MR imaging parameters predict white matter histopathologic parameters.
定量磁共振成像技术可以提高磁共振成像对白质异常的病理特异性。我们的目的是确定 ADC、FA、MTR 和 MRS 代谢物是否与 X-ALD 患者的白质损伤程度相关；在体内观察到的 ADC、FA 和 MTR 差异是否保留在新鲜和福尔马林固定的死后脑组织中；以及这些差异是否可以预测组织病理学。
在 7 例 X-ALD 患者的 3 个白质区域（NAWM、活跃脱髓鞘和完全脱髓鞘）中测定 MRS 代谢物、MTR、ADC 和 FA，并与 14 例对照值进行比较。评估了 15 例 X-ALD 患者和 5 例对照患者死后脑组织的 MTR、ADC 和 FA。将值与星形胶质细胞增生程度和髓鞘、轴突和细胞密度相关联。通过线性回归分析计算了从磁共振成像参数估计组织病理学的方程。
MRS 显示活的 X-ALD 患者的 mIns、Lac 和 Cho 增加，tNAA 减少；这些值取决于脱髓鞘的程度。与活体白质相比，死后白质的 MTR、ADC 和 FA 值不同，但与白质损伤程度相关的差异仍然存在。异常白质的 ADC 较高，FA 和 MTR 较低。组织病理学发现与磁共振成像参数之间存在较强的相关性。ADC 和 FA 的组合能最好地预测病理参数。
存在于活体内并与白质病理严重程度相关的定量磁共振成像参数的变化，在死后脑组织中仍然存在。磁共振成像参数可预测白质组织病理学参数。
