Mascalchi Mario, Cosottini Mirco, Lolli Francesco, Salvi Fabrizio, Tessa Carlo, Macucci Marco, Tosetti Michela, Plasmati Rosaria, Ferlini Alessandra, Tassinari Carlo Alberto, Villari Natale
Section of Diagnostic Radiology, Department of Clinical Physiopathology, University of Florence, Viale Morgagni 85, 50134 Florence, Italy.
Radiology. 2002 May;223(2):371-8. doi: 10.1148/radiol.2232010722.
To investigate whether proton magnetic resonance (MR) spectroscopy is a useful complement to MR imaging in patients with degenerative ataxia.
Brain MR imaging and single-voxel proton MR spectroscopy of the right cerebellar hemisphere and pons were performed in 30 patients with sporadic (n = 16) or inherited (n = 14) degenerative ataxia and in 20 healthy control subjects. Several indexes of brainstem and cerebellar atrophy were measured on MR images, as well as the N-acetylaspartate/creatine (NAA/Cr), choline/Cr (Cho/Cr), and myo-inositol/Cr (mI/Cr) ratios in the MR spectra. Differences between patients and subjects were evaluated with the Kruskal-Wallis and Mann-Whitney tests, whereas correlation of clinical, MR imaging, and spectroscopic data was assessed with nonparametric Spearman rank correlation.
Measurements of brainstem and cerebellar atrophy obtained from MR images revealed patients had olivopontocerebellar atrophy (OPCA) (n = 11), spinal atrophy (SA) (n = 8), or corticocerebellar atrophy (CCA) (n = 4). Seven patients did not fulfill the criteria for any group and were considered undefined. In patients with OPCA, the pontine and cerebellar NAA/Cr and Cho/Cr ratios were significantly decreased when compared with those of the control subjects. Pontine and cerebellar NAA/Cr ratios were also significantly reduced in patients with SA and CCA. Five patients with undefined ataxia had a substantial decrease of pontine or cerebellar NAA/Cr ratio when compared with that of the control subjects. In patients with OPCA, the pontine NAA/Cr ratio (but not the atrophy measurements) showed a correlation (P =.04) with disability.
MR spectroscopy is a useful complement to MR imaging in patients with degenerative ataxia.
探讨质子磁共振（MR）波谱是否是退行性共济失调患者MR成像的有用补充。
对30例散发性（n = 16）或遗传性（n = 14）退行性共济失调患者及20名健康对照者进行了脑MR成像以及右侧小脑半球和脑桥的单体素质子MR波谱检查。在MR图像上测量了脑干和小脑萎缩的几个指标，以及MR波谱中的N-乙酰天门冬氨酸/肌酸（NAA/Cr）、胆碱/肌酸（Cho/Cr）和肌醇/肌酸（mI/Cr）比值。采用Kruskal-Wallis检验和Mann-Whitney检验评估患者与对照者之间的差异，而临床、MR成像和波谱数据的相关性则采用非参数Spearman等级相关性进行评估。
从MR图像获得的脑干和小脑萎缩测量结果显示，患者存在橄榄脑桥小脑萎缩（OPCA）（n = 11）、脊髓萎缩（SA）（n = 8）或皮质小脑萎缩（CCA）（n = 4）。7例患者不符合任何一组的标准，被视为未明确类型。与对照者相比，OPCA患者脑桥和小脑的NAA/Cr及Cho/Cr比值显著降低。SA和CCA患者脑桥和小脑的NAA/Cr比值也显著降低。5例未明确类型的共济失调患者与对照者相比，脑桥或小脑的NAA/Cr比值大幅降低。在OPCA患者中，脑桥NAA/Cr比值（而非萎缩测量值）与残疾程度存在相关性（P = 0.04）。
MR波谱是退行性共济失调患者MR成像的有用补充。
