MR在遗传性脊髓小脑共济失调中的应用(附一家系报道)

The Application of MRI in Hereditary Spinocerebellar Ataxia

目的观察遗传性脊髓小脑共济失调(spinocerebellar ataxia,SCA)的MR表现,初步探讨MR在其诊断中的应用价值。资料与方法一SCA家系2名患病者及4名表现正常的其他家庭成员共6人行头颅MR常规扫描及小脑蚓部单体素1H磁共振波谱(MRS)扫描,2名SCA患者行磁共振扩散张量成像(DTI)。观察中枢神经系统的形态及信号特点,DTI彩色FA图上脑桥横向纤维显示的完整性及MRS小脑蚓部NAA/Cr比值和Cho/Cr比值。结果2名SCA患者小脑蚓部及双侧小脑半球轻度萎缩,T2WI连续两层面脑桥基底部隐约可见中线稍高信号,小脑上脚层面DTI彩色FA图脑桥横向纤维显示不完整、不连续,小脑蚓部NAA/Cr比值略低于参考值范围。1名有轻微体征及1名表现正常的的家庭成员NAA/Cr比值在参考值范围内偏低水平,另2名表现正常的家庭成员NAA/Cr比值接近参考平均值。所有家庭成员Cho/Cr比值均在参考值范围内。结论MR多种检查技术可以反映SCA的主要病理改变,为其诊断提供多种有力依据。

Objective To describe the MRI findings of spinocerebellar ataxia （SCA） and discuss the value of MRI in the diagnostic of SCA. Materials and Methods Two sufferers and four other asymptomatic members of a same family with SCA were performed brain routine MRI and single-voxel 1^H-MR spectroscopy （MRS） with a stimulated echo acquisitionmode sequence （STEAM） in the cerebellar vermis. The two sufferers were performed diffusion tensor imaging （DTI）. The shape and signal intensity of the central nervous system were observed. The integrality of the transverse pontine fibers were showed on the DTI colour FA images and the NAA/Cr rates and Cho/Cr rates of the cerebellar vermis were calculated. Results The cerebellar vermis and bilateral cerebellar hemispheres of the two sufferers from SCA were atrophic, more obviously in the vermis. Midline high signal intensity was demonstrated in the pontine base on two consecutive T2WI in the two sufferers from SCA. The transverse pontine fibers showed incompletely on DTI colour FA image at the level of superior cerebellar peduncle in the two sufferers from SCA. The NAA/Cr rates in the cerebellar vermis were mildly decreased in the two sufferers from SCA, compared with the reference value, and were on the low side of the reference value in one family member with mild physical sign and one asymptomatic family member. In other two asymptomatic family members, the NAA/Cr rates in the cerebellar vermis were close to the average of the reference value. The Cho/Cr rates in the cerebellar vermis were in the range of the reference value in all the family members. Conclusion Various of MRI techniques might reflect the main pathologic findings of SCA, and can provide clues as to the diagnosis of SCA.