磁共振成像在肾上腺脑白质营养不良诊断中的应用

Application of magnetic resonance images in patients with adrenoleukodystrophy

目的探讨氢质子磁共振波谱成像（1H-MRSI）和弥散张量成像（DTI）在肾上腺脑白质营养不良（ALD）诊断中的价值，并应用弥散张量白质纤维束追踪成像（DTT）技术显示ALD纤维束受累情况。方法对6例ALD患者行。H—MRSI、DTI和常规影像学检查，比较不同病变区域N-乙酰天冬氨酸（NAA）、胆碱复合物（Cho）、肌酐（Cr）、表观扩散系数（ADC）和各向异性分量（FA）的变化及相关性，选择胼胝体和锥体束进行白质纤维束成像。结果病变起始区域NAA／Cr比值（0．55±0．19），NAA／Cho比值（0．22±0．11）降低（F=7．693、7．751），Cho／Cr比值（2．54±0．37）升高（F=6．348），ADC值最高（1．49±0．36，F=5．226），FA值最低（0．21±0．08，F=5．139，均P〈0．05）；病变区域近周NAA／Cr比值（1．16±0．03）和NAA／Cho比值（0．45±0．17）降低较远周明显（t=1．769、1．842，P〈0．05）；病变发展区域ADC值（0．89±0．03）低，FA值（0．45±0．07）最高；NAA／Cho与ADC负相关（r=-0．71，P〈0．05），与FA正相关（r=0．31，P〈0．05）；DTT结果显示病变区域胼胝体和锥体束均受累，走行中断或呈不连续碎片样。结论1H—MRSI和DTI为ALD提供了更多的早期诊断依据，并且可动态监测脑白质病变进展，DTT可直接显示ALD患者纤维束受累情况。

Objective To explore the role of proton MR spectroscopic imaging （1H-MRSI） and diffusion tensor imaging （DTI） in the diagnosis of adrenoleukodystrophy and to demonstrate the involvement of fibers by using the technique of DTT. Methods 1H-MRSI, DTI and routine imaging examinations were performed in 6 patients with ALD. The values of NAA, Cho, Cr, ADC, and FA were evaluated in different regions of lesion. The involved fibers were demonstrated by using the technique of DTT. Results The ratios of NAA/Cr （0.55±0. 19） and NAA/Cho （0.22 ±0. 11） were lower （F=7.693, 7.751）, and Cho/Cr （ 2. 54 ±0. 37 ） was higher （ F = 6. 348 ） in the initial lesions, where higher ADC values （ 1.49± 0. 36, F = 5. 226） and the lowest FA values （ 0. 21 ± 0. 08, F = 5. 139 ） were also observed （ P 〈 0. 05 ）. The decreases of NAA/Cr （1.16±0. 03） and NAA/Cho （0. 45 ±0. 17） in adjacent regions were more distinct than those of remote regions （t = 1. 769, 1. 842, P 〈 0. 05）. In the developing regions, the ADC values （0. 89 ± 0. 03 ） were lower and the FA values （0.45 ± 0. 07 ） were the highest. There was negative correlation between NAA/Cho and ADC values （r = -0. 71, P 〈0.05）, and there was positive correlation between NAA/Cho and FA values （ r = 0. 31, P 〈 0. 05 ）. Discontinuations and fragments of fibres were observed in corpus callosum and pyramidal tract. Conclusions Combination of 1 H-MRSI and DTI can offer a sensitive method for the early diagnosis and monitor the progress of white matter. DTT can be used to directly observe the involvement of fibers.