苯丙酮尿症儿童脑部病变常规MRI及^1H-MRS研究

Diagnostic Value of Conventional MRI and ~1H-MRS in Brain Lesions Caused by PKU in Children

目的采用磁共振质子波谱成像(1H-MRS)研究苯丙酮尿症(phenylketonuria,PKU)患儿脑白质内病灶的代谢特点,并观察不同白质病变区代谢的变化。资料与方法对8例临床确诊的PKU患儿及性别、年龄相匹配的8名健康儿童(对照组)分别行T1WI自旋回波序列(SE)、T2WI快速自旋回波序列(FSE)及液体衰减反转恢复序列(FLAIR)检查。1H-MRS检查选择侧脑室后角T2WI异常信号区及放射冠正常白质为兴趣区(ROI),测量1H-MRS谱线上氮-乙酰天门冬氨酸(NAA)、胆碱(Cho)及肌酸(Cr)等主要共振峰的面积,并计算下列化合物的比值:NAA/Cr、Cho/Cr、1000*NAA(Cho、Cr)/H2O。结果在T2WI上,所有未经治疗的PKU患儿侧脑室后角周围白质均可见非占位性、斑片状、条带状高信号。1H-MRS显示未经治疗及治疗后PKU白质异常区及放射冠诸代谢产物与正常对照组差异无统计学意义(P>0.05)。结论 MRS可作为无创性研究PKU病理生理过程的方法。

Objective To investigate the features of conventional MRI and 1H-MRS in the brain lesions caused by PKU in children.Materials and Methods Eight patients with PKU and 8 age-and sex-matched health volunteers underwent MRI,included T1WI,T2WI,fluid-attenuated inversion recovery（FLAIR）,and 1H-MRS examination.The white matter around the posterior horn of lateral ventricle and in coronal radiation were selected as region of interest（ROI）.Cerebral metabolites,included choline/cretine,NAA/cretine,in the ROI were calculated.Results Patchy areas of hyper intensity signal on T2WI were located symmetrically in the parieto-occipital white matter in all untreated PKU.MRS metabolites in the ROI had no significant difference between PKU patients and controls（P〉0.05）.Conclusion 1H-MRS as a noninvasive method can indicate the neuronal damage in lesions,and help to understand the pathophysiological process of PKU.