MRI诊断儿童下丘脑错构瘤

MRI diagnosis of hypothalamic hamartomas in children

目的总结儿童下丘脑错构瘤的典型与非典型MRI表现,旨在提高对该病的诊断水平。方法回顾性分析18例经临床病理证实的下丘脑错构瘤的临床及影像学表现。男12例,女6例,年龄1～15岁,平均5.6±3.8岁。14例临床表现为性早熟,7例表现为痴笑样癫痫。18例患儿均行MRI矢状面T1WI、T2WI和冠状面T1WI平扫,矢状面和冠状面T1WI增强扫描。结果具有典型表现者8例,即肿块位于垂体柄与乳头体之间,呈圆形或椭圆形,T1WI等信号,与脑灰质信号一致,T2WI等信号或稍高信号,信号均匀,增强后无强化。不典型表现者10例,其中信号典型而发病部位不典型者有3例:1例位于鞍背后部,1例跨视交叉生长,1例位于乳头体上方;7例为发病部位典型而信号不典型,T1WI表现为低或等低混杂信号,T2WI为高或高低混杂信号。结论对于发病部位及MRI信号特征均典型的下丘脑错构瘤,诊断不难;对发病部位典型MRI信号不典型或发病部位不典型而MRI信号典型的患者,结合其特征性临床表现即性早熟或痴笑样癫痫,可作出正确诊断。

Objective： To sum up the typical or atypical MR imaging features of hypothalamic hamartoma and improve the diagnostic level of this disease. Materials and Methods： Eighteen cases of hypothalamic hamartomas were conformed by pathology, 12 males and 6 females, aged 1-15 years, mean 5.6 ± 3.8 years. The clinical and MR imaging findings were retrospective analyzed. The clinic symptoms included precocious puberty （n=14） and gelastic epilepsy （n=7）. All patients were examined with sagittal T1 and T2 weighted imaging, coronal T1 weighted imaging, sagittal and coronal T1 weighted imaging enhancement. Results： Typical performance of 8 cases were round or oval mass located or between pituitary stalk and the mammillary body, 8 cases showed iso-intensity on T1 weighted imaging, similar with grey matter and slight hyper-intensity on T2 weighted imaging, On contrast MR scan, there was no enhancement in all cases. In 10 atypical cases, 3 cases were with atypical location but typical signal （1 case was behind the saddle department, 1 case grew across the optic chiasm, 1 case was above the mammillary body）; 7 cases were with typical location but atypical signal, they showed hypo-intensity or mixed intensity on T1 weighted imaging and hyper-intensity or mixed intensity on T2 weighted imaging. Conclusion It is not difficult to diagnose the hypothalamic hamartoma with typical location and MRI signal characteristics, when MRi signal or the location of lesions is not typical, combined with its clinical features that precocious puberty or gelastic epilepsy, a correct diagnosis may be achieved.