前脑发育异常的CT表现(附5例分析)

CT findings of prosencephalic anomaly

目的 :分析前脑发育异常的CT表现。方法 :回顾分析经CT检查发现的 5例前脑发育异常 ,4例为前脑无裂畸形 (其中 3例为半分叶型 ,1例为分叶型 ) ,1例为视 隔发育不良。结果 :在 3例半分叶型前脑无裂畸形中 ,端脑灰质团块不分裂者无侧脑室前角形成 ;分裂不全者前角狭长 ;分裂完全者前角呈方形、前缘平。其中 1例增强扫描中发现单一大脑前动脉和呈横带状跨中线后部行走的脉络丛。 1例前脑无裂畸形类似于视 隔发育不良 ,因第三脑室形成不良而归类于分叶型前脑无裂畸形。 1例视 隔发育不良表现为透明隔缺如伴侧脑室前角发育不良。结论 :CT检查可以清楚地把前脑发育异常的结构显示出来 ,具有很高的诊断价值。根据端脑灰质团块分裂和前角形成的程度可判断畸形的严重程度。增强扫描有利于对前脑无裂畸形中所伴随的颅内血管结构和脉络丛异常的观察。

Objective:To analyze the CT findings of prosencephalic anomaly.Methods:CT findings of five patients with prosencephalic anomaly were retrespectively analyzed. Of these five patients,1 case was septooptic dysplasia and 4 cases were holoprosencephaly,including 3 cases with semilobar holoprosencephaly and 1 case with lobar holoprosencephaly.Results:In one of 3 cases with semilobar holoprosencephaly,the anterior horns of lateral ventricles were absent without cleavage of the central gray matter of the telencephalon. Another case showed a long and narrow anterior horn with incomplete cleavage. In the third case with complete cleavage,the anterior horn tended to be square shaped.In one of these three cases with hemilobar holoprosencephaly,the single anterior cerebral artery was found in anterior interhemispheric fissure,and the choroid plexus of both sides was found not separated and crossed over in posterior part of the brain in post contrast CT scanning. One case with septooptic dysplasia showed absence of septum pellucidum and dysplasia of the antertior horns of lateral ventricles.Conclusion:CT scanning can show the abnormal structures of prosencephalic anomaly clearly,and is valuable in the diagnosis. According to the degree of seperation of the telencephalic grey matter and formation of the anterior horns,severity of the malformation can be estimated. Postcontrat scanning is helpful in observing the abnormal structures of vessels and choroid plexus.