目的探讨遗传性痉挛性截瘫(hereditary spastic paraplegia,HSP)伴薄型胼胝体的颅脑和脊髓MRI特征,以期提高对该病的认识。方法回顾性分析5个家系8例临床和遗传学确诊为HSP伴薄型胼胝体患者的颅脑和脊髓MRI资料。分析每例患者的MRI特点,并分别测量胼胝体膝部、体部和压部的厚度,分别在C3和T2水平测量相应平面脊髓的前后径及横径,另选取20例在本院行颅脑平扫MRI及颈椎MRI的正常病例为对照组进行相应测量方法进行比较。结果 8例颅脑MRI均表现为胼胝体变薄,以膝部和体部明显,分别为(2.2±1.6)mm、(2.0±0.9)mm,与正常对照组比较差异有统计学意义(P<0.05);胼胝体压部未见明显变薄(P>0.05);C3、T2脊髓的前后径、横径明显小于对照组(P<0.05)。8例均出现双侧脑室周围白质内及额顶叶深部脑白质对称性异常信号灶,液体衰减反转恢复序列(FLAIR)呈高信号。7例有脑萎缩,7例有颈胸段脊髓萎缩且其中1例胸髓末段显示异常信号灶。结论 HSP伴薄型胼胝体的颅脑和脊髓具有典型的MRI特点,主要表现为胼胝体膝部及体部变薄、脑萎缩、侧脑室周围脑白质内及额顶叶深部脑白质对称性异常信号灶及脊髓萎缩。MRI对临床诊断和鉴别诊断有重要意义,但确诊还需结合临床表现和基因检查。 Objective To investigate the MRI features of hereditary spastic paraplegia (HSP) with thin corpus callosum in the brain and spinal cord in order to improve the understanding of the disease. Methods We retrospectively analyzed MRI data of 8 cases of brain and spinal cord from 8 pediatric patients with clinically and genetically diagnosed HSP with thin corpus callosum. The MRI features of each patient were analyzed. The thickness of the corpus callosum knee, body and pressure were measured respectively. The anteroposterior diameter and transverse diameter of the corresponding planar spinal cord were measured at C3 and T2 respectively. Twenty patients Plain MRI and cervical MRI of the normal cases for the control group for the corresponding measurement methods were compared. Results All 8 craniocerebral lesions showed thinning of the corpus callosum, which were significantly (2.2 ± 1.6) mm and (2.0 ± 0.9) mm respectively in the knee and body, which were significantly different from those in the normal control group (P < 0.05). There was no obvious thinning of the corpus callosum (P> 0.05). The anteroposterior diameter and diameter of the C3 and T2 spinal cord were significantly smaller than those of the control group (P <0.05). In all 8 cases, bilateral symmetry abnormalities were found in the white matter and the parietal lobe of deep parietal lobe. FLAIR showed high signal intensity. 7 cases had brain atrophy, 7 cases had neck thoracic spinal cord atrophy and 1 case had abnormal signal foci in the distal segment of the thoracic cavity. Conclusions HSP and thin corpus callosum have typical MRI features of the brain and spinal cord. The main manifestations are thinning of the knee and body of the corpus callosum, brain atrophy, abnormal white matter lesions in the white matter around the lateral ventricle and deep parietal lobe, Spinal cord atrophy. MRI is of great significance for clinical diagnosis and differential diagnosis, but the diagnosis also need to combine clinical manifestations and genetic tests.