脑裂头蚴病的CT和MRI诊断(附5例报告)

Diagnosis of cerebral sparganosis on CT and MRI

目的 回顾分析了5例脑裂头蚴病患者的CT和MRI表现,并结合文献提出了影像学诊断的初步意见。方法 5例患者临床症状主要表现为癫痫发作伴一侧肢体无力等,且病程多在半年以上。患者均接受了CT、MRI、血清免疫学(比色ELISA法)检查,以及CT引导下的立体定向切除术。结果 CT和MRI平扫均显示病变区域脑组织为大片不规则的低密度或混杂信号改变,且占位效应轻微,增强检查示病灶内小结节状、小环状或粗细不均的条带状显著强化灶。患者血清免疫检查均显示裂头蚴抗体阳性,血及脑脊液常规则无异常。手术切除了孟氏裂头蚴活幼虫和包裹着的变性虫体各一条,5例病变组织术后病理均显示了嗜酸细胞性脓肿并外围肉芽肿形成。结论脑裂头蚴病的CT和MRI表现具有特征性,其中MRI具有较高的诊断价值。血清免疫学检查及立体定向手术,则有助于明确诊断和彻底根治脑裂头蚴病。

Objective To retrospectively analyzed cerebral sparganosis appearances and characteristic findings suggested on CT and MRI. Methods 5 cases of cerebral sparganosis treated at our Hospital between March 2001 and May 2003. The patients ranged from 30 to 80 years (median 41 years). Seizures with paraparesis were their main signs. Diagnosis was based on radiological findings, serological test results, operative findings, and histopathological ex-aminations. Results Characteristic findings eonsisted of local white matter degeneration and mixedsignal lesion (low or identical in the central and high in the peripheral regions T2 - weighted images) with irregular nodular dense en-hancement of central foci in five, and changes in the location and shape of the enhancing lesion in follow-up studies on magnetic resonance (MR) in one. The enzymelinked immunosorbent assay for antisparganum antibody was positive in all. A live worm with surrounding granulomatous tissue was removed in one, and degenerative worm with surrounding granuloma complete removed in four. Examination of the resected lesion revealed the characteristic plerocercoid larva, enclosed in inflammatory exudate, resembling an abscess. Conclusion Characteristic findings of cerebral sparganosis may observed on CT and MRI, and MRI is superior to CT scan in the evaluation of cerebral sparganosis and is nearly diagnostic. Removal of granuloma together with worms, whether they are alive or degenerative, is the treatment of choice.