Purpose:Cerebral sparganosis is a rare parasitic infection of tapeworm larva from the genus of Spirometra in central nervous system, which is quite difficult to diagnose from other space-occupying lesions in the brain , brain abscess and other parasitic granulomatous cerebrates, such as paragonimiasis, toxoplasmic encephalitis. In China , the disease mainly prevails in the coastal area of Zhejiang ,Fujian ,Guangdong and Guangxi provinces ,with the highest incidence of Guangdong province. For human being ,there are several pathways of infection. Some patients ingested either uncooked or improperly cooked frog , snake and or crabs . Patients could also get infested by cyclops-polluted water. In this study, we summarized the MRI characteristics of 16 patients with cerebral sparganosis and did a follow-up in order to improve its diagnosis . Methods: In our studies ,the patients with cerebral sparganosis were presented with seizures , hemiparesis , dizziness and altered mental status, which lack of specificity . 16 patients with cerebral sparganosis received MRI scans before cinically verified and in the follow-up . The all findings were retrospectively investigated. Siemens Magnrtom3.0T TrioTim scanner with a quadrature head coil was used .9 patients received MRI scan with the same protocol during follow-up , ranging from 1-34 months after the initial scans . Results: Among 16 patients with verified cerebral sparganosis ,11were males and 5 were females with average age of 27 year-old (10-54 year-old ). 28 lesions were found in the 16 patients. Lesions were solitary in 6 patients , and multiple and asymmetrical in other 10 patients . The locations of these lesions were as follows : 24 in cerebral hemisphere, 2 in cerebellar hemisphere and 2 in brain stem . The lesions were mainly presented with abnormal signal of patchy shadow as slight hypointensity on T1W1, moderate hyperintense on T2W1 and hyperintense on FLAIR , surrounded by perilesional brain parenchyma edema but no remarkable occupied effect . Mixed intensity were presented in 4 cases with irregular patchy of hypointensity inside the hyperintensity lesions .Enhanced MRI showed characteristic patterns of a peripheral ring, or a tortuous beaded, or a serpiginous tubular shape ,or multiple enhancements tangled as “clinch”. Among those 9 patients who received follow-up MRI scans during follow-up ranging from 1-34 months from initial scan , 3 patients were presented with changed morphology of lesion enhancement , 2 patients with changed locations of lesions , 2 patients with increased numbers of lesions, and 2 patients with lesion vanished , and 2 cases with no obvious changes of lesions . Conclusions:Recent publications demonstrated that imaging technique , particularly MRI has become an useful tool to diagnose this rare disease at its early stage . Other than serum tests , MRI could provide additional information to the diagnosis of cerebral sparganosis . The following is a summary of MRI characteristics of cerebral sparganosis. First , a serpiginous tubular, a beaded or a tortuous beaded enhancements of the lesions may be present in the images, due to twisting of the worm bodies , which might be of great significance in differential diagnosis with other similar diseases . Second , by comparison between initial and followup MRI scans , we could infer that the sparganum can survive for a long time and migrate from one area to another , which could cause local inflammation progression and metastatic multiple lesions simultaneously or chronol ogically . Third , the lesions were present with obvious perilesional edema in brain parenchyma but without remarkable mass effect . Long survival of sparganum and its resultant long-term inflammation could lead to brain atrophy and dilation of ventricular systrm. If the above characteristics of cerebral spargnosis emerge in the MR images, then the disease should be considered. Then, ELISA should be appled to further test cerebrospinal fluid and blood serum for sparganum antibodies to reach a final diagnosis. MRI and serological tests are the most important methods for the clinical diagnosis of cerebral sparganosis .