ObjectiveTo describe the MR features of Rasmussen encephalitis (RE).Methods The MRI of 10 pathologic confirmed patients (7 male,3 female,mean age 11 ± 4 years) with RE were retrospectively analyzed in this study.Routine axial,sagittal and coronal (perpendicular to the oblique long axis of the hippocampus) scans were obtained for T1WI,T2WI and fluid-attenuated inversion recovery (FLAIR)images. The location and degree of cerebral atrophy,gray matter signal changes,and the evolution of these findings were evaluated. Results Brain atrophy included the enlargement of lateral ventricle(8/10),temporal horn (9/10)and lateral fissure (9/10); widened sulci and small gyri in the isolateral hemisphere (7/10) ; atrophy in caudate and putamen nucleus (6/10).The cortical atrophy was extensive at late stage of the RE,and usually was hemispheric or involved more than two lobes.The signal changes included hyperintensity involving extensive cortical and/or subcortical regions (9/10). The follow-up MR study demonstrated the progression of brain atrophy and extensive signal changes.Conclusions RE usually presents in pediatric patients. The imaging findings included progressive unilateral brain atrophy,enlargement of lateral ventricle,lateral fissure and sulci,and small gyri with or without cortical T2hyperintensity.Deep nucleus atrophy may be involved in RE.

Objective To discuss the diagnostic value of multi-slice spiral CT (MSCT) in distinguishing the severe acute respiratory syndrome (SARS) from community acquired pneumonia (CAP), and to evaluate the prognosis in these two groups. Methods A retrospective study was performed on 64 cases with SARS (28 men, 36 women, aged 18-93 yrs, mean age 42.3 yrs) and 46 inpatients with CAP (29 men,17 women, aged 28-88 yrs, mean age 70.1 yrs). Pathogens of respiratory tract were found in 23 patients of CAP. All of patients underwent MSCT scanning of the chest. Results The sensitivity, specificity, and accuracy for diagnosis of SARS using a combination of 3 factors, including ground-glass opacities of lung parenchyma in chest CT, age, and WBC counts were 93.8%, 60.9% and 80.0%, respectively. The sensitivity, specificity, and accuracy for excluding SARS using a combination of consolidation of lung lesions, fiber stripe components and thicken bronchus wall of lung CT in CAP patients were 91.3%, 82.8%, and 86.4%, respectively. The death in SARS and CAP was 7 (10.9%) and 4 (8.7%), respectively. The late follow-up results indicated that 48.8% (21/43 cases) of SARS cases left abnormal manifestations in the lung. The lung sequela of the patients over 50 yrs tended to be severe with the age. Conclusion In outbreak region of SARS, MSCT plays an important role in early diagnosis, but we need to closely combine the density features of lung lesions and other manifestations of lung with clinical condition of patients to increase the accuracy for the differential diagnosis of SARS from CAP. The prognosis of patients over 50 yrs with SARS is relatively poor.

Objective To determine MR manifestations and pathologic types of benign meningiomas and their relationship with tumor recurrence.Methods There were 218 patients (160 females,58 males; age range 4-79 years) with benign meningiomas in the study,including 31 recurrent meningiomas (recurrence group)and 187 primary meningiomas (primary group).All patients were proved by postoperative pathology.Differences of pathological types and MRI manifestations between the recurrence group and the primary group were evaluated by using x2 test and rank sum test.Logistic regression analysis was performed by taking tumor recurrence as the dependent variable,and age,gender,vital structures involvement and pathologic types as independent variables.The recurrent time intervals were compared by rank sum test.Results There were 30 patients with intracranial vital structures involvement or extreintracranial communication tumors in the recurrent group,which was obviously higher than that of the primary group (61 patients).The difference was statistically significant (x2 =57.672,P =0.001).The tumors located in the skull-base and juxtasinus in the recurrent group were obviously more than those in the primary group,and difference was statistically significant (x2 =10.990,P =0.001).Multi-logistic regression analysis showed that the recurrent risk of benign meningiomas was elevated significantly only with vital structure involvement or extre-intracranial communication tumors (wald x2 =31.863,OR =3.820,P =0.001).The recurrent risk of dural sinus involvement was 3.820 times of cerebral artery trunk and cranial nerves involvement,and the risk of the latter was 3.820 times of the non-involved.There was no statistical difference between the two groups in pathology type,location,peritumoral edema,tumor morphology and tumor size.The relapse time of dural sinus involvement and cerebral artery trunk involvement in the recurrent group was 24(13 to 180) and 126(12 to 187) months,respectively.There was significant difference (Z =2.197,P =0.028).Conclusions It is more common that the recurrent benign meningiomas located in the skull base and juxtasinus.The recurrent risk significantly increases when benign meningiomas with vital intracranial structure involved or with extra-intracranial communication tumor.The relapse time of dural sinus involvement is possibly shorter than that of cerebral artery trunk involvement.MRI plays an important role in predicting tumor recurrence and prognosis of benign meningiomas.

Objective To investigate the MRI classifications and imaging findings of dysembryoplastic neuroepithelial tumor(DNET). Methods MR images of 34 patients with pathologic confirmed DNET of Beijing Sanbo Brain Hospital were retrospectively reviewed in this study. The classification was made according to the number of pseudocysts, scope of involvement, morphology and location. Results MRI appearances of DNET were divided into three subtypes: cystic‐like, polycystic‐like and diffuse type. Twelve cases had cystic cortical, including front lobe (5 cases), temporal lobe (5 cases), parietal lobe (2 cases). These cases presented quasi‐circular or oval shape, with hypointense on T1WI and strongly hyperintense on T2WI. T2‐FLAIR was observed hyperintense ring sign in the tumor periphery and the cystic content was close to CSF but having the largest difference to that of CSF, which signal was higher than CSF. Twenty cases were polycystic‐like, front lobe (7 cases), temporal lobe (7 cases), parietal lobe (5 cases), occipital lobe (1 case). In these 20 cases, they had slightly hypointense on T1WI and strongly hyperintense on T2WI. Located in the cortex and subcortical matter, with wedge shape, gyriform or triangle shape.On T2‐FLAIR, internal septation and hyperintense"ring sign"were observed. Two cases were diffuse type, bilateral (1 case), unilateral (1 case). In these 2 cases, diffuse lesions involving multiple areas with hyperintense ring and internal septation on FLAIR, including subcortical white matter, deep nucleus and periventricular area. Conclusions The MR appearances of DNET are variable. Understanding the MR imaging type of DNET might improve the MR diagnosis of DNET.