Objective To improve the diagnostic value of MRI on orbital diseases,especially on benign and malignant tumors,through analyzing the characteristics of orbital diseases with dynamic contrast-enhanced MRI.Methods Forty-one patients with solitary orbital masses, including 31 benign tumors and 10 malignant tumors,underwent MR examinations. All the cases were verified by pathology.1.5 T MR system and head coil were employed.Conventional scan was performed with axial,sagittal,and coronal T_1WI,as well as axial T_2WI and the slice thickness of 4 mm.After the injection of contrast agents,dynamic contrast-enhanced MRI was immediately performed so as to observe dynamic changes of lesions.Enhancement rates(E%) was calculated and time-intensity curve was portraited according to the signal intensity of conventional scan and dynamic-contrast enhanced scan.SPASS Ver10.0 was used to do the statistical analysis,while cartographies were completed with Powerpoint.Results(1)Comparision between benign and malignant tumors in average enhanced rates of the 1~(st) minute: it was higher than 60% in malignant tumors,while lower than 60% in benign ones(P

Objective To study CT and MRI features and classification of brain schistosomiasis granuloma. Methods CT and MRI data of 30 cases of brain schistosomiasis granuloma were reviewed.All cases were proved by the surgery or pathological examination and clinical laboratory test.There were 20 males and 10 females, and their age ranged from 5 to 58 years, mean 29.2 years.Plain and enhanced CT were performed in all patients with GE MAX 640 scanner.Ten patients were examined by plain and enhanced MRI with GE Signa profile 0.2 Tesla open scanner.Results The lesions located in supratentorial region in 27 cases and in infratentorial region in 3cases.The nodules were isodense or slight hyperdense on CT plain scan, iso or hypointense on T_1WI, hyperintense on T_2WI, Slight hyperintense on FLAIR.After the contrast material was injected intravenously, CT and MRI findings were multiple or single enhanced nodules at the cortical or subcortical area.There were four types of imaging features: (1) multiple small nodules in 5 cases (presenting as bright stars in the dark sky); (2) single large nodule in 8 cases; (3) mixed nodules in 14 cases; (4) circle-enhanced nodules in 3 cases.Conclusion The brain schistosomiasis granuloma has typical CT and MRI findings.CT and MRI classification is not only helpful to its diagnosis and differential diagnosis, but also might be useful for the choice of clinical treatment.