Objective To analyze the MRI findings of the optic chiasmal lesions, and to evaluate the value of MRI in demonstrating the optic chiasmal lesions. Methods MRI findings in 117 cases of optic chiasmal lesions confirmed by clinical data or pathology were analyzed retrospectively. There were 54 males and 63 females, with the age from 9 months to 67 years, mean 37.4 years. Results There were 24 (20.5%) cases with direct involvement of the optic chiasms. 11 of them were gliomas of the optic chiasm which showed enlargement or mass of the optic chiasms with involvement of optic nerves and/or optic tracts. Diffuse enlargement of optic chiasm with inflammation of adjacent structures, particularly meninges, was found in 5 cases of inflammation. Metastases were found in 5 cases, of which optic chiasm involved by retinoblastoma spreading along optic nerves were found in 4 cases, and linear enhancement of optic chiasm was found in 1 case. Circumscribed enhancement of the optic chiasm with mass of optic nerve was found in 1 meningioma. Abnormal shape of optic chiasm with encephalomalacia of the frontal lobe was found in 1 case of trauma. Irregular enlargement of the optic chiasm showing short T 1 and long T 2 signal was found in 1 case of intrachiasmal hemorrhage. The displacement of the optic chiasms compressed by the lesions arising from adjacent structures was revealed on MRI in 93 (79.5%) cases. Of which superior displacement of the optic chiasms was found in 51 patients, anterior displacement in 2 cases, inferior displacement in 10 cases, and posterior displacement in 1 patient. Only one aspect of the optic chiasms was compressed by the lesions in 13 cases, and the optic chiasms were poorly defined in 16 patients. Conclusion MRI could accurately show the optic chiasmal lesions, which could contribute to clinical diagnosis and treatment.

Objective To evaluate the clinical application of diffusion-weighted MR of low field in hypera-cute cerebral infarction. Methods Conventional MRI and DWI on 0.35T were performed in 15 patients with highly suspicious hyperacute infarction within 6 hours after presenting symptoms. The coincidence between conventional MRI ,DWI and final clinical diagnosis was analyzed to compare the sensitivity and specificity of diagnosis among DWI,ADC and conventional MRI. Results 12 patients were diagnosed as hyperacute cerebral infarction, identical with final clinical diagnosis. 3 patients were negative on DWI ,who were finally diagnosed as TIA by clinical doctors.The high-intensity zone on DWI appeared infarction in following CT or MRI examination. The sensitivity and speci-ficity of DWI were both 100% ,and those of conventional MRI was 20% and 100% ,respectively. The infarctional region on DWI appeared high intensity and it was in low intensity on ADC maps. Conclusion DWI combined with ADC maps can be an important index in the diagnosis of hyperacute cerebral infarction. Its accuracy for diagnosis was high, which provides objective proofs for early clinical thrombolysis treatment.

Objective To assess the value of MRI combined with CT in the diagnosis of ovarian sex cord stromal tumor (OSCST).Methods The CT and MRI features of 29 cases with OSCST confirmed by pathology were analyzed retrospectively.Results Fibrothecoma in 19 cases showed a solitary round mass with a regular border,solid in 12 cases (63.1％) and cystic-solid in 7 cases (36.9％),calcification in 2 cases,isointense on T1WI and hypointense or slight hyperintense on T2WI with slight enhancement.Granule cell tumor in 9 cases showed a solitary cystic solid mass with thick wall,without nodules on cystic wall,and slight enhancement in the solid parts.Sertoli-leydig cell tumor in 1 case showed a solid mass,slightly hyperintense on T1WI,hyperintense on T2 WI,and obvious enhancement.Conclusion CT and MRI manifestations of OSCST demonstrate some characteristics.Combination with MRI and CT can improve the accuracy of the diagnosis.

Objective To investigate the CT findings of histocyticnecrotizing lymphadenitis(HNL)in the neck.Methods CT data of 10 patients with pathologically confirmed HNL in the neck were retrospectively analyzed,7 males and 3 females,aged from 4 to 75 years old(median age 26 years old).Nine patients had plain CT scans and 5 of them had contrast scans.One case had only contrast CT scan.Results Totally,127 lymph nodes were identified in the neck,mainly located in the area of Ⅱ,Ⅲ,Ⅳ and Ⅴ.The maximum diameter of the involved lymph nodes ranged from 0.5-3.6 cm,1.3 cm in average.One hundred and eight lymph nodes were homogeneous and 8 were heterogeneous in plain CT images.Seventy nine lymph nodes had homogeneous enhancement and 27 had heterogeneous enhancement One hundred and ten lymph nodes had unclear margins and the surrounding fat was blurred.Conclusion CT findings of HNL of the neck are variable and non-specific.Clinical findings and laboratory examination may be helpful for the diagnosis and differential diagnosis.

Objective To explore the clinical features,diagnoses,differential diagnoses and treatments of superior cerebellar artery aneurysms.Methods The clinical data of 16 patients with superior cerebellar artery aneurysms,admitted to our hospital from January 2013 to March 2018,were retrospectively collected.Their clinical manifestations,imaging features,surgical effects and related problems in the process of diagnoses and treatments were analyzed.Results Among the 16 patients,11 were caused by aneurysm rupture;8 had subarachnoid hemorrhage alone,and three had subarachnoid hemorrhage accompanied by ventricular hemorrhage;CT and CTA confirmed that 8 were superior cerebellar artery aneurysms,two were posterior cerebral artery aneurysms,and one was with unclear diagnosis.In the other 5 patients,three had eyelid ptosis and two had abducent nerve palsy;CT,CTA or MR imaging showed that two were considered as ventral brainstem occupying lesions,and three did not have clear diagnosis.Finally,all patients were diagnosed as having superior cerebellar artery aneurysms by three-dimensional DSA.Five patients were treated with interventional embolization first,and one was treated with surgical clipping because of vertebral artery stenosis and difficulty of catheter access;two patients were transferred to our department for surgical clipping due to aneurysm rupture after embolization treatment in other hospitals;and 9 patients were treated by surgical clipping directly.After treatments,one patient was in bed for a long time due to cerebellar infarction and systemic complications,and the other 15 patients recovered well;two of them underwent ventricular peritoneal shunt due to hydrocephalus.Conclusions Superior cerebellar artery aneurysm has onset of subarachnoid hemorrhage mostly,and oculomotor and abductor nerve paralysis,and space occupying manifestation around the brainstem sometimes.For patients with suspicious posterior circulation aneurysms whose diagnosis or location are unclear,three-dimensional DSA examination should be performed early to confirm the diagnosis.Treatment should be taken as soon as possible once the superior cerebellar artery aneurysm is defined.Interventional embolization may be the first choice,but it is necessary to master the methods of surgical clipping in order to treat the disease timely.