Objective To evaluate the characteristic appearance and diagnosis value of central neurocytoma on magnetic resonance imaging (MRI).Methods MRI data of 9 patients with central neurocytoma confirmed surgically and pathologically were retrospectively reviewed.Results All the lesions located in the lateral ventricle septum pellucidum,adjacent to Monro hole,in the anterior 1/3 to 2/3 of the lateral ventricle.Most of them were irregularity,sublobe and sharpness of border.They presented as inhomogeneous intense signal on MRI,with slight to equal enhancement on enhancement.DWI could be high or slightly high signal.Conclusion Central neurocytoma has the characteristic appearances on MRI,being helpful to the diagnosis.

Objective To study the multi-detector spiral CT (MDCT) features of pancreatic tuberculosis to improve the awareness and correct diagnosis. Methods Imaging features of MDCT were retrospectively reviewed on 9 cases with pancreatic tuberculosis that were diagnosed from 2003 to 2009, among them two patients underwent MDCT angiography, the features were compared with those of operative and pathological findings. Results One case of pancreatic cancer, 2 cases of cystadenocarcinoma and 1 case of pseudocyst, 2 cases of pancreatic cancer with retroperitoneal lymph node metastasis, 2 cases of lymphoma were diagnosed by MDCT, and all the lesions were diagnosed as pancreatic tuberculosis pathologically, and the misdiagnosis rate was 100%. Pancreatic tuberculosis often presented as pancreatic head mass, sometimes pancreatic body and tail were involved. MDCT showed isopycnic or low density solid-cyst mass, occasionally calcification was present, with slightly or moderate ring-like enhancement after contrast injection. There was no enlargement of the pancreatic duct. The retroperitoneal and adjacent lymph nodes were always enlarged with ring-like enhancement. Sometimes there was evidence of tuberculosis of other abdominal organs. Conclusions Ring-like enhanced lesions with ring-like enhanced lymph nodes without enlargement of pancreatic duct are characteristic MDCT features of pancreatic tuberculosis.

Objective To assess the effect of iDose4 in image quality and radiation dosage in CT angiography of craniocervical arteries.Methods Imaging data of 50 patients with 256-slice spiral CT angiography of craniocervical arteries were randomly divided into two groups:(A) 120 kV,250 mAs (25 patients),(B) iDose4 100 kV,180 mAs (25 patients).Dose length product (DLP) of the two groups were compared.Objective image noise was compared by two blinded readers,t test and nonparametric tests were used for statistical analysis.Results The overall image quality score of group A (3 points =1 patient,4 points =6 patients and 5 points =18 patients) and group B (4 points =5 patients and 5 points =20 patients) were shown.The image noise of group A (1 point =1 patient,2 points =5 patients and3 points =19 patients) and group B (2 points =4 patients,3 points =21 patients) were also evaluated.There was no statistical difference in revealing rate of image quality scores and objective noise between the two groups (Z =-0.334,-0.218,P ＞ 0.05).The estimated effective radiation dose was reduced by 56％ in group B than in group A.DLP was significantly lower in group B [(642.4 ±36.6) mGy · cm]than in group A [(1462.1 ± 64.3) mGy · cm].Conclusion Low dose contrast medium of CT angiography can display craniocervical arteries and the intracranial arteries very well with high image quality.

Objective:To investigate the specific chest computed tomography(CT) features of corona virus disease 2019 (COVID-19) and to evaluate its clinical diagnostic value.Methods:The clinical data of 35 cases with suspected COVID-19 from Shanghai Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine and Shanghai East Hospital Affiliated to Tongji University from January 1 to February 14, 2020 were retrospectively analyzed. A total of 17 cases with positive results of two times of real time polymerase chain reaction (RT-PCR) for 2019 novel coronavirus (2019-nCoV) were evaluated as the case group, and the remaining 18 cases with negative results of two times of RT-PCR for 2019-nCoV were evaluated as the control group. The features of chest CT images of 35 cases were obtained. The frequencies of four CT imaging indicators including ground glass opacities (GGO), crazy paving, heterogeneous consolidation and mutiple subpleural lesions were analyzed. The sensitivity, specificity, positive predictive values (PPV) and negative predictive value (NPV) for COVID-19 were calculated.Results:In the case group, there were 11 cases with GGO, seven cases with crazy paving, six cases with heterogeneous consolidation, and 16 cases with mutiple subpleural lesions, while in the control group, there were seven cases with GGO, one case with crazy paving, six cases with heterogeneous consolidation, and five cases with mutiple subpleural lesions. When multiple subpleural lesions or any two of the CT imaging indicators were used as the characteristic indicators, the diagnosis efficiencies were better, with the sensitivity, specificity, PPV, NPV and Youden index of 94.12%, 72.22%, 76.19%, 98.86% and 0.66, respectively, and 88.24%, 77.78%, 78.95%, 87.50% and 0.66, respectively.Conclusions:Chest CT indictors are of high clinical diagnostic value for COVID-19. Any two of the four CT indicators (GGO, crazy paving, heterogeneous consolidation and mutiple subpleural lesions) or the single characteristics (mutiple subpleural lesions) are of high diagnostic efficacy.