COVID-19 is caused by a novel coronavirus-severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which has being spreading around the world, posing a serious threat to human health and lives. Neutralizing antibodies and small molecule inhibitors for virus replication cycle are the main antiviral treatment for novel coronavirus recommended in China. To further promote the rational use of antiviral therapy in clinical practice, the National Center for Infectious Diseases (Beijing Ditan Hospital Capital Medical University and the First Affiliated Hospital, Zhejiang University School of Medicine) invited experts in fields of infectious diseases, respiratory and intensive care to develop an Expert Consensus on Antiviral Therapy of COVID-19 based on the Diagnosis and Treatment Guideline for COVID-19 ( trial version 10) and experiences in the diagnosis and treatment of COVID-19 in China. The consensus is concise, practical and highly operable, hopefully it would improve the understanding of antiviral therapy for clinicians and provide suggestions for standardized medication in treatment of COVID-19.

Objective To investigate the MRI manifestations and diagnostic value of adenomatoid tumor (AT)of epididymis. Methods The MRI features of 5 patients with AT of epididymis were analyzed retrospectively,which were confirmed by histopathology,and some relevant medical literatures were reviewed.Results The epididymal tumor was manifested as moderate signal on T1 WI and T2 WI,similar to adjacent testicule,and as moderate signal with slightly high rim-enhancement on enhanced T1 WI in 4 cases.Secondary infarction and chronic granulomatous inflammation in 1 patient was found and presented unevenly moderate signal on T1 WI,slight hypointensity on T2 WI, hyperintensity on DWI and rim-enhancement on dynamic enhancement MRI.Few hydrocele was detected in all 5 patients.Conclusion AT of epididymis is a rare benign neoplasm with some characteristic MRI features which is helpful for the preoperative diagnosis.

Objective To study the thalamic metabolic alterations and its correlation with cognitive impairment in patients with cerebral small vessel disease(CSVD).Methods The cognitive function of 34 patients with CSVD and 26 matched volunteers were evaluated by Montreal cognitive assessment(MoCA), and received single voxel 1H-MRS examination to detect the content of NAA,Cho and Cr,and record the ratio of NAA/Cr and Cho/Cr on bilateral thalami.The differences of NAA/Cr, Cho/Cr on bilateral thalami between the two groups were compared, and the correlation between NAA/Cr,Cho/Cr and MoCA total score and its sub-items score in CSVD group were analyzed.Results ①The MoCA of total score as well as its sub-items such as visual space and executive ability,memory,attention and language for CSVD group were significantly lower than that for the control group(P<0.05);②NAA/Cr on bilateral thalami in CSVD group were both lower than that in the control group(left 1.57±0.18,1.68±0.17,t=2.46,P=0.02;right 1.66±0.21,1.78±0.19,t=2.23,P=0.03), the differences were statistically significant (P<0.05);there were no significantly differences in the ratio of Cho/Cr between the two groups(P>0.05);③In CSVD group, the ratio of NAA/Cr on both bilateral thalami were significantly positively correlated with MoCA score (left r=0.83,right r=0.79,P<0.05)as well as visual space and executive ability(left r=0.65,right r=0.46,P<0.05), memory(left r=0.59, right r=0.50, P<0.05), attention(left r=0.42, right r=0.52, P<0.05),language(left r=0.52, right r=0.41, P<0.05), abstraction(left r=0.47, right r=0.40, P<0.05), orientation(left r=0.48,right r=0.42, P<0.05),Cho/Cr were not significantly correlated with MoCA total score and its sub-items(P>0.05).Conclusion The thalamic neuron has been damaged and dysfunctioned in patients with CSVD,and this metabolic abnormality may be related to a wide range of cognitive impairment in CSVD patients.

Objective To investigate the feasibility of computer-aided pancreas segmentation based on three-dimensional (3D) Dixon MRI at 3.0-T.Methods Five volunteers with health pancreas underwent upper abdominal 3D Dixon MRI at 3.0T with the same scan parameters while holding breath.The automatic segmentation of pancreas is based on the Medical Imaging Interaction ToolKit (MITK) with homemade software.A experienced radiologist performed manual segmentation and computer aided segmentation of the pancreas on the opposed phase and water phase images twice.Similarity was analyzed and compared for the manual and automated segmentations for the two group images.Similarity was presented as Dice coefficients.Results Both of the oppose phase and water phase images of Dixon MRI showed that the signal intensity of pancreas was higher than that of the surrounding tissue,the similarity of water phase was obviously higher than that of oppose phase and the differences were statistically significant.Based on Dixon MRI water phase and oppose phase images,the mean dice coefficients for the manual segmentations were 0.81 ± 0.01 and 0.85 ±0.03,respectively,for both the oppose phase and water phase images (P=0.013).For the automated segmentations,the dice coefficients were 0.69 ± 0.08 and 0.75 ± 0.03 for water phase images and the oppose images,respectively,and the difference was not statistically significant (P =0.155).Conclusions 3.0T oppose phase and water phase of Dixon images could clearly show the pancreas,and automated pancreas segmentation based on water phase Dixon MRI obtained higher similarity,which was feasible.

Objective To assess the efficacy of dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) of the breast in the detection of residual lesions of early stage breast carcinoma after lumpectomy. Methods 53 patients with breast masses confirmed to be malignant tumors by pathology after lumpectomy underwent the dynamic contrast-enhanced breast MR imaging and then further surgical treatment by lumpectomy. The DCE MRI-based diagnoses were compared to the results of pathological analyses after the second lumpectomy. Results 17 (32%) cases were detected with abnormal enhancement. 8 cases presented mass-like enhancements , and 6 of them showed tumorous residuals (P < 0.01). 6 presented focal enhancements, taking up 35% and one of them was confirmed pathologically to have tumorous residuals (P < 0.01). 3 cases presented mass-like enhancement, taking up 18% and 2 of them were confirmed with cancerous residuals . MR dynamic enhancement showed 68% of the them presented no abnormal enhancements in the breast and 33 of themhad no residual cancer , taking up 92%. 3 of them were confirmed with tumorous residuals , taking up 8%. The The positive predictive value and negative predictive value of DCE MR imaging for diagnosing residual malignant lesion were 52% and 92%, respectively . Conclusion The dynamic contrast-enhanced MRI of breast is helpful for evaluating residual malignant lesion after lumpectomy and affects positively subsequent treatment.

Objective To explore the characteristics of occult damage of cerebral white matter in patients with small vessel disease by using diffusion tensor imaging (DTI)technology,and its relationship with cognitive impairment.Methods Twenty-eight patients with CSVD and twenty-three matched volunteers all received T1 WI,T2 WI,DTI examination and montperllier cognitive function scale (MoCA).Then compare the difference between the two groups,and analysis the correlation between ADC and FA value of each re-gion of interested and MoCA score in CSVD group.Results ①FA values on bilateral frontal white matter in CSVD group were lower than control group,and ADC values were higher than control group,the difference was statistically significant (P <0.05 ).There were no significant differences in FA and ADC values on corpus callosum genu and splenium between two groups (P >0.05 );②In CSVD group,the FA value of bilateral frontal lobe white matter were positively correlated with the MoCA score (P <0.05 ),and the ADC value were negatively correlated with the MoCA score (P <0.05 ).there were no significantly correlations between FA and ADC values on corpus callosum genu and splenium and MoCA score (P >0.05 ).Conclusion Bilateral frontal white matter exist fi-ber occult damage in patients with CSVD,and the change of FA and ADC value can reflect the severity of cognitive impairment on a certain degree in patients with CSVD.

Objective:To investigate the correlation between the breast cancer MRI schedule of reinforcement and the shrinkage pattern of tumor after neo-adjuvant chemotherapy, and its clinical significance in the guidance of formulating operation plan. Methods:Dynamic contrast-enhanced MRI scan was performed before chemotherapy and before surgery after a whole-range N-Acety-L-Cysteine (NAC) treatment in 55 patients with loco-regionally advanced breast cancer who received the neo-adjuvant chemotherapy. MRI sched-ule of reinforcement and the shrinkage pattern of tumor after neo-adjuvant chemotherapy were obtained in the treatment, and the corre-lation between the two was analyzed. Results:Of the 55 patients, the unilateral breast mass was found in 54 and the bilateral lesion in 1. There were 56 neo-plastic foci in these patients. The mass-like enhanced image was seen in 24 of the total cases (43%), of which 23 presented with a centripetal shrinkage, 1 with an annular decline, (P<0.01). Multifocal mass-like enhancement image was found in 13 of the total cases, (23%), of which 2 centripetal shrinkages were the singular mass, 11 remained a multifocal lesion after the tumor shrinkage (P<0.01). The mass with peripheral non-tumor-like enhancement image was seen in 8 of the total cases (14%), of which 4 showed a centripetal shrinkage and another 4 a honeycombed multifocal decline (P>0.05). There were 11 of the total cases with non-tu-mor-like enhancement (20%), in which 4 assumed a centripetal shrinkage and 7 a honeycombed multifocal shrinkage (P<0.01). Conclu-sion:The tumor shrinking pattern and its accurate radiological image evaluation are the keys to the selection of breast-conserving sur-gery and the control of local recurrence after treatment of NAC regimen. We can predict the shrinking pattern through the type of the le-sion on baseline before NAC, which is important for the patients and surgeon to get a reasonable expectation in the subsequent treat-ments.

Objective To compare the image quality of chest low dose CT (LDCT) using automatic exposure control (AEC) and constant current control (CCC) and explore a more reasonable scanning protocol. Methods Two hundred and eighty participants were examined with 64 CT scanner at 7 centers in China. All were divided into 4 groups. Two groups underwent LDCT using AEC with standard deviation set at 25 (A1) and 30 (A2) respectively and the tube current ranged from 10 mA to 80 mA. The other two groups underwent LDCT using CCC with tube current set at 40 mA (C1) and 50 mA (C2) respectively. The axial and MPR images were evaluated by two radiologists who were blinded to the scanning protocols.The radiation dose, noise and the image quality of the 4 groups were compared and analyzed statistically.Differences of radiation dose and noise among groups were determined with variance analysis and t test,image quality with Mann-Whitney test and the consistency of diagnosis with Kappa test. Results There was a significant lower DLP in AEC group than in CCC group [(82.62±40.31)vs ( 110.81±18.21) mGy·cm (F =56. 88 ,P ＜ 0. 01 )], whereas no significant difference was observed between group A2 and group A1 0. 05]. The noisy of AEC group was higher than that of CCC group both on lung window(41.50±9.58 vs 40.86±7.03) and mediastinum window (41.19±7.83 vs 40.92±9.89), but there was no significant difference( Flung =0.835, P=0.476, Fmediastinum =1.910, P=0.128).The quality score of axial image in AEC group was higher than that in CCC group (superior margin of the brachiocephalic vein level: 4.49±0.56 vs4.38±0.64,superior margin of the aortic arch: 4.86±0.23 vs 4.81±0.32,the right superior lobar bronchus Level:4.87±0.27 vs 4. 84 ± 0. 22, the right middle lobar bronchus Level: 4.90±0.25 vs 4.88±0.21) except on the right inferior pulmonary vein level(4. 92 ±0. 25 vs 4. 93 ±0. 17) and superior margin of the left diaphragmatic dome level (4. 91±0.27 vs 4.93±0.22) on lung window, but no significant differences (F=0.076-1.748, P＞0.05) were observed. A significant higher score in AEC group was observed on mediastinum window compared with CCC group on superior margin of brachiocephalic vein level (2.57±0.77 vs 2. 46 ± 0. 59, F = 8. 459, P ＜ 0. 05 ), however, the score of AEC group was lower than that of CCC group on other levels without significant differences (superior margin of the aortic arch:3.36 ±0. 63 vs 3.45 ±0. 60,the right superior lobar bronchus level: 3.94 ±0. 56 vs 3. 95 ±0. 51 ,the right middle lobar bronchus Level: 3.80 ±0. 58 vs 3. 87 ±0. 50,the right inferior pulmonary vein level: 3.72 ±0. 56 vs 3.78 ±0. 53, superior margin of the left diaphragmatic dome level: 3.58 ± 0.63 vs 3.68±0.56,F=0.083-3.380,P ＞ 0.05 ). The MPR image quality of AEC group was better than that of CCC group both on lung window and mediastinum window (Zlung =-2.258, Zmedlastinum=-1.330, P＞0.05). For all participants including the underweighted group, the normal group and the overweighted group, the image quality of A1 group was better than that of A2 group without significant differences (the underweighted group: Zlung=0.000, P=1.000, Zmedastinum= 0.000, P=1.000;the normal group: Zlung =-0.062, P=0.950, Zmediastinum =-0.746, P = 0.456; the overweighted group: Zlung = - 1.177, P = 0.239,Zmediastinum =-1.715, P=0.144) both on lung and mediastinum windows, and for the higher BMI participants, a better image quality was obtained in A1 group than in A2 group on the mediastinum window (Z = -1. 715, P = 0. 144). Conclusions The total radiation exposure dose of AEC group is significantly lower than that of CCC group, but no statistical significant differences are observed between both groups in image quality and noise level. The AEC technique is highly recommended in thoracic LDCT scan for screening program, and the SD25 ( SD value = 25) scan protocol is suggested for higher BMI population while the SD30 (SD value = 30) scan protocol for lower BMI population.

Objective To investigate the impact of imaging quality of pitch on coronary CT angiography (CTA) with 64-detector row CT. Methods 566 patients were divided into four groups according to heart rate (≤ 50,51-70,71 ～ 80 and ≥ 80 bpm). Three dimensional reconstructions were used such as volume rendering (VR) ,maximum intensity projection(MIP) and curved planar reformation(CPR). Each group was divided into control group and cxperimential group randomly, using normal pitch and revised pitch respectively, and the imaging quality and influencing factons were analyzed among the four groups. Results There was significant difference in imaging quality among the four groups (P < 0.05). Each group had difference in imaging quality with normal pitch and revised pitch. Conclusions The revised pitch helps to improve the imaging quality and meet the demand of diagnosis.

Objective To investigate ~1H-MRS findings of brain tumor and the clinical application of ~1H-MRS.Methods 80patients with brain tumors clinically or pathologically-proved underwent ~1H-MRS.Normal opposite hemispheres in 30 cases were used as control group.Single voxel spectroscopy(SVS) or 2D-MRS imaging was performed with excited echo sequence.The mean ratio of metabolisms with difference was compared.Results Compared with control group,NAA of tumor decreased in certain degree(P