False-Negative Results of Real-Time Reverse-Transcriptase Polymerase Chain Reaction for Severe Acute Respiratory Syndrome Coronavirus 2: Role of Deep-Learning-Based CT Diagnosis and Insights from Two Cases

The epidemic of 2019 novel coronavirus, later named as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still gradually spreading worldwide. The nucleic acid test or genetic sequencing serves as the gold standard method for confirmation of infection, yet several recent studies have reported false-negative results of real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). Here, we report two representative false-negative cases and discuss the supplementary role of clinical data with rRT-PCR, including laboratory examination results and computed tomography features. Coinfection with SARS-COV-2 and other viruses has been discussed as well.

The angle measurement of adult knee joint and the influencing factors on it / 实用放射学杂志

Objective To explore the changes of related angles of knee joint in adults in recent 30 years according to the angle value of knee joint compiled by Qi Zhongzheng in 1984,to provide the basis for clinical individualized diagnosis and treatment.Methods 102 healthy volunteers underwent digital X-ray photography of lower limbs.The femoral angle,tibial angle and femoral tibial angle of bilateral knee joints were measured and compared with historical reference value.The correlation between height,weight,BMI and each angle was evaluated.The differences between different sides and different genders were also analyzed.Results There were statistical differences between the mean value and historical mean value of femoral angle,tibial angle and femoral tibial angle (P＜0.001).In female volunteers,the height was weakly correlated with tibial angle and femoral tibial angle (P＜0.05),the weight was weakly correlated with femoral angle (P＜0.01),and the weight was moderately correlated with femoral tibial angle (P＜0.0 1).BMI was weakly correlated with femoral angle or femoral tibial angle (P＜0.05).There were significant differences in femoral angle (right),tibial angle and femoral tibial angle between different genders (P＜ 0.05).Conclusion In the last 30 years,there is a statistical difference between the angle value of the knee joint and the historical reference value.There is also a statistical difference in knee joint angle value between both genders.And in female volunteers,height,weight and BMI show some correlations with the knee joint angle value.However,the cross-sectional survey data of multicenter,large sample size and the whole population are still necessarily needed for further study.