David A. Bluemke, MD, PhD, Editor of Radiology discusses four research articles from the December 2019 issue of Radiology. ARTICLES DISCUSSED – Summary of Intra-articular Corticosteroid Injections in the Hip and Knee: Perhaps Not as Safe as We Thought?. Radiology 2019, 293:656-663.; Summary of Relationship of Lower-extremity Deep Venous Thrombosis Density at CT Venography to Acute Pulmonary Embolism and the Risk of Postthrombotic Syndrome. Radiology 2019, 293:687-694.; Summary of CT-based Airway Flow Model to Assess Ventilation in Chronic Obstructive Pulmonary Disease: A Pilot Study. Radiology 2019, 293:666-673.; Summary of Classification of Cancer at Prostate MRI: Deep Learning versus Clinical PI-RADS Assessment. Radiology 2019, 293:607-617.