Dr. Johnson received his medical degree from the Medical College of Wisconsin in 1996. He was a resident with the Radiology Residency Program at OSF Saint Francis Medical Center and the University of Illinois College of Medicine at Peoria. He returned to OSF after completing a 1-year Abdominal Imaging Fellowship at the University of Wisconsin in Madison, WI. There he worked with several nationally and internationally recognized experts in the area of Ultrasound. During his fellowship, Dr. Johnson did research in percutaneous radiofrequency ablation and cryoablation of the kidney. Dr. Johnson is regionally recognized as an expert in this area and also an expert in the performance of Ultra-sound and CT guided percutaneous procedures.

During his residency, Dr. Johnson was co-author on several publications and posters for national meetings, winning the Cum Laude Award at the Society of Computed Body Tomography and Magnetic Resonance, in 2002.

Board certified by the American Board in Radiology in 2001, he is a member of several professional societies and associations including the Radiological Society of North America, American Roentgen Ray Society, American Institute of Ultrasound in Medicine, and the International Society for Magnetic Resonance in Medicine.