Dr. Nelsen received his medical degree at the University of Washington Medical School. He completed his internship in internal medicine and residency in diagnostic radiology at the University of Washington Medical Center. Dr. Nelsen also completed his interventional radiology fellowship at the University of Washington Medical Center.

Dr. Nelsen received his board certification from the American Board Radiology in 2000. He is a member of the Radiological Society of North America, American Roentgen Ray Society, and Society of Cardiovascular and Interventional Radiology. Dr. Nelsen joined Valley Radiologists in 2001.