Dr. Penfil's interest in imaging began during his medical school career at Henry Ford Hospital in the department of Radiology. After graduating from Wayne State University, College of Medicine he did internship and Diagnostic Radiology training at University of Southern California, L. A. County General Hospital. The training program was interrupted by serving two years with the National Center for Radiologic Health.

After receiving his Certification from the American Board of Radiology in Diagnostic Radiology in 1971, Dr. Penfil entered Private Practice by opening the radiology department at Fountain Valley Hospital. While there, Dr. Penfil built a group practice which later moved to Anaheim Memorial Hospital. Dr. Penfil maintained an office near Fountain Valley Hospital and opened additional offices in Newport Beach and Irvine. In 1973, while in the private practice, Dr. Penfil co-founded Neuroscan, the first American company to design and produce CT scanners. In 1974 he sold the technology to GE and continued the private practice of Radiology. In 1984, Dr. Penfil co-founded Medstone. This company designed and produced lithotriptors, the device which converts kidney stones and gallstones into particles small enough to pass in the urine and bile.

Dr. Penfil's special interest is Body Screening