What is Medical Physics?


Ultrasound, Magnetic Resonance, Computed Tomography, Nuclear Medicine, X-rays, Radiation Therapy, are all branches of medical physics where continued research is being conducted by a very large group of dedicated researchers consisting of highly qualified physicists, engineers and radiologists. The field of medical physics as we know it today started with the discovery of x-rays and radioactivity in the 1890's. The first radiograph was taken by the physicist Wilhelm Conrad Roentgen (1845-1923) in his Wurzburg University laboratory in Germany. It was a radiograph of his wife's hand. For his thorough scientific investigations of x-rays he received the first Nobel prize in Physics in 1901. Follow the links at Emory to share in the excitement of those historical months of January and February 1896.

Physicists were also pivotal in using radiation as a treatment for cancer. We can be very proud that Canadian physicist, Harold Johns (1915-1998), developed in the late 1940s the first Cobalt Therapy Unit. For his continued dedication and research he was made an Officer of the Order of Canada in 1976. The medical profession also honoured Dr. Johns by inducting him into the Canadian Medical Hall of Fame in 1998.

Physicists have contributed positively to the advancement of the diagnostic and therapeutic fields of medicine. They will continue to play a primary role in the development of physical principles to medicine.

Who are Medical Physicists?

Medical physicists are health care professionals with specialized training in the medical applications of physics. Their work often involves the use of x-rays, ultrasound, magnetic and electric fields, infra-red and ultraviolet light, heat and lasers in diagnosis and therapy. Most medical physicists work in hospital diagnostic imaging departments, cancer treatment facilities, or hospital-based research establishments. Others work in universities, government, and industry.

What do Medical Physicists do?

Most medical physicists work in one or more of the following areas:

  • Clinical Service
    The responsibilities of a clinical medical physicist lie predominantly in the areas of radiotherapy and diagnostic imaging. The roles of a medical physicist in radiotherapy include treatment planning and radiotherapy machine design, testing, calibration, and troubleshooting. The roles of a medical physicist in diagnostic imaging include machine purchasing and installation, testing, quality control, and operation.

  • Radiation Safety
    Medical physicists have expertise in radiation safety. Canadian regulations recognize medical physicists who are certified by the Canadian College of Physicists in Medicine as Radiation Safety Officers for medical radioisotope facilities.
  • Research and Development
    Canadian radiotherapy physicists play a central role in such areas as the design and construction of radiotherapy treatment equipment, the use of heat and lasers in cancer treatment, the theory of radiation absorption and dose calculation and in radiobiology. Imaging physicists are continually developing and improving methods to image body structure and function. Canadian laboratories are leaders in positron emission tomography, magnetic resonance imaging, ultrasound, x-ray and radionuclide imaging, biomagnetic mapping, among other areas. Excellence in Canadian Medical Physics Research is recognized annually via the awarding of the Sylvia Fedoruk Prize.
  • Teaching
    Most medical physicists are affiliated with universities. Many medical physicists teach in graduate and undergraduate medical physics and physics programs. They also teach radiology and radiation oncology residents, medical students, and radiology, radiotherapy, and nuclear medicine technologists.

Professional status

Most Canadian medical physicists belong to the Canadian Organization of Medical Physicists (COMP). COMP promotes the application of physics to medicine through scientific meetings, technical publications, educational programs, and the development of professional standards. COMP is linked to medical physics organization in other countries through the International Organization of Medical Physics.

Many Canadian medical physicists are also members of the the Canadian College of Physicists in Medicine (CCPM), which was established in 1979 to recognize proven competence in physics as applied to medicine. Candidates with suitable educational background and experience become members of the college by passing written and oral examinations. CCPM certification is becoming widely accepted in Canada and other countries and is often required at senior levels in medical physics. Each year the college supports continued professional education by sponsoring symposia on specialized topics and by providing a travel award for a young member in honor of Harold E. Johns.

Employment of Medical Physicists in Canada

There are approximately 550 medical physicist members working in Canada: 75% work in hospitals and hospital-based research establishments, 7% work for government, 8% for industry, and an additional 10% are university faculty who are not hospital-based. The number of medical physics positions has generally increased by about 5-10% per year.

Medical Physics Training Programs

A prospective medical physicist should first have an honors degree in physics. Courses in computing, electronics, and mathematics are advantageous. They may then undertake graduate work in medical physics or another area of physics followed by a one or two year training program in medical physics. Many universities and clinics across Canada provide training programs and also introduce undergraduate students to medical physics through summer employment programs.