Physics brings numbers to medicine
That sentence captures the essence of medical physics. Medicine rests on observation up to a point; but in imaging and treatment we need to be reliable, repeatable, countable. The discipline that turns into a number how much radiation a tumor receives, how much dose a CT delivers to a patient, how sharp an image is — that is medical physics.
What is medical physics?
Medical physics is an applied science that puts the principles of physics to work for medicine. Behind nearly every image modern medicine produces — and every dose it computes — lies a physical principle: the attenuation of X-rays in tissue for radiography and CT, the magnetic resonance of nuclei in MRI, the echo of sound waves in ultrasound, radioactive decay in nuclear medicine.5
The main fields of clinical medical physics are diagnostic imaging (dose and image quality), radiation oncology (delivering the right dose to the right place in a tumor), and nuclear medicine — accompanied by radiation protection, quality assurance, dosimetry, education and research. The common denominator in all of them is the same — measure, verify, optimize.
Pioneering works
Every major imaging method we use today is, in truth, a physicist's (or engineer's, or chemist's) discovery turned into medicine. A brief timeline:
- 1895 — X-rays. Wilhelm Conrad Röntgen discovered an unknown ray and named it "X." The discovery earned the very first Nobel Prize in Physics, awarded in 1901.2
- 1896 — Radioactivity. Henri Becquerel found that uranium salts emit radiation spontaneously — the discovery of natural radioactivity.2
- 1898 — Radium and polonium. Marie and Pierre Curie isolated new radioactive elements. Together with Becquerel they shared the 1903 Nobel Prize in Physics; Marie Curie won a second Nobel (Chemistry) in 1911.2
- 1970s — Computed tomography. Allan Cormack and Godfrey Hounsfield made cross-sectional imaging possible. They received the 1979 Nobel Prize in Physiology or Medicine "for the development of computer assisted tomography."3
- MR imaging. Paul Lauterbur and Peter Mansfield turned magnetic resonance into an image. They shared the 2003 Nobel Prize in Physiology or Medicine "for their discoveries concerning magnetic resonance imaging."4
The medical physicist today
These pioneers opened the door; today's medical physicist keeps that technology safe and effective. In diagnostic imaging, in practice this means:
- tracking CTDIvol and DLP across CT protocols,
- assessing mean glandular dose and image quality in mammography,
- contributing to patient and staff dose management in fluoroscopy,
- supporting activity, contamination and image-quality processes in nuclear medicine,
- ensuring equipment performance stays within safe limits through quality-control tests.
On top of this lies optimizing protocols to the lowest dose that still preserves diagnostic quality.
So the "measuring" in Kelvin's words goes on, today, in hospital corridors. DoseSave is part of that tradition too: making dose and image quality visible, measurable and understandable.
References
- Thomson W (Lord Kelvin). “Electrical Units of Measurement”, Institution of Civil Engineers'a sunulan konferans, 3 Mayıs 1883; Popular Lectures and Addresses, Cilt 1 (Macmillan, 1889) içinde yayımlandı.
- The Nobel Prize in Physics 1901 (W. C. Röntgen) ve 1903 (H. Becquerel, P. Curie, M. Curie). nobelprize.org
- The Nobel Prize in Physiology or Medicine 1979 (A. M. Cormack ve G. N. Hounsfield) — “for the development of computer assisted tomography”. nobelprize.org
- The Nobel Prize in Physiology or Medicine 2003 (P. C. Lauterbur ve P. Mansfield) — “for their discoveries concerning magnetic resonance imaging”. nobelprize.org
- Bushberg JT, Seibert JA, Leidholdt EM, Boone JM. The Essential Physics of Medical Imaging, 3rd ed. Lippincott Williams & Wilkins, 2011. (Görüntüleme modalitelerinin fiziksel temelleri.)