Medical Physics Online
The American Association of Physicists in Medicine is a member society concerned with the topics of medical physics, radiation oncology, imaging physics, health physics, hospital physics, medical radiation, physics careers, ionizing radiation, brachytherapy and diagnostic imaging.
https://www.medphys.org/
International Society for Magnetic Resonance in Medicine
Science, Physics, Medical Physics, MRI - International Society for Magnetic Resonance in Medicine. The ISMRM is a nonprofit professional association devoted to furthering the development and application of magnetic resonance techniques in medicine and biology.
https://www.ismrm.org/