4 essential things radiologists should know about physics in medical imaging


Trainees in radiology are expected to know a significant amount of information about the physics behind each modality. But is there a point where it becomes too much?

Ehsan Samei, PhD, Duke Clinical Imaging Physics Group, Duke University Medical Center, tackled this subject in a web-exclusive commentary for the  American Journal of Roentgenology.  Samei explained that understanding physics in imaging is “of crucial importance,” but trainees are being expected to know more and more as the industry continues to evolve.

“Over the past few decades, the physics education provided to radiologists has matured significantly, with increased attention given to clinical relevance and pictorial examples,” Samei wrote. “At the same time, however, the magnitude of the material has increased dramatically, in consideration of the continuous advancement of technology and procedures.”

This trend, Samei noted, could be having potentially negative effects on the next generation of radiologists.

“This increased magnitude has the unintended effect of flattening the material,” Samei wrote. “When everything is important, nothing is important; all topics are treated equally, with little differentiation. This not only chips away at the joy of learning, it also further undermines the attention of the trainee to topics of crucial importance and deteriorates the underlying schema that should provide the foundation of the education, on the level at which information is sorted.”

To help alleviate this issue, Samei broke the essential information down into four categories for trainees. These represent a snapshot of what radiologists should know for each modality:

1. Scientific bases of image formation

This first category touches on the “underlying principles” involved in medical imaging, including the science behind contrasts, and so on.

2. Technologic Components of Image Formation.

This covers details of both the hardware and the software used to capture images.

3. Parametric Dependencies

This is when the radiologist learns details that help produce the most clear, detailed scans possible. How do beam attributes affect the quality of x-rays? How does kernel choice affect the resolution of a CT image?

4. Constraints for Optimum Use

This final category, Samei concluded, is where it all comes together.

“Given the knowledge base consolidated in the first three components, the purpose of this component is to address the ‘how’ questions: How imaging parameters and procedures should be selected so that necessary levels of image characteristics are achieved,” he wrote.