The Medical Physicist | Part of the Team

As the annual number of imaging procedures increases, the role of the medical physicist is expanding. Today, the physicists are not only essential to ensuring the safe and effective use of radiologic technology, but they are also playing a greater role in maintaining compliance with state and federal regulations and accreditation requirements for radiology.

At a recent expert panel meeting, Mahadevappa Mahesh, MS, PhD, Chief Physicist at Johns Hopkins Hospital, discussed the increasing responsibilities of medical physicists, as they are becoming an important member of the radiology team.

“I feel strongly that the role of the medical physicist is evolving,” said Dr. Mahesh. “We used to do backend work, mainly evaluating equipment. We still do so in the evening, but often nobody knows who the physicist is unless something goes wrong. There is a requirement now to have a protocol team and this team is generally comprised of the radiologist, physicist, and technologist. As a result, physicists are on the front line, working with the team, and I think that dynamic has completely evolved our role.”

As new CT imaging technologies emerge, the focus is increasingly on radiation dose management. Understanding that radiation doses vary substantially, depending on the specific equipment and exams, and even across institutions; a concerted team effort which includes medical physicists to collect and analyze exposure data is warranted. Serving as a radiology team advisor is a critical role of the medical physicists as new regulations are implemented and enforced.

Dr. Mahesh discussed the role of medical physicists and new technology in managing radiation dose with Lawrence Tanenbaum, MD, Vice President and Chief Technology Officer, Medical Director Eastern Division, Director of CT, MRI, and Advanced Imaging, RadNet Inc. View video.



One dose-monitoring technology being incorporated into clinical practice is the NEXO[Dose]® Multi-Modality Radiation Informatics software offered by Bracco. The fully automated, vendor-neutral software is capable of tracking and monitoring radiation exposure in real time, improving efficiency and patient safety. Other equipment manufacturers have developed similar software, including Bayer’s Radimetrics™ Radiation Dose Management Solution, Guerbet’s Dose&Care® digital solution, and GE’s DoseWatch Explore.


Bracco’s NEXO [DOSE] Multi-Modality Radiation Informatics is a single-server, fully automated system that streamlines reporting and documentation with easy access to enterprise-wide radiation dosing data, real-time alerts to assist with identification and correction of outliers, and a centralized database to implement performance improvement initiatives.


There are numerous benefits to radiation-dose tracking; experts agree collecting this data is a best practice that can improve policies and inform personalized clinical decision making. For example, cumulative radiation-exposure data can help alleviate patient concerns about risks associated with such exposure. Additionally, with clinicians and healthcare systems obligated to observe ALARA guidelines to minimize radiation exposure; dose tracking software can help optimize protocols, reduce unnecessary exposure, and help ensure facility compliance with regulations. Medical physicists are actively involved in this process, acting as drivers of dose-monitoring data collection and analysis.

“The physicist can be a key person but has to be supported by administrators and physicians. Ideally, a medical physicist should be key in driving dose monitoring because he or she understands the factors which go back to the radiation dose, including the parameters that are changing or may be impacting things,” said Dr. Mahesh.

The utility of radiation-dose management systems has been validated across large healthcare networks, pointed out Ryan Lee, MD, Section Chief of Neuroradiology and Vice Chair of Safety and Quality at the Einstein Healthcare Network. “Radiation dose monitoring software is the key. Without it, you really have no way of knowing what is going on between the scanners. Prior to that, all we got was a DLP report on the specific scan. There was no way to tally what was happening on a more global basis between scanners, departments, and sites. So, the first piece of puzzle for us was to have software that allowed us to pull that information.”

With the dose monitoring software and assistance from their medical physicists, Einstein’s radiology department has reduced variability in the radiation dose exposure by monitoring dashboards that show practice variations occurring at different sites within their network.  This has allowed the entire group to adjust imaging protocols, as necessary. Additionally, detecting and removing outliers from the datasets is assisted with the incorporation of analytics.  The team at Einstein is looking at ways to integrate contrast utilization data into the same software, with the goal of creating new dashboards that can correlate the different input factors, such as radiation dose, pressure, and patient body habitus.  

Perhaps the most valuable role played by the medical physicist is ensuring radiation dose is balanced with image quality. Excessively high doses pose a significant safety risk to patients, while too-low doses may result in poor image quality and require additional studies. In this capacity, the medical physicist works with the rest of the radiology team to balance patient safety and image quality needs while ensuring a personalized approach to patient care.

Daniele Marin, MD, Medical Director of Multi-Dimensional Image Processing Laboratory at Duke University Medical Center, and Dr. Mahesh discussed this balancing act in this video.


In Dr. Mahesh’s opinion, there are challenges to optimizing the use of dose-monitoring software. “Often radiation dose management systems are implemented to satisfy regulatory complexity,” he said. “Satisfying regulatory compliance is important, but the true benefit is gleaned when you use the data to improve the practice.

The need for a physicist who can champion the process of effectively managing all that data is essential; otherwise you have tons and tons of data and there is no point in that.” The expert panel agreed that leveraging the medical physicist in radiology is critical, particularly with advancements in technology and the vast amounts of data collection.

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