Patient Perceptions of Imaging Modalities and Ionizing Radiation

September 15, 2020

Improving patient communication not only augments patient understanding of their radiation exposure with imaging studies, but it bolsters trust in their healthcare providers, as well.

Patient understanding and informed consent is particularly important when dealing with ionizing radiation. But, how can we expect patients to understand the risks they are taking when 28 percent of surveyed physicians are not even aware that forms of imaging like mammography utilize ionizing radiation at all?1

Patient education is largely influenced by patient-physician communication, it and plays a large role in a patient’s ability to provide informed consent. Additionally, effective communication and teaching is thought to enhance the patient-physician relationship and increase patient levels of trust and satisfaction with the experience. This piece investigates patients' perceptions of radiation from magnetic resonance imaging (MRI) and computed tomography (CT) imaging in the healthcare setting. This analysis further reviews recent work that quantified the degree to which effective patient and physician education is taking place and identify areas for improvement and growth.

According to a survey of emergency department patients, when asked to compare the perceived radiation dose of MRI, CT, and a conventional chest X-ray, approximately 30 percent of individuals answered that they all had equal amounts of radiation.2 In that study, when comparing each to a conventional chest X-ray, roughly 40 percent thought that CT was 10-to-100 times greater, while 28 percent thought MRI was 10-to-100 times greater.2

Right away, we can see that at least one-third of patients are unaware that MRI emits no radiation at all. Even more shockingly, when asked to compare radiation exposure levels between CT, MRI, and a nuclear power plant disaster, less than 40 percent of participants were certain that CT scans involved less radiation exposure compared to just 20 percent with MRI.2

When looking at patients’ understanding of lifetime cancer risks associated with various imaging methods, the numbers were varied. When asked, “Do 3-to-5 abdominal scans increase lifetime risk of cancer?,” less than 5 percent answered yes for MRI.2 The results look encouraging, however, when posed the same question about CT. Just over 5 percent answered yes.2 Roughly 25 percent for both groups reported having no idea.2 These results are unsurprising given the limited information available to patients on lifetime risks and specifically the effects of a single scan. Furthermore, a survey of physicians found that 90 percent either did not know or severely underestimated the amount of radiation associated with CT.3

In a specific example, only 65 percent of patients in a study receiving a mammogram reported being informed of the risks before the procedure.4 Discouragingly, 60 percent of informed patients still over-estimated the amount of radiation they had received.4 In another study, the number of patients reporting a lack of communication about the radiation associated with their scheduled tests were as high as 92 percent.1 It is in this same study that 28 percent of surveyed physicians stated they were unaware of mammography utilizing any ionizing radiation.1

Effective patient-physician communication is key to ensuring informed consent is obtainable and has even been shown to have therapeutic effects for patients.5,6 However, with low percentages of patients reporting communication about radiologic testing and physicians self-reporting knowledge gaps in these areas, patient education is hindered. Evidence is supportive of the benefits of educational presentations for ordering providers’ understanding of radiation exposure and risk.7 

Radiologists, therefore, must be aware of and work to address the knowledge gaps reported by attending physicians. Whether through direct communication with patients about risks, hosting educational conferences for colleagues, or simply re-distributing pertinent information, radiologists have a responsibility to ensure patients are educated on the radiological tests they are undergoing.

Based on the results of these studies and surveys, it can be concluded that both patients and physicians have misconceptions and lack comprehensive knowledge about the risks and benefits of diagnostic and therapeutic imaging modalities.1,2,3,4 Physicians that undergo radiologist-designed educational training are more informed on these risks and, therefore, can better communicate radiation risks and benefits to their patients, thus increasing patient understanding and ability to provide informed consent.7 As an additional benefit, this increased communication positively affects patients’ feelings of trust and understanding towards their providers and future procedures.5,6 As of now, further work is needed to clarify misconceptions surrounding radiologic imaging and the associated risks of ionizing radiation.


1. Ricketts, M. L., Baerlocher, M. O., Asch, M. R., & Myers, A. (2013). Perception of radiation exposure and risk among patients, medical students, and referring physicians at a tertiary care community hospital. Canadian Association of Radiologists Journal, 64(3), 208-212.

2. Repplinger, M. D., Li, A. J., Svenson, J. E., Ehlehbach, W. J., Westergaard, R. P., Reeder, S. B., & Jacobs, E. A. (2016). Emergency department patients’ perceptions of radiation from medical imaging. WMJ: official publication of the State Medical Society of Wisconsin, 115(1), 22.

3. Renston, J. P., Connors, J. A., & DiMarco, A. F. (1996). Survey of physicians' attitudes about risks and benefits of chest computed tomography. Southern medical journal, 89(11), 1067-1073.

4. Hollada, J., Speier, W., Oshiro, T., Marzan-McGill, R., Ruehm, S. G., Bassett, L. W., & Wells, C. (2015). Patients’ perceptions of radiation exposure associated with mammography. American Journal of Roentgenology, 205(1), 215-221.

5. Travaline, J. M., Ruchinskas, R., & D'Alonzo Jr, G. E. (2005). Patient-physician communication: why and how. Journal of the American Osteopathic Association, 105(1), 13.

6. Zener, R., Johnson, P., Wiseman, D., Pandey, S., & Mujoomdar, A. (2018). Informed consent for radiation in interventional radiology procedures. Canadian Association of Radiologists Journal, 69(1), 30-37.

7. Hobbs, J. B., Goldstein, N., Lind, K. E., Elder, D., Dodd III, G. D., & Borgstede, J. P. (2018). Physician knowledge of radiation exposure and risk in medical imaging. Journal of the American College of Radiology, 15(1), 34-43.