The Value of Oral Contrast from the patient’s point of view

Oral Contrast

The authors raise this question from a patient-centered approach: “What would patients choose if given the option to drink or not drink oral contrast material, and why? Some patients might prefer a risk-averse approach and prioritize diagnostic accuracy, whereas other patients might prefer a comfort-based approach and prioritize examination comfort. Asking patients how they value these trade-offs can inform an optimal imaging strategy.”

Modern oral contrast (diluted Omnipaque) is tasteless and odorless. Most patients think they are drinking water. But, it significantly increases diagnostic accuracy, particularly in cases involving GI questions.

These authors concluded, “If oral contrast material has any diagnostic benefit, most outpatients (89%) would rather drink it than accept any risk for missing an important finding.”

Optimizing CT Radiation Doses Across Institutions Leads to Dose Reductions

This excellent research from UCSF documents that education about best CT dose practices has a significant impact. The authors state, “The project strategy was to collectively define metrics, assess radiation doses, and move toward dose standardization. This article presents the results of our efforts using a combination of facility-level audit and collaborative efforts to share best practices.”


Patients’ awareness of radiation dose and risks associated with medical imaging

In this article, the authors discuss how awareness of dose and risks of medical imaging by patients can facilitate shared decision making and reduce unnecessary radiation exposure.

Revolution CT Scanner at UW Medical Center Department of Radiology


Reducing dose via iterative reconstruction technology

As this article demonstrates, iterative reconstruction is a very powerful way to reduce dose without impacting diagnostic ability. Key points of the authors include, “To reduce patient and operator radiation dose involves optimization of medical imaging equipment and best control of the equipment by the operator. … The results of our study confirm in a large patient number reflecting the routine clinical setting that the image noise reduction technology allows a significant reduction in radiation dose.  … The substantially lower radiation dosage achieved in a routine clinical setting with the image noise reduction technique, provide further evidence of the substantial impact of the new technology. They indicate potential reduction in radiation dosage in invasive and interventional cardiology with more diffusion of newer radiation technology in clinical practice.”

Low-dose Radiation

Low-dose Radiation Not Harmful

To quote the American Association of Physicists in Medicine:

  • The risk from medical diagnostic radiation in doses below 50 mSv as a single dose or 100 mSv as a cumulative dose is too small to be measured and may be non-existent.
UW Medicine Physicists

UW Medicine Physicists

Reducing dose for CT pulmonary angiography

Paying attention to limiting Z axis coverage yields big dose saving dividends! See this article for results of this study designed to assess the safety and efficacy of radiation dose reduction in hospitals lacking iterative reconstruction.

Optimizing Radiation Dose

Standardizing dose description parameters and metrics is an ongoing and very active area in ACR and nationwide. This will be a big help to comparing metrics between institutions and over time. The SSDE (Size Specific Dose Estimate) is a good step in that direction.

But this article also points out the large impact of exam appropriateness on dose. It is an impressive fact that a profound way to lower population dose is to avoid doing inappropriate exams. Tools such as the ACR Appropriateness Criteria or Computerized Decision Support at the point of order entry can empower appropriateness review. And every radiologist needs to increase their awareness of exam appropriateness in daily work.

CT Radiation Overexposure Still a Problem, Regulation Issues are Complex

Unfortunately, ct scan radiation overexposure continues to be a problem in hospitals and imaging facilities across the country. However, the question of regulation of dose from ct scanners is a complex issue. Many say that the best pathway to regulation is through the existing American College of Radiology mechanisms – such as certification of CT sites and subspecialty certification of both radiologists and CT technologists. This may expand to include requirements for regular monitoring of dose from typical exams and reporting the results of such monitoring to a central ACR registry.

Others advocate a role for the FDA, though that government agency may turn to a group of experts, such as the ACR or the Society of Computed Body Tomography. A national registry of individual patients which records dose from each CT exam for each patient, and cumulative dose for each patient, would also be a best practice – Europe does this now in the EU.

Finally, we need many and repeated courses, texts, electronic educational media, and monographs focused on the topic of how to consistently achieve CT scans at much lower dose than a few years ago. This education should be widely available and ongoing.

Our recent UW Symposium on Low Dose CT was a repeat from six months ago, and was equally well attended.

Team Effort Needed in Push for Low Radiation Dose CT

In the days that followed last month’s Low Dose CT Symposium, I had time to reflect on how wonderful it was that the event drew an unprecedented number of attendees. The interest in the symposium was evident by how far some attendees traveled to get there. I was also struck by the segments of the industry that were represented in the audience: technologists, radiologists, technicians and administrators were all there. It made me think about each segment’s relationship to one another, and their ability to impact change in the industry.

When driving toward much lower radiation dose in CT, it’s good to remember that a team effort is needed. Technologists must be educated on all the tricks and skills needed and must fully understand why dose reduction is important. They can help radiologists be more conscious of dose exactly when radiologists are urging technologists to pay close attention. Both techs and radiologists can use their knowledge to help educate administrators about the importance of investing in low dose CT. Everyone can help educate referring clinicians about thinking of dose when they order, both for an individual study and cumulative dose (over time) in individual patients. And it is the whole chain of providers who monitor appropriateness of studies at each and every level.

Educating Patients About Radiation Risk Not Always Easy

Lots of articles are published on a regular basis that talk about public awareness (or lack thereof) of CT scan risks and benefits. This one’s a recent example. But here’s the thing, which I’ve discovered through personal experience: educating patients about radiation risk is very challenging. This is because extremely low rates of risk are hard to comprehend. It can be talked about in terms of background natural radiation, or risk of driving a car, for example. While it is important that patients be informed, it is also important that they not be scared away from a test that stands a good chance of helping them – a lot. This is a fine balance.

Practicing medicine in an emergency room environment is different from in a clinic or a hospital. The diseases are different as is the acuity. What may not be appropriate in a family medicine clinic population may be appropriate in an acutely ill ER patient.

This is why specialists in radiology and emergency medicine are continually reviewing appropriateness criteria, like those published by the American College of Radiology.

Patients Want To Know About Radiation Risks

A new study published in the November issue of the American Journal of Roentgenology concluded that patients from the emergency department are more concerned about having their condition diagnosed with CT than about the risk of future cancer from radiation exposure.

Although the patients in this study did not estimate the risk of development of cancer as high, the majority of patients wanted someone to discuss the risk and benefits of testing them. This is not as simple as it sounds. How do we best educate patients about radiation? Who is responsible for educating patients about risks and benefits of radiation exposure from CT – the ordering provider, the radiologist, or the CT technologist?

Right now it seems that nobody is doing such education likely due to time constraints and the fact that it is a difficult topic to discuss.  There is no standardized way to discuss radiation with patients and research shows that many physicians don’t fully understand radiation, radiation doses from common tests or possible risks from exposure to radiation from medical imaging. This is a topic that is not going away. We know what our patients want and need, it’s up to us as their healthcare providers to deliver.