ACR Guidelines Still Best Resource for Determining Appropriateness of CT Imaging

William R. Hendee, Medical College of Wisconsin, makes some very valid points in a recent article about overuse of CT scans and the harmful effects unnecessary exams have on both patients and the healthcare industry. Specifically, he says that radiologists can “play a big role in educating ordering physicians about what scans are appropriate and when.”

A big part of the training and experience-based learning of radiologists is what imaging tests are appropriate for specific healthcare problems and what imaging tests are inappropriate. Inappropriate means the imaging test has little chance of adding significant value to the diagnosis and therapy of the patient, especially relative to its cost.

The American College of Radiology (ACR) has spent more than a decade developing imaging appropriateness guidelines for hundreds of clinical problems and indications. These ACR appropriateness guidelines are based on the best available scientific evidence and were written by panels of best sub-specialized experts. The guidelines each get revised every three to five years as new evidence becomes available. There is no better source available for appropriateness of diagnostic imaging.

The decision support computer programs mentioned in the article start with the ACR appropriateness guidelines and create a quick way for referring physicians to know if any imaging test they order is appropriate. At the point of computerized imaging exam order entry into an electronic system, the decision support examines the entered indications for an imaging exam and then either agrees with doing the exam, or cautions that the exam may be only marginally indicated – or states that by generally accepted criteria the requested exam is unindicated. There is education involved, as the evidence-based reasons an exam is unindicated are provided to the ordering physician, along with suggestions for a better approach to the patient’s problem (often involving some other type of imaging). These decision support programs are now running in several healthcare enterprises, and they hold good hope for decreasing inappropriate complex imaging exam utilization without blocking access to appropriate tests.

4 thoughts on “ACR Guidelines Still Best Resource for Determining Appropriateness of CT Imaging

  1. Hi Terry-

    This is a difficult question since it is a risk/benefit assessment – both of which are hard to quantify. The AAPM statement recently suggests that 50 mSv in a single dose or 100 mSv as multiple events over some period of time (say 6 months – arbitrary) form some sort of safety threshold below which there is no proven risk. Whiule ALARA holds for each event, part of the job of a radiologist is to make these judgments about risk/benefit ration. When such judgments are difficult, I find a direct conversation with the odering physician usually leads to an agreement.

    Dr. Shuman

  2. Dr. Shuman,
    We are looking for clear guidelines for the use of CT.
    We have growing concern about the # of CT scans ordered on a single patient. For example a 34 year old male came thru the ED last night.
    He had his 8th CT study within the last year. Most o f the CT’s are abd/pelvis.
    I realize the ACR has clear criteria for the use of various imaging techniques, as well as alternative options such as ultrasound and MRI.
    I guess I need to know when we pull a trigger to say, “This patient is at their maximun permissable dose for the year or for lieftime?”

  3. Hi Gary –

    The recommended maximum is an arbitrary dose level. But the assumption is that dose and risk increase linearly, as best we know. Thus the judgment for the appropriatnenss of the first initial increment of radiations is also on the same basis as the judement for the increment which would take someone over the arbitrary limit. As always, it is a risk/benefit judgment, probably best made by radiologists.

    Sure – happy to take my Low Dose CT, Grand Rounds, I think talk on the road. Am currently scheduled to give it at Overlake on Nov. 4. But will give it to anyone else who wants to hear.

    Sorry to be slow responding — I was away in France and had only intermittent internet access.

  4. I receive between 3-5 phone calls and 6-8 website inquests about radiation exposure weekly – with the majority coming from pediatricians or concerned mothers about the possible long-term effects from x-rays and CT scans their patients/children have received or are due to receive. We discuss ALARA and the Image Gently program in conjunction with the radiation dosages of the various scans. I then reference several sites for additional information for them and in follow up conversation, the ACR site appears to be the one that answers their questions in a manner that provides the most reassurance to them.

    We are in the process of implementing a tracking system for radiation exposure for our pediatric patients – with adults to follow. The sticking point between the various radiologists is this: what do we do when a patient nears the recommended maximum dosage – both annual and lifetime? And how do we do this in a way that does not cause problems with the referring clinician? I would be interested in getting your perspective on this.

    Also, do you take your presentations on the road? We are across the lake in Bellevue and I could guarantee a large audience if you came to speak here.


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