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Interviewer: All right. Here's a question. How can you reduce the use of imaging tests for patients that you are evaluating for appendicitis? That's what Dr. Eric Glissmeyer's research focused on. Thank you for coming to help answer that question. First of all, why did you want to answer that question?

Dr. Glissmeyer: Well, particularly when we're evaluating children that are being seen for abdominal pain and they may have appendicitis, we like to not do dangerous things or harmful things to children. It's not uncommon that a CT scan, a test with ionizing radiation that exposes the child to potential risk of harm, is done, especially in uncertain cases. So we wanted to try to set forth the protocol with the support of our surgeons and our radiologists that helps us one, standardize our approach and two, reduce CT use and that was our primary objective.

Interviewer: How have people tackled this problem before?

Dr. Glissmeyer: Well, there are a number of places around the country that have done great work in establishing protocols that many times have been just developed iteratively in a quality improvement kind of way, that have had the focus of reducing CT use.

I think that one unique approach that we took here is we didn't want to just know when is CT scan used in patients who are ultimately proven to have appendicitis, but when is it used in that larger demographic, that larger denominator of patients who are evaluated for suspected appendicitis? The doctor goes and feels their belly and says, "They may have appendicitis. I better rule them out for appendicitis."

What do you do next? We have a lot of tools at our disposal and there's a lot of variability in what people do. We wanted to standardize that with that objective of reducing advanced imaging tests like CT scans.

Interviewer: All right. Here's the moment of truth. What do you do?

Dr. Glissmeyer: What we believe the best thing to do is to take a standardized approach driven by physical exam and utilizing a scoring scale. We use something called the Pediatric Appendicitis Score and there are a number of other scores being used. We don't really think it matters exactly what the score is. We don't think there's any magic in one particular lab value or one particular physical exam finding.

Appendicitis is sneaky and it likes to present many different ways. What we've found though is with the support of our surgeons and our radiologists all working together to determine an algorithm, that as we go down and we do a blood count and we do an exam and we see what some of those initial results come back as, we can either put the patient into a category of low risk and, "Gosh we're done." We really don't need to have much worry about appendicitis unless things get worse, intermediate risk, where perhaps an ultrasound test and certainly you have to have an organization that does ultrasound well.

Pediatric ultrasound for appendicitis is not an easy test. Our ultrasonographers have been doing this a long time at primaries and are very good at it. We actually know based on what they see on the ultrasound there are four different grades for the ultrasound result. We know what the likelihood of appendicitis is for those different grades.

So we've got some great data to drive our decision making out of the results we get. You know what? There are some patients who don't even need an imaging test to diagnose their appendicitis. If it's a classic case, straightforward, the labs support it, you're done, call the surgeon, take the appendix out. This was done 20 to 25 years ago with no imaging tests regularly because they didn't have any. So we kind of need to go back to that in some ways.

Interviewer: And in your research, how accurate was this method?

Dr. Glissmeyer: For patients who come in and we see for having appendicitis, I want to first say how do we know when we were looking at this retrospectively that the patient was actually being evaluated for appendicitis? How did you crawl into that doctor's mind and determine, "Well, did they actually suspect appendicitis or were they just coming in for gastroenteritis?"

We developed a surrogate definition, whether they had an ultrasound done, whether they were coming in for a chief complaint or abdominal pain and the word appendicitis was used in the note and a CVC was obtained that 95% of those patients were evaluated for appendicitis.

It had a sensitivity and a specificity of 95%. We're confident that we could evaluate the patients or rather identify the patients that were being evaluated for appendicitis. So in that group, I think the real question people would want to know is what were you doing before you did this protocol and what did you achieve after in terms of the CT use?

Interviewer: Yeah, did it reduce it?

Dr. Glissmeyer: We were one of the lower utilizers in the country in CT. Our baseline data showed we were doing CT scan only 15% of the time in this cohort of patients being evaluated for appendicitis. If you look nationally, it's more around 30%. So we were already a low utilizer of CT.

But what I was so pleased to find was that as we instituted this protocol that has not just the standardization but this follow up option that we'll talk about too, we were able to drop that low rate in half again, from 13% to 6%, from 13% to 6%. So we were really pleased to see we were even able to cut that in half further.

Interviewer: Is there an ability to even cut that more, do you think?

Dr. Glissmeyer: I think potentially. But I think you achieve a certain baseline minimal rate where you get your unclear cases, you get your cases where your patient has been having pain for a week or so and you really suspect that this is a ruptured appendicitis and CT scan is really the optimal test to use. I think around 5% or so is probably about the minimum you want to achieve.

Interviewer: All right. Explain the follow up option you were talking about.

Dr. Glissmeyer: Probably somewhere around a third of patients who have abdominal pain are being evaluated for appendicitis. It's not totally clean, a third, a third, a third, but let's talk about it in those terms because it makes it easy.

If a third of patients come in and it's pretty obvious after your exam and some labs they don't have appendicitis, you're done. You don't need imaging tests. About maybe less than a third, somewhere around 15-20% and they come in and they have pretty clear evidence of appendicitis, labs support it, you call surgery, they get their appendix taken out, no imaging tests needed there.

Then there's this larger middle where the fall into an intermediate range of a Pediatric Appendicitis Score that we have called between 4 and 7. If they have that score, you do an ultrasound scan first. Boy, when it shows the appendix and it shows it's normal or it shows the appendix and it shows it's not normal, that's really helpful. Then you can make your decision based off of that, but if it doesn't see the appendix, what do you do then.

The patient still has some tenderness, you're still a little uncertain. Do you just go stick them in the CT scanner to get your answer? That's what I think historically has been done, when the ultrasound fails to give you the answer you want, we go and scan them. We work with our surgeons to say, "You know what? We've observed this patient for a couple of hours here in the ER. Their pain is not really getting worse. It's not a clear cut appendicitis. Why don't we have them come see you tomorrow morning in clinic?"

So if it's Sunday night between Sunday night or Thursday night where they could go the next morning, that being between Monday and Friday, they can show up at about 7:30, 8:00 a.m., come into surgery clinic, get their belly pushed on, be examined, get lab tests repeated if they need to, perhaps do another ultrasound if necessary and find themselves in the hands of another expert the next morning also with not a second ER charge, which is nice, but being able to come into the clinic.

We thought, "Are we going to go and be doing surgery clinic follow up now? Are people going to just be like all the time overrunning the surgery clinic the next morning?" Actually it's only about one patient every ten clinic days that utilizes this resource. But the fact that you can offer it to them in the emergency department the families love and the docs love because in the faces of uncertainty, it gives them a plan. That's been the magic of the approach.

Interviewer: What's the next iteration then of this research? Where do we go from here?

Dr. Glissmeyer: We've been pleased with what we've been able to achieve at Primary Children's Hospital. It's to take it to other hospitals within Intermountain Healthcare, University Healthcare, having the support of surgeons at those other hospitals is key and radiologists as well, we're working on that. But only half of the appendix case present to the tertiary children's hospital here, Primary Children's Hospital. We want to address that other important half and that's where we're going next.

Interviewer: Getting that feedback from the surgeon afterwards for the patients that didn't get the imaging but had the operation and you find out how successful you've been or haven't been. Have these tools proven to be pretty successful?

Dr. Glissmeyer: That's a great question. You wouldn't want to be going and admitting to the surgery service a lot of patients who you as the ER doc are convinced have appendicitis and then they go in there to take it out and then, "Uh-oh, it looks normal." That happens on a rare occasion. Nationally about 5% is the rate of negative appendectomy. You go in and, "Oh, we thought it was appendicitis and it's not."

Our rate here is about 2-3% and it's not increased since the use of the protocol. So going in and taking out patients' appendix without ultrasound test or any imaging test, it still is successful and doesn't increase that negative appendectomy rate.

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Dr. Miller: Benefits of having a CT scan versus having an MRI. We're going to talk about that next on Scope Radio.

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Dr. Miller: I'm here with Dr. Ulrich Rassner and he is a radiologist here at the University of Utah. And we're going to talk a little bit about the difference between a CT scan and an MRI scan. Ulrich, can you tell us a little bit about the difference and kind of in a nutshell what would be the concern for patients? I know that some patients are concerned about the potential for radiation exposure with CT scans and MRIs use magnetic fields and there's no ionizing radiation in there. So should everybody have an MRI?

Dr. Rassner: No, not everybody should have an MRI. It depends very much on the question that we're trying to answer.

In general terms, a CT is a fancy X-ray. And fancy in the way that we acquire a lot of individual X-rays and then the computer can assemble them and allow us to have cross-sections like we're cutting through the patient. And that is tremendously helpful with complex anatomy. So for example, the facial bone fractures, where if you tried to figure out what is going on a plain film on an X-ray, it is very difficult because there are so many overlapping structures. While on a CT scan, you can see them to much greater detail and see what is injured and needs treatment.

Dr. Miller: Now, how about the MRI? Does it not do the same thing?

Dr. Rassner: The MRI does do the same thing. However, MRI uses the magnetic properties of tissues. So when we put the patient in the scanner, and the scanner's a very powerful magnet, the patient actually will become magnetic while they are in the scanner. And then we can manipulate that magnetization in the patient with radio waves and they are just the same wavelength as a TV channel or so you might tune in.

Dr. Miller: But that's not dangerous.

Dr. Rassner: That is not dangerous and there are very specific guidelines from the FDA in how much energy we can put in a patient. But there is no ionizing radiation so there is no cancer risk associated with that.

Dr. Miller: Now, a CT scan's ionizing radiation exposure is multiple times that of a plain X-ray so get that better imaging, it comes at a cost of greater ionizing radiation.

Dr. Rassner: With CT, yeah. CT has higher radiation doses than a radiograph, but in a lot of cases, the added information that you get is beneficial. And also, in some cases, for example, if you want to look at the skull with a radiograph, you need a lot of different views so you can't just look from the front. You may have to look from the side and then obliquely, and so all those individual radiographs can add up to a similar dose as a CT and yet you don't get as much information out of them. So sometimes, doing the correct study or the better study right away can actually save radiation, rather than doing the first one and then decide, "Well, we can't actually see what we need to see."

MRI, again, just to come back to that point, looks at a magnetization, and then we can look at tissue property. In a sense, when we manipulate it with the radio frequency waves, how long do they stay magnetized and how long does it take to regain magnetization? And the differences between soft tissues is quite striking with that and so we can resolve soft tissue detail that is invisible in CT. And so we can pick up lesions that cannot be seen with other imaging studies. And there are certain things we can see and certain things we cannot see so we are basically looking at hydrogen in the body, which is mostly is in water and which is in fat. And so those tissues that contain that, we can see very well. Other tissues, like bone, we do not see directly. We see the bone marrow, but not the bone.

Dr. Miller: So tell me how a patient would know or how they might sense they would be better off with an MRI versus the CT. I mean, there are a lot of articles out now in the press about the dangers of ionizing radiation. And some patients may think that they should have an MRI just simply because it doesn't have any exposure to ionizing radiation. We talked a little about the need for CT scan for certain types of tissues in the body and MRIs look at another set of tissues in the body, maybe better than the CT scan. So what would a patient to sort of distinguish whether they would benefit most from an MRI or a CT scan?

Dr. Rassner: It depends very much on the question that's trying to be answered. And again, if there are certain soft tissue tumors, it might easier to see them with MRI than with CT, but there is no general rule. What also enters into the equation is that an MRI scan is a much longer study.

Dr. Miller: More expensive, perhaps?

Dr. Rassner: More expensive, as well and in part because it is longer. So while a CT scan, the actual scanning part, may take 10 seconds, an MRI examination may take 50 minutes to an hour or even longer. And so a lot of images, to just acquire them, may take on the order of five minutes. And so, for example, if you're imaging the chest, you can hold your breath for 10 seconds, but you can't hold your breath for five minutes. So there may be much more issues with breathing motion so some lesions that are easily seen on CT, we might see as well on MR because there's a lot of movement during the examination.

Dr. Miller: I suppose one appropriate question from a patient might be, "Have you discussed with radiologists which test might be best for me?"

Dr. Rassner: Yeah.

Dr. Miller: I don't think that happens very often, but that could be a very good question for a practitioner to hear. "Have you discussed that with the radiologist," and that might give them some additional comfort in which test was being ordered.

Dr. Rassner: Yeah. We are always happy to discuss it with our clinicians, and in fact, it often helps us, especially in complex cases, when we do know more of the history of the patient and what is specifically of concern, especially with MRI. The MRI is a much more targeted exam and there are many different ways we can acquire images. And we target those for a specific question. And so, in difficult cases, having that specific information helps us do the best study for that question.

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updated: July 31, 2018
originally published: January 28, 2016