When would be an indication for CT, AP, with and without? Right. So typically when you are looking for a tumor or significant pathology that requires enhancement of the organ, vascular enhancement for delineation of the lesion, we go with the contrast. If you're looking for just a perforation or a foreign body, you could go without a contrast. But John, you have a comment on that? Yeah, I would say the same thing. It kind of depends on, it's a pretty broad question. There are a lot of reasons to order a CT of the abdomen and pelvis with or without contrast, you know, including just undifferentiated abdominal pain and the emergency department to something ultra-specific like wanting to, you know, follow up pancreatic necrosis and to, you know, determine if it's infected necrosis or what have you and all kinds of things in between. So it's a pretty broad question. I would actually love to ask the attendee who submitted that question to follow up with another question that's more specific, because I'm kind of guessing you're probably driving at something more specific than your current question specifies. Right, right. Thanks, John. I'll try to, I think we're a little behind in the Q&A, but we'll try to address some of these questions real quick here. There's a question which is frequently asked, which is, I have a patient with Barrett's without dysplasia. And so what's the rationale for PPI? Will it make the Barrett's go away and so forth? So in the guidelines, patients who have non-dysplastic Barrett's should remain on PPI as best as possible to minimize acid exposure, because acid exposure along with multiple other factors has been purported to, you know, you know, impact transformation from non-dysplastic to dysplastic. The PPI will not take the Barrett's away. The only thing that takes Barrett's away is endoscopic therapy. But there is an element of chemoprevention, if you might call it, that PPI is attributed to. So best practice, leave them on the PPI and educate them how to take it. There's multiple other questions. When initially diagnosed with Barrett's, but two subsequent endoscopies show no intestinal metaplasia or goblet cells, do you continue to monitor with surveillance EGD? This is an amazing question, because this happens a lot. It happens in two different contexts. If you're biopsying the GE junction versus if you're biopsying a tubular segment of Barrett's, the answer is different. If you're biopsying the GE junction, then it could be intestinal metaplasia at the GE junction, which is a very controversial topic. And unfortunately, if someone somewhere has properly documented that that was the case, I think the endoscopist and the practitioner is stuck with following that, because a lot of GE junction cancer still presents without underlying visible Barrett's, and that is truly the GE junction cancer. When you're biopsying a tubular esophagus, and you are encountering a discrepancy such as the one you have described, then it's likely a sampling error. And if your endoscopy shows columnar lined epithelium up three centimeters, then it's just a sampling error or a pathology read error. So you need to follow up on that for sure. So Dr. Kahl, we have Dr. Shields for just a little bit of time, and there's a few questions in here about the HIDA scan. So I'll read the first one. Should a patient with suspected choleodocus esciasis have a HIDA scan? I had a patient recently who had a colado on abdominal CT and ultrasound, and the hospitalist then ordered a HIDA scan, which noted that there was no flow into the gallbladder, apparently indicating a cyst duct obstruction. I was unsure why the HIDA was ordered. Dr. Shields? Yeah, so that's a good question, because this does sometimes happen. So the question in that case is, it looks like we've already established that the patient has a common bile duct stone based on one of the prior imaging studies, either the CT or the ultrasound. Really the only reason to order a HIDA scan is if you thought that the patient also had cholecystitis, which is actually pretty unusual. Now you're talking about having both a common bile duct stone and cholecystitis, and the two don't usually run together, even though they are commonly confused. So I agree that the HIDA scan was probably unnecessary in that case. The patient had already had an imaging study which warranted proceeding to an ERCP to manage the stone. There were a couple other questions regarding HIDA scans. I think I might have hit a nerve when I talked about not using HIDA scans for chronic abdominal pain, and it's kind of a touchy topic, especially amongst other providers, surgeons. The underlying question is, if you have somebody with suspected functional gallbladder disease, and you're considering sending them for a cholecystectomy, does a HIDA scan really help your decision? You can do HIDA scans and give cholecystokinin and measure their ejection fraction, but the studies show that there's a very poor correlation between a low ejection fraction and improvement after cholecystectomy, which is, that's really what you want to know. You want to be able to tell the patient that they're either going to feel better or that they're not after their gallbladder is removed. And in that situation, having a low ejection fraction just doesn't really predict very well who's actually going to get better after their gallbladder is removed. So that's why I try to steer clear of ordering these, because now I'm, if it does come back up normal, now I'm left with something that may or may not be in the patient's best benefit to send them for a cholecystectomy. It actually, the studies show that it's actually better, a better predictor of how they're going to respond is, do they have biliary type pain? But the truth is, if you don't have an objective finding of stones or sludge or another reason to take out the gallbladder, you've got to be really judicious about who you actually send to see a surgeon. Dr. Martin? Yeah, go ahead. Oh, sorry. I think Dr. Martin wanted to chime in on that. Please. I just wanted to ask Aaron if I could chime in on the issue of HIDIS scans in general. Because one thing that I encounter with my trainees frequently is, there's a lot of confusion with HIDIS scans that results from the fact that a HIDIS scan and a CCK stimulated HIDIS scan are two completely different tests that are used to diagnose two completely different clinical disorders, right? So what is HIDA? HIDA is a radio tracer. It's taken up by your liver and it's secreted into the bile. And following that tracer to the gallbladder or into the duodenum, where bile's supposed to go, is those two spots, right? Is the purpose of the HIDA radio tracer is to show whether bile's going where it's supposed to go. A regular HIDA scan is used to see whether or not that HIDA makes it out of the liver into the gallbladder because the underlying cause of acute cholecystitis is cystic duct obstruction. So if the cystic duct is obstructed, the HIDA doesn't fill the gallbladder. And the presumption is that the cause is that there's cystic duct obstruction causing cholecystitis. A CCK-stimulated HIDA scan is where HIDA is given. And after the HIDA radio tracer is getting excreted into the bile, cholecystokinin, which is a protein that stimulates the gallbladder to contract, is administered. And you're continuing to image the HIDA. And you want to see if the HIDA radio tracer that is collecting normally in the gallbladder is then excreted properly by a contracting gallbladder so that the gallbladder ejection fraction of that radio tracer is as high as it is supposed to be. And if it's below a certain ejection fraction, then the ejection fraction is low. And that is assumed to be because the gallbladder ain't working correctly in its squeeze function. So CCK HIDA scan is to look for gallbladder dyskinesia. Regular HIDA scan is to look either for whether there may be cystic duct obstruction causing acute cholecystitis or the liver is not excreting the HIDA radio tracer like it's supposed to because of liver abnormalities. It's a pretty unusual use of that test. In order to see if the bile duct is obstructed and therefore the HIDA and the bile aren't getting into the duodenum like they're supposed to, again, that last is an unusual use of the regular HIDA scan and highly supplanted by other much better tests these days. That's it. Just wanted to clear up the difference between HIDA and CCK HIDA because my fellows ask me that all the time. Yeah, this is really good because you can tell that how much discussion the HIDA question generated. I mean, I can say that I probably see, I don't know, a thousand patients a year with this pancreatic biliary issues and I probably order HIDA myself less than five times a year. And I think the one time that the HIDA is really useful is in the inpatient setting when there's a question about a bile leak and you've got to decide an ERCP. And the JP drain is all colors of golden. So that's really, really helpful and all the points made by both Dr. Shields and Martin are very valid. Eden, we have some time for more questions. Oh, we absolutely do. If it has not resolved, do you continue PPI long-term or add H2 blocker? What is recommended EGD follow-up after that? So that's more for a Gerd or Barrett, so I try to answer for both. I think if the patient has a clinical symptomatic reflux, then acid suppression is the way to go. If you've done pHmetry and impedance and all those other tests that were discussed earlier by Sarah and John and bona fide diagnosis of reflux, acid reflux, you need to treat it to suppress the acid completely. Occasionally, we still will use a combination of PPI with H2 blockers. One of the H2 blockers was taken off the market. It's kind of sort of back in a different form. But the important thing is don't take them together because the PPI medications require active proton pumps to be effective. And if you kill the proton pumps with an H2 blocker, then the PPI is might as well a sugar pill. So separate them. Maybe a morning event and an evening or a night bedtime event would be the way to go. But lifestyle modification is probably equally, if not more important. Medicines will not do anything if you don't do all the other things that need to go along with managing reflux that were discussed today. Okay. And this next one, yeah, might be for Jill. Is it true that you don't need both positive celiac serologies and duodenal biopsy if someone has diagnosed dermatitis herpetiformis in the setting of positive celiac serology? Is that true? So I was reading that question. I'm not sure if I'm completely clear on it. So when patients, dermatitis herpetiformis is pathognomonic for celiac disease. So that diagnosis will then drive the referral to gastroenterology department. So depending on whether a patient has already gone on a gluten-free diet, then hanging your hat on the fact that both serologies and your duodenal biopsies need to be positive, I don't think you need both confirmatory in the setting. I don't know if anyone else wants to weigh in on that, Dr. Kaur. I mean, I think the question was endoscopic biopsy for celiac. I mean, it remains kind of the gold standard, but I think you mentioned the fact, again, that dermatitis herpetiformis is another board question. The boards love that question, but yeah, I think you answered it very well. Okay. And Dr. Shields has indicated he'd like to answer this question. Is it better to do a nuclear bleeding scan of colonoscopy and EGD where normal, but patient continues to have anemia, or is it better to do a pill cam? So this is a very good question because it kind of addresses what the indications are for each of those tests. So nuclear bleeding scan is really most helpful for somebody who's having acute bleeding. So a patient comes into the hospital and perhaps you do a colonoscopy and upper endoscopy and don't find a bleeding source, tagged scan, tagged RBC scan, sometimes called a bleeding scan is indicated in that situation. It's really not particularly helpful for somebody who has chronic GI bleeding. So if they've had, let's say, recurrent anemia, iron deficiency anemia, you haven't been able to identify the bleeding source with any endoscopic evaluation. And that's a situation where video capsule can be very, very useful because you can evaluate the small bottle, which not easily accessible with a traditional endoscopy. Thanks, Aaron. There's another question here for Jill. Do you have any recommendations for patients with type 2 refractory celiac with T cell lymphoma? How to get them to treatment, chemo, and so forth? You know, how to help patients who have difficult to treat celiac disease and potentially concern for lymphoma? I think you addressed that in your talk, but it sounded like that's a concern. I did, but depending on, yeah, I was pretty, pretty transparent. I haven't had to encounter a case like this. Absolutely. Reach out to the Celiac Disease Foundation. Gosh, because I'm sure there's also challenges with insurance. It sounds like this type of case also comes along with the difficulties with insurance, but reach out to your nearest tertiary center, but look to see what other resources are in the area. I used to see when I was growing up, and John and others may be able to comment on this as well, is anytime this type of question came up, they said, call Peter Green at Columbia and send it to him. John, you remember that? I actually don't remember, Peter. That's really interesting. Peter Green was, or is still, I mean, he was one of the pioneers in this space, but there's other centers that have come up, including the Mayo. I know Amy Oxentenko has had a significant interest in this, but there are centers of excellence for celiac that should be sought out. There are actually clinical trials going on now, too, and so reaching out to the Celiac Disease Foundation and see what they can do to help you. Wonderful. Dr. Vickery has his hand up. Dr. Vickery, did you want to add anything? Actually, Vivek really emphasized the point I was going to make, and that's referral to a tertiary center, so I will lower my hand. Yeah, I mean, the thing is, I think the person who asked the question, I think, how do we get to those? Some of the society websites will have that information. Google is very easy nowadays, but there are, you know, just like for eosinophilic esophagitis for celiac, these are very, very focused areas of research, and there are at least between five and 10 centers in the country that people, this is their life's work, so such patients belong at those centers, no question about it. Now, there's a question about indication for contrast. We addressed that. When do you do abdomen and pelvis imaging, Aaron? What's the importance of the pelvic imaging in a typical patient who comes for GI consult? You know, if, I mean, we do oftentimes perform the two tests together, you know, for somebody who has lower abdominal complaints, right, lower left lower quadrant pain, you want to make sure that your images do include the lower part of the abdomen and into the pelvis. The only times that I typically will just order an abdomen is if I'm doing, for example, a triple phase liver CT, and I'm not interested in any of the pathology in the lower part of the abdomen, or pancreatic protocol CT, again, you're not, you don't have any reason to look at that area. But, you know, for most patients that come in for evaluation of abdominal pain, if that's your indication for doing the test, your best bet is to include the pelvis in your exam as well. And your physical exam and your history will dictate really where you're going to go. So that's good. And then I think we had a question about a patient came in for some other problem, an endoscopy was ordered and patient was found to have unsuspectingly high grade dysplasia in a bad setting. So that's not uncommon. A lot of my referrals internally from from within the institution come exactly like that patient came in for GI bleeding, and one of my colleagues judiciously performed a biopsy and then in the in the transition clinic, the outpatient clinic after admission and such. This was followed up and then the referral comes in. So that's not an uncommon event. We're coming up, I think from the close, I'll try something really quick here. And I know, Aaron, you have to head on to a more fun afternoon with the reunion. Good luck with that. And thank you. Thanks for your contribution up till now. It's a pleasure to have you and thank you for your talks and for your expert opinions. I wanted to try something and Aaron, you're included in this before we let you go, is for each of your talks, Aaron and Jill, can you leave the audience with one a one liner that would be the most important takeaway before they go to lunch? So Jill first. One liner. We used to call it stump the chumps, but what's the one thing about celiac disease would you would like the audience to leave as they move for lunch? I think the most important is base your testing on a gluten full diet. Really discriminate your patient's dietary history and make sure you're initiating your testing for celiac disease with a patient that's level set and they're on a and they're ingesting gluten in their diet. That makes a lot of sense. Thank you, Aaron. Yeah, I did. Good. Fantastic. So, so my one liner would be learn how to access your radiology images and get in the habit of looking at them. Even if you don't know what you're looking at, read the radiology report, look for the nice little marks that the radiologist makes on the images to show you where the abnormal findings are and you can become a little expert on imaging studies.

medical imaging

gastroenterological conditions

contrast

CT scans

Barrett's esophagus

follow-up