gastro radiology
Summary
This on-demand teaching session will cover the basics of the undergraduate Royal College of Radiologists curriculum relevant to GI and will also include a lot of additional 'gold star' content to showcase radiology and its role in diagnostics. Tips will be given on how to examine patients and interpret X-rays and CT Scans. Discussions will include causes of small and large bowel obstructions, the expected pathology of a 43 year old woman and examples of sigmoid vuls and cecal signs. Attendees can expect to leave with a greater understanding of radiology, as well as brushing up on their knowledge for medical school examinations.
Learning objectives
Learning Objectives:
- List and explain the anatomy and changes that occur in an abdominal X-ray.
- Identify and describe similarities and differences in small and large bowel obstructions apparent in medical imaging.
- Distinguish between sigmoid volvulus, cecal volvulus, and other causes of large bowel obstruction.
- Demonstrate the ability to interpret the imaging of common abdominal pathologies.
- Describe the 369 rule in interpreting abdominal images.
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Computer generated transcript
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The following transcript was generated automatically from the content and has not been checked or corrected manually.
Cool, thank you, Sherry. OK. So um let's get started. So I've kind of reference a little bit um of what I'm included today in um the based on the RCR undergraduate curriculum, it doesn't say much particularly in pertaining to GI so cover kind of the bare minimum or the main things that they will examine you. But also because I'm a radiologist and uh I really want to encourage people. I've included a, a lot of extra kind of gold star content that is, you know, it's probably difficult and it's not gonna come up in your exam, but it's just to showcase radiology as um kind of a career and what we do on a day to day basis. So, um hopefully this would be entertaining if nothing else. Um So I guess a few tips to start the session. Um I think it's very difficult to try and learn radiology in isolation and it's probably quite boring just looking at pictures over and over again and it's not what we do in real life kind of. So it, everything has to be contextual in terms of interpreting the images so similar to the Acies. Um The clinical vignette that they provide, you would be the most kind of important bit for you to get your differentials and imaging is just simply there to confirm or um you know, or uh confirm that it's not the diagnosis, you need to think about something else, but it's not, it shouldn't be your primary diagnostic tool. So, um I think I have seven cases so we'll just run through the cases and um feel free to put in the chat if you've got any questions, there are a few kind of questions in between. Um, if nobody responds, I'll just continue. Don't worry about that. So, case one, you've got a 43 year old woman who is coming with abdo pain and it's going on for two days. She can't really eat and drink, she's vomiting. So, um the other thing is she hasn't opened her bowels for the, the last two or three days since the illness started and she's not passing any gas as well. In terms of significant past medical history. She's had operations, um including a hysterectomy and removal of her ovaries. When you examine her, the abdomen is really distended and it's very tender and she's guarding and these are her observations. So, um she's got tachycardia, she's breathing really quickly. Her BP is fine though. So you do all that, you present the case and they're like, oh, I get a chest, get an abdomen X ray and then this is what you see. So you know, that's m maybe the astute among of you would have spotted a few things that you want to discuss. But what I would say when presenting something like this is just to park this image in one side and then just until your consultant, you just gotta play the game in terms of a scan, stick to the script. So you need to first do, do the whole act of confirming that this is the right patient. This is the right scan. Um And this is um the expected imaging that you've ordered. You've got an abdominal X ray, you've it not examined like the limb or something. Um You wanna assess the quality um of the image and that's usually a spiel that you can just regurgitate in terms of uh a in real life, the the the computer screen and the software we use can actually alter um the interpretation quite a lot. So it's less of a problem now that everything is digital. But for us, you probably just wanna have uh ii first of assess the quality of this film to make sure that the exposure is adequate and the penetration of the X ray room is sufficient, something like that, something on the radar, two cafe or um gy metics would suffice. And the most important thing is to have a system. So you can either go from inside, out, outside, in or this is what I've got off geeky medics, where in terms of Abdo xray, you wanna have kind of BBC in mind, which is bowels, bones and calcification. So just another comment about quality um films like this, which you often see on kind of geeky medics or I really think of another undergraduate um website, but they have the pertinent pathology, but they're often not um too standard in terms of quality. And unfortunately, this reflects real life as well. You often just get images like this, what you really want and what the Royal College of Radiologists um accepts as a good quality abdominal X ray is that you have to include both the diaphragms. So this one, you know, it's the best I could find online, but it doesn't actually include both the diaphragms and you need to have the whole pelvic ring. So this one just cuts off a little bit and these lines here, they have a name uh pro peritoneal line though, you don't need to know that. But what it means you need to include it laterally enough that these lines are included. So this is the best I could find online, but you need to know that these are the bits that need to uh be included in terms of an X ray and anatomy. There's actually quite a lot and you know, places like uh the radiologists have annotated diagrams. Um but realistically what you need to know is not that not that much um in terms of ay for medical school. So just going back to this image that we saw of that 42 year old lady with abdo pain and vomiting. Um Anybody wanna put in the chat or shout out what they think the pathology here could be. Ok. No guesses. Um So what I can see and hopefully you can too is there are some bowel loops here. Your bowel obstruction. Yeah, perfect. Um Very good, sorry, very specific. Um Yeah, so that has dilated bowel loops as you can see here. And what's important is it's in the central location and it shows that they are small bowel because they've got this Eval convents and histologically or you know, if you open them up and what you can see or what proves that this is small bowel rather than large is you can see these mucosal folds that go all the way along. So when I be, when I start an X ray, they're quite difficult because you're like, oh, actually here it doesn't go all the way along. But what you need is just one line that goes all the way along. So to confirm to yourself that this is small bowel. So yeah, so she's got small bowel obstruction. So in terms of small bowel obstruction, a few points is the most common cause for something like this is adhesions. So, adhesions are just kind of scar tissue that forms in the layers in your abdomen and often uh more often than not, they are from prior surgery. So in the history, she's, this lady in particular had hysterectomy. So if they provide you a opinion, they have to give you a history of surgery to then lead you to small bowel obstruction, secondary to adhesions. And, uh, a, a top tip is, is actually more common for adhesions to occur in laparoscopic procedures rather than open surgery. A couple of um, other causes that you probably wanna have up your sleeve is elis. So ili is some is just small bowel kind of stunning. They're a bit lazy, they're not doing their job and often it's also after surgery. Um, you can also have small bowel obstruction secondary to hernias and they can also happen when you've got peritonitis um from an infective source that doesn't have to be bowel can be like cholecystitis or something. But the, the fluid that's circulating in the abdomen is um infected and that will just cause the bowel to kind of be angry and sluggish and not do its job and dilate. So that's small bowel obstruction. So this particular lady, um she had this X ray and then proceeded to CT. Um, now nobody would expect you to interpret this. I think the average uh nonradiology consultant would find this rather difficult unless they're also surgical incline. So there's no expectation to interpret safety. But I'll just include here for your completion, what you can see here and what the arrows are pointing is that this loop of bowel here is kind of squished. So this is bowel that is dilated. Um, there's kind of no normal segments here, but maybe this one is kind of normal ish in terms of, um, width, but this one is squished and it, it is squished because of a band that goes across it. That's all the CT is gonna add in terms of the, in, um, investigation. So I've just got a companion case to show you something else um in terms of bowel dilatation, et cetera. So this is large bowel obstruction. Now, what's different here is it's less central. You can argue this is central, but the the thing is with large bowel, it kind of forms a picture frame in the abdomen x-ray. So here this is your transverse colon. It's very common for it to dip down like that. But it generally has a more outside um distribution and the thing to note or to mention in the exam to, to confirm to the examiner, you know what's small and what's large is Haustra Falls. So Haustra Falls is lines that don't go all the way across. Now, you can argue this one is one line that go all the way across. But the fact that it's in the periphery, more like a picture frame would go towards large B than small because all this is just all a single two D picture of a 3D structure. So it's always very difficult to kind of be very conclusive about it. But yeah, the next thing to note is large b obstruction in an adult, most commonly is caused by cancer. You can also have other causes such as diverticular stricture. So, diverticular stricture is um, strictures that form uh following repeated infections follow uh from diverticulitis. So, if you don't know what uh diverticulitis is, it's kind of out pouchings that form in the bowel wall. Um And it's kind of uh things that can get infected. They typically in the sigmoid colon. Um Yeah, and the other thing with bowel, large bowel obstruction is there are two other kind of specific ones that people like to uh put x-rays. So you need to know about them and they are sigmoid vulval and sco. So just whilst we're here, there's also the 369 rule. So, um this is just general for all abdomen films. Three is the maximum diameter of a small bowel six is large bowel and nine is cecum. So the serum can go extra um compared to the rest of the large bowel and the cecum is the one that's on the right side. Um Yeah. So sigmoid vulval is what they often teach you in textbooks is uh the coffee bean sign. Uh And although that is one that is commonly associated with sigmoid vuls, it's not very specific for it because other large bowel pathology can also give you a coffee bean looking image. And this one, I'm not sure I would call that a coffee bean, but I've got better image here. That probably is more representative of coffee bean. But what's most specific to d differentiate between cecal and sigmoid flu is a hatra. So the large power has lost its hatra falls, it becomes so d it's lost its um uh sigmoid. Vuls typically accounts up to 5% of all large obstruction. The other key differentiating uh point between sigmoid and Sigal VVS is the patient cohort. So usually sigmoid vs is someone very old. They're much older. They are have Parkinson's MS. And what often happens is this, they have sigmoid vs, they get reduced and it happens again and again and again. Um they don't always need to have surgery for this. You can just insert a flare tube through the rectum and decompress the vulva um per se. So that's just just a different diagram to illustrate what actually happens in the Volvulus. So this is your sigmoid colon and it is a segment of the colon that's just generally a little bit more mobile than the rest of the colon. So what it does is it kind of twists on itself and give you this um dilated coffee bean appearances. So, like I said, the, the main differentiating um point to note between sigmoid and cecal is the population. Typically they're younger and also the fact is they're less common. Um You can see some haustral falls here, which is different again from the sigmoid one. typically you it would originate from the right left fossa, but similar to the sigmoid. It's very mobile so it can go anywhere. So yeah, just to summarize again between sigmoid and sigel sigmoid is older people, the more frail and it can happen repeatedly. The more specific sign is the loss of the house to fall. But the one that they probably want you to say is the coffee bean sign, sickle vs is rare and they're younger. This is just another picture of caco favolus and maintenance of the house. Ok. So I've just include this as a kind of an extra um case. So do you think this is small or large bowel dilatation or both? Yeah. Yeah. So it's, so here you have mixed small and large bowel um dilatation. So in this particular case, they actually have a primarily large bowel problem which cause large bowel uh dilatation. But because the ial valve, which is where the small bowel connects to the large bowel in the right colon, um it doesn't work as it should do. There is the back pressure kind of goes into the whole length of the colon and then into the small bowel and cause some of the small bowel to be dilated as well. So it can happen like this, you can have both small and large bowel dilatation. So just a few other indications of abdominal X ray that they might include in um S you get, you have IBD renal stone follow up and foreign body ingestion. I can't spell um uh of these three, I'm not really gonna talk about these two, so I'll just focus on inflammatory bowel disease. So within this, there are kind of three main buzzwords that you need to know. One is thumbprinting that pipe and toxic megacolon of the three lead pipe is a chronic appearance. So it doesn't happen in the acute phase. People won't come in, have an x-ray, uh come in with abop pain. Have an x-ray. You get a lead pipe that's very uncommon. You're more likely to get thumb printing or toxic megacolon. So this is just a chronic appearance of a burnt out IBD kind of uh picture thumb printing is very acute and why you have thumb printing is because the bowel wall is really, really thickened. So um if the Haustra before that you've seen is just one thin line, it's just much thicker now and it just gives you the appearance of thumb printing, that's all it is. It's just bowel wall thickening. Similar similarly in toxic micro colon, you kind of have thumb printing, you've got this extra mucosal islands which are just inflammation um in like a spotty dis distribution. But also the colon itself is dilated. That's why you get toxic megacolon. So you have to have dilatation for toxic me. I mean, it's a name. Um, but it also has the features of the acute thumb pain because it's just bowel wall thickening, which is the first sign I guess you would get if something was to be inflamed. So these are the three, buzzwords that you need to know for IBD. They're probably gonna ask you for thumbprinting and then maybe toxic megacolon. The only thing to note here is both these toxic megacolon and thumb printing can also occur in infective causes such as C diff. So that just exactly the same in terms of um cause and what you see on imaging. So I'll just move on to case two. Um OK, so we've got a 32 year old male who had an Ibuprofen overdose, sudden severe onset epigastric pain and it presents in septic shock. Um when you examine the abdomen is peritinic with generalized starting. So somehow they've kind of tricked you to order a abdominal X ray, whatever the conversation is. So you order that and this is what you see and you know, it doesn't look right, the dilated loops of bowel and maybe the astute among you can see that maybe this bowel has herniated um to the chest. But in this kind of situation, what one should kind of gather from it is what they're trying to say is they might have had perforation from like a duodenal or gastric ulcer because of the Ibuprofen overdose. So actually, what you probably should request for first or together with the X ray of the abdomen is an erect chest X ray because this would be the best uh imaging modality for you to identify gas under the diaphragm or pneumoperitoneum. Suggesting that something has perforated regardless of where it is in a duodenum or, you know, in the gas uh stomach. So just going to zoom in, into this a little bit more, there's also this r sign that's very, very often kind of taught or expected in medical school, which is um a feature of a pneumoperitoneum. So what it is or what it's supposed to show you is the double wall sign where you've got the wall of the bowel and you can kinda see it in both sides. The reason for this is because there's air now in the abdomen. Um That's kind of delineating it normally between bowel is fat. So you won't be able to see the wall so crisply like that. Um I've just got a different picture here. That's kind of e un equivocally pneumoperitoneum and that rigorous signs. So you can see the kind of gas on one end and the gas on the other end. That's what rigor sign shows between the walls. So there's gas inside the bowel and outside. So you can see a crest line. That's what rigger sign is supposed to, um, describe and it suggests pneumoperitoneum. So let's just see. Um And then case three is a 29 year old male, three day history of abdominal pain and loss of appetite. The bloods are really, really deranged and he's got kind of really classical tender and mc Putney points. So hopefully, you're already thinking about appendicitis and this should be a clinical diagnosis, but often more often than not in today's age, we would request a CT and um, this is just to comment about CT, um, interpreting a CT if you go in this view, which is what we call the coronal view is kind of like your anatomy. I don't know if you've used that in Cardiff when you learn anatomy, but it's just exactly how the anatomy is laid out. There's no trick here. We just get to see in CT that's all. And, you know, there's lots of websites that you can try and learn this from. Um, but this is not how we interpret CT S in radiology. We kind of look at it in a, a form. Um, why is that? I don't, I guess it's just kind of passed down and in the past when they acquired the pictures, they did it in this form rather than the Coronal. So we're just all forced to learn in this way. And I guess that's just how we've continued. But, you know, when you start out, this is perfectly fine to try and figure out where things lie. And I think this is quite a good way to learn anatomy as well. So I would just skip that. I'll skip that as well. So just going back to the case of a 29 year old guy with classic appendicitis, what you could see on uh CT is this stone here where the appendix would lie? So hopefully, you know that on radiology, because you're looking at the patient like at the bedside, the feet is facing you. This is your right and this is your left. Um what you can see here in the region of his right left fossa where the appendix is expected is this stone here. So this is the appendicolith and this is the culprit for the appendicitis. And here you can see again this kind of blind ending structure that's very, very dilated and it's this stone here that's caused the kind of obstruction. So normally the appendix should be less than five millimeters. But when it's obstructed and subsequently inflamed, it can be really, really large like this one. So I just wanted to make a point that, you know, ct is very useful. Um And in the past when they didn't have, they had to do an operation and sometimes the appendix could be completely normal. And one of the common radiology diagnosis that we can contribute is this thing called epiploic appendage appendicitis. So again, this is way beyond what would be expected to uh in, in Os, but maybe you, if you're on a surgical ward, you can impress them if you know, you know what it is. So what it is is that often in the right left fossa or even in the sigmoid area, the fat that's kind of surrounds the organs just gets um kind of inflamed and there is no cause or effect that's not like not like this appendicitis. You had the stone, it's just without any kind of clear explanation, it becomes inflamed and um it causes the same irritation to the pararenal lining, et cetera similar to an appendicitis. But unlike appendicitis, it is self-limiting. So you don't need to do an operation. Um All you need to do is just take some analgesia and then it will settle on its own. So this is kind of like a common thing that can happen. That is a mimic of appendicitis that uh CT is particularly useful because this guy, if we diagnose him, right, he doesn't have to have an appendix removal or go under anesthesia for any reason. Um I'm conscious. We're already at seven. Sorry, I don't know if we want to keep going more. Yeah. Yeah, I think keep going. Yeah. OK. Cool. So case four, we've got a 70 year old male who fell out of bed um onto his left side and he complains that side of the body is painful. Um I was gonna get everyone to scroll together, but this is just to illustrate that he, you know, even though that mechanism of injury was very, very minimal. Uh what he did. Ha what happened to him was he had a splenic laceration. So, again, this is your left side. This is your right side. The spleen typically lives on your left side. And the liver here on the right. And what you can see here if you believe me, this is the normal spleen, but this part where it's so irregular is the spleen that's kind of um injured. It's got lacerated and these here, this other shade of gray is um blood. So, um that was more so to go through CT, but I'll move on to a proper case. Um So he's got a 45 year old male this time and he's got abdo pain. This has been going on for three days. Uh It's typical, it's more in his right upper quadrant and it, it gets worse when he eats. He's had a few episodes over the past year. But normally this improves over a couple of days and he never has to go to hospital. But this time it is really, really bad. And when you examine him, he's got yellow skin, you know, he's got this Murphy sign where when you examine him in the right upper cord and it's really, really tender focally and the bloods, especially the liver function is just really off and he's got some inflammatory markers. So hopefully with this vignette, you're kind of already thinking, oh, is this gallbladder problem? Is it called cystitis? So that's what they thought and they were like, oh, let's do an ultrasound. So, um, maybe some of you've had ultrasounds before, but in general, what this is kind of the layman's expectation of what an ultrasound, um would involve. So, um, when we examine that particular patient's abdomen, what we can see is this black one here is the gallbladder. This bit here is the liver, so that, you know, the gallbladder kind of lives close to the liver. This one we're not gonna talk about, but inside the gallbladder, there's this thing here round and what this is, is a gallstone and we know for sure that this is a gallstone because, um, this is black shadow here. So if you imagine, um, the ultrasound waves are coming this way, things that would absorb the ultrasound wave would be really bright. Things that would just pass that ultrasound wave pass would be dark. So the fluid in the gallbladder doesn't absorb it. So it just goes through, that's why it's really black and that's what most fluid would behave. This stone is probably quite calcified and it's absorbing loads of the waves and none of it is passing through the back. That's why the back is black and then this particular thing is really, really bright. So just kind of gives us an indication of what kind of material things are made of on ultrasound. So we confirm that he's got a gallstone. Yeah, that's just the technical terms And when we kind of use a different angle, remember, the ultrasound is very dynamic and often they always say like, oh it's a user dependent or operator dependent. We can see that the wall is also really thick. So here to here and in between again, we said black is fluid, there's also fluid in between the wall and the outside. So this is the liver. So it's got a very thick wall and it's got fluid um surrounding it. So that suggest an a little of edema. So couple of these findings together, he's got acute cholecystitis basically. And these are just a few other pictures of the gallbladder. Not sure why. I'm sorry, that's repeated itself. Um Yeah. So findings of cholecystitis on ultrasound, you get thick wall and if you put this color thing, which is called called Doppler, you can see that's hyperemia. So what the color Doppler shows is the number of vessels that are around. So something is very inflamed. The vessels also get inflamed and you get this thing called hyperemia. That's all. And like I said, you've got edema wall wall thickening more than eight, sorry, more than five is abnormal. This is eight. But yeah, so these are the typical findings of cholecystitis and just a comment about the spectrum of biliary disease. So you got this pes little gallstone, if it's in the gallbladder and not doing anything, we call it cholelithiasis, just gallstone and gallbladder. If this gallstone is causing irritation because it's blocking something it'll be called. Um, and the gallbladder gets inflamed. It's cholecystitis. If the gallbladder comes, sorry, if the gallstone comes out of the gallbladder move somewhere in between the common bile duct that's called liars. So, stone in the duct that's outside of the gallbladder. And when you have stones here, bile can pass to where it needs to go in the duodenum. That bile is stagnant. very, very rich nutrient and becomes infected. And what you can get is cholangitis or sometimes people also call ascending cholangitis. Um and you can have this Charcot triage triage with uh cholangitis. So the other main imaging to know with regards to um called by the pathology is MCP. There's also ERCP, which is something I guess one can get mixed up. But MRI, if you think about Mr as an MRI, um it's MRI based scan that kind of looks specifically at the cholangio or bile pancreatography is the pancreas. So the bile ducts in the pancreas region and what is very, very useful is you can see stones that are in the bile ducts with Mr CP. You can also see a ERCP, but it's a way way more invasive exam. So MCP is often done prior to E RCP. So um on this image here is a coral segment, so you slice them kind of top down as you're facing them. And this black thing here is the stone and that stone is causing blockage and the bile duct is now really, really big. So normally you wouldn't, you won't see it so prominently. Um So we've got that choledocolithiasis stone in the bile duct um management. So typically, fluids, antibiotics, analgesia. And like I said, ERCP, which is e for endoscopy is the thing that you can do to remove the stone itself. So what they do is put a camera down your mouth, try to get through your Jordan and then back into the ducts and then remove the stone like that. Um This is also a commonly used term that can be confusing cholic that uh no, that's not what I want. It's supposed to be cholecystostomy here, cholecystostomy is um a drain that you insert on the ultrasound. So the patient just goes, has local anesthesia to the area. Under ultrasound guidance, we can put um wires and a tube directly into the gallbladder. It does traverse some of the liver. So it does puncture the liver. And um what it can do is help remove all those back, uh back flow obstructive fluid in the gallbladder, out and help relieve some of the sepsis. Um And it's only a temporizing measure, um, and often only selected for people who are deemed not fit enough for surgery because ideally if they're fair enough, you can just do a cholecystectomy, which is the um operative procedure to remove the gallbladder. So, um just a couple of terms that can be confusing, cholecystectomy versus cholecystostomy. OK. And this is just an extra, extra uh thing that, you know, can come up in conversation on the surgical wards but not gonna be in your exam. Um Mirizzi Syndrome. So it's uncommon one in 1000 apparently. And what it is is that, that stone that you can see that's, you know, causing trouble is it can be within the gal itself or it's, it could be that it's migrated out, um, into the ducts. Um, most importantly, not the common bile duct, but the cystic duct. So the one that goes from gallbladder into the common bile duct, that one, the one in between, um, and it's causing compression into the intrahepatic duct. So, unlike the stone in the CBD, this stone is not yet gone into the CBD is often within the gallbladder or the cystic duct or knee, but it's already causing, um, dilatation into the hepatic duct. Hopefully, that's clear. I think that's a bit confusing. Um, but yeah, so it's just a syndrome and this is what it describes. Ok. Um, shall I keep going? Yeah. Yeah. Go, go. Um, keep going. I heard about half six. So, um, if we have an hour it'll be. Oh, sorry, you're right. We did start. I keep thinking we start it at six. That's ok. I'm very sorry. Thank you. Um, so this is case six, we've got a 78 year old male with ABDO pain and it's generalized, so, not localized to any particular, um, part of the abdomen and it radiates to the back. His bowels are fine. He never, he's never had any previous surgery. He's only got hypertension and that's well controlled. He's really slim. And you think when you examine him, you actually can feel a pile mass in the mid mind. Um, and his obs are that he's a bit tachy and hypertensive. So hopefully you're already thinking that this is could this could be an abdominal aneurysm kind of picture. And sure enough, you know, they obtain a CT which is appropriate. And what you can see here again, let me or to you, this is the right side, this is the left, this is the spine. He's got, this is his kidney with a large cyst. So that must be the liver. And what you can see here just in the midline is this huge thing that has kind of different shades in it. So, um this thing is an abdominal aneurysm and it has ruptured and we know that because all this extra gray here is abnormal and it's blood um as to why it has this kind of different shapes of gray, it's just the contrast of opacification. Often when you've got an aneurysm, you've got this kind of mural thrombus. So it's just kind of layer um of clot in the wall and that's just part of the atherosclerotic process. But the most pertinent finding beyond the fact that he's got this huge aneurysm is that it's burst. Um, this is just another view coronal view of the aneurysm and you can see there. So he then has um, an endovascular procedure or, er, which is um done by the interventional radiologist. And um, what they do is often a small puncture in the groin, um, or, or the neck, whatever is more suitable um from the assessment on the scan and they can put in the stents. Um And that's supposed to help bypass uh the area that's burst so that the blood flow from the heart can just bypass wherever the hole is, that's causing this hemorrhage and supply the rest of the body. So this is a endovascular graft. So often there are kind of um co they come in like these three bits. Um you have this main limb that looks like a trouser. They do often re refer to as a trouser. Um This one usually goes first and then they will come in with the other one to make this kind of Y shaped thing. And this is what it looks like. Um on ct these are not the same patients, but this is what you can see. So it's just bypass that area. Um That's aneurysmal and like I said, these kind of uh gray will persist and it's just a part of the wall that's not very um resistant or resilient. So, what we want is something that's more resilient that's not gonna burst and bypasses the blood flow. So this is a typical post er appearance. Um, in terms of aneurysm, I think what you need to know is the nice surveillance guidelines. Um, there are kind of few numbers less than three is normal between 3 to 4.4 is a small aneurysm. They can get enrolled to a surveillance program and you just scan them every year. If it becomes bigger. 4.5 to 5.4 it's considered medium and you want to repeat the scan a little bit more frequently every three months. Uh And more than five, it's large and you need to do something about it. So you can either have, er, which is endovascular repair like we mentioned or open surgery. Um Yeah, this is just a summary. Basically 5.5 is the number that you want to remember. Um, more than five, you want to repair less than five. You want to have surveillance with ultrasound, but this interval could be different depending on the size. So I think this would be something that they could ask you on. Um, again, this is just another gold star extra not gonna come up in your exam, but I thought it would be nice to talk about. So beyond the fact that um people as they grow older, get these kind of atherosclerotic, um, aneurysms, you can also get aneurysms secondary to infect and typically they're bacterial and come from ineffective endocarditis. So, in case you don't know what infective endocarditis is, it's just, um, the valves of the heart got infected and they've kind of got little bits of ineffective foci stuck there. And those kind of infective blobs, I suppose can travel in b bloodstream and get stuck pretty much anywhere in the body. And one of the places it can go, such as the one we have on this case is the arterial wall. And um there are a few imaging differences that you can appreciate between a mycotic and atherosclerotic aneurysm. Um And typically the mycotic or infective one is more saccular in appearance. It has more of a abrupt change in its caliber compared to the atherosclerotic one. But like I said, this is bonus. So case seven, I think this is also um a good one. So 68 year old female with dysphasia, she's come in. She's like, oh, I can't really swallow solids anymore in the last couple of months. So I've kind of not really eaten much. I've lost some weight. So this is um one of the investigations that can order which is a barium swallow under fluoroscopy. So barium is a radio peak agent. So rape just means something that will come upright on x-ray. Um swallow is swallowing. Uh fluoroscopy is the x-ray machine that we use um specific for procedures like this. But the beams that is projected is similar to an X ray machine they just have slightly different dose um and functionality, I suppose. Um this is just a normal one. So uh it's dynamic studies. So when they swallow, we kind of take a picture and then we move the machine so that we can examine the whole gi tract. And often we do it in different angles like one is ap so anterior, posterior one is kind of oblique. So the angle sometimes we do them with the patient lying down as well. Um This is just an example. So this one is the one of the case I was talking about. So if you can see here compared to this one, there's just some irregularity here. Hopefully you can see that. And this particular appearance is what we call shouldering. And it's very path um specific for a esophageal cancer, typically adenocarcinoma. But um yeah, so this is normal and this is shouldering. So it's just that normal caliber is no longer there. Oh Yeah, to help. Um again, this is just extra from a curriculum just to show you what radiology can do. So once you have identified that they've got some esophageal tumor, what you can do is an endoscopic ultrasound. So you put the camera with the ultrasound probe down the throat into the esophagus and go where the tumor is because you want to look at how far and um the tumor extends beyond the uh esophageal wall. This is just showing that it's got an extra node around it. But this is kind of the length that you want. So, if that's normal, that's probably way too big for it to be normal. And this is all tumor probably. Um, the other thing that they often do is CT, because you want to make sure that that cancer hasn't spread anywhere. Typical locations are the mediastinum, the lungs, the liver bones, maybe. Um, you know, that's pretty good. Uh, the average radiologist will be able to pick up the um uh most of the metastases. But the other thing that we have been doing recently, depending on the type of cancer is a pet CT and on the CT, like, you know, I was trying to illustrate here that's a thickening, that's just not normal. And on pet C it just lights up like a Christmas tree. So what pet C does is you inject um like a agent that specific um specific for. Well, it's just sugar. But what it does is it where, where the body, where in the body is, um there is an area that has more sugar uptake than normal. And typically cancers do that because they have a higher cell turnover. That's why, you know, you get tumors and outgrowths. Um what it will do in the pet CT is go to those area. And what you can see is um areas of higher uptake of sugar. That's all it is. So if you got metastases into the liver as in the cancer here has spread elsewhere. This will also appear in the liver or the bones. So it's just a little bit more um sensitive in terms of detection. But there only some cancers that do this, some cancers don't behave in the same way and that is not then um I guess helpful and ok, we got time and the last bit I just want to cover is um what imaging or radiology you have in terms of cancer surveillance and screening. So I've already learned about one of the screening programs such as the AAA um screening program, but there are just a few more that actually radiology um contribute to in terms of GI. So the first one is um in the patients who have liver cirrhosis. So I appreciate you might not have seen many liver ultrasounds, but this one on here is the normal one. What you expect to see is the overall kind of texture of the liver is um very nice, very smooth, very homogeneous. So they're kind of not different, they're just the same throughout. Um And the border is very smooth, it's not kind of shaggy. Um Whereas in cirrhosis such as the one here, the border is just really difficult to see and where you can see the outline is very, very non smooth or nodular is what we say. And inside you can get different shades of gray. Um and it just doesn't have the detail that you expect because everything is kind of really, really distorted in the cirrhotic liver. So there are a few guidelines um as, as everything in medicine in terms of surveillance. Um And we in the UK, typically follow the el which is a European um guideline. So what people in people who have um cirrhosis, they get an ultrasound scan of the liver every six months. And what we're looking for is really focal nodules um because they can become HCC, which is hepatocellular cellular carcinoma. So they get an ultrasound every six months. And that's just kind of one of the things that we do um for this cohort of patients um more interestingly moving on from the liver is also um there's this new thing that we do, I mean it's not maybe 10 years or so and it's um instead of a colonoscopy. So it's a CT VC. So CT um virtual colonoscopy and what it does is um you get like a 3d format of the bowel. So you can detect for like polyps or any tumors growing up. There's a little video here that should be line through from that CT scanner data. This allows this would happen to be a cancer. This allows us to travel through similar to what a gastroenterologist would see as a sort that line through from that CT I'm not sure if that sh shared but yeah, basically, it becomes like a video and you follow it through and what you're looking for is kind of these polyps. Um they are different size criteria and appearances as to a benign and uh molecular one, but that's probably beyond the curriculum. Um And in the NHS, we kind of only use it where colonoscopy is incomplete or people who basically can't have colonoscopy, it's not a direct substitute, it's like a, I guess bailout procedure if you can't have a colonoscopy. Um But that's also a lot of work into it. Um progressing into like maybe a primary um screen rather than using a colonscopy. But at present, um colonoscopy is the most accurate one for detecting polyps or cancer in the colon. Uh I thought that was one more. Um But yeah, so just to summarize um imaging in os scan in real life should really just be used to confirm your diagnosis that you've already made based on the history taking. And hopefully the cases will have illustrated that um I guess in exams you wanna just use the passwords that are expected of you like such as thumbprinting coffee bean sign because the radiologist, sorry, the examiners are often not radiologists because they are often only incorporated as part of the vignette that's larger than the radiology component. So it'll probably be like a gi case with a radiology component rather than a solely radiology um exam. Yeah, that's it. Um Have you got any questions? I'm happy to go through anything that might have been a bit more difficult, but otherwise that's all for me. Thank you so much. Um That was really good. Thank you. Um I'll just send out the feedback from now. It's just bad for me. Um Yeah, so the feedback form is below and we'd really appreciate if you could give us some feedback. Um And uh after that, you'll also get an attendance certificate and you'll be able to access the recording of the session. Um If you have any questions, um, feel free to pop in the chat or, um, mute yourself and I'll stop the recording now.