Abdominal Imaging by Consultant Radiologist, Dr Pai



This free online teaching session offers a deep dive into Abdominal Imaging for medical professionals. Doctor Pa will guide attendees through a detailed overview of the imaging modalities available for this medical emergency--focusing on CT scans, in addition to other modalities including plain films, MRI, ultrasound, PET, and interventions such as embolization, drainage, and stenting. Along with discussing the role of imaging in helping diagnose, treat, and follow up with patients, attendees will also be taken through practical examples of abdominal x-ray, small and large bowel obstruction, and the importance of a good history, examination, and clinical diagnosis.
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This 45 minute teaching session provides junior doctors with an opportunity to deepen their understanding of abdominal imaging with an interactive presentation delivered by Consultant Radiologist, Dr Pai. Participants will be exposed to imaging modalities, interesting cases and presentations they will see regularly in their practice.

Learning objectives

Learning Objectives: 1. Understand the causes of acute abdomen. 2. Learn to identify key features on abdominal x-rays. 3. Demonstrate an understanding of the various imaging modalities used for acute abdomen. 4. Learn to differentiate between imaging findings for small and large bowel obstruction. 5. Demonstrate an understanding of the role of images in diagnosis, treatment, and follow-up for acute abdomen.
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The following transcript was generated automatically from the content and has not been checked or corrected manually.

Hi, good evening everyone. My name is um Suleiman. I'm one of the fy twos. Uh I along with Shaan and um are a few junior doctors that I've arranged um a free online teaching series, um called Radiology In Focus Alongside Mind the bleep who've been assisting us as well. Um So today we've got doctor Pa and he's going to be presenting abdominal imaging um for you all. Um So in terms of the events that we're hosting, there's a number of events you should have received the poster. Uh If you haven't, you can drop a comment into the box and um we can make sure that's delivered to you. Um So without further ado, I'm going to introduce the consultant radiologist, um doctor and he's going to um start his presentation. Ok. And if you have any questions today, just pop it in the chat and um either doctor will um Alton Tab to the comments box or we read out your um question or answer. Thank you. Yeah. Thank you very much uh Suleman Shahan and Busch for this opportunity. I think it's a great initiative uh to start with because radiology is not taught that much uh at the junior doctors level. But I'm a bit confused as well today because usually I do this teaching for junior doctors F one F two level. But I know that most of the audience today are aspirants who wants to become radiology trainees. So that way it has become a bit confused in the sense you may already know most of these affect things which I'm going to talk because uh you are already trying to get into radiology. You might have attended a few teaching sessions. But I will keep it simple. I will talk as if I'm talking to the junior doctors and at some areas, I may change my way of talking as if I'm talking to the radiology trainees. So to make it a bit interesting, so let's see how it goes with this technical things which has uh talked to me just this evening. Hopefully it goes well. So the topic is mainly about abdominal imaging. But I want to choose only acute abdomen and CT because as you can imagine, uh covering all modalities of like abdominal imaging will be difficult in 45 minutes to one hour. So main focus is on acute abdomen and that to concentrate on CT, but there is some consultation will be on some plain films as well. So as junior doctors F one F two level, you might have realized that acute abdomen is one of the common acute medical and surgical emergencies um that you come across. Um but the problem is it is not only the abdominal causes, which can give rest to the symptom, it can be an extra abdominal causes, metabolic causes also can give rest to similar symptoms. Patient might just say acute like abdominal pain and it can be various causes. Now, the problem with doctors is that to find out the cause and so that we can treat accurately. But to reach that accurate diagnosis and management problem is we need to have acute history, accurate history. We need to have examined the patient and we need to have a clinical diagnosis, then choose the relevant imaging modality, then only we can reach the right area. Otherwise, if we just request scans without knowing what you are talking, what you are looking for and what you're suspecting, we may do the wrong investigation, wrong modality of uh imaging. And then we may not reach anywhere or we may cause harm to the patient by making the wrong diagnosis. So I know that you are all radiology, aspirants, but important topic. The message which I want to uh I think get across is that without the first two steps of history, examination and having a clinical diagnosis, uh whatever imaging modality you do, we we may not reach the right area or we may cause the harm to the patient by making wrong diagnosis. That is important. Uh point I want to get across as you can see on this slide, there are so many causes of acute abdomen. So can anyone tell me uh is there any causes which is not highlighted here? Are there any causes which is not shown there? Or you can unmute an answer if that makes it easier? Doctor Pa you might need to go to the previous image cause we can't see it anymore. Which one? Yeah. Uh No, no. Go back. Yeah. Just stay over here for a minute. Yeah, I think are you able to read out because I'm struggling to go, go through that way? No, we can, we can read them. Yeah. So there is a list of G I causes. There are, there's some list of uh gynecological causes here. Are there any which is not mentioned or not highlighted? Here, we have a renal colic and bowel obstruction in the comments. Yeah. Good. Yeah. Renal is the one which is not shown here. Very good. And as I said before, extra abdominal causes are not shown because basal pneumonia as you know, can present as acute abdomen. Patient may not have respiratory symptoms but they may have abdominal pain because of referred pain. Uh It can be a problem in Children who may not give the right uh like exact history and also metabolic causes. You know, if the patient has hypokalemia, hypercalcemia, hypocalcemia can also have uh like bowel obstruction, like pseudo obstruction type of presentation. So, and diabetic ketoacidosis, you might have seen the patients who come with acute abdomen and they have diabetic ketoacidosis. So like that there are so many causes which, which is not listed here. That's why the history is very important so that you can uh examine and suspect what you are like what you want to rule out and then ask for imaging that will be better. Otherwise just writing abdominal pain on the reas and getting CT scan may not take us anywhere. So the aim of the presentation is mainly to highlight the CT in acute abdomen. And what are the basic principles? What are the techniques of CT and what are its limitations? Even the CT is good, but it has got limitations as well. If there are limitations and what are the alternatives to choose? Those are the things to highlight and the role of imaging as all of you know, is not only diagnosis, we are treating the patients as well with the interventional radiology, we do the drainages, we do the uh like embolization of bleeding arteries, nephrostomy, biliary stents, ureteric stents. There are so many things. So it's not only that we diagnose, we help in diagnosing, we help in treating as well. So imaging helps to rule out or rule in your clinical suspicion like you suspect appendicitis and you want to know whether it is the right diagnosis or something else, then you have to do imaging and if there is some diagnosis, then we need to know the cause. For example, if there is bowel obstruction, we need to know what is causing bowel obstruction, whether it's mechanical obstruction, if it's mechanical, whether it is intraluminal, extra Luminal like that, so it will help to find out the cause as well. And once there is a diagnosis, we need to know any complications of the primary problem. Like patient may be having bowel obstruction. Is there any complication like whether it is perforation or if there is any some collection of pus or uh uh any hemorrhage around that area, we need to know that as well so that it will help the surgeons to manage it appropriately. And uh and also as I said before, we help in managing the treatment with the embolization, drainages and stenting as well. So there are so many things as you can see here, radiology is not only about diagnosis, it is helping with the treatment as well and also it helps in follow up like patient had surgery and then you want to know whether it is completely clear or not. So that way imaging is helpful as well. Now, imaging modalities, what are the imaging modalities we have? I just want to give a few seconds for you to answer and then we can go through the list. Are there any answers Suleman or? So we have abdominal x-ray ct MRI pet ultrasound Bari. Um excellent. It's covered most of the things. Very good. You are ready for radiology, trainees. So yeah, intervention, radiology is the one extra nuclear medicine is very, very rare. Uh Even if you have not mentioned that's spine and MRI, as I said, so there are so many modalities now, which one you choose will be depending on what you suspect if you suspect, for example, gallstones better to go for ultrasound rather than CT because non calcified gallstones may not be seen on CT. So plane films are very, very rarely used, but um, it has got its own role in some areas. And MRI is the one which we use. Uh, if you're having gynecological pathology or MCP, uh for gallstones and biliary obstruction and CT may not be helpful like that. Uh We need to know what you suspect. Then only we can choose the right modality. So I, as I said before, plain film is less and less useful, but we are still doing them since we are still doing them better to know what to look for and what other abnormal it is, it is good for. So this is an example where you can see this patient, patient presented with the abdominal pain and vomiting and abdominal distension. You suspected bowel obstruction and then we have done the x-ray. So, has it shown bowel obstruction or is it normal? So, in this E x-ray, there is no doubt that it is bowel obstruction and it is small bowel obstruction. So it, because there are too many loops of dilated bowel loops. And you can see there are mucosal folds which are continuous rings and there are too many of them and in the middle of the abdomen. So that is all small bowel. We are not seeing any large bowel obstruction. There is some ascending colon. We can see with feces but not distended. It means the pathology or obstruction is somewhere in the distal ileum. But we don't know the cause. We can't see the cause on this one. That's why we go for CT after this. So that is an example of small bowel obstruction. Similar another case where there is typical features of small bowel obstruction in the middle of the abdomen. There are too many loops which are dilated and we can see the mucosal folds which are too many and they are continuous and they are complete. So that is the importance of uh looking for uh like small bowel obstruction, the picture. So when you have got this type of picture, then it's fine to say a small bowel obstruction when we go for CT to find out the cause. This is an example which looks different to the previous one, isn't it? So this is a large bowel obstruction. You can see the distension of the bowel is too much and the loops. Uh I mean, the mucosal folds are not many, they are only infrequent and they are incomplete like this one stops here. This one stops here like incomplete and too much of distension. And from below, from this point downwards, we are not seeing any distended bowel. So it means this patient has large bowel obstruction somewhere around the splenic lecture. Again, we can't see the cause. Then we go for a CT scan to find out what is the cause for the obstruction. Usually it is malignant process in that area, if not always. So that's how uh we try to evaluate. Now, this is an example which I want to highlight is this patient has presented with abdominal pain, vomiting, not opening bowels distension. And you suspect clinically bowel obstruction. And when you do the x-ray, this is the finding. Does it mean patient doesn't have bowel obstruction so you can answer your, you can put the, uh your comments in the chart box. So like clinically it was bowel obstruction. But when you do the x-ray, it looks different to the previous x-rays we have seen. So does it mean this patient have no bowel obstruction? Is there an answer? So we've got one comment saying it's hard to visualize. Can't rule out need CT to confirm. Yeah, that's good. Um But in this case, like clinically you suspected, but we did the x-ray. It doesn't look like anything like we saw the previous slides. So I just want to highlight that bowel obstruction does not always have to be gas filled, bowel loops. It can be fluid filled in the, the patient comes a bit later to the hospital fluid, which are like the bowel loops which are dilated may be filled with fluid rather than just the gas. Then we may not see, uh, anything on the x-ray. Because on x-ray, we are dependent on seeing the gas, then we can see the bowel loops. But if the bowel loops are filled with fluid, everything will be same density. So we will not be able to see anything on x-ray. So when this patient had ct this was the finding. So it was still bowel obstruction, but we couldn't see it anything on the x-ray because these are all filled with fluid. So that's the importance of uh examination and history. So that if you had just done this x-ray without knowing how the patient is, we would have just taken it as a gasless abdomen and without taking any further action. But since you had seen the patient, you are suspecting clinically obstruction. That's why the CT scan showed that that finding same, same finding another patient. This x-ray is done because patient has abdominal distension but no vomiting opening bowels. Ok. And not acute presentation. So it looks the same you think compared to this x-ray, it looks the same, isn't it? But history is different here. What do you think is going on here? Anybody to answer any answers there? Not yet good. Ok. So that's fine. It looks the same, but the history was different. So the renal colic, right side. Sorry, somebody's asking renal colic. Yeah. So yeah, I think you are seeing all these these are all bony lesions. This is a patient with breast cancer, with bony Mets and patient distention was due to abdominal fluid ascites. So, but as you can see the history was different and appearance was the same. So what helped us to differentiate between ascites and bowel obstruction on a plane film is the history? So that's why the history is important. Only then we can interpret the images properly. Otherwise, we can easily lead you in the wrong direction. So this was a gross ascites. When there is a lot of fluid ascitic fluid, it will be, it will compress the bowel loops because of that, we will not be able to see the air within the bowel loops. That's why uh it looks bland uh like the previous one, but the previous one was due to bowel obstruction, but bowel looks filled with fluid. That was the problem. So those are the examples just wanted to show that uh how the plain films can helpful be helpful in looking at bowel obstruction. Other importance of acute abdominal imaging or x-rays is along with the abdominal x-ray, we have to do chest x-ray as well because we will be looking for uh pneumoperitoneum. So it may not be always easy to see it on abdominal film. That's why we do the chest x-ray where a patient has to sit up or stand at least for 10 minutes and then we look for uh gas under the diaphragm. So this is a typical example where nobody should have any problem to say it is gas under the diaphragm. And patient has acute abdomen as well. It's not always easy. But this is another case. So, can anybody tell me if there is any gas under the diaphragm on left side or right side? Yes, right side, good. So this patient was examined and patient was Peric and suspected clinically something ab abnormal when we did the x-ray, this is magnified just the ordinary x-ray. We couldn't see it very well. But when there was clinical suspicion, we magnify the image slightly, then we can see small amount of free gas, which is difficult to see if it is not magnified. So that's why we have to look for that area. Otherwise we may not see it. So bowel obstruct, I mean free gas can be as small amount as that. So that's why it's important to look for carefully. Most commonly, we see the gas under the diaphragm on the right side. It's not always the case. In this case. As you can see it was on the left side uh between the stomach and the diaphragm, there was a small amount of free gas. So that's what we need to look for. All those things we'll be looking for when you have seen the patient. And when you're suspecting clinically that something is wrong. Otherwise, we will see this has any other x-ray and then take it as normal. So that's the problem. So I don't want to spend too many uh too much of time on abdominal x-ray showing pneumoperitoneum because we see it usually on a chest x-ray when but and sometimes we can see the pneumoperitoneum on the abdominal x-ray. The, the things to look for is if there is any solid organ looks very well defined, it means there must be some gas around it. So on the left side, we can see the renal shadow but not very well defined. Here, you can see it very well because instead of fat, there is gas around it. That's why it looks very nice and crisp. And this is the liver border. Usually we don't see the liver border so nice and crisp, but there is gas around it. That's why we can see it very well. So this is one examples we can look for as a pneumoperitoneum. Other thing to look for is ari sign. You might have heard that name before. R sign means when we can see the wall of the bowel nicely, both inside and outside. Normally, we can see the inside wall very nicely because there is gas within the lumen. When there is perforation, there will be gas outside the bowel as well. That's why we can see the wall of the bowel nicely. It's like a um wire running across. That's what is a sign we can see the similar thing here as well. Doctor Py, there's a question asking about Chile. Chile Di's pseudo pneumoperitoneum sign. Yeah. So that is sometimes we see that Chile where there is bubble loops is interpose between the diaphragm and the liver. Usually it will have some hostile folds within the uh free gas area. Then it goes in favor of chili. It's not always easy. But if the patient has no acute abdomen, the patient has got only like not much peritonitis and all those things and you see it, then you can start suspecting whether it is really chili or whether it is really gas under the diaphragm. So, unfortunately, in some cases, the only way of knowing is by looking at the previous film. So like these patients would have had previous x-rays, then similar finding might have been there. That helps sometimes to say it is. But if the patient doesn't have any previous imaging and patient has acute abdomen and you're not sure you better to go for a CT. So always look at the previous one because I GT findings like bowel loop between the diaphragm and the liver will would have been there in the previous xrays. Uh It's another example of a regular sign. Ok. This is another x-ray, which is important, which shows continuous diaphragm sign. So normally we don't see the diaphragm going across the midline continuous because it stops in the midline. But when there is gas under the diaphragm, uh that gives an impression as if the there is continuous diaphragm. So that is an example of lucency running across the midline. Uh That is an example of pneumoperitoneum. Uh This one I don't want to highlight. Ok. Tho those are the examples of a free gas. Uh As I said, mainly it is a chest x-ray which is helpful but abdominal x-ray also, we can look for those signs. This is an x-ray. You should be able to uh say what it is. Uh because the history he is here, patient has got diarrhea and it is bloody diarrhea and acute abdomen. So with that history, you have done the x-ray. So what is going on here? What is the finding? If you're not aware of this type of finding? You should uh be aware because that's one of the things you should be expected to see and interpret in an acute setup. Anybody. So we've got a few comments, I'll read them out. Um One person said left side is colon carcinoma. Um We've got lead pipe sign. Yeah, and we've got IBD flare bowel thickening. Yeah. And lead piping again. Good. So what we are seeing here is the finding called thumb printing. Can I see this? That is mucosal edema and there is no feces in that part of the bowel which is abnormal. If you look at the scenic colon, we can see the fess a descending colon is collapsed. But I think they are right because there is thickening of the wall of the column there. That's what they're referring to a lead pipe. So this is the thumb printing sign, which is an important sign. It is a mucosal edema. In a young patient, it is due to ulcerative colitis or like inflammatory bowel disease. Uh in an older patient, it could be due to ischemic colitis. But that's what you need to look at. When there is thumb printing that picture, that part of the bowel will not have feces because that is inflamed, part of the bowel. If it it it it won't let the feces to stay in the inflamed area. That's why they get the diarrhea. So that is an example of thumb printing another example, similar picture. But in the descending column, can you see that all this is mucosal edema th printing and in this part of the bowel, there is no feces but there is fas in the proximal colon. And this patient has got abdominal pain, diarrhea, and sometimes bloody diarrhea. So that goes that with the history and that, that's when we look for these findings. This is another example where there is transverse colon is inflamed. That's why we there is no faces and there is the mucosal folds. We can't see any mucosal folds. You should usually, you should, we should see the hostile folds which is all destroyed because there is inflammation, inflammation leads to destruction of mucosal falls. That's why we are not seeing plus there is no faces. And then we see this edema that is the transverse colon showing colitis picture. In a patient who is known to have inflammatory bowel disease and who comes in with acute abdomen. They do the x-ray. Can anybody tell me why do do x-ray for a patient who has acute abdomen and has got history of inflammatory bowel disease, colitis, uh ulcerative colitis and or Crohn's disease. There is one surgical emergency. You want to rule out what is that any answers? So we've got toxic megacolon and yeah, excellent when there is history of that, like when patient is known ulcerative colitis and comes with acute abdomen, very unwell, we do the x-ray. So this is an example of that, this is a mostly distended transverse colon and you can uh somebody said before, lead pipe picture. So this is that it is a bit subtle here, but this patient is known to have ulcerative colitis and when you're acutely unwell and this is the finding, this is an example of toxic megacolon. And if you see carefully here, there is some lucency gas under the diaphragm on both sides, very subtle. But those are the things we need to look for in acutely ill patient with that type of history if that type of history is not given. And x-ray is done without saying all those things then it can be all those things can be missed when that history is there. We make sure that we look for those signs. There is a there is pneumoperitoneum toxic megacolon and then chronic like features of ulcerative colitis without any Feiss in the inflamed descending colon. Doctor pipe. Sorry, someone's just asking. So does the thumb printing sign mean colitis? Yeah. In like the patient is young. It is colitis. The patient is older. It can be ischemic colitis or sometimes like mucosal metastasis can also give rise to that appearance. But yeah, for practical purposes, it is colitis. Yes, this is another picture. You need to be aware of. What do you think? Is this one? If you see this, you should be able to diagnose straight away. This patient has got abdominal pain, not open bowel for a few days and coming with that history and you have done the x-ray. You are a this finding. We've got volvulus and toxic megacolon. Yeah, good. So toxic megacolon, not because with toxic megacolon means patient has colitis, you usually lose the host fold. But in this patient, we can see the host folds and this is the coffee bean sign. You might have heard that name before coffee bean sign. When there is large ball is grossly dilated with the mucosal folds still being seen. And the proximal colon is also been dilated. Gross dilatation of the large ball is seen in volvulus. When you see this and other part of the large ball is dilated and it is sigmoid volvulus. And when you don't treat it or patient comes a bit later, it can be as grossly dilated as this. You can see this. So there is gross dilatation, mucosal folds, hostel folds still can be seen and patient doesn't have any ulcerative colitis history. So this is a sigmoid ulus. So we need to differentiate it from scal ulus. This is how it looks because with the cecal voles, what happens is we get gross distinction of the large bowel but other bowel loops which we see are all small bowel loops. We don't see any rest of the large bowel lobes being dilated because cecum is twisted there, there's no gas going into the like into the rest of the large bowel. That's why we don't see the rest of the large bowl. What we see is the small bone being dilated because twisting of the cu leads to dilatation of the small bowel loops and the distension and the scal pole will be seen in the left upper quadrant on the s on the sigmoid volvulus, it will be on the right upper quadrant. Those are the things we use to differentiate because the treatment is different. If it's sigmoid volvulus, they can take time uh to think about what to do whether to pass the tube and deflate the sigmoid. But if it's scal ulus means only treatment it is, is a surgical. There is no other treatment uh for the scal vol because it is dangerous to leave it alone. It can rupture and then cause uh fecal peritonitis. So just want to show that gallstones can be seen sometimes, but please don't request abdominal x-ray for suspected gallstones because only 10% of gallstones. We can see gallstones are seen only when they're calcified. Most of the gallstones do not have calcification. They are just cholesterol stones. We may not, we will not be able to see them on x-ray. But if you see it, it is a bonus. But if it is not, it doesn't mean patient has no gallstones. So this just want to give a flavor of uh wanted to give it, just show a plain film where it is useful. But as you can see in an acute abdomen, plain film has a lot of limitations. It is not good for G I bleeding bowel ischemia, AAA rupture or AAA itself, gallstones and cholecystitis appendicitis. There's so many things, it can't help us. It is helpful only to say if there's bowel obstruction or if there is a foreign body injection by Children or uh mentally abnormal, uh or like depressed, older patients can swallow all sorts of things in such scenario. Otherwise, please don't request abdominal x-ray. I just want to go to the CT straight away because it is an excellent tool for acute abdomen. Um It is an, it is x-ray, but as you know, it is, it is, it uses a lot of uh x-rays and a lot of radiation dose. And that's why we have to use it uh carefully in small Children and younger adults and, but it is excellent, but it has got its own limitations that I want to highlight as well. Um And also there are various techniques of CT, that's why we need to know what you are suspecting to rule out. Otherwise, we may not do the CT in the right way, then we may not get the right answer. So the basic principles, as I I said at the beginning itself is history and clinical diagnosis important, then uh we need to suspect uh right, what you suspect clinically try to look at the previous imaging as I said before. If there is a still or loop of ball between the diaphragm and the liver, it may be longstanding finding, then we may not worry about it. And once, once you have done the imaging and if things are not matching because you suspect something else and the report comes as something else, it's not matching, isn't it? It means uh we need to have discussion otherwise, uh if you don't have discussion and things are not matching with the clinical and imaging, we may be causing damage to the patient. So we need to have discussion and then think of alternatives. So things are not matching here. What should we do? Should we go for another imaging or do another test or need to have more information like how the blood gasses are, how the electrolytes are and things like that, that helps many times to sort out the problems. Otherwise, if you work separately, like clinical or radiological, separately without any discussion in in between it, it can be a problem. So yeah, this is one I have highlighted before. The thing highlight want to highlight again is that we change the technique of CT depending on what you suspect all the CT is not, not done the same way. So what are the CT techniques we change? Um We don't do precontrast like mm ordinary CT without any contrast for all patients. Unless you suspect these things. If you suspect abdominal aneurysm, suspect G I bleed or pancreatitis, biliary obstruction, we do noncontrast ct first to look for any calcification uh in the pancreatitis pic patient or in a G I bleed. We need to do non contrast CT first because after giving contrast, if there is any G I bleed, we can see that extravasation of the contrast into the lumen of the bowel. If that is not, if the noncontrast CT is not there, then we will not be able to say what is what we are seeing in the lumen of the bowel is blood or just ordinary content. That is the importance of that. If you have not told us that, then we may not do the CT right away. And sometimes we have to do the CT in the arterial face. Arterial phase means patient has IV contrast and then we wait for 25 to 30 seconds. Then we do a CT that helps to show the arteries very well. It may not show the veins very well but arteries. But that is important to know if you are suspecting aneurysms or if you're suspecting bowel ischemia. Because what we are looking for is enhancement of the wall of the bowel. If this phase is not done, we may not reach the diagnosis of bowel ischemia. And if that is not mentioned on the request card, we may not do it and then we may not get the diagnosis. And if you're suspecting stones like urinary stones, we don't need to give any contrast. Just patient is done as an ordinary CT because we are looking for, for stones in the kidneys and ureters. If you give the contrast contrast is excreted by the kidneys and it may mask the stones. That's why we need to know what you're suspecting. Um, oral contrast is preferable, but we are not giving too many patients. But if you're suspecting G I bleed bowel ischemia or renal stones, we don't need to give oral contrast because if you give the oral contrast, G I bleed will be masked bowel ischemia. We may not be able to see the enhancement of the wall very well. If there is already contrast within the bowel lumen. That's why the importance of knowing what you're suspecting so that we can change the technique of the CT. But if you're not given any history, it's just abdominal pain, we just end up doing this ct where we give the contrast and wait for 60 to 70 seconds. By the time, all the contrast would have circulated in the body and it is seen in both arteries and veins that is called portal venous space. That's what we do. If you're not told us what you're suspecting, we can see there are so many techniques we have to use depending on what you are suspecting. That's why you need to tell us what you want to rule out. Otherwise, we may not do the right CT a delayed phase ct. Sometimes we have to look for if there is like ureteric obstruction, I'll show some example. So what are the advantage of CT? Is that any small collections or free gas? We can see and if there is bowel obstruction, we can find out the cause. And what is the site if there is any solid organ pathology, like a metastasis or any trauma setup? Uh laceration of the organs we can look at and it can look at the complications, it is reproducible so that we can use for follow up. Like there is a problem with ultrasound because ultrasound is operator dependent. Uh how they do the scan will affect how we use it whether we can use it for follow up or not. But in CT, all the CTS are done the same way. That's why there is no problem whether it's operator dependent or not, it can be used for follow up. And for comparison, yeah, it is sometimes good for management of the patients. Uh when we want to drain the abscess, which is deep inside when ultrasound may be difficult to use, that's why it is useful as well. So I just want to have a few seconds here. Just tell me what are the signs we should look for in an acute ct abdomen as ominous signs, like dangerous signs. You give a few seconds, just uh write your comments like on the chest x on abdominal x-ray. We look for ball dilatation and free gas like that. What are the things we have to look for when the patient has ct abdomen and done for acute symptoms? We've got one comment saying fat stranding. Yeah, good. Ok. So, uh go through one by one. So you're right. First shining is one of them, uh like dilated bowel loops as we discussed in the plain film. Now, gas in the wrong place means pneumoperitoneum. If the gas is outside the bowel lumen, then it is ominous sign, we have to do something about it. Or if the bowel gas, if the gas is in the bowel wall is also very dangerous because it could be ischemic bowl will have gas within the wall. And if there is gas in the solid organs, it's also dangerous. It means uh like if there is gas in the gallbladder wall, it is emphasis or if there is within the liver, maybe abscess or portal venous gas. Those are all the dang, if there is gas within the tubes, like if there is gas in the biliary CBD having uh gas, it can be indicative of gallstone ileus or within the ureters, suspection of uh like very bad uti things like that or fluid in the wrong place. Normally, we should not have any fluid outside the bowels. But if there is a fluid outside the bowel and it is a high density is also worrying high density fluid means whether it is pus or hemorrhage and there should not be blood in the wrong place. We want blood circulation. But if the blood is in the wrong place, like outside the bowel loop or dilated uh a arteries, aneurysms is uh dangerous. And if anything increases in density after the IV contrast means there is active bleeding. So you do the contrast and there is some fluid and the density of the fluid increases after you have given the IV contrast, it means there is blood going into it. Um that is dangerous as well. Or if there is any dilated vessels like aneurysms and abnormal vessels, uh arterio venous malformations. Those are the things. Yeah, stranding of the fat which you said is dirty fat. It means there is some edema within the fat. It means usually it is infection, inflammation, those things are dangerous. So those things we look for on AC T. So let's see, send some examples. This is a CT which is done without any contrast. You can see there is no contrast in the bowel and there is no contrast in the uh IVC or AORTA because you suspected patient presented with left groin to groin pain. And you suspected uh ureteric, that's why this was done plain CT. Now, you can see there is a calculus within the urethra. So that was the cause. So that's why if the patient already had contrast, then contrast would have been excreted by the kidney and it it would have amassed because contrast looks high density, it would have massed the stone. That's why not giving contrast is important. And that's why without knowing you are suspecting ureteric stone, we may not do the right ct another case where the clinical suspicion was not very clear. This patient also had left line pain but they didn't think clinically it is tic stone. That's why you can see oral contrast was given and there is contrast in the arteries. And uh you can see the kidney is nicely enhancing compared to the previous one. We can't see it. So, but we ended up seeing some dilatation of the kidney. You can see the right renal pelvis is collapsed and not dilated, but it is dilated. Then we started seeing some similar fluid density outside the kidney as well. So then that becomes a bit doubtful why there is fluid around the kidney, whether it is just a pe pe perinephric collection due to infection or something else. And then we did another ct lower down, there was a stone within the distal ureter. So now you can see how the CT can show everything nicely. There is distal ureter stone, there is dilatation of the left renal pelvis. There is hydronephrosis, but the only problem is there is some fluid around it. What is that due to is the question, that's why we have to do the CT in a delayed phase. Like we give the contrast and we waited for 10 minutes and then did the CT. Now you can see all the contrast is excreted by the kidneys. There is contrast in the right kidney uh in the right renal pelvis here. Also we can see it but there is some high density within the fluid outside the kidney. Like we saw there is some fluid. Now that helps to show that there is some rupture of one of the renal Cali or pelvis itself might have ruptured. That's why the contrast has gone outside the renal pelvis into the collecting from the collecting system around the kidney. So nicely, it shows how various phases of the CT helps to diagnose this condition. This patient had a renal pelvis rupture due to a stone in the distal ator. So that is various phases of the CT, how it helps. This is another case where a patient had acute abdomen history and amylase was raised. That's why we did the CT to rule out pancreatitis. So that is the normal pancreas here around it. The fat should be dark like this, that is a normal fat. This should have been this finding here. This is an example of dirty fat or stranding. When there is inflamed structure in the middle, the fat surrounding it will be edematous. That's why it looks brighter compared to the dark fat. You can see the subcutaneous fat is dark, same thing we should have seen here but it is not. So that is the meaning of stranding of fat. It it just means there is edema within the fat when we look for the organ within the center of it. In this case, it is pancreas and the history is there amri was raised. So that is an example of pancreatitis. Now we get the CT request saying this patient has a good pancreatitis and we want to rule out pancreatic necrosis. What we look for is whether the pancreas is still bright and enhancing or not. If the pancreas is not bright and enhancing, that is what we look for for necrosis. So that in this case, there is no necrosis but just pancreatitis with involving the tail of the pancreas, another case, same history, typical history. But all of the pancreas you can see there is enhancing, it is bright and there is some stranding of fat around the tail. The pancreatitis was limited to the tail of the pancreas. That's why we get the stranding of fat only around the tail. It's an example of that. It is just a focal pancreatitis. This is a case of pancreatic necrosis. You can see you can see the bright pancreas there. But this in this area also we should have had pancreas extending as a bright but it is not it is this part of the pancreas has got less blood supply because of necrosis. That's why we see it as black. That is what we look for on a CT. This is an example of pancreatic necrosis and there is some uh shining of fat around it when the patient had further follow up, patient was getting unwell, that became even more worse, that ended up as a pancreatic capsule. This is what we see in abscess. There is air fluid level and there is a lot of pockets of gas within it. This is not within the bowel. You can see the stomach is pushed to the front, this is not stomach, stomach is here and the rest of the bowel loops were also pushed on either side. So this is an example of pancreatic capsules. So we look for air fluid level and make sure that it is not bowled by looking uh for other bowel loops around it. So until now, those are the examples where we look for dirty fat air fluid level and things like that. Now, this is an example of fluid is there, as you can see, there is liver, there is spleen around the spleen, there is fluid around the liver, there is fluid but abdominal signs as I highlighted at the beginning fluid of different density or high density is more worrying. So that fluid is ok. I don't know how much well, how well you can see it, that density looks different to this. Can you appreciate? This is a bit high density. That is a bit low density. And when the when you have the fluid of different densities is worrying, it means that may be hemorrhage or pus. But this patient presented with the acute abdomen and dropping BP, it means we are suspecting hemorrhage that was the hemorrhage around the liver. And when we tried to find out the cause, we found this abnormal blood vessel. You can see now in this area other than aorta, we should not have any blood vessel bigger like this. Uh This was an pseudoaneurysm. This patient had acute pancreatitis and one of the complications of acute pancreatitis is a pseudoaneurysm because that weakens the wall of the vessel which can dilate and it can bleed. That's what happens. So this is all hematoma. It's all hemorrhage unless we look for different in density, we may not appreciate it or we can just leave it as just a free fluid without looking for it carefully. But the history was important here, patient has acute pancreatitis, a sudden drop in BP. All those history was there. That's why we were very, very careful to look for all these things. Otherwise, if that history is not there saying just acute pancreatitis, we may not see these things in detail. So there's an aneurysm PSE aneurysm from the gastroduodenal artery, which was the cause. And this patient did well. Actually, uh patient was transferred to hull from here and our interventional radiologist embolized that part and then patient uh got better. So another thing we look can look for in acute abdomen is uh bili biliary should not be normally dilated within the liver. We normally liver should be bland like this high density without any dilatation. But when you see linear high density uh sorry, low density structure, that is the dilated bili that is next to the port algin branches. When you see it, we try to look for CBD, follow the CBD all the way down. And that is the CBD which is dilated and within it, there is some high density. Normally, it should be only bile but in this case, there was high density. So it was a CBD stone. So this is an example of a CBD stone causing obstruction. So in this case, the stone was calcified. That's why we could see it. Please don't rely on CT to diagnose CBD stones because if the stones are not calcified, we may not see it. This is an example of that. This patient has cholecystitis. That is the gallbladder, which has got thick wall and patient has presented acutely CBD was dilated but we couldn't see anything within it. But when we did the MR RCP, we could see the stones later. So I just want to show that all CBD stones are not seen on CT, unless they are calcified, we will struggle to see them. Uh That's why we have to go for a MC P later. It's an example of a gas, as I said at the beginning, if there is gas in the wall of the solid organ, like in this case, gallbladder has got gas in the wall, it means it is emphysematous cholecystitis which can happen in uh diabetic patients. So, yeah, I think I got 15 more minutes. I think one hour is ok to carry on. Yeah. Yeah, that's fine. So just, uh, want to show some examples of bowel obstruction. So as I said, one of the ominous signs is bowel obstruction. As you can see here, this is dilated bowel loops and that is a small bowel. You can see a lot of mucosal folds that is small bowel. This is a large bowel which has got feces and it is not distended. It means there is some bowel obstruction but not due to the large bowel. It is somewhere uh in the lower part of the abdomen. There may be some cause for it. When we see this, we try to find out the transition point where we see the dilated bowel and collapsed low bowel and just to work around it and see if there is any cause we can see. Yeah, this patient, same patient uh had a ct lower part. You can see the dilated loops of bowel there and next to it, there are collapsed loops. That is the area we try to look for if there is any cause, like if there is any tumor or stricture due to Crohn's disease and things when we don't see any cause. And at the transition point, then we usually label it as likely cause of obstruction is additions, additions. We can't see it is diagnosed by excluding other causes uh of bowel obstruction. So that's what we do. Uh This is another case where there was bowel obstruction. But at the point of transition, there was a large polyp within the lumen of the small bowel that was a large polyp causing bowel obstruction. Another case, uh we couldn't see the cause, but there was intussusception. You can see there are four layers of bone there. Uh intussusception, we couldn't find the cause. But when the patient went for surgery, they found a polyp which was uh the cause for the intussusception, which we couldn't see it on the ct another case there is intussusception. But this time, uh the dragging point was having low density, which usually means fact. So it was a lipoma, even the lipoma can also cause intussusception. Uh that was the cause for a bowel obstruction. So this is another case, we did the follow up disease. As you can see in the lower part of the pelvis, that is the symphysis pubis and hip bone area, patient had bowel obstruction. And when we searched around the transition point was around the left hip joint where there was dilated loop and then collapsed loop inside the abdomen. Then the cause was this femoral hernia. So that you can see the femoral vessels, medial part, there is a short segment of the bowel, you know, femoral canal is very narrow. That's why uh we can get bowel obstruction easily and there is small short segment can get stuck there and cause a bowel obstruction. So, unless we look for this area, sometimes femoral hernias have been missed on CT because you don't look for it, uh then it can be missed. We can say that is a normal side and that is the bowel loop which is stuck there, which was the cause for bowel obstruction. An example of a femoral hernia causing that another example where at the point of transition, we can see there is some abnormal thing which is enhancing, that is a normal bowel look, which I mean, it is distended but the wall is thin. But in this area, you can see there is something which is enhancing and high density within the lumen. So it was a small bowel cancer which was the cause for bowel obstruction. Another case where we can see the dilated small bowel loops and we can see the dilated bit of uh distended ascending colon. And I can't see the I, I, I'm sorry, I can't show all the pictures. The transverse colon was collapsed. So distended loop and con like non distended trans colon was there in the subsequent slide. And just at the transition point, there is some abnormality within the c uh hepatic flexure that was a tumor which was causing the obstruction. That's what we try to look for. If the small ball and large bo both are dilated, then we choose to follow the large bo and see whether there is any change in transition. This is what happened in this case. Uh bowel obstruction is not always due to Luminal cause, it can be due to extra Luminal. Uh This was a patient with the ovarian cancer, uh with metastasis. And all the liko and peritoneal metastasis can cause obstruction of the bowel from causing obstruction from outside like that can happen as well. Those are the, some examples of bowel obstruction and what we do and what we look for and other cause we will do the CT is for inflammatory bowel disease. Yeah. So you have seen the previous uh CT is where the bowel wall is very thin. But when there is inflammatory bowel disease, like in this part, this is the terminal ileum, which is very thick wall. That's what we look for. And like terminal ism is involved long segment or then may skip areas, then diagnosis becomes easy. That is an inflammatory bowel disease due to Crohn's disease. Sometimes Crohn's disease can have complications. We can see there is a thick wall, small ball, another thick wall, but in between the two thick wall bowel lobes, there is another gas containing structure but this was not a bubble, it was bubble like small collection between the bowel lobes. So it means there was some localized perforation uh due to Crohn's disease. I just want to highlight this example, you know CT is very good. One of the new, one of the ominous signs we we have to look for on CT is free gas. If you see, look at the CT, there is free gas here. If I show it, if I point at it, you can see it but always it is better to look at the CT abdomen in a lung window as well. Because on a lung window, all these pockets of gas will be shown straight away, easily be on, on this type of window where the soft tissue window, the ga the fat and bowel loops and containing uh free gas may be a problem to look for. So this is an example of that this patient had CT colon after the CT colon, he complained of pain. Then on this particular soft tissue window, everything looks ok because this is distended bowel because we have done CT colon with the pushing in a lot of air. That's why it is distended. But when you look at in the lung window, we can see this gas which is outside the bubble, it is not inside. But if you use only soft tissue window, that can be easily missed, that's why we always make sure that when we have done the CT abdomen for acute cause we look at the abdomen in a lung window, then any pocket of gas outside the bowel can be easily seen otherwise it can be easily missed. Yeah, I just want to highlight about ischemic bubble, acute abdomen. You are suspecting ischemic ball clinically because uh patient is unwell, uh lactic acidosis and all those things that's ok. But don't rely on CT to make the diagnosis because if it is early phases or subtle findings, we may not see it. What we look for is the enhancement of the bowel like that. If there is any bowel loop next to it, not enhancing, well, that's what we look for. But in this case, there is some finding if you compare this loop of ball here and compare it with the next one like adjacent to it. There is some pockets of gas within the wall which can be difficult. If you don't look for it, if you look for it, you will look for it. Only when there is good history to say that you are suspecting ischemic bowel. That's what we look for. That is an example of uh gas in the wall of the small bowel. This is more bit more advanced. You can see there is a gas linear pockets of gas within the bowel loop. This patient is very unwell and that history is the lactic a cirrhosis and things. This is ischemic bo with necrosis, same patient, uh upper part of the abdomen showing the similar sort of picture. Compare this with the this bowel look which is not involved. And that is ischemic bowel with necrosis, similar when where there is pockets of gas within the wall in advanced cases uh of ischemic bowel. What happens the gas can get into the portal vein radicals and then it will go into the portal vein. That's what we see. These are all gas in the portal vein. Uh This is ominous sign because patients usually don't do well after this. Once you have got ischemic ball, then we find out the cause, isn't it? So what we look for is if there is any thrombus within the artery or vein, in this case, there was a thrombus uh within the uh sorry super meric vein and there's another case where there was a thrombus within the su meric artery. That's what we look for as a cause for the ischemic problem. Um Just want to have a couple more uh slides. I just want to highlight that importance of history and how we change the CT accordingly. This patient had a CT, we didn't have much history. It was like acute abdomen cause that type of history. We did the CT, we said everything is OK. We can't see any cause. But later they came with a history. Oh, you reported the CT is ok. But this patient is very unwell, inflammatory markers are very high and it's tic and all those things. We are suspecting collection. That's why we changed the CT. This time. We give the patient oral contrast and then did the CT again. Now you can see this and this part they look the same, isn't it? That looks like a bowel? This looks like a ball. But when we did the repeat CT with contrast, that is a small bowel with contrast. But this part didn't have any contrast at all because that is a collection outside the bowel. That was an abscess which we couldn't see in the first ct I mean, we saw it but we thought it is just a ball loop. That's why it is important. Then we changed the technique of the CT. Then that was a diagnosis of abscess that was due to uh some diverticulitis or something. That's how importance of history. Uh One more example where contrast was given later when we got the more history, the contrast leaked out from the stomach and there was a collection with the, with the oral contrast going into it. And that was the gastric perforation. One more example showing the leakage of contrast from the stomach into that collection. It is not a ball, it is a collection. Um I think I'll skip through quickly uh because it's already one hour. Uh These are the examples of diverticulitis. This is sigmoid colon with diverticular changes. And there is a focal collection that is outside the bowel, that is a localized collection when the collection gets bigger. This is how it looks and then it can fate into the bladder. That's why we get the gas in the bladder. So, diverticular disease can cause colo cycle fistula. That's an example of that. And if there is infection, it can spread into the liver, this is an abscess, liver abscess. But I just want to highlight that your necrotic mets can look the same. That's why if there is a history that patient is unwell with sepsis and things. And you see this then usually we say it is a liver abscess, but history is weight loss and not doing well. Inflammatory markers are OK and things then the same finding can be necrotic metastasis. That is the importance of history. Otherwise we can label it as abscess or metastasis wrongly, appendicitis is this is how, what we look for. And this is another appendicitis. But this is a complicated appendix with a lot of collection around the scal pole. But we couldn't see the appendix when we don't see the appendix. If there is collection around the scal fold, then, then it is a P perforated appendix with abscess. Just want to show an example of like not giving like if you suspect uh G I bleed, we should not give oral contrast. This is what we look for when there is non contrast CT. And after giving contrast, the lumen shows increased density. That is what we look for. And if there is contrast already in the lumen, then we will not be able to see this, that will be masked another example of active ization. So this is the initial phase CT. And when we did the later phase CT, there is contrast going out and it was not within the bone, it was outside. So there was a uh bleeding vessel aneurysm. I just want to quickly go through it. And yeah, this is what uh aneurysm looks like abdominal aortic aneurysm. And this is a rectal sheath hematoma. Uh patient with the abnormal coagulation can have rectal sheath hematoma. Even with minor injury. Typical history is usually dog jumping on them and then they develop abdominal pain. Uh This is another example to show different density of fluid around the liver. Uh that was a hematoma but this time, it was due to an hepatocellular cancer bleeding uh around the liver. That was the cause. So just want to say that in a, a female patient comes with acute abdomen, don't forget about gynecological causes or obst causes that. What that's what happens most of the time acute abdomen means we always, always worry about kidneys and the bowel. And don't think about these things is an example of ovary. And to uh this uh this is the same patient with the Coronal three format. That's the Tory. So again, CT is not good for non calcified gallstones. As I said before, early changes of bo ischemia may not be seen. And if you're suspecting PD ectopics and things better to go for other modalities than CT. Um yeah, just want to wanted to show some as you can see, it is difficult to cover everything in one over. Uh That's why I chose only the acute abdominal part for today's discussion for, I mean uh teaching and presentation. So I just want to highlight that however advanced technology we may have but there is no alternative, all good history and examination findings and clinical diagnosis. Only after that, we can choose the right modality so that we can reach the right diagnosis. And we should always be aware of clinical or radiological association where the clinical and radiological findings do not meet or match. Then we need to have clinical diagnosis to say what we need to do. So I just want to highlight again that all CTS are not done the same way. That's why we need to know what you're suspecting to rule out. So thank you for your attention. And uh I will ask, I mean, ask for any questions. So any questions anything we can see though? Yeah. So there's a question there uh from Doctor Adi, when do you do a nonradiating Mr Virtual Iny uh what we are doing? What I mean? I think you are talking about small bowel pathology. I think. So, small bowel pathology. Um We take the decision whether it is CT or MRI depending on the patient's age. If the patient is younger, like maybe less than 50 or something like that, we try to do MRI. But, and other thing is if the patient is already known to have inflammatory bowel disease and things we go for MRI because these type of patients, we always will have the need for repeated examination. And if you keep on doing CT S, we'll be giving them too much of radiation. Uh If the patient is older uh where we are not too much worried about radiation, uh Then we go for CT uh because CT gives much better appreciation of things around it. Like on MRI, we may not see the other structures uh on CT, on MRI, we may see the bowel loops very well, small bowel loops. But um we may not be able to appreciate uh other abnormalities. That's why. So it all depends on patient's age group and if the patient is already known to have Crohn's disease and things, we tend to use more of non radiation type of IMA imaging like MRI otherwise we go for CT. Mhm. So you want to see the CT before the ovarian cancer? I think it will take time to uh search for it. Yeah. I think that is just uh wanted to show that um like bowel obstruction can be due to like metastasis. Uh That's what the idea of showing that image. I think it is one hour. So it's too long. Uh uh So thank you very much for all your attention. Hopefully, it was uh useful. Um As I said, even with the, I mean, using acute abdomen and only see it in plain films, it takes more than an hour to show and describe. Oh, thanks doctor for delivering that presentation. Honestly, it was great. I really enjoyed all the different um ct and images examples that you had. Um Guys, please don't forget to provide click that feedback link and provide some feedback. Doctor pa kindly donated his time um to and effort to present this. So the feedback will greatly help him. Thank you. Uh So when is the next one? Sometime sometime in September? Isn't it by radiology? Yeah. So, so guys, we've got some more um some more teaching sessions upcoming uh they are all on our med all link so you can click and preregister for them. Um And we did um share um like a PDF poster which should have gone around too. Um All right, thanks guys. Have you got any more questions? Ok, lovely. We'll see you at our next talk every week.