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It's working, I can see it. Um OK. So um we're gonna talk today about imaging modalities in general. We'll talk about um what the what imaging modalities are available to you as a, as a clinical, as clinical team. Um What you can order what you can request, what will help answer the right question for your patient. Um The slides I've inherited um they're very, very good slides. So when I, when I do make slight corrections, it's not a criticism, it's just a slight tweak. Um And I'm said I'm a radiology do um registrar at Nottingham. So um we're gonna go through the key modalities, understand the indications limitations. We'll learn some basic principles and we'll touch on why, why we care so much. Um Some ground rules if you wouldn't mind, like I'd much rather you interrupt me at any point. There are not many people in the room. I don't know if you know each other, but this is, I want you to treat this as a sort of safe space. Say the dumbest thing possible. It's not dumb. Most people like most doctors don't, don't know a lot of this information. Um Because I see it when I vet scans, for example, they'll ask for a scan. Lots of people don't understand this and that's totally OK. So ask stupid questions, ask any question at all, interrupt me at any point. Um And if you feel comfortable to say something out loud, just say it out loud, otherwise put it in the chat. Um So I understand this is the first in a series of lectures um of like what is like radiology in general. Um And so what is radiology? It's, it's the simplest way of saying it is with doctors that look at images. Um And we examine images to come up with a reasonable um differential diagnosis, that's a, that's effectively. Um And it's, it, it is similar to a clinical examination in the sense that you pick up a bunch of nonspecific features or findings. Um If you were to clinically examine somebody, you'd pick up some nonspecific er findings with your hands and your eyes. Um And all the, the inputs are different, they're now visual inputs, the inference coming to the right diagnosis, coming to the right differential is exactly the same. Um So that has didn't really change when I switched from clinical to radiology that it's roughly the same sort of uh diagnostic skill. Um And so it's, it's important to modern medicine. Um it becomes more and more important um every decade because the technology improves like, like so, so much within a decade itself that we can answer so many more questions. And so more and more is being relied on for answering really specific questions. And so some of them like accurate diagnosis, of course um monitoring progression. Um We also use them in intervention particularly ultrasound. Um And so we use them in all sorts of like the entire spectrum from emergency to chronic it's on it you encounter imaging. Um And so we covered these broad broad topics. Um OK. X-ray radiographs. Um some indication. Can you still hear me? I am not just talking to avoid. Yeah, we can hear you clearly. Awesome. Um So x-ray radiographs to me, this sounds like chai tea or Naan bread or liver cirrhosis X ray is a radiograph. So I will say this is a chest radiograph or a chest X ray. Um Also uh small point about liver cirrhosis. You can only get cirrhosis in the liver. There's no point in saying liver um same, same principle. So X ray or radiograph and it is a two D image. So you've got like a we used to use film. Now we use it's all digital. There's an X ray tube and the X ray tube generates X radiation which is on the electromagnetic wave, it fires it at, at the patient and what you get at the end of it is a density gram. Sorry, I should have said before, I'm gonna go one level deep for each modality deeper than you probably need to know and I want you to treat it in your mind like trivia, you really don't need to know this. But hopefully in the back of your mind, it might inform you to dec decision making one day in the future. So no stress about remembering any of this stuff. Ok. So what do we have, we have X radiation coming from this tube? We have a screen like a digital screen with uh pixels that pick up um your X radiation and the more dense the stuff, the more stopping power it has for that X radiation. So that area will seem white. So bones, maximum stopping power will seem white air, very little stopping power and effectively it, it correlates with density. Um but it also has to do with the atom itself. Air doesn't really block much X radiation, it looks black um because all that X radiation goes. So you've got, you start with a white film if you like and then it starts to get filling in with the black X ray where the X ray hits it. So we use the classic indication is a chest X ray um classically done for bone fractures, um abdominal imaging, not so much anymore. So we used to do abdo X rays for bowel obstruction, perforation, et cetera. Um We generally tend to find that it's got rubbish correlation with act. Um So you'll see like small bowel loops which seem really um dilated, you think small bowel obstruction on the CT, it's normal and vice versa. So, in Nottingham, at least we just, we just forget it. We just go, go straight to the CTA, if you think there's obstruction, that's just as an aside. So, yes, they're fast. They're widely available. They're cost effective. Um, X rays are really good because they're not much radiation as well. So, compared to the other modalities like CT, you're not giving like a chest X ray is like, it's the equivalent of having one or two days extra background radiation just like living one or two days more is the equivalent of having a chest X ray. It's not that much. Um There is po poor soft tissue contrast. It's actually really good for bone like you see bone really well because bone really comes up well against air and soft tissue. The two D sorry. So the two D information lacks, lacks all sort of depth information. Um That is true. One more thing I'd say about X radiation, drop my mind, it'll come to me later. Um So we'll go through a case scenario. We have a 45 year old man uh presents to the edo on an outstretched hand, what's called a fouche? Complains of wrist pain and swelling. And you notice, for example, here, I don't know if you can see there's a fracture in the distal radius. Um And yeah, so there's a, there's a fracture over here it says there's a collie's fracture. And the truth is how can you tell on this? This X ray? Does anybody know there? Somebody said any ideas? And if nothing you can't, you need two views. Um And so one view is no view at all. So this is just again trivial until you need to know it. There are diff different types of distal radius fractures. If you fall on your outstretched hand, it's a fool. You're gonna, you're gonna cause your distal um segment of your radius to angulate um dorsally, just dorsal angulation. And we, so when you talk about dorsal or var angulation, it's to do with the distal fragment. So you can say see this diagram, this wrist has gone this way and that's the dorsal, this is going dorsally. It's the distal segment we care about. So we called dorsal angulation. Var angulation is the Smiths. Nobody really cares. It's a fractured radius and I'm gonna see on the X ray. Um So the eponymous names, I think it's useful for exams, but I don't think it really matters. You. I would call this a do um dorsal angulation. Um ra ra F and almost just not even call it a colleague if I was reporting it. Um What, what have we done here? Oh yeah, yeah, sorry. Um Can I anybody please just say anything you like? Is this a normal or abnormal chest X ray? Can you see anything on the chest? X ray. Um, and if you do, what do you think it is? Any suggestions? Fair. But I'll, I'll, I'll rely on you to tell me what's in the happening in the chat. If anything, um, other, you're, you're feel free to, like, contribute as well. Um, we've not got anything yet. Oh, people are saying, ok, the o megaly enlarged heart, uh, in my heart. Ok. I sort of see what you're saying. Um, Now this looks like a, I don't know if it's APA or an AP, but I think this is APA based on the fact I can't see the scapular, so it's fine to assess the heart size if I actually assess the heart size. And II take my fingers to either edge and I sort of ignore the pericardial fat pads. I'm gonna shift it over and I think it's just underneath the cardiothoracic ratio of 50%. On top of that, there are no other features of like real heart failure. I can see, I can't really see um some sort of peri highly sorry as well. There's no cell sign. Um If you see behind the heart, it's about the same density as the other side. C sign, you'll see an extra line, right? That's not the, you'll see an extra line in the middle, you'll see a definite like difference in like density in the medial side compared to the lateral side. That will be, then you'll also see volume loss in the left lower lung, right? It's not there anything else they're saying hilar consolidation. And someone else also said, where are the pericardial fat pads? Wear a better college of pads? Ok. Can you see my mouse as well? Yes, we can see it. Does that show? Ok. Lovely. Ok. So pericardial fat pad this bit here is the pericardial fat pad. So I always sort of ignore it when I'm like ignoring like that's not heart, right? That's just stuff around the heart. And when you, when you start looking at some CT scans, so I can see the heart border sore of coming in here. I can't say exactly where the heart border is. So I share an office. It's like a really tragic part of my life. Um So this is the, the, this is the edge here. I can see an edge here. I can see roughly. So I sort of like, look from here to here, sort of shift it along to from the this part of the vertebra. Look here and I sort of assess the cardio ratio that way any other suggestions, peri consolidation, not really. So you have to sort of this is, this takes some time to get your iron, but you sort of have to imagine the pulmonary artery coming down and sort of subtracting from the image. And if it's more than that, more than what you expect, then you'd call it consolidation. Um I don't think there is peri consolidation. Anything else? Um Marina said enlarged hilum on the right. Yeah, similar. So I, II don't think so. And this, this is just my, this is what II think. Um, sorry. Er, and I, it's confirmed on city so I know, I know, I know with hindsight as well it's a, it's a really difficult one higher. I'm notoriously difficult. Anything else? No. Have we done? Um, everything? I think someone's also said that there is nothing on the X ray. Perfect. That's also reasonable. I think calling this no, is totally fine. Uh There is something annoyingly um this sort of lesion here. I don't think it projects super well, but there's like a slight density there. If you, the way you call this sort of thing is you sort sort of see this side and you sort of see the symmetry of the other side. It is more density of the other side and like this is the sort of thing you'd only see in retrospect after seeing the C EC, but it is 100% there. I know like very senior registrars who would call the chest x-ray normal and that would be totally OK. With the retrospectoscope, you can see the small area here now that you've seen this little bit of consolidation. What do you think it is? Does anybody have any differentials? Like, what principles wise, what could it be any of this? Anything someone's at? Pe OK. Yeah. And they're all lumbar pneumonia and pleural uh pleural. No. Um I mean, it could be a pleural plaque, but that's usually not bad shape consolidation. I'm thinking this is within the parenchyma, right? This thing here. So within the parenchyma, it could be generally, it's cells which is like lung cancer. It could be pus which is pneumonia. It could be blood which is a hemothorax. Um sorry lung contusion. Um A hemothorax is within the pleura, uh lung contusion is blood within the parayno. So contusion, it could be so does apply principles. It could be cells, blood pus and actually, there are all types of cells now that think about it. But like, um this is, this is actually er sly, this is a, a consequence of AP which is here and I don't think you'll ever get such a beautiful example. But here on the right, you can see, can you see if you can see my mouse, this is the right pulmonary artery, this is the left pulmonary artery, the C TPA is windowed a bit weirdly, but this is a filling defect here and this is where the pe is, this is what we're seeing on this side. And I think histologically when you see this sort of thing, it is consolidation and histologically when you see this sort of thing, it is actually blood. So, um infarct lung infarction is actually um just it's a micro hemorrhage. And that's how, just a, that's just how it pathologically manifests and that's what we're seeing on the scan when we see these things. Um So that, that's, it's a lung infection. My point about this is this is typical for radiology, you know, when we, you see or you need to clinically correlate that that's sort of, sort of seen as a sort of cop out for radiologists in general. It's not, it could be literally anything and it really depends on the clinical context of what it is with the C TPA. We have more information to competent, we call this an infarction. But without this, how can you say? All right, like, and that's the point in all sorts of modalities, you'll see loads of non specific features like this. You have to bring it together in a, in a diagnosis with all the available information and sometimes you just don't have enough information and then you have to say, sorry, it depends on the clinical context. Um I have GP friends who, who take the piss out of me for this, but like this, it's true. This is just how um this is all the information you have. So that all makes sense um stop me if you want me to stop there. But otherwise I'll continue. OK. If that all make sense, I'm gonna go to CT, which is X radiation. Again, it's x-rays except uh it's x rays that rotate in this massive tube. So in CT, very different to Mr the donut looks really, really similar, but it functions totally different. So this, this donut is consists of a X ray source and a multiple row detector, right? And that just rotates and it rotates at insane speed. If you ever see this with a lid off it, it, it's really fast. Um And the important thing is the bed translates. So this keeps on, this keeps on acquiring images and the bed translates. Um And if you can think like you're getting these sort of rotational x-rays in L like a really high speed, right? How does that come out? And how do you get through the information out of it? Uh And the, and the way is like you sort of get this thing called a sonogram. So uh this is too much information, don't take this in trivia. Um The sonogram is a collection of three dx rays. It's just how the raw data looks and then you can reconstruct your actual body. So this Phantom egg, if you take act of this, you will get the sonogram and then you do something, you do some algorithmic things like filtered back projection to come from this thing sonogram to the actual image. So you just with computers, you reconstruct the image. Um But the principle is the same as X ray, it's a density scan bones look white, air looks black and it's the same concept. It's just tomographic tomo means um if you ever see Tomo, I in the wild tomo means cut in, um, Greek. So it's just CT, cut, cut graphy. Does that all make sense? I'll, I'll move on if that doesn't the benefits of CT, um, are that it generally produces quite high resolution. It's quite noisy. Like we, we have the principle in the UK where, which is as, as low as reasonably possible for, um, X radiations for, so for CT dosage, um, we're generally used quite low compared to other countries. Um but it's enough to get the diagnosis right. So you can really whack up the dose and you can get more X rays within your sonogram and get a higher signal to noise ratio. You'll have slightly higher resolution, higher, slightly sharper images. Um but we try to balance it with radiation. So we don't try to get too many X rays in our sonogram otherwise like, yeah, you've got the super crisp image but why you're getting the same diagnosis? So there's a balancing act. Um You'll see scans from India, for example, CT head scans from India, amazing quality, but they've given like double the radiation. Um OK. That all make sense. Please stop me. If I'm not making sense, you want me to clarify. So ct just to clarify is A, is X ray in 3D, that's it. Um The donor and the bed look the same as MRI but I'll go into that in a sec. It's totally different. So we commonly use CT it's our work course for um uh for, for heads for body um Abop pelvis, chest abop Pelvis. It is really good for oncology. Um Giving contrast, we can look for like vascular problems, um essential in emergencies. You have a big trauma scan, you've scanned them from head to toe. Uh no, that's not true. Head to pelvis. Um and there's a high radiation dose, that's the, that's the downside. And so, but the, the advantage is it's fast. So this whole thing, er, this spins really, really fast. This bed translates super fast. So we ask the patients to hold their breath and we can scan their whole body in that breathhold, right? That's how fast it is. Okey dokey. And that's what I, that's what it also limits respiratory motion, right? You don't want lungs moving up and down. Uh ok. Case scenario two, this 70 year old female presents with left sided weakness and slurred speech lasting one hour stroke, suspected patients within the 4.55 hour window of thrombolysis CT head. I think the role of CT head and stroke imaging is generally generally to rule out like bleeds. That is typically true. Er, because that uh makes them eligible for thrombolysis if necessary. Um ok. And we see the clinical outcome here is CT shows no hemorrhage. Um, the son has been an acute ischemic stroke. Um Does anybody see? So I personally think that this clinical history and outcome does not match what I'm seeing on the CT head, on my left, on my, on my left. Does anybody have any ideas? Why any suggestions and your rule? Say the dumbest thing possible? Like why, why am I like? This is not right. This is a different patient. We've clearly got the history of somebody else that any others, nothing. No. Someone said maybe an aneurysm. No, that's the pine, this, this thing in the middle. That's the pineal gland. It calcifies. It's very central. Yeah. Is we're getting uh more responses as well. Someone said, uh left-sided infarction shouldn't have left-sided symptoms. Perfect. Great. That's, that's one of them. So, um Cortic spinal tract and Decco in the pyramids. Um So yeah, you get contralateral hemiplegia. That is one and I think the next the other findings are very difficult. So I, I'll just talk any other suggestions just so I can like clarify. Um Someone's asking is the distribution of the abnormal finding. No, this is, this is typical for the MCA territory, right? And that would, that would match the left side that would match like a hemiplegia. That's, that's ok. So this is the MCA territory. AC A territory is more medial that will affect like some of your like primary motor cortex particularly. I think your leg um ac A infarcts. Um We don't see many of them to be honest. Um But no MCA S matches hemiplegia. PCA infarct would be like right here and that would like take out your oxr lobe, which is your visual cortex. So no anything else. Other suggestions are hemorrhage, hemorrhage and atrophy in frontal lobes. Ok. Atrophy in front of look, people have very variable um you know amount of like CSF that say and the brain is not like um and the brain is like sort of, it's sort of like jostled around with CSF. And you can see these patients lying back and this will be the part of the brain that's just touching the skull at this point because it's dependently coming down. I don't think this is atrophy to call it atrophy. Really. We'd have to look at it throughout and we don't have enough information for atrophy, but I suspect m maybe not, not sure. Don't know. What was the other one? Sorry, go, there's another one, hemorrhage, no hemorrhage. I can't see hemorrhage. Um If you wanna ask me where it is, I can't see any hemorrhage. Um What I do say, what is wrong for me? I'll just, I'll just start talking now. Uh What is wrong for me is that like you see black um ischemia like this, this is infarcted tissue, this is gone. They're not suitable thrombolysis. This looks way past acute, this is more subacute. So I'd say this is at least a few days old. Um And this is we're breaching maximal swelling. So, what am I saying? I'm seeing MCA stroke, dense hypoattenuation. Um the sulci. Can you see the sulci all gone? That's all edema. Edema is just like squishing them all there. Um I probably can't make this out very well. So you can see the er posterior horn of the lateral ventricle that's completely obliterated here. What it means is it's a face, it's pushed, pushed by the edema. So there's a lot of swelling here. Um That's the swelling. Uh hypoattenuation means cell death, it's gone. Uh So this doesn't match what we're seeing cos they wouldn't be in the thrombolysis when it's my suspicion. Uh This would be more that case, for example, can anybody see where the stroke is? I'll just say it's the stroke, it's, it's ischemic stroke in this anywhere. Anybody's any suggestions, any sw anything at all, anything of or should I just keep, shall I just get the answer? I'm just, I'm just waiting on the chat. No one's said anything yet. Ok, fine. I'll just, I'll just say it. So, oh, wait, someone, someone said right side as ventricle or smaller, right side is ventricle smaller. So I think that the, you know, when we're cutting through the, the, the head, um, you know what we're talking about the size of the frontal lobes as well. You can't really tell in one slice. I don't think it is massively smaller. They just might be positioned one slightly higher than the other. It, I don't think it means anything. Um, if you're thinking that there's swelling here, really look at the sulky. So you can see these sulci are normal size, whether not normal size is here. This is where the stroke is. Sorry. It's impossible for you to pla tell. Um uh especially when, you know, know what you're looking for. So, what am I looking for? I'm looking for cortex here. Normal cortex and this is gray matter, right? Er Sorry, sorry, idiot. What gray matter is the cortex, white matter here, right? What I'm seeing here, the gray matter is gone. There's a coral infarct here. There's swelling here like the si have gone. I should see this Sulci this side, right? Something that I don't, that's the, that's the area infarct, that's what we're looking for in CT head and CT heads. You can see how insensitive they can be in the hands of a, a bad, like a bad neurologist or a bad radiologist. What may miss that? I've seen these sorts of misses. Um and not we in neuro center so we typically don't miss things like this, but you can see how it is missed. So um I'm just saying that's more this kind of patient, this is the sort of thing we'd be expected to pick up and you can see it's not CT is not particularly sensitive for acute stroke but the, but the signs are there to call. Um But in the hands of a bad operator, you're not gonna pick them up. So let's move on to Mr. Um any questions about the previous one about CC in general or X ray and if not, I'll just keep going, Mr, I'm not gonna go into the figures. Got Mmr, but it's pretty magical. So in Mr, this tube looks the same as CT and this bed looks the same, it's really not the same. In this tube. You have a bunch of like coils and they are put on and they put off er underneath this whole Mr is a big magnetic field. These coils help direct. Um I'm gonna say this really badly but you basically get your position of um how do I describe this in a nice easy way. So magnetic field exists all the time. The magnet number one, you need to remember the magnet is always on this radiographer. She'll tell you to take off everything metal like around you. That magnet is always on when you want the magnet to go off. It's a, it's a big hoo ha like it's not, it's not easy. Um And so they'll tell you to take up, they'll sometimes call us to just check. People don't have a pacemaker, et cetera when we don't know, for example, um the fear of them will say I remember once I was going to in San Francisco and uh some potato become on, you have to live in the, you have to study it. Sorry. Um Yeah. Yeah. Um Sorry. Can you hear me up still first you to study, take it. Yes, we, we hear you. OK. Cool. Sorry, that already distracted me. Um So the Mr, there's an Mr field that exists, there's a really strong magnetic field, the calls in their direct signal basically and we're trying to get like positional information from each part, each part of the. Um So you Mr looks really at water and like the extent of water you have in different parts of your body. That is the core principle because water contains hydrogen atoms and we try to align hydrogen atoms and we get positional information from them from the coils that we electrically turn on and off within this tube. That's broadly all you need to know, you don't need to do more than that. But I can hopefully you can see with this Mr, you can see some really crisp definition between this poor quality image but like like it's really like poor resolution for us, but you can see really nice differentiation between gray and white ma, right? You can really see see like crisply like the differences between different parts of the brain, like with much higher signal to noise ratio and also different stuff, right? We can we know where the water content is. That's a different information to like the density gram that the CT is this knee. Uh You can see all the ligaments, we can't see ligaments in CT. That's just not another thing we can see it's mad. So this is the PCL we can see here, this is the, the meniscus. Uh this is the, this is obviously the tibia. Um, yeah, this is the um, femur and this is the tibia and er, yeah, let's keep going. So the magnet is always on, like, honestly, it's always on, always on. Like there have been so many accidents where people underestimate how strong the magnet is and when you have to turn this off, you had, there's a big quench button and you go quench and then all the helium that is, there's a bunch of helium that is used to superconduct the magnetic um coils um that is all quenched and that goes through like mass like through the ducts, et cetera and then the magnet no longer works fun like efficiently. And then that all goes down to re get the helium. You need to get liquid helium back into the system and it's so expensive. So we try not to have these accidents and you can see how strong that field is, right? Just don't, don't take any chances. Uh The beautiful part is that there's one, there's no ionizing radiation. So we scan fetuses, we scan pregnant women to look at the fetus. Um Some of some of the pediatric neuroradiologist, examine the fetal brain to look for like lissencephaly and like different sort of like uh um pediatric like like fetal um problems. So like there's no ionizing radiation really nice. Um There's superior, soft part tissue contrast, there is multiplanar imaging capability. The one thing I'll say, one of the limitations of MRI is that it takes ages, it takes so long. So when you look through an MRI scan and in Nottingham, we have 1.5 Tesla scans act head scan takes literally one breath hold to take like perfectly isotropic isotropic, meaning each voxel is like tiny and it's like the same shape. And you can get like 300 slices with CT beautiful and you can like examine each other slices separately in Mr because it takes so long. And we're, we're like interrogating each part of the body, each part of the brain with a core, turn it on, turn it off, et cetera. It takes like 5 to 10 minutes for an Mr head and then we do different sequences. So the sequences change the way the signals come back and they tell us different things about the body. So so some sequences favor water, some sequences favor fat, some sequences favor like water movement, et cetera. So you get so much more functional information from Mr. So that's another strength that's not written here. And it's like all that functional information that you get from different sequences that you can do is fantastic. And you can, you can imagine that for neuro problems and neuropathology, you can interrogate one pathology in so many different ways. You can see what's the fat content. What's the water content? Where's water restricting? Um Not only can you see the soft tissue better, you can see, um you can see all these different functional things about it and you can make a much better call about how this pathology is behaving in the brain. And what is, what are those main components that you can never do in CT CT just tells you. OK. It's, it's hyper dense, it's not dense. Um There's not it and you can sort of make out a lot of like structural features, like density features but nothing else, nothing to the level of Mr. But the downside of Mr is that we're taking 30 slices where CT take 300. So we're taking like big blocky slices. Uh So sometimes you lose that resolution in the Z axis. You can take um you can take the full isotropic like CT, but that will take a long time. Uh That takes 20 minutes. It's really, it's really long and peop some people don't tolerate it. Does that all make sense? Um Let me know if that didn't make sense or any clarification. I've explained some of that horrifically. Um So do let me know if you wanna go back. Um But I don't know if you can remember this patient. We just talked about the left, left frontal, so left, left, left and right. Uh We're looking at the patient as if their feet are towards us, head away. So this is left, so there, there's the left frontal, in fact back. Um And on Mr, like you can see CT you can't really, it's hard to pick up if you're not looking for it. If you're not looking for stroke, you will not pick this up on Mr with the diffusion weighted sequences, it lights up like above anybody can pick this out as an abnormality, right? This is what we do in acute stroke. We say this bit is acutely infarcted. Um If it's white on, um if it's white, if it's diffusion restricting on, if the diffusion restricting, that doesn't mean it's dead. If it's white on T two, that means it's dead. You know how we were saying it was dark on the CT earlier that's dead. There's no saving it. Um That's not necessarily true. Uh It just shows that it's intensity diffusion diffusion restricting now. And that's due to the like partly due to the edema and the, and the, the, the cell death that's going on. OK. Uh Just for interest we can do in this sort of scenario, we do CT perfusion often. And the purpose of this is to look at how blood is flowing through the brain on the left side here, blue is sort of showing that it's like less flow in this area. It's a different patient. So don't, don't worry about matching the area, but left, you can see left MTA S has less flow. Uh why do we bother? So, in the diffusion, we're seeing high diffusion restriction here. Um And that usually means cell death. Right. So, II, let me correct one myself here. It does mean death. You're not saving that bit of brain. That's death. That's cytotoxic edema. Um Right. Like, and that's, that's why the, the fluid doesn't move anywhere. Um That's why it's diffusion restricting now, but around it is you've got like areas where it's not perfusing. Well, and that's the penumbra. So this is umbra like a shadow penumbra is like the perry shadow bit. Um That mismatch is where you look for. Basically, that's brain, you can potentially save with intervention like thrombectomy or thrombolysis. Um So Mr beautiful in, in MS, for example, this 25 year old woman with weakness and tingling in the left arm, she has these plaques um on Mr that you just wouldn't see on CT, you just can't um they'd see like hypo like these big ones, maybe small ones, definitely not. Um It's just a bit too noisy. Um So that's why you, you'd, you'd only want to examine this on Mr um what else to say about this? Yeah, Mr s it's great. Uh but you have to tailor to examination. So the 11 big advantage CT has over Mr is one is bone. We talked about that earlier to fractures. You'd really wanna examine that with CT. The other one is hemorrhage, hemorrhage looks like really strong and bright on CT. Um And yeah, so hemorrhage and fracture is the main reason. So when we have a trauma, the first thing we do is a CT head. It's not an MRI head. Why don't we do everything for Mr is a CT is quicker and it looks at the more important structures first. OK. Any questions? Oh I need to speed up any other questions and if not, I'll keep moving. No questions have popped up in the, in the chat yet. Cool, cool, cool, thanks. Um Is this, is this the right level? Do you want me to talk about anything else? Um Just let me know and I'll, I'll have to talk about it. Ultrasound. I'm assuming you're all medical students you may have seen ultrasound. Uh ultrasound is to me a totally different beast. It's just like it's handheld is non, non ionized, no radiation. Um So the nice thing about ultrasound is if, if you can image it uh great if you can't image it trying. Um but it's so good for um real time assessment. So when you put your probe on tissues move and you can see it, it's a real time live representation of the tissues in front of you. Um So you can do procedures with them, you can put needles, um you can put needles in, see where your needle going or a lot of intervention is done with. Um it, it's done with er ultrasound and fluoroscopy, which we'll, we'll move on to. Um, but ultrasound works mainly by sound reflection. Um I remember doing my imaging sciences like BSC, like ages ago, the physics of ultrasound are harder than the physics of Mr like easy. But the basic principle to take in mind is that it goes through tissue because tissues have a similar sort of density to water. Roughly it doesn't go through air. That's why we use jelly between the probe and the tissue. It doesn't go through bone, bone just absorbs all the er sound waves. So you really need a window for ultrasound to work. So on tissue, fine, abdomen, fine, you can't image the brain because the bone absorbs all the sound waves. You can image the brain in Children because their bones are still forming like in, in like in like very young Children, like babies. Um What else you can? Uh that's the general principle. So you can go, you need an ultrasound sound window with tissues that are of similar density to water. So water is your friend on ultrasound. Um And it's a real time assessment. No radiation. That's probably all you need to know. Really um any questions or I'll move on. I have to move on. So, yeah. Poona real time imaging. It's very operator dependent. It's in, it's in that individual operators hands, if they don't go to the right part of the liver, if they don't see the lesion, it's kind of noisy and it's kind of it's not great quality images. Give me a sec. I'm sorry. It's not great quantity images. So OK, give me, give me one second guys. Sorry. OK. Hi sir. Can you show me? Yeah. OK. I'm gonna show what's going again. You can tell. OK. Can you see that? See that? No outside. Yeah, we can see this lovely apologies. Any questions to? No, I'm I'm gonna, I'm gonna do a quick, quick comment about the obese patients. Ultrasound is like so difficult. Your ultrasound beam attenuates by the time you get deep and so it's very difficult ct um obese patients are are a dream because the fat really gives good contrast between all the organs and you can see them really, really nicely in a young patient in CT everything's squished together and it's really hard to make out. This is bowel next to liver next to like, you know, other stuff very difficult. Um scenario four. So pregnant ladies, 20 weeks gestation, reduced concerns of reduced fetal movement. Um something is measured here. Um suggesting growth, retardation, placental abruption. Um ultrasound is really the main main um main thing in obst imaging. Um and you can see a real time assessment of stuff which is really nice. Uh You can also do a real time intervention if you needed to like you can take some amniotic fluid and sample that. Um yeah, the interesting thing about ultrasound, I guess for you to know is that probably radiologists don't do obstetric imaging, sonographer do, but the obs and Gyne people do most of the obstetric imaging. We just leave that alone in the U in the UK. Elsewhere. It's different. Um fluoroscopy. A lot of misconceptions about fluoroscopy. Um So fluoro is um fluoroscopy, it's just basically video X rays and that's what you have to keep in your mind. That's, that's all it is. Every anything to mention, somebody mentions fluoroscopic or fluoroscopy. It's, it's video X ray is what you should, should take in mind. And so this is on the right is a barium swallow. Um and fluoroscopy in general, like there's a general principle is really good. Why would you want video similar to ultrasound? You, it's fantastic for maybe not the structure of things, but definitely how things move. So you can imagine that they're very good for like functional tests. So if you want to assess somebody who's swallow and you wanna see how their esophagus peristal is then, yeah, it's great. Um And you can see like you can assess the like motility of the bearing swallow, er PCL, like when the, when the cardiologists do chorioangioma. Um somebody in the chat, please tell me which, which, which answer this is um if some th this is also a fluoroscopic procedure, right? Like this is video x rays, it's the same tube that they use here. Um It's not hovering there. Uh It's usually on ac arm, but that c arm has the X ray tube. Right? And same in the cardiologist suite. Right. It's, it's fluoro, it's a fluoroscopic procedure. Um, this one is a, um, procedure. Sorry. This seems like I'm joking on the cardiologist. I'm not. So, this is a, uh, complication post that very same like PCI, um, where some of these access, er, they've, they've clearly caused a pseudoaneurysm. Can you see that here? You can see it blush up there. That pseudoaneurysm you normally try to, yy, you, they will have punctured the, um, the common femoral artery, er, and on their exit they haven't like compressed hard enough or, um, or the, and afterwards they've tried to thromb an injection, it hasn't worked. And so these people here are putting a stent here and that stent contains a sort of like covering like it's, it's not like just bare metal. It's got like a, it's got sort of like a cloth and that'll just hopefully cover it, but that's like a third line intervention for this same sort of thing. All fluoroscopic, this is all fluoroscopic procedures, right? These are just video x-rays, you can insert contrast, you can get, um, do procedures with a, um, it's a similar to ultrasound, ultrasound and FOSC are the mainstay of interventional radiology. Someone, someone on the chat is asking RCA. Yes. Perfect. Good, good. Uh, you know, because it's looking around, uh, allergy comes in. Sorry, there was also a question in the chat where someone was asking if in the UK, whether ultrasound is done by a doctor or by an ultrasound test. Um And it's, it's uh depends on your center. Um How the split is between like what, what the sonographer do, what we do. Um The sonographer do, it's very, it's very dependent on the center. So in Nottingham Sonographer do obstetric imaging, they do abdo imaging, they don't do, do low limb Doppler. Um It's very sensor specific, it's not like standard across the same. What I will say is that sonographer reports are very different to radiologists, reports, like radiologists, reports are very tailored to the clinical question with, with often terrible imaging sonographer reports get like fantastic imaging um er with like a beautiful like image of the kidney and a beautiful measurement um that frankly most people don't care about. Um but they're very good in like getting your standard images. Um And it's great to train from both sonographer and radiologists. So I'd recommend doing that. Um but I don't, I don't think the reports are really the same. They're, they're, they're, they're not equivalent. Um Hopefully that answers your question. I'm I'm happy to talk more about that. So the strength of fluoroscopy similar to ultrasound is real time imaging. Um They're essential for interventional guidance. Yeah, they are widely available. Um There's a lot of ionizing radiation. So um the ionizing radiation exposure in fluoroscopy can reach, you can imagine in a really difficult procedure and things aren't working and you keep trying, you keep trying, et cetera. You can be there for an hour. That's like video x-rays. Imagine how many x-rays you're getting to one concentrated spot. You can be, it can be a lot of ionizing radiation um will, will come later to, to, to deterministic effect of ionizing radiation. And some of them are um like some thrombectomy procedures have led to really high dose of radiation causing like hair loss. It's like really that bad. So um we try to limit it as much as possible, contraindications of vas due to aspiration risk that will be related to bearing swallows. So sometimes we do assess for swallows specifically during the bearing swallow. Um and it requires patient cooper for swallowing. But these are, these last two points are specific to swallows um not specific to the test. Um Another fluoroscopic procedure. Um This is of the kidney. Um This is a before and after. Does anyone suggest what's happened here? What they're looking at? I can move on. But it's quite ii think these are quite, it's quite useful to like make mistakes, any others anything someone said there's a kidney tumor on the left image. OK. Tumor is a reasonable thing. But look if you look. So this is a, remember this is a dynamic intervention, right? So they've, they've got a catheter in the right, like right main renal artery right here. I think it's the right kidney um right main uh renal artery, it's gone here and it's, it's sort of some contrast has reached the cortex. Um A lot of the contrast is still within the arterial system. Why is it enhancing so avidly? Now, tumor is a reasonable shout. But I think on a dynamic video, you'd see it, see this come up and immediately wash out. So what this was was an AVM. Um And what they've done after that, if you can see this coil here, they just place that coil to like just block it off. And it doesn't that was the feeding artery to this arterio venous malformation, which is a shunt from artery, an artery to a venous which is ballooned, um which is not good because it causes mass effect and it can bleed and, and he's, and he's dealing with as a result that interlobar artery was probably supplying this bit of cortex, which is now not enhanced. So they're probably gonna lose that bit of cortex, but it's better than like having this bleed out or caused by the mass effect. Does that make sense? Uh This is just an example of um some of the cat angiograms we do for actually just somebody want to suggest what, what this is an image of? There's a gastro angiogram of something. So it's in the arterial face. Does anyone suggest which part of the body we're looking at? Um people in the chat are like brain. Perfect. Yeah. So this is the, this one, this this big main oy, this one, any others? Can you see my nurse? Any? It is sorry, I'm no, no basil. So um good shout. Uh This is the internal cross and you know, because um I think mainly the hold you to um this is just um this is the cavernous, this is the cavernous portion of the um inter crot. Um And it just does loop around that in inside the, inside the temple bone of the, of the head. Um And then it joins the circle of Willis and you can see the AC A is coming off them uh here and this is cycle. So um P CS will probably come here. Your basil will probably come somewhere here like that. Yeah, I think they have got that horrifically wrong. So I'll just double check afterwards. But I think that that's the ICA um other fluoroscopic procedures you can do is uh are um L PS. So you can do because they're dynamic. You can literally put a needle anywhere. So this, this this person is probably difficult to do a regular LP on. They may be um they may have large body habitus which makes it really difficult to do body landmarks. I think L PS are the last like landmark procedure left in clinical medicine. Um And so if they, if they have large body habits are sometimes very difficult, so we used to sometimes used to send them to interventional like interventional neuro, no, the neuro people who do the sonograms, but you put a needle and you can visualize it uh ap and lateral to see where exactly where your needle is and get within pass the ligamentum flavum into the, into the canal. That way. Uh case number five person with gastro oesophageal reflux disease, you know, dysphagia, um anyone who have a real time assessment of their swallowing um and the fluoroscopy reveals a distal esophageal stricture. Um and they go undergo dilation to relieve the symptoms. The stricture here has caused um this is not a normal esophagus, this is really dilated and you can see sort of like um these contractions in the thing, these are called tertiary contractions and they're sort of like um remnant peristalsis. But basically, they've been fighting against the stricture for so long. Um It's sort of, it's, they've now got like a global sort of like failure of it and I I'd call this Aloia. Um OK. Any questions? I'll be super quick for these last few slides. I'm so sorry. Second, so long. Um If no further questions, we'll just go through nuclear med. Nuclear med is really interesting. So nuclear med typically in radiology, you have an outside source of radiation in nuclear med, we inject the source of radiation into the patient. So they release the, they release the um radiation which is super different and what this means is that this is another sort of functional test we can do if you, you, if you make a fancy molecule that particularly target certain types of cells or certain types of molecules, whatever you can sort of image that and you can see which part of the body it is coming from, which is really cool. Um So like the common one, the commonest one is pet, pet uses glucose. So you can see which parts are taking up glucose. Typically, cancer, typically, tumors, bone scans. Um we use uh a form of technetium that's, that's um added to a phosphate which goes where osteoblasts, there's a high turnover of, of osteoblasts. So, osteoblastic activity and bone scans can look for metastases for particularly for sclerotic metastases. Um spec scans for cardiac perfusion imaging. Um You sort of attach it to, I think it's something specific for, I'm not sure, I'm not sure if I have to look that one up. Um But yeah, you can see a bone scan. So on the on the left, you can sort of see a bone scan in the knees. You can sort of see some arthritis. That's where osteoblasts are, are are working. You can sort of see some degenerative changes in the spine, that's where osteoblasts are, are working. Um You can sort of see uh contrast filling in the not contrast um uptake in the pelvicalyceal systems of the kidneys and the bladder, right? And that's all it's effectively a normal study in this one. In this one, you can see loads of hotspots of sclerotic metastases from prostate cancer. Right. It's really specific. You can do some really interesting things. So a VQ scan also nuclear med, right? They breathe in krypton and they are, are injected with technetium. So they have technetium in their blood in their lungs and they have krypton in the alveoli in their lungs and what you're looking for is a mismatch between them. So I think the top one is normal if I remember and the bottom one, you have some defects here, right? And that's all you're looking for. There's a, there's you can see perfusion is, is missing there. It's, it's ok there, the perfusion is missing there and I think the ventilation is also probably missing there. But these are, these are the, the P ES you can pick up with a VQ scan. Um This one was a, which one was this? This was a white cell scan. So um this was thought to be just a um I don't know, I think there was some diagnostic confusion as to like what this was. I thought this was just a maybe a simple collection or something. Um They did a white cell scan and found that like this was just tracking down the leg, et cetera. So these are all like this is like sources of infection. Um But that's really, I think that's really cool. That you can just tag white cells and see where all the in like occult infected sources are. Um And you can do weird stuff like this with N me because um you're tagging individual cells and molecules. Um So they are very functional tests, different functional tests. This is a classically pet scan. So this pet scan, you're getting great, quite good resolution compared to the previous SPECT scans. Um And that's because pet is um one it 3D and it, it releases in two different directions. So you can really like pinpoint where the um emission came from. Uh anyway, so in pet, you're looking at glucose. So the brain uses loads of glucose. Um the trace has been collected on the kidneys and you can see loads of er activity in the kidneys and bladder. That's just normal, it's just been excreted. Um Here, this patient has breast cancer. So this is overload on the CT. So this is a breast ct um pet ct breast cancer. Um Me on node a node. Um sorry, ignore this one. This is just the um oh I'm gonna go this one left ventricle. Um This is the breast. This is no, this is um this is breast as well. Won the game wrong. Ok. Not much. So, so it's a breast cancer with uh X ray. No. Um So functional metabolic information really specific for certain diseases. There is a radiation exposure, I don't think it's massive. So we generally, generally when it needs to be done, it's just done. Um but it is limited availability because you can imagine making these uh injectable tagged white cells or glucose. It's hard. You need a cyclotron. Uh It's a huge piece of equipment. It costs millions of pounds. Um And so they eliminating limited qualities. Um case scenario six, non small cell lung cancer has possessing back pain, pet CT for staging. And it does an amazing job at at picking up where it is very sensitive for picking up um all your lesions. So you can see them. So on the left you have your CT middle, you have your fused image on your right, you have your pet image and is very good at picking up these lesions. And if you look at the CT, there's no way you would have picked that up on the CT like it just looks a little bit sclerotic but they're hot on pet, meaning they're active lesions and that, that's really the value of um nuclear medicine. OK. Do we have, do, do people want to continue? Um It's, it's eight o'clock now, I'm, I'm happy to stay and answer any questions. But the last things we have to talk about are choosing the right Moity and the bit of safety. Um Happy. See you, by the way, um The people are, everybody seems happy to continue. OK. Cool. Yeah. Yeah, I won't take too long. Um Fine. So um the safety in radiology, um, comes down to. Ok. So, MRI safety and ultrasound, you can generally consider them safe, don't worry about it. They're perfectly safe. Um, MRI safety is just, just make sure you don't have any metal. Um, there are theoretical risks but I'm not gonna go through them because they are genuinely theoretical, um, the radiation risks from ionizing radiation. Um, so there is a long term cancer risk, the skin burns cataracts. Um And we have a, we have a principle called alara as low as reasonably achievable. And that's what we're trying to achieve in the UK. Um It's more, for example, our scans, CT scans are low quality um technically than like other, other scans from, from around the world. But it's because we're adhering to this principle. Um And so when we're doing fluoroscopy, we wear lead a prince shields, minimize the exposure time. Also with the patient, of course, not just not just us. Um So the the what this is getting at the skin burns cataracts, cancer risk is getting at two different effects that we have. Um So I was talking about hair loss and cataracts, right leg and colonoscopy. We have the patient in thrombectomy, we're scanning their head again and again and again and again, and they will lose their hair from a direct effect. So this effect is called deterministic. This effect is called ST stochastic. The risk of cancer comes from stochastic effects um outside of medicine, just the terms deterministic and stochastic generally mean the stochastic is random deterministic is uh if this, then that like it it will happen. Um So deterministic effects are dose dependent, right? There's no effect up to a certain amount of dose and then almost linearly, the more dose you do, the more um the more in this is incidents in, in your population. But like it's a dose dependent response you do if you achieve a certain dose of radiation to the eyes, for example, you've got cataracts. So we achieve some radiation dose to the, to the head. You'll, you'll, you'll get hair loss. Um And that's like within, within an interaction, um which is really different to the stochastic effects. Stochastic effects are, um, it's the concept that no amount of radiation is technically safe. We just have to limit it. So if you try to imagine that, like I have a, uh a six face diet D dye and let's say I have 100 of those. So I have 100 dice, right? So the maximum number I can get is 100 times 6, 600. Um So, and you have a risk of cancer from, um, if you hit the number of 333 you'll get cancer every time you take a radiation hit, you just roll the dice, right? And the idea is that the more times you roll the dice, the greater the cumulative chance, um, of getting cancer even though each individual chance is very low over your lifetime. If you were to say like an 80 year old, compared to a 20 year old from just cosmic microwave background radiation has received like um four times much as much um background radiation. Their cumulative risk of developing a cancer is like four times greater. And it, and I say four times because it's a, it's considered a linear effect. Um So it's four, it's four times greater risk. Um, even though each individual dice roll is the same um cumulatively, uh you, you, you are quite at risk. The other thing to say is that cancers do, they don't, don't just declare themselves immediately. You'll have the, the DNA damage now and then maybe 10 years later, there's a big latent period, maybe 10 years later. You, you get a leukemia. Um I think that's all I wanted to say, I guess a bit of trivia is Marie Curie probably died of aplastic anemia, which is an a, er, deterministic effect, which is like a direct de like damage to her bone marrow. Uh That's the only trivia I can think of. Um another little bit of trivia. Uh A lot of these, um these models, et cetera are based on, er, survivors of the Hiroshima bomb and that's not a bit of trivia. That's all I can think of in terms of trivia. Um Does that all make sense in terms of safety? Like this is, this is more than you need to know. But this is like what people think of and they think of cancer risk and um skin injury, etcetera, etcetera. Any questions for those and if not, I'll move on to like, yeah, go on. Kim was asking in regards to magnetic safety. Are there any metal items that used to be contraindicated that we now have like nonmagnetic equivalent for? Yeah. Yeah. Pacemakers, for example, pacemakers are Mr safe. Some of them um hip replacements like big pieces of metal in, in the for orthopedic stuff can be Mr Safe. We can, we can, we can scan people with big screws in their spine. Um It really depends and I think it's just I II don't, I can't think of a list off the top of my head, but there are loads of examples. Um The Mr radiographers are all completely on top of this. Um But yeah, loads of stuff and you can do this thing where you can um you can usually go back to whatever operation they've had and see like if it's Mr safe and it's usually in the like in the this online documentation of the type of thing that they're having um type of um medical device they're inserted, which will, which will say if they're Mr safe or not. Um things like clips and coils in the head because they're so small. Um If you had um then you're not Mr Safe because they, they will move. Um, so that's generally we have no Mr alternatives for those, but the big, big orthopedic stuff generally can be Mr, um, pacemakers and hopefully that answers your question. Um, I'm not sure it did a great job. Any other questions? No, we missed, we missed a question earlier but someone was asking whether, um, nuclear medicine was classed differently to fluoroscopy. Yeah. Yeah. Yeah. Totally. Totally. Totally. Totally. Nuclear med is I inject um some radioactive tracer into your veins, right? That's totally different to I have uh an X ray to you that I bring to your chest while I uh inject some contrast. This is X radiation. This will be um this will be electromagnetic radiation of a diff different sort. This will be gamma radiation and it comes from the source as you the patient. Um Whereas the source for X ray fluoroscopy is this, is this radiation source? Is the X ray tube totally different. Does that make sense? Hopefully that answers the question. Um uh OK. Just let me know if it doesn't make sense. I'm happy to, I'm I'm keen to get to what didn't make sense. Um OK. Choosing the right pal see big big thing. So when I'm vetting scans on hot seats, um everybody gets it kind of wrong. And the um the Ir Junior has got this, this slide completely correct. It really depends on the chrome question specifically. What pathology are you trying? To like evaluate, it depends on the patient's condition. So obviously you can't do MRI ing with pacemakers, er, or like small bits of metal ct and X rays you try to limit in young people. Um So, yeah, you need to, you need to take into account the clinical question, what pathology are you looking for? What can the patient actually have and whether it's available that, that roughly generally tells you which modality to go for. It's really pathology focused and it's, it's really specific. Like there's no good way to tell you all the different things. You just need to know something about pathology, which is hard. So for example, the first time you have a seizure, we're, and we're not worried about trauma like hemorrhage or CT uh hemorrhage or fractures. Then we don't need to do a CT head and an MRI will tell you so much more about like the types of pathology that cause seizures. For example, like small mass lesions or like if your, if the middle part of your temporal lobe or your hippocampus is if that's atrophied or if it's sclerosed or all those things you cannot tell in CT, you can tell an Mr, how do you know this? You've done Mr Head reporting and CD head reporting. So you sometimes you can't know and sometimes you just pick it up based on whatever clinical jobs you take up. So I wouldn't worry about choosing the right modalities, somebody will guide you. If not your consultant, then at least the radiologist betting that scan, we'll go through the examples really quickly. So we've gone through a stroke. Um, we've gone through so really good for stroke. Start with a CT head because you want to make sure that there's no bleed, bleed is picked up in CT. You need act first Mr Definitive for like acute ischemic stroke. That's why you choose Mr for these things. Um Mr for like really specific neuro things, you're not going to pick up, pick them up in noisy ct scans. Um Case number for, sorry, we had a case number one, didn't we? Sorry. Case number one was yeah, plain PHS, plain PHS you can do, you can do Mr which will pick up the ligamentous stuff. It's and it can pick up occult fractures in on Mr. But the first line thing to do is uh is an X CT, you probably don't need that much radiation to determine where the fracture is and sometimes you do and you, you, you then do it um because it gives you that 3D information when the fracture is not so obvious. Um For ultrasound, that was the case here. Uh it has to be ultrasound for obstetric monitoring. Um If you need more information, you can go for Mr for, for the reasons we said earlier, it's safe and um you get more 3D information, um less dynamic, but sometimes you need more detail. You'll go for Mr uh there's nothing really replacing fluoroscopy for us. So if you need intervention, you know, the ultrasound and fluoroscopy, a nuclear med has its specific indications like like a bone scan and looking for sclerotic mets or um pet scans to look for like hot spots from cancer, like cancer hotspots. It's all really specific and this is a discussion you'll have with your local friendly radiologist. Um So there's no one size fits all. I'm sorry, it just, you just need to think about the patient and their, and their, your specific question and their particular condition. Um I'm not gonna talk about this. So that's um that's a, that's, that's, that's this talk. So hopefully I'll give you a broad idea of what each image imaging modality does. Um when it's sort of useful, all these bits of trivia that you've hopefully picked up have in the back of your mind, it may inform your decision making in the future. But hopefully, for example, you understand the difference between a fluoroscopic angiogram and a CT angiogram. Um So a fluoroscopic angiogram. OK, if you don't understand, ask me, but hopefully you understand the difference between those two. And so when people say a DSA like or they say CT angiogram or a DSA, they are different things, digital subtraction angiography is just a technique in fluoroscopy. So that's a fluoroscopic angiogram which where you're directly in, in er injecting contrast and you're seeing it real time CTA is you take act when you've got contrast in the head, very different, right? So hopefully that gives you a more informed understanding of like which test to order and um we has to order and roughly what each imaging modality can like offer you. Um Thank you very much. So any questions would be very much appreciated and thank you for listening. We have a few questions actually in the chat. Ok. Um I'm just chat myself. Um OK. Chat. Are you able to see the chat function? Yes. OK. Regarding magnetic safety, metal items. How closely do NM and radiology work? Um uh It's a for us it's a branch of radiology. So you can subspecialise in nuclear med. So, so a lot of the nuclear med radiologists also report like diagnostic CT E body, et cetera. Um So very closely it's done by the same people. There is an internal medicine, there's a I NT pathway through it that I found out very recently. I don't know enough about that. Um OK. Hopefully I'll answer that question. Just do say it doesn't. Um Oh, thank you. Um Regarding sarcastic effects. Are there any studies on medical works? Diseases? Statistic? Yes. Um I haven't looked at them so sorry. Um There are so I think the the landmark of the stochastic effects were the Hiroshima bomb survivor um stuff. And like the weird thing is that's been extrapolated to like the the problem with getting information about, um, like cancer incidents in a large population. Um, and seeing how much ionizing radiation they've cumulatively got. And it's like, it's very difficult. Right. It's like, sort of saying, like this person throughout this life, their life has had this diet and this person has this, had this diet, um, how has that changed their cancer incidence? And it's really messy. And so you just have to sort of rely on like large scale observational studies, which is why they relied on the Hi Hi studies. Um And um so yeah, some of the Hiroshima stuff has been ex er extrapolated to large scale longitudinal, really large, like really longitudinal over like decades of like information because that's what you need. You need like sometimes 4050 years worth of information to say, yeah, this person has like had increased incidence and then you have to remove all the um confounding factors which is like pretty much impossible to say that yes, the radiation has caused this cancer, right? It's, it's difficult to do. Um So if you find any good studies, let me know, send them to me. Um Is the internal gamma radiation much safer than contrast x rays and fluoroscopy generally, yes, generally lower gen just lower um fluoroscopy. It depends on the, on the study fluoroscopic exam. So I did a barium swallow this morning. I did very few acquisitions just because I needed just like um a dynamic assessment of the swallow. Um And I was done so like very few in a thrombectomy that lasts an hour. That's so much more, right? Like, so it depends on the amount and we convert all of these X rays, gamma rays into like um radiation dose measured in sieverts. Um So you can imagine that sieverts depending on the procedure and the procedural time um can be very little or very large. Um So that varies massively, whereas typically in the nuclear me, it's not super, super high. Um So, and there's no sort of alpha or beta radiation if that makes sense. Um OK, next question, aside from blood fluid post delineation is the rule of thumb for CT scans, similar, similar. So it's like that's the sort of um that's the sort of same thing in X ray, same thing in CT, it's the same principle, right? Um Different levels of density. Um Has this been recorded? Yes, hopefully. Um Thank you for thank you. Uh Great. Any other questions? That's all the questions I can see um on my side. Thank you so much for hosting that session. Uh Doctor overall. Um I will just say that um in your emails, yes, you would have gotten the feedback form. OK. And if you feel if you fill out the feedback form, you would all be able to get um certificates for attendance as well. Um And I think doctor but has also put that in the chat. Ok, lovely Yeah, thank you so much for attending this first session. My pleasure. Thank you all for listening. Um Any questions I'll put my email in the chat. If you have any further questions, I'm based on Nottingham if you want to do a placement here. Um Yeah, just, just contact me, feel free. Um There's no, no, no pressure to do so either. Thank you very much for having me. Thank you for listening. Please fill out the feedback. I need it for my end of year assessment. Um And the recording should be available that's hopefully come to me as well. Um So goodbye. Thank you for having me. All right. Thank you, everyone. And um yeah, if you can fill out the feedback forms, then we'd really appreciate it and next week we'll have another session. Thank you. Bye. Thank you, everyone. Bye.