- Today's lecture really is about imaging in a very broad context, looking at why there's been such a massive increase in demand in imaging in recent years, whether we're using our resources in the right way, and if we keep on doing so, what the future will look like. So this is a controversial question. Have we become too reliant on medical imaging? So what I'm going to talk about is what imaging is, how we currently employ it in different ways in terms of diagnosis, screening, and treatment, why it's so important to be doing those things, but what the relative risks are of over scanning or under scanning, and whether we've learned anything at all from the COVID pandemic? Some of you may be familiar with normal x-rays. This is a chest x-ray to look at the heart and lungs, and an ultrasound scan, this is a gallstone within a gallbladder. Some of you may not be aware that we now use much more advanced imaging techniques, particularly with contrast being swallowed on a chest x-ray, for example, to look at the esophagus. There's a CT scan of an appendix, a brain tumor on an MRI, and we're now doing even more advanced techniques looking at glucose, delivery on a PET scan in the brain, and even more specific targeted molecular imaging in the liver. So as a quick show of hands, how many of you actually have had any form of imaging at all in your lives? Interesting, almost everyone. And that tells you a little bit about how we use imaging. Even the young people who didn't put their hands up have actually inadvertently probably still been imaged before they were born.'Cause in the 1980s we started ubiquitous scanning during pregnancy. Here you can see ultrasound and there's clearly a fetus there. We can talk a little bit about the historical developments that have happened, but really not much has happened in the last 40 years or so since CT and MR was invented, apart from a massive expansion of availability. So most hospitals now have almost all of these techniques available there at their practice. I'm not sure if we're quite at the point where we're able to diagnose things on iPhones, nearly, and I dunno whether we're quite at the point where we're scanning and showing people what they see on iPhones. But what I'd like to suggest to you is by some of the images that I show you and some of the things that you're familiar with, or not, this evening, is you should try and ask yourself, are these essential healthcare or are these luxuries and nice to have? So for example, screening during pregnancy to pick up any complications in the baby or the mother is clearly quite sensible and an advisable screening program. This is a four dimensional scan of a baby's face and we can do that through time, showing how the baby moves in utero. Is that essential imaging that the NHS should be supporting and is that best use of our resources, or is that nice to have and reassuring for the parent? And this is where the dilemma comes. So there's no doubt at all that medical imaging improves healthcare. You will all have had a scan, you all have benefited from it in one way or another. And radiology now is part of almost every diagnostic pathway in every specialty. Rapid access to that imaging is really the key. So if you are unfortunate enough to trip and you think you might have fractured a bone in your ankle, getting to A&E, getting an X-ray is the key part to triaging whether or not you have had a fracture or not and what you should do about it. Alright, it might take several hours in A&E, but there we are. You will leave either with a cast or not and you will have been managed appropriately. And we know that for things like stroke imaging, that time it takes for you to get a scan is one of the best predictors of what the outcome will be. So rapid access to that imaging to tell you what's happened inside the body is a really good predictor of how well you will do afterwards. And I'm going to talk a little bit more about the importance of early diagnosis in terms of cancer, and then monitoring and surveillance and a little bit of the softer side of imaging and how we use that in current practice. So what is medical imaging? You'll be used to thinking that actually what you need is a complex scanner. First you need the scanner, at significant cost. Excuse me, you need much more than just a scanner. You need highly trained technicians, sonographers and radiographers to run that scanner. And then radiologists to be able to advise on who's best to be scanned and to interpret the images. They're supported of course by a big admin team who are making sure that you get the right appointment at the right time, physics support to make sure the scanner runs, there's a governance aspect, all of that. And then people to help make sure that you get the right scan appropriately. You might need anesthetizing for your scan. So there's a whole team of people. So even though you might only see one person when you go to hospital for a scan, there's a whole team of people making sure that everything that happens to you is as correct as it can be. And there are entire departments now in hospitals. So radiology department is being redeveloped in a hospital in Sweden. You can see that in fact there are specialist areas now for CT scanners, MRI scanners, ultrasound scanners, and making sure that the patient flow through these departments is as easy as possible. What is becoming too reliant on something? So part of the initial question, too reliant on something, like to me it sort of means, you are unable to continue without it. So we need to think a little bit about what are the risks of not scanning enough, under imaging, and what are the risks of scanning too much, or over imaging? Well, not scanning enough is clearly bad, we would make mistakes, we would miss diagnosis. That would be bad for the patient, either in terms of completely missing things or delays in treatment, and that would be bad for the doctor, and they get worried about missing things. So is every scan necessary? Can we over scan? Can we over image? Well actually, if we're scanning where there's no clinical benefit and it makes no difference to you, then actually we haven't helped in your pathway. We might have exposed you to a small amount of radiation unnecessarily, and actually incidental findings are becoming a big problem, and I'll touch on on this later. What we're effectively doing by over scanning is clogging up the system, scanning patients unnecessarily, and what that does is generate waiting lists, and you'll all have heard a little bit about waiting lists in the media recently, and I'll explain to you why they are so big and what we're going to try and do about them. So the radiologist historically was a bit like Gandalf in "Lord of the Rings". They were the gatekeepers of who accessed imaging. In fact, 20, 30 years ago when when I was in training, the radiologist was very much like this, stopping a lot of unnecessary scanning going ahead. I think the expansion of imaging availability really means that we've relaxed that a little bit, and I think now a lots of scans are happening where they might be unnecessary. How many scans do we do? How big is this problem? So can you believe that we do 43 million radiological procedures a year in the NHS? That's 120,000 scans a day, and that's increasing by about a million per year. So these figures are quite interesting because the demand for CT and the demand for MRI has doubled in about a six or seven year period. So the biggest problem for us is that now that demand outstrips our capacity to be able to supply that demand. So if you look at how things have changed even from 2012 to 2018, whilst the majority of what we scan here at the bottom in the blue is x-rays and the dark blue is ultrasound, this middle part, CT and MRI, more complex imaging techniques, has also grown massively over that time period, and by about a million a year. So that's about 8 million more scans. Who are all these people we're scanning? They're you, as you said at the beginning. But why are we doing it? Where does imaging fit to the patient pathway? And actually, imaging now fits in almost everywhere at every step. So in terms of if you have risk factors for a disease or we think that there might be a purpose in early detection, that's effectively screening, and we screen for diseases using imaging. We use imaging to diagnose disease and we use the same imaging to prognose and to say how well you're going to do as a result. We use imaging a lot in treatment, and you may not be aware of all the advances in interventional radiology that have been there. And we now use imaging to see how successful the treatment has been and to survey on whether or not the treatment has worked and whether or not disease has returned. So I'm going to talk about each of those in stages, each of them one at a time to try and explain to you why imaging is so important, and therefore the problems with having to deliver all of this imaging will be. So let's start with diagnostic imaging. Let's take a very simple example, appendicitis. Everybody knows what appendicitis is, the appendix at the end of the colon is a vestigial organ. It doesn't do anything, but it gets inflamed. When it does, it gives you right iliac fossa pain in a characteristic location with a bit of fever and some bowel problems, and characteristic symptoms and signs. Do you need a scan to confirm what that would be? This is an American slide that was taken, obviously,'cause actually CT and ultrasound are down there at the bottom. Well, what happened in the good old days when imaging didn't exist? What happened before ultrasound and CT? Does anybody know the significance of this picture? This is a white lily. No, not at all. No? Okay. So a lily white appendix is a normal appendix that has been taken out in error. So surgeons 30, 40 years ago talked about their negative appendectomy rate. The rate at which they did an appendix, I can't say it, appendicectomy and removed a normal appendix, a lily white appendix. So it wasn't red, it wasn't inflamed, there was nothing into it. And those rates of normal appendices being taken out during appendix operation were as high as 30-40%. So clearly, using ultrasound to say, hang on, this appendix is inflamed, there's clearly distended, elongated, and lots of blood supply going to it is clearly advantageous. Ultrasound can't always see the appendix, so sometimes we use CT scans. So as you can see here, ultrasound can't go through gas in the bowel, and therefore sometimes appendix hide. So you sometimes need more advanced imaging to do that. So this is the ethos that actually a scan is better than a unnecessary operation. We would all accept that. So we'd now expect in 2021, 2022 that actually the negative appendicectomy rate should be pretty low. Very interesting recent study showing that actually, unnecessary appendix surgery is still performed quite a lot in the UK. Why is that exactly? So if you're a man, your negative appendicectomy rate is likely to be about 10%. If you are a woman it's likely to be about 30%. There are other organs in the pelvis that can mimic appendix type pain. But why aren't you then getting a scan? So this recent study is very interesting of over 5,000 patients in UK hospitals, and this study tells us two things, quite a lot were women, two thirds of patients were women, and actually only 32 were given a risk score based on some clinical index of of suspicion that we have. And here's an example of a scoring table. We're not very good at using scoring tables that tell us who's likely to have appendicitis or not without a scan. The other issue here was that actually most women didn't have the right scan, didn't have a CT scan. People are a little bit afraid of CT scans because of the small increased risk of radiation. So we are not doing the best for our patients even in a simple setting because there are issues about what people think about scanning. So is it really true that ionizing radiation is bad for you and that we shouldn't be scanning as a result? Well, it's very difficult to try and explain to people what radiation dose associated with some of the medical imaging is. And people try and compare it to the number of hours of flying you might have or your exposure to natural background radiation. We're all exposed to radiation all of the time, and of course, some scans like ultrasound and MRI, don't involve radiation, but some x-rays and CT do. But trying to contextualize and quantify that is quite difficult, and you probably haven't quite got the idea yet from this diagram what a CT scan involves. Well, what about bananas? People eat bananas, we can equivalent the number of bananas you eat to the amount of dose you would get from a CT scanner. How many bananas do you need to eat to make yourself slightly radioactive? One. So there's natural radiation in every banana, and Brazil nuts are the same, for example. And of course, there'll be a lethal dose of bananas that you could eat, but it's a bit silly to talk about these things in these terms. So CT scans and and normal x-rays do have a small amount of ionizing radiation, but because we're exposed to these things all day in everyday life, the small increase you get from a scan shouldn't really be contextualized in terms of how much radiation. It's really about, do you need the scan, versus what happens if you don't have the scan? So really it's a risk benefit analysis about what the scan will show. And there's been a huge campaign recently, a large piece of work done by Kath Halliday, who is the current Royal College of Radiology president, talking about getting it right first time. That's what we need to do. If you need a scan, that's what you should have. If you need a CT scan, that's what you should have. And her and her team have made lots of recommendations about how we get the right patient, to have the right scan, at the right time. Some of those things are about the facilities and the infrastructure different hospitals can offer, but actually most of it is about a clinical decision support tool. So when you think, does this patient need a scan, actually there's a risk of factors, there's a range of things we need to take into consideration to try and work out what the probability of helping people is. And again, this is all about the ethos here, is getting the right person, the right scan, at the right time, and we'd all agree with that as an idea of what we should be doing. Some of the things you may not be aware of is how imaging is now being used as part of treatment. So not as part of a diagnosis, but as part of a treatment for helping you in your patient pathway. So if you have a kidney abnormality, diagnosed maybe on a blood test, and we need a sample of the kidney to look at it under the microscope, we can now, using an ultrasound probe and a needle, take a sample of the kidney fairly straightforwardly. So a kidney biopsy is a routine procedure now happening every day up and down the hospital and the country. You might have a slightly more complicated problem. So this CT scan shows that this person has an abscess in their kidney. So in fact by turning them upside down on the CT scanner, we can actually put a small needle through into there, we can take a sample of the pus to make sure that's what it is, and we can now put a drain in, a small plastic tube into the kidney, using imaging, to try and drain that. So in fact this idea is about a scan really preventing an operation. The scan becomes part of the operation to treat you. And if you take that a step further, everyone who's had laparoscopic surgery where things like laparoscopic surgery of the bowel or maybe to take the gallbladder out, there's a number of gallstones here in this gallbladder. Actually every laparoscopic surgery must have had a scan beforehand to know what they're dealing with. So imaging is helping push people towards the right treatment. Ultrasound heats things up very slightly. So if we can get a very small ultrasound probe at very, very high intensity, we can actually use the heat that it produces to treat problems. So this is an example of high intensity focused ultrasound where somebody's got a liver lesion, and actually using a very, very small focused beam of of ultrasound, we can actually use that to treat the lesion without the patient needing an operation or needing anything else. And we've come a long way from using stethoscopes to listen to hearts. We now use a lot of ultrasound and echocardiography to look at hearts and how they function, how the valves work, what the severity of the valve disease might be. And now steps further, we're now able to use 3D imaging of the heart, in terms of CT and MRI, to look at how ventricles pump, to look at how the heart function as a completely. And on the basis of that, you may know that interventional angiography is now the art, if you like, or the skill of putting a catheter in the femoral artery, feeding a catheter up to look at the heart, and then by injecting a small amount of dye, using imaging, we can see where the problems are in some of the coronary vessels. Can you see the area the red arrow is pointing to where there's a blockage in that vessel? Not only that, we can put balloons in through the same access and we can balloon up those areas, or can put a stent in, a metal stent, to keep those areas open. So imaging is now not only forming part of the diagnosis but for a part of the treatment, and again, saving people an invasive operation. And no more so than in endovascular treatment of stroke. So this is where if you have an acute stroke and a plaque blocks one of the blood vessels in the brain, using the same approach through a blood vessel in the groin, we can now put catheters all the way up into the head and actually destroy the plaque where it is, or in fact put a coil through and remove it. So that to me is one of the miracles of modern medicine, to be able to look inside the body, send in catheters, wires, stents and give treatment, if you like, in real time, operated from outside, using imaging to get the patient to avoid an operation and therefore to get home quicker, without side effects, etcetera, etcetera. That I think is one of the major advances of imaging. But of course there are massive resource implications in doing this. Some of the softer side of imaging, I would say, is about follow up and monitoring what happens to patients. So they are things like surveillance. What happens if you have an illness that we haven't treated or we maybe treated a little bit, but we need to know whether it's coming back? We might use imaging to follow up and see what happens there. And monitoring, we need to know what happens to a diagnosis you have and look at how that changes over time. So examples of that are after an operation you might have a scan that shows here a brain tumor, immediately postop, there's still a bit of swelling around there. So you might have a couple further scans to show that that's resolved. But what's interesting here is a scan begets another scan effectively. So you came in for one scan and actually your whole treatment pathway is going to be four or five scans. What happens if you have a smaller but slightly more complicated brain tumor? Before you are given a smaller amount of treatment, actually you might get a scan every year to see whether or not that tumor has changed so that we can stand in. So we are using scanning to assess disease progression. Perhaps the question for you is, how many of those scans are unnecessary? Are they unnecessary in retrospect or actually are they reassuring in confirming that actually we don't need to do anything? Are they vital for that patient going through the pathway? For that particular patient, they would say yes. For society and the NHS as a whole, I'm not sure where that decision is made. And we talk a little bit about screening. Imaging is used quite a lot in screening, and screening is a different approach, because screening is about investigating patients, people without symptoms, for the potential for disease. So we're trying to find hidden important disease in a population. Some of you might have slightly more risk factors than others, but trying to find a hidden disease, there's got to be a risk benefit analysis to doing that. So we know that cancer screening programs work, we know that they save lives and the breast, cervical, and bowel cancer screening program in the UK saves about 10,000 lives every year. But the benefits for the individual patient versus the population need to be taken into account. And there's a question about screening, which is, should we be doing more or less? Let's take breast cancer screening as an example, because breast cancer screening is done by a mammogram and it's fairly rapid access and can quite easily tell you whether or not there's a cancer there or not. The difficulty is that cancer's unpredictable. So it's hard to know what would've happened had we not screened for it. Some cancers will grow very quickly and spread and be fatal. Others will grow very slowly and actually maybe never cause any harm. So are you better off knowing about those cancers or not? So if we take the example on the left there of, for a thousand women who go through the screening program, without screening, 21 would die of breast cancer and 37 would be treated and survive their cancer treatment. With screening there would be more diagnoses, fewer deaths, which is great, but actually there would be about 17 over diagnoses. So we're identifying abnormalities, which actually have no impact on the life of of the patients, and all we're doing really is generating anxiety. So screening programs work, they do say save lives, but they don't come at zero cost. So put very simply, for every a hundred women who go through the breast cancer screening program, the vast majority are normal and don't need anything doing, but to find one cancer there will be four or so that actually need further tests. We've created anxiety, we've found an abnormality, often need more imaging, to discover what that is, and so we've added to the system rather than subtracted. So you might think that's okay, that's a small price to pay. But we screen over a million women every year. So a million women every year to find 10,000 cancers, which means there are about 40,000 women who go through that process and don't have a cancer at the end of it. Lung cancer screening is another area where we should be looking into because actually the vast majority of patients diagnosed with lung cancer at diagnosis have relatively advanced disease, and the survival is very poor. There's a big trial just been carried out in the Netherlands of high risk patients, so former or current smokers, where they were offered CT scans at two yearly intervals. And actually after 10 years of screening, in the screening group they picked up lots of cancers that were very early stage and they did better than the non-screen group. So your survival from lung cancer is better if we screen you using CT scans throughout your risk period. So maybe we're not doing enough screening or maybe we're not getting the right target populations. And there was a vogue a couple of years ago for cancer scanning rolling out at the supermarket. Has anybody seen this or participated in these? Yeah, trying to get patients to come forward for screening tests like CT and MRI to diagnose disease early. But the more you scan, the more you find, and finding incidental things can be problematic. Are you aware of this idea of incidental findings? So finding things that we weren't expecting to find, because we've done a scan. So that can be helpful, that's serendipitous. That's great, thank you, I didn't know that already. Or it can be extremely unhelpful. So let's take for example a woman who comes off a a long haul flight and she becomes breathless and has a swelling in her calf. So that could be a DVT, a deep vein thrombosis, and it could be that her breathlessness is due to a pulmonary embolism. So the right scan for that is a CT scan. She comes to hospital, she has her CT scan, she doesn't have a pulmonary embolism, but she does have a tumor in her breast. So what happens as a result of that is she goes into the breast cancer program, she would have a mammogram to confirm that diagnosis, an ultrasound and a biopsy, and she would be very relieved that her breast cancer that she wasn't aware of previously has now been detected and she's been treated appropriately. But how often does that happen? Well, in her survey of about 35,000 chest scans, actually about 25 breast lesions were identified. So this is going to happen less than one in a thousand times. So actually that isn't the right way of going about doing things. And in fact, what's more likely is that we find a tiny little nodule of something that we don't really know what to do with. So if you come for a chest CT scan for another reason and we find a tiny little nodule, we are not sure how to manage that. We're not sure what to tell you about what that means. We're not sure what the best thing to do is next. What you probably need is another scan. So if you're at high risk and actually you're a smoker or something, actually you're probably need a biopsy to check that that isn't cancer. If you're at low risk, you might either need a particular scan or maybe scan you in three months or six months to see whether anything has changed. So from a single scan that you weren't really expecting to have that problem from, now, knowing you have that problem, you are now buying into two, three, four further scans. And that's not just lungs that that's relevant for, it's also relevant for liver. So a small liver lesion. Here's a small liver lesion, picked up incidentally when we were scanning for something else in an adult, what do we do? Well, we've got quite complicated ways in MRI scanning of identifying how that lesion behaves to different contrast that we give. But you've effectively bought yourself another scan, and if that is normal or abnormal, in order to find out what's happening to that lesion over time, we need to scan you again. So you'll come back after three months or after six months, or perhaps more regularly. So we're effectively one scan of an unexpected finding often results in more scans. And we fairly effectively don't have capacity to do all of these scans. The commonest incidental finding is an adrenal problem. So the adrenal is a small gland that sits just above the kidneys, it produces lots of important hormones, including adrenaline. And about 10% of people when they die have completely asymptomatic, completely inactive adrenal lesions. And they're so common, they're called adrenals or incidentalomas. So if we scan the population, 10% of you would have these small lesions. They're very rarely malignant, they very rarely do anything exciting at all. But once we've scanned, what do we do with the information? What do we tell you? Actually, should we measure the hormones? But actually that won't tell us whether or not it's malignant. So you end up getting, you've guessed it, another scan in a little while to see. And where does all this scanning now come from? And I think one of the things driving this is fear. I think we're afraid of doing the wrong thing. Some of that is justified,'cause if you look at the misdiagnosis claims in NHS hospitals, actually most of the misdiagnosis and the litigation claims are about the wrong diagnosis, missing the diagnosis, or finding a diagnosis too late, and it's too late to do something about it. And the five top areas where that's problematic for are fractures, which we know imaging can pick up fairly easily, and cancer, which we've just described in quite detail how imaging can pick up. So failure or a delay to send for a scan can often mean a misdiagnosis. A failure to see the abnormality as a radiologist often is problematic. And then a failure to follow up correctly and do the right thing afterwards, and make sure that you're scanned three or six months later is really what's driving all of this force behind imaging. So whilst we all agree that an unnecessary scan is better than an unnecessary operation, would you agree that an unnecessary scan is better than an unnecessary lawsuit?'Cause I think this is where some of the referral patterns are coming from. What is an unnecessary scan, by the way? Because if I send you for a scan for something you are never likely to have, you'll go, oh, that's a relief, I haven't got that. Was that unnecessary? You won't think so necessarily. So I think medical imaging has become a little bit of a comfort blanket. We've become victims of our own success. We've made things available, we've shown that things are possible, and so people have become a bit reliant now on needing to have the imaging in order to be be able to proceed. And it's become a little bit like a path of least resistance. And I have great sympathy for GPs seeing patients for, I dunno, 5 minutes or 10 minutes and trying to decide who needs a scan or not. It's very difficult to decide. So it's easier to send than it is not, isn't it? So this idea of scanning just in case is a reasonable approach, but it's generated a massive amount of work. So we have a quandary here, which we have lots of people that need imaging and we don't have enough resources to meet that demand. So how would we test the system? Can we test it? Can we suddenly stop imaging everybody we don't want to image? Well, that's really interesting because that's sort of what happened during the COVID pandemic. So I'm not going to talk anything about the patients who had COVID and the medical workforce, and how they were all affected through the COVID pandemic. But in March, 2020 elective imaging effectively stopped overnight. You were only allowed into hospital if you had a true emergency or it was COVID related. That's entirely reasonable at the time. But the effects then on imaging departments in terms of the added social distancing, the infection control, needing to deep clean after patients, and some imaging stuff were redeployed elsewhere, meant that you couldn't provide the imaging service you were normally expected to do so. So one of the key questions here is about who didn't get scanned during COVID? So this concept is, what was the pandemic effect on patients without COVID? So our diagnostic imaging at the point of entry actually continued, but was obviously massively reduced, less people came to hospital. Our interventional radiology continued, but again, massively reduced 'cause we weren't able to provide that service. Screening was reduced, people didn't go to hospital for their screening test, and surveillance, in terms of checking how people were doing month or month, or year on year, pretty much stopped. So what was the net effect of that? Well, there's been a massive reduction in the new breast cancer diagnoses, and of course there's been a lot fewer heart operations and bowel cancer operations, which would've happened anyway. But those people with those diseases haven't disappeared. So they're simply out there in the community now, and I think we're only now, two years on, starting to realize what the effect of the pandemic was on all of the diseases that we didn't diagnose during that time. So you might think that's fine, because now we can catch up, and now when you're diagnosed, everything will be okay again. But actually there's a serious quality of life issue here about delay in diagnosis. And if we take hip replacements as an example, because there are 330 hip replacements done every day in the NHS. So 60,000 people waited an extra six months or so for a hip replacement because of the pandemic effect. So that's fine. You might think that's okay, because actually there's a quality of life lost whilst the operation wasn't happening, but in fact, with hip replacements, operations are not as effective if there's been such a delay. So actually the quality of life once you've had your operation can be significantly reduced to actually outweigh any benefit that you would've had. And we did a small study in our own hospital, children's imaging, about how many patients came and what happened during the pandemic? The dotted line in the middle here is the number of inpatients we saw during, and the top line is the number of outpatients. So you can see that the inpatient line, the line in the middle actually didn't change very much during the lockdown tiers and during COVID. So the sickest patients were still in hospital, still getting the treatment they needed. But those patients who are still being seen as outpatient, so these are children that we are monitoring, we're surveillance, and using imaging to check on the progression of disease, actually that dropped massively during the lockdown. Patients were encouraged not to bring their children to hospital. But what was the effect then on all of these patient groups over time? So in fact, what we've calculated is that we had about a 40% reduction in all the patients that we saw during the tier four lockdown, and about a 25% reduction overall. So instead of seeing about 70,000 patients a year, we saw about 50,000. So what's happened to those 18,000 missed outpatient appointments? And this is just about imaging. Well, if we assume that we had a 10% increase in working capacity, actually it would take us two and a half years to catch up on all of that activity, to see all of those patients. So the two critical questions for the hospital at the time that we realized this and were going through trying to get things back to normal is, one, is how do we recover that activity? How do we get to see all of those children? Secondly, do we need to, what have we missed? And I think we genuinely don't know. What we do know is that NHS waiting lists are three times as large now as they were 10 years ago. So in 2012 there were 2 and a half million people waiting for routine hospital treatment and there are now six, seven million. There were about half a million people waiting for an MRI or CT scan, there are now one and a half million. So the queue is getting longer and longer. If you combine that with the fact that actually we have some of the lowest numbers of CT scanners per head of population, and some of the lowest numbers of radiologists per head of population. So we're not starting from a good place in order to be able to play catch up with some of the appointments that we've missed. And overall, in terms of the number of doctors and nurses we have, the UK is, what, just below Lithuania and the Czech Republic in terms of Western Europe, in terms of how well staffed we are, purely in terms of people able to offer that service. And again, if you look at the shortage, the availability of CT scanners by country. So the UK is here, and MRI scanners similarly, we started off on a low baseline in 2011, and actually by 2016 we don't have many more scanners. In 2022 it doesn't look any better than this. And other countries have clearly invested in their technology. So the quandary gets worse. We've got lots of people needing imaging, we haven't got enough resources to meet the demand, and now we've got a backlog due to a chronic shortage and the COVID pandemic. And some people are arguing, actually forget the pandemic, the NHS decline was happening for years before we even got there. So what are we to do? What are the potential solutions to solving this problem? Do we just need more machines, more staff, bigger hospitals, more throughput? Or do we need to be slightly cleverer about how we do things? And actually, I think we need to be a bit more judicious about the use of imaging that we have and to try and adapt things slightly cleverer. What about home imaging and what about artificial intelligence? Home imaging, I dunno if you saw this, so this device won the James Dyson Award in the UK this year. This is a tool to spot breast cancer at home. This is a very simple superficial ultrasound machine that can bluetooth to your mobile device, and it can pick up any abnormalities under the skin. So because several breast cancers are superficial, this is not a bad way of trying to pick those up. This is very much at the developmental stage. And I dunno how many of you would feel comfortable using something like this at home. In 2016, one of the AI pioneers, Geoffrey Hinton, said that we should stop training radiologists completely. He said, "It was completely obvious to him that within five years deep learning", computer technology, artificial intelligence,"Would do much better than radiology." And if you want to watch him say that, there's a YouTube link to his video. So what did he mean by that? So can you train machines to do what radiologists do? Well, if we ask a simpler question, can computers help us? Can computers help us identify abnormalities on images? Well, yes they can, once we train them. So if we train an algorithm to say, look, there might be fractures in this bone and look there might be abnormalities on this chest x-ray, then the next image it comes across, it could help identify those. So it's very sensible to think about developing artificial intelligence as a way of accompanying medical imaging. But in fact, deep neural networks and artificial intelligence are actually also really easy to fool. So with the simple addition of some stickers on this stop sign, that computer interprets that as a completely different image. Computers can also see images of, what's that, a king penguin and a starfish, where we wouldn't interpret that, and can make lots of different mistakes about what different imaging are, depending on what we show it. So they're too easy to fool at the moment. And where you or I might recognize that actually this is a scan of a patient with a spine, a liver, and things, and actually all they've done is breathed during the scan, actually that completely fools an artificial intelligence machine, and they make mistakes, finding tiny blobs of things which radiologists trained to look at those would disregard, and artificial intelligence picks up. So we are not quite there yet. But if we think about where computers could help us in this pathway, actually, I think there's a lot of work to be done on risk factors. So it might well be that your genetic makeup, together with your lifestyle choices, actually would push you into receiving imaging for early detection of different diseases that an artificial intelligence algorithm could tell us much earlier than a radiologist would pick up on a scan. So I think there's a place for artificial intelligence to help funnel people, perhaps, into the most appropriate imaging, but maybe it's not in interpreting imaging themselves. And of course, by the time you've got to have a scan that isn't really part of the problem, the part of the problem here is access to scanners in the first place. So artificial intelligence might be able to help us become more efficient in the way that we do things, helping people through the patient pathway a bit better, making sure that things are done in a timely fashion, or maybe interpreting the results, sending you the results back and making sure that you're seen in the clinic appropriately next time. So what is the answer to the question, are we too reliant on medical imaging? Well, clearly there's a balance here, isn't there, between over-diagnosing and over scanning versus underdiagnosing and under scanning. So if fear is pushing to scan a bit more, what we're going to do is we're going to find more incidental findings in an otherwise normal population. I think the bigger problem here is that we've got a very limited resource in an ailing population. So I don't think there is a quick fix, but what we're trying to look for is, of course, we're trying to aim for the right test, at the right person, at the right time. So maybe I should push the question back to you and ask you, do you think we are too reliant or are we just reliant enough on medical imaging? The question really here, who doesn't need to be in this queue? Thank you.(audience applauding)- I've got a couple of questions from the online audience if, I may, to begin with?- Of course.- So the first one I've got here is, assuming we can't simply print more money, what would reduce any overuse of medical imaging the most?- So there's the so-called worried well, I dunno if you've heard of this concept? So those are people who are anxious, they're worried about something happening to them, and they might go and seek medical advice over less important symptoms. And of course we have the opposite, which are people who actually need urgent healthcare who don't come to medical attention. That's always the dilemma, and I think GPs are seeing both of those populations, but far more of the worried well than they are of the people who really need them. So how would we diagnose those people is interesting. I think they're often sent for a scan"just in case" or as a reassurance. But I think reducing that would really help. I think the other thing that we have a problem with is those patients who don't attend their appointments. So this is true for GPs as well as in hospitals and clinics. And I think that's the point at which I suspect somebody from a political standpoint might want to start charging for. So the most inefficient use of medical resources is not to turn up. So that might be another area where we can become a bit more efficient.- Professor Arthurs, I've got a question here from the online audience. Would there be issues on waiting lists if we haven't had a pandemic? I think you've sort of answered that, haven't you, there would be.- Yes, I think so. And the argument is that actually before the pandemic, I think, that the waiting lists were about double what they were 5 or 10 years ago, and now they're triple. So we had a problem before the pandemic existed. Some people are saying that actually what the pandemic did in terms of this context was really just to accelerate things and brought forward two years, probably, of of change into about a month. So yeah.- Thanks. Great lecture, you covered lots. So there seems to be correlation between how good the medical imaging quality is over time and the number of people who are scanned. So should we just stop trying to improve medical imaging?- That's an excellent question, isn't it? So the natural progression is to try and improve everything, and we'll continue to do that,'cause actually we make better diagnoses that are better for patients, and patients will get better access to healthcare and recover better as a result of those. So holding back technology isn't one of the solutions here. I think more judicious use of that technology is really where we're going to improve.- [Audience Member #1] I think read last week that there is a plan, potentially, for national screening for lung cancer, particularly for those who are ex-smokers or current smokers. Do you believe that that is a good use of resources given the shortage of scanning capacity?- So with every new idea and new plan that comes along, it usually requires additional resource. So if it's going to be occupying scanners that are currently used for other things, then actually all we've done there is just generate a larger waiting list. If that's going to be resourced outside, either with mobile scanners or those sort of clinics, then yes, I think that would be good. The end results to try and improve the health of the patients and the population is exactly what we're trying to do. So if imaging can help doing that, I think that's what we should be doing. The difficulty is the sheer volume of things we now need to try and cope with because of the illnesses out there, and we are unable to try and cope with all of that effectively to try and, yeah, meet that demand.- I've got couple more questions for online, and then we can go back to the in-person audience. So there's one here on, how do we take the rationing decision in an ethical way in the public health system rather than private money, ensuring they're seen when they want to be seen?- Yeah, so some people can buy themselves out of waiting list by going private, but actually that's still a resource of people who are running scanners, of technologists, of radiologists. So we haven't really solved the problem by just moving that slightly. And if you could say the question again? It was about?- The rationing decision.- Yes.- In an ethical way?- So let's imagine all of you were on a waiting list for a particular operation to happen in the next six months. How many of you would say that you would be happy to wait a bit longer? Couple of you, okay. If the effect of waiting longer was that you would have a worse outcome so then the treatment would be less effective, so if you think about the hip operations we talked about, how many of them would offer to give up your place in the queue? So this is very difficult. So these judgements won't be made probably at the patient level, and of course, it's very difficult to do that as a doctor with a patient in front of you. So it happens at the population level where waiting lists, you simply get added to a list that actually doesn't move. So I think they're very difficult. I think they are policy decisions and they're government decisions about how much resource we want to put in to trying to get rid of a backlog.- There's another question here on is there a point where blood tests could replace scanning?- Yeah, absolutely. So all of the technologies we have are evolving in parallel. So if you could have a blood test that told you you had a cancer marker or not, and then we would have to scan you to see where the cancer was, that could very easily refine a lot of the screening programs we have, couldn't it? So instead of coming for a scan to see whether you've got a cancer, if a blood test would give us the same information, and may well be able to detect earlier disease or tiny molecules of disease, then I think those advances would be really beneficial. It probably wouldn't reduce the amount of scanning we need to do, but it'll be better use of the resource for those who need it most.- [Audience Member #2] So you spoke about being more judicious with choosing who gets screening and who doesn't, but what about the problems that arise on a case by case basis, the reputation of the public healthcare system, and how people view it?- And what do you mean by on a case by case basis?- [Audience Member #2] As in, people aren't going to be happy if they're denied scanning.- Yeah. So it's quite difficult,'cause I'm not sure that you have much of a voice when you're on a waiting list. And people are being denied treatment effectively by drawing out the wait that they have to try and get something. If you need emergency treatment and you go to A&E, the chances are you'll receive that treatment within hours or days. So we are prioritizing urgent care. What we're not prioritizing is those things that we think as a population "can wait", and I'm not sure that they're decisions that we necessarily are making.- [Audience Member #3] I'm glad a previous question had mentioned blood test,'cause I was thinking, is there a risk for displacing, kind of saving radiologists the time, and then you've just got extra pathologists who have too many blood tests to do as well? And linked to that, if the fear of a lawsuit is motivating a lot of this scanning, like what's the situation with qualified immunity? Is there some way of escaping or at least preventing legal jeopardy, which might give some doctors the courage not to scan?- Hmm, so if I take their second question first, wow, would it be nice if there was some sort of protection for doctors so that if they made mistakes they were indemnified? There sort of is. But many of the lawsuits in America, which fuel a lot of the fear in the UK, are about people not being sent for a scan or the abnormality being missed on a scan. And that happens repeatedly, the commonest example is of a lung cancer that was on a chest x-ray that was done a while ago, and people didn't look at it and people didn't pick it up. So by people, radiologists didn't do that. So I think you'll never be able to remove the fear. But scanning just in case is very much a luxury of western healthcare. So in the developing countries, you can't scan just in case. So if we start to look at the way they model their healthcare, we could learn quite a lot from how they prioritize their cases and which are perhaps the populations that we are starting to image and starting to look at. And perhaps the risk benefit isn't really there. What was your first question again, sorry?- [Audience Member #3] It was about displacing radiologists with.- Yeah, so you could argue that computers could help quite a lot in automated blood test reading. We've already automated quite a lot of blood test analysis. And so actually, to add another one of those in terms of DNA or tiny fragments of potentially cancer DNA, I think you could automate quite a lot of that, but I'm not a pathologist. I think you would end up displacing a small amount of it and hopefully you would recover that in the sense of reduced numbers of those people going for tests.- I think we have a question from there.- [Audience Member #4] Although it wouldn't be solving the actual problem of what's causing the increased amount of scans, would you think opening more scans in GP practices, such as, you know, CT, MRI, PET, and all that, X-rays, would that help reduce the volume, although it's not treating the original course?- Yeah, so I'm going to borrow from Professor Helen Stokes-Lampard, who's the Chair of the Academy of Medical Royal Colleges, who wrote a very nice article in "The Times" recently who said, "It would be naive to think that just money would solve this problem. But it would be equally naive to think that we can solve this problem without money and the resources." So by moving some of those imagings into primary care, into a GP setting, we still have the problems of staffing them and making sure we have the right qualified people there to look at them, and then radiologists to look at them. So there's currently a 10% vacancy rate for all radiographers and all radiologists across the country. So if we had 20 new scanners tomorrow, we simply wouldn't be able to staff them rather than run them for the right reasons. So you'd almost just be moving the problem around.- [Audience Member #5] I think at the beginning you said that the radiologist was the gatekeeper. I've had a few scans in my day, I've never had a radiologist say no. So my question would be, should radiologists be saying no? Are radiologists really the people who know best whether the scans would be useful, and are they in the role today where they're able to say, no, we're not going to do those cause they're not going to help- Yeah.- your diagnosis or are not going to help the quality of life, we'll take that one instead?- Yep. So as a radiologist, I'm clearly biased in what I'm going to say next. I think they are the right people to make those decisions because they often have the overview of the entirety of the population that they're scanning and the majority of symptoms that patients get. Often people ask for a scan, so they might send you for an ultrasound, when in fact a radiologist will know that isn't the right test for the suspected symptoms you have, and in fact what you need is a CT. So we are very much are doing that on a day-to-day basis and actually changing around what people need in order to make sure that they get the right test. Historically, we were gatekeepers because there was quite a lot more fear about ionizing radiation, doses of CT scans, and things 10, 20 years ago were much higher than they are now. And I think what we've caught up with a little bit is we haven't exactly opened the floodgate, but we've certainly become a lot more relaxed about needing scans. I think we've become more sympathetic to pressures in other parts of the NHS where A&E doctors and GPs are also pushed to try and make the right diagnosis for the patients they see. So I think we've become more sympathetic to recognizing that we may not have all of the symptoms and all of the right information, perhaps, for the patients to have a scan, but probably a scan of some sort is the best thing to do. And once they start in the pathway we'll be able to triage them accordingly. The difficulty with that is incidental findings.- Thank you. What scans are easier to interpret abnormalities, please?- I'm not sure that any scans are easier than others to interpret. I think the skill and training of a radiologist is to be able to cope with all of the images that they come across. There are issues with the right specialist seeing the right scan, and that is particularly a problem in less specialist hospitals. So in my specialty, for example, in children's medicine, we know that most children's scans across the NHS are not interpreted by specialist in children's imaging. So that causes about a 30-40% error rate. So if the same were true for, say, brain imaging that wasn't seen by a neuro, or pancreatic imaging that wasn't seen by a specialist, across the country, that would lead to a reasonable amount of misdiagnosis. So I don't think anything is harder or easier to interpret than anything else. But not everybody has the same skill set to be able to do that on a local level. And that that's not doing anybody a disservice, that's trying to provide the right imaging service for the population that you have at hand.- [Audience Member #6] So one of the figures you showed, it showed that Greece had many more radiologists than anywhere else, any idea why that is?- I think there are a lot of private clinics in Greece and I think there's a lot of money in medicine in Greece, but that would probably be speculation on my behalf, yeah.- Please join us again when Professor Owen Arthurs returns for a lecture with Professor Joe Delehanty Casey,

Where Two Worlds Collide on Thursday the 19th of January, 2023.- Yeah.- 6:00 PM. Thanks so much, Professor Arthurs.- Pleasure, thank you.