Hello, and welcome. I am John Sable, Clinical Research Manager for Konica Minolta Healthcare. Thank you for joining us today. The RSNA is committed to promoting excellence in patient care and healthcare delivery through education, research, and technologic innovation. Konica Minolta Healthcare is thrilled to have the support of the RSNA for this webinar on the clinical applications of dynamic digital radiography in thoracic and musculoskeletal imaging. We will get started in just a moment. Please note that this webinar is being recorded and will be posted to RSNA's Online Learning Center and its YouTube channel in the coming days. Please feel free to type any questions that you may have in the question box on your screen, and we will answer as many of these as we can at the end of the webinar. This webinar will consist of five parts with four different speakers. I will kick it off with a description of what dynamic digital radiography, or DDR, is, how the technology works, and explain some of the advanced analytics that can be done with these images. We will then have three presentations by clinical experts who are currently using DDR in their practices and research efforts. Doctors Don Benson and Thomas Fitzmaurice will both speak on clinical applications of DDR for thoracic imaging, followed by Dr. Eric Wagner, an orthopedic surgeon who is going to discuss how he uses DDR in the care of his shoulder patients. Finally, there will be a live question and answer session where we will address any questions that you may have. As we're moving along, please enter your questions for the speakers in the question box on your screen. We'll then address them in this final session. To start with, please take note of the disclosures. I'm an employee of Konica Minolta Healthcare, which is one of the vendors of DDR technology. Thomas Fitzmaurice has received support for conference travel and attendance from Konica Minolta. Don Benson and Eric Wagner have nothing to disclose. Also, unless otherwise explicitly stated, the imaging technology and all of the analytic applications described have been cleared for use by the FDA in the United States. Now, let's get started. For over 125 years, radiography has meant acquiring a static image of a patient's anatomy. Technologies were developed to enable capture of patient motion, but these entailed the use of specialized equipment, often requiring moving the patient to the imaging equipment itself. With the advent of fast readout, highly efficient digital detectors, we're now capable of acquiring dynamic imaging, capturing patient motion with the same equipment and in the same way one would acquire conventional static images. This enables us to observe anatomic and physiologic changes as they occur and offers the potential for improving the quality and efficacy of patient care. What is dynamic digital radiography? Dynamic digital radiography, or DDR, is a recent advancement cleared by the FDA in late 2018 that enables the acquisition of a series of static images at 6 or 15 frames per second. With current implementations of this technology, the maximum acquisition time is 20 seconds and it can be acquired over the full 17 by 17 inch field of view of a large format flat panel digital detector. In addition to highly efficient fast readout, the system requires a pulsed x-ray source to ensure very low dose. For example, for a 15 frame per second chest acquisition, the typical dose is just over 7 micrograys per frame for a total of about 1.5 milligray. The resulting image data sets are viewed as standard DICOM objects on a PAX, either in a cine loop or can be paged through frame by frame. Individual frames can be extracted from the series and utilized for archiving for further analysis, just as a conventional static image would be. DDR is currently available on four different acquisition platforms from three different vendors. In addition to conventional overhead x-ray room and floor mounted straight and U arms, it has recently been FDA cleared for use with a wireless detector in a mobile x-ray unit. This variety of platforms enables DDR to be used wherever conventional radiography is done today, whether at a large hospital or a small imaging center or orthopedic clinic. In the last few years, over 130 systems have been installed globally, the majority in Japan with growing utilization in the United States. It's important to note that DDR images are acquired with an advanced x-ray system that is also a general x-ray system and that can acquire all of the conventional static imaging views. Dynamic and static images can be acquired with the same system in the same session. A DDR acquisition typically only adds about a minute to the overall exam time. Shown here are a variety of possible patient positions and exams that can be done with a U-arm DDR system. It's important to note that DDR is not fluoroscopy. There are a few key differences. First of all, DDR does not provide real-time imaging. There is a one to two second delay between the start of an acquisition and visualization of the initial fully processed image on the operator's console. DDR is also limited to a maximum 20 second acquisition. Shorter acquisitions can be programmed and of course the exposure will terminate any time the technologist releases the hand switch. Unlike fluoroscopy, DDR has a very large field of view, dynamic exams can be captured over the full 17 by 17 inch field of view at lower dose than fluoroscopy. Also unlike fluoroscopy, a physician does not have to be present in the room during the acquisition. Thus these sequences can be scheduled and acquired with the same workflow as a conventional radiography exam. As with all x-ray exams, dose is of critical importance. We did an analysis of the technique and incident air kerma entrance dose for 55 patients receiving shoulder DDR at Emory Orthopedics and Spine Center in the July to February timeframe of last year. The effective dose was calculated and compared to reported values for conventional static radiography, shoulder arthrograms, and CT. As you can see, the dose from a DDR acquisition is very low, comparable to a standard x-ray and much less than fluoroscopic arthrograms and CT. Relatively speaking, the effective dose of a DDR acquisition is about 25% higher than a conventional static exposure and almost 40% lower than an arthrogram. To understand the dose of a thoracic acquisition, we examined the dose for four patients, all of whom received conventional two-view x-ray, DDR, and fluoroscopy at the University of Alabama, Birmingham. The fluoroscopic entrance dose ranged from 11 milligrays to 36 milligrays with an average of 21 milligray. The DDR dose for the maximum duration 20-second DDR technique was just 1.78 milligray. Again, as we saw with the shoulder, the DDR dose is comparable to conventional static radiography. DDR provides not just dynamic images but a rich data set that enables advanced analytics that are not possible with static imaging. To give you a sense of this potential, I will briefly describe a pair of advanced analytic applications for thoracic imaging analysis. During respiration, the regional x-ray attenuation in the lungs changes as the bronchi and alveoli fill with air. Similarly, changes in blood volume within the pulmonary vasculature cause changes in local x-ray attenuation over the cardiac cycle. In a dynamic scan, we visualize these attenuation changes as pulmonary motion. We can extract data frame by frame and region by region to do advanced time series analysis over the cardiac and respiratory cycles. To look at changes over the cardiac cycle, we first segment the lung regions, define an ROI at the cardiac border, and use the variation signal within this ROI to estimate the heartbeat. We then define a frame at end diastole as the reference frame. We can then examine individual ROIs throughout the lung area, bandpass filtering the data to the cardiac rate. We then use this data to compare the signal in each ROI to the reference frame. A color map is used to represent the signal difference between each frame and the reference frame. This gives us a color map of relative signal changes throughout the lung over the cardiac cycle. In an analogous way to extracting the data over the cardiac cycle, we can extract it over the respiratory cycle. Similarly, we create a reference frame which corresponds to maximum inspiration. We bandpass filter over the respiratory cycle, and we apply this bandpass filter to the signal change in the array of ROIs throughout the lung area. We can then create a color map of attenuation changes between the reference image and each individual frame. The utility of both these analytics is demonstrated in an interesting case study by Dr. Yamasaki and his colleagues at Kyushu University. A 74-year-old man presented with dyspnea, and these novel images detected normal ventilation dynamics in bilateral lungs, as you can see in the top image on the far left. However, there was severely decreased perfusion in the left lung, as we see in the image below it. Lung ventilation perfusion scintigraphy showed the ventilation perfusion mismatch of the left lung, which is very similar to the findings of DDR. Afterwards, CT pulmonary angiography and iodine mapping acquired with Dual Energy CT also showed a similar finding to the pulmonary perfusion image of DDR. After careful examinations, the patient was diagnosed with giant cell arteritis and pharmacological therapy was started. Another advanced analysis tool is the use of an optical flow algorithm to quantify motion of the lung in the cranial-caudal direction. The amount of motion during respiration is shown using a green color scale, from areas of no motion, shown in black, to areas of up to four centimeters of motion in the bright chartreuse. In the dynamic sequence on the right, areas of very low motion, less than 1.5 millimeters, are highlighted and superimposed on a frequency-enhanced dynamic imagery. A number of published studies have shown this to be useful in detecting adhesions to the chest wall and evaluating pulmonary dynamics after surgical interventions. Now I'd like to introduce the first of our clinical speakers to discuss the clinical utility of DDR in thoracic imaging. It's my pleasure to introduce Don Benson of the Department of Radiology at the University of Alabama, Birmingham. Don studied physics and mathematics, continuing on to earn a PhD in physics from the University of Notre Dame, before attending medical school at the University of Arkansas. Following his radiology residency at Arkansas, he completed consecutive fellowships in clinical MRI and cardiothoracic imaging at the University of Wisconsin-Madison. Before joining UAB, he was an assistant professor at the University of Arkansas. Currently at UAB, they have been routinely using DDR for thoracic imaging over the last year and a half. Go ahead, Don. My name is Don Benson. I'm an assistant professor in the cardiopulmonary imaging section at the University of Alabama in Birmingham, and I'm going to spend the next few minutes talking about clinical cardiopulmonary applications, dynamic digital radiography, or DDR, as we call it. I have no disclosures. So we've been using DDR for a little over a year now. We've had a lot of fun using it, and we're still trying to figure out how to tap into the full potential of this new modality. Just a simple area where it has some utility is in the assessment of lung nodules. Sometimes it's unclear whether a nodule is truly in the lungs or if it's in the chest wall. This is just a nice example to show how you can clearly see that this nodule here in the right lower lung is within the lung parenchyma itself and not in the chest wall as it moves up and down with the adjacent lung parenchyma. This was subsequently confirmed with a CT that was obtained subsequently with this calcified nodule in the right lower lobe. This is the corresponding case of a chest wall nodule. You can see here that the lung parenchyma is moving up and down while this nodular opacity here projecting at the left lung base is actually fixed relative to the chest wall, suggesting that this was a chest wall lesion, and most people would probably question that as being a nipple shadow, and that was confirmed. This patient had a subsequent CT for a different indication, and you can see that this nodular opacity moved out more laterally as the patient lifted their arms above their head for the CT scan, so this was indeed a nipple shadow. This is just another example showing the symmetric nodular opacities in the bilateral lung bases, which remained relatively fixed to the chest wall compatible with nipple shadows. This is a little bit more of a clinically interesting case. This was a patient that came into the clinic. He's a post-cardiac transplant patient, and he had a routine chest x-ray that was performed as a follow-up, and it was noted that he had this nodular opacity on a different routine chest x-ray that was performed, so he's brought back to have this TDR performed, and you can see that this nodular opacity moves up and down with long brachyma, confirming that there is some kind of nodular opacity within the right lung. You can see a similar nodular opacity here on the left side as well. Subsequently, the patient got a chest CT, and this was the nodular opacity that we were looking at on the DER examination, and this is the tiny nodule we saw on the left upper lobe. These were subsequently biopsied, and the patient was found to have cryptococcus. The big application that we've found useful application of DDR is in evaluating the diaphragm. This, of course, is also going to be discussed by Dr. Fitzmaurice, but our ultimate goal as well is to also replace chest fluoroscopy with DDR. We feel like it shows a larger field of view. You can see more of what's going on in the chest, and I think most of us feel like it's better at assessing the diaphragm, but I'm going to show a few cases to kind of go along with what Dr. Fitzmaurice is going to show as well. This first example is a patient that came in for a pre-lung transplant workup. It's a patient with COPD, so you can see the esophageal pH monitor in place, but he got this DDR, and if you look at the images here, you can see that there's flattening of the diaphragm with somewhat limited excursion bilaterally, but if you compare the left to the right hemidiaphragm motion, you can see that the right hemidiaphragm is not moving quite as well as the left hemidiaphragm, and that was confirmed with this excursion graph where the purple line is used to mark the right hemidiaphragm and the green line marks the left hemidiaphragm, so what you see here is that the right hemidiaphragm is moving significantly less than the left hemidiaphragm. This is an example of bilateral weakness, but asymmetrically worse on the right side. This is another case for a patient that came in to be assessed for elevated right hemidiaphragm, and what you see here is as the patient takes in a deep breath, the left hemidiaphragm goes down normally, but the right hemidiaphragm appears to move up slightly, suggesting paradoxical motion, and this was confirmed with this excursion graph where you can see that the purple line indicating the right hemidiaphragm moves opposite to the green line indicating the left hemidiaphragm compatible with paradoxical motion in this patient with diaphragmatic paralysis. This is a corresponding case, very similar to the one that we just looked at, where you see an elevated right hemidiaphragm, and as the patient begins to do the sniff maneuvers, you'll see that there is this suggestion of paradoxical motion with the right hemidiaphragm moving up as the left goes down, but if you pay close attention, you see that there's this separate shadow back here at a similar level to the left hemidiaphragm that's moving in a similar pattern to the left hemidiaphragm, suggesting that there's a portion of the right hemidiaphragm that's functioning normally. And this was confirmed on the lateral radiograph that was performed, so you see this markedly elevated anterior mid-portion of the right hemidiaphragm with normal position of the posterior right hemidiaphragm, so this appearance is consistent with the eventration. We have another similar patient with eventration as well, and we have the frontal images here where you can see this paradoxical motion of the eventrated portion of the right hemidiaphragm. You don't see that posterior shadow as well, but we also did lateral EDR on this patient, and what you can see here during the sniff portion of it right here is that the posterior aspect of the right hemidiaphragm is moving very rigorously, whereas the anterior portion of the right hemidiaphragm is showing that paradoxical motion. Again, this is an example of eventration. The other big area where we've found success with this modality is in lung transplant evaluation. So patients that come in for workup for lung transplant will get a chest x-ray along with a fluoroscopic sniff test to assess for the diaphragm function, and they also get nuclear medicine perfusion imaging. These are all things that we can assess with EDR, as I'll show in this example patient here. So this was a patient that came in with idiopathic pulmonary fibrosis, so you see the diffuse fibrotic changes throughout both lungs. This is his preoperative DDR examination. Again, this is a patient that shows some weakness of the diaphragms, likely due to the underlying fibrotic lung disease. There is asymmetrically decreased excursion of the left hemidiaphragm, but both diaphragm are moving fairly well, so no evidence of paralysis here. At a similar time point, the patient also got this imaging where he was performing a breath hold. So by doing the breath hold, you remove any of the motion associated with respiration. And what the software is able to do is look at each pixel individually and look for changes in attenuation in these pixels. And by doing that, what's being assessed is the pulmonary perfusion, since you've eliminated all of the potential changes that could be going on in the lung parenchyma due to respiratory changes. So this gives you a potential way of assessing pulmonary perfusion to each lung. So by doing this, the computer software will give us these pictures that attempt to estimate the regional perfusion to the lungs. So you see that we get 68% to the right lung and 32% to the left lung. So around the same time, this patient also got a nuclear medicine perfusion study, and they got 65% to 35% on the nuclear medicine study. So very similar to what we see, only about a 3% difference in both lungs. So this is another potential thing that can be assessed with DDR. And then a few weeks after the patient had his lung transplant, he came in for his first post-operative visit to the clinic, and he got this DDR performed. So you can see the transplanted left lung allograft. It's fairly normal, but if you'll notice throughout the respiratory cycle, the lung motion on the left is decreased relative to the right. And the left hemidiaphragm is also rarely moving at all. So it's unclear at this time point whether this is just expected post-operative weakness, given that patient had recent surgery or if there was some kind of injury to the phrenic nerve during the surgery. So this patient hasn't been followed up since then with DDR, but it would be nice to get that imaging down the road to see if this improves over time. And again, this is a potential application of following up these post-operative placements to see if they recover all of their lung function and diaphragm function following surgery. Also, we were able to compare the pre-transplant and post-transplant estimated perfusion for this patient. You can see that the perfusion to the transplanted left lung improved, resulting in a normalization of the overall lung perfusion between the two lungs. Indicating a positive perfusion response in this patient. So DDR gives us the potential to assess these lung transplant patients with one modality instead of three different modalities. These final two cases are just some curious cases that we've had recently that are related to the airways. This was a case in which a patient had a lung transplant and this was another transplant patient that came in. So this patient has COPD and appears very similar to the earlier case that we had with the flattened diaphragms and limited diaphragmatic excursion secondary to the hyperexpanded lungs. If you look at the trachea here, it's fairly normal in caliber. It doesn't really change much throughout the respiratory cycle. However, this patient also had lateral DDR performed at the same time. Here you can see marked narrowing of the AP diameter throughout the respiratory cycle, suggesting some element of dynamic airway narrowing or malacia. And this final case is another is a patient that had AML and was treated with a bone marrow transplant and subsequently developed constrictive bronchialis. And was also infected with atypical mycobacterium and developed this extensive bronchiectasis. This is just a fun image to show how these dilated airways react throughout the respiratory cycle. If you look at these airways here, you can see them opening up widely and then closing down throughout the respiratory cycle. You can see a few over here as well. And this is just a zoomed in image. I'll let you see the zoomed in image. Well, to really show just how compliant these dilated airways are. So this was a curious case that's fun to watch and look at. And I think that's really the fun of this modality is just watching things in real time and seeing the physiologic aspects of it. And like I said, we're very pleased with this modality. We've enjoyed a lot of the cases that we've had, and we're still trying to figure out how to get the most out of this modality. Thank you for your time and attention. Thank you, Dr. Benson. I would now like to introduce Dr. Thomas Fitzmaurice, who joins us from the UK. Dr. Fitzmaurice has been using DDR for a number of years at the Liverpool Heart and Chest Hospital. He is currently completing his PhD in radiologic imaging of cystic fibrosis and has pioneered the use of DDR imaging in this patient population. Dr. Fitzmaurice, please tell us more about your clinical and research experience using DDR for thoracic imaging. I'm Dr. Fitzmaurice. I'm a Specialty Registrar in Respiratory Medicine in Liverpool in the UK. I'm also a Researcher in Respiratory Medicine at the Liverpool Heart and Chest Hospital and an Honorary Lecturer at the University of Liverpool School of Medicine. Disclosures. My team is based in North West England. The Liverpool Heart and Chest Hospital, or LHCH for short, is a large tertiary cardiothoracic centre and research active teaching hospital. It is made up of academics and clinicians from LHCH and the University of Liverpool. I've been using DDR for around three years at LHCH, both for research and clinical purposes, and I'll talk a little bit about how we do it and what we've been doing with it. Specifically, analysis of diaphragm function, cystic fibrosis, and some other areas including lung volume reduction analysis. We've used DDR predominantly for chest imaging, hence referred to as DCR, dynamic chest radiography. This is echoed in a lot of the nomenclature of literature and test applications of DDR. We have a standalone new arm system currently being upgraded to a seating mount to allow more versatility in image acquisition. We found the entire process of image set up, acquisition, and patch transfer takes around five minutes per exam. We do have a recorded voice protocol for breathing instructions, though most exams are directed by radiographer. The exposure settings that we use are similar to those of other centres and other clinical studies using DCR. First, let's go into diaphragm function assessment. So the first and obvious use of DDR is as an advanced fluoroscope to look at moving structures such as the diaphragm. Damage to the muscle or innervation of the diaphragm can lead to paralysis, and functional imaging is needed to differentiate between a raised diaphragm due to other causes. This is usually done by performing a sniff to a breath during fluoroscopy or ultrasound, augmented by other tests of innervation or respiratory function. DDR seemed to us an obvious choice for doing this, as it produces high resolution, wide field of view images of the thorax in motion. Here's a comparison between traditional fluoroscopy and DDR. As you can see, the field of view is much larger and the image quality is good. You can see the hemi diaphragm being tracked by the DDR software during respiratory maneuvers on the DCR image on the right. This motion analysis is captured and graphed automatically by the DDR software, quantifying the degree of impairment. In another individual with diaphragm palsy, on the graph of motion of the left hemi diaphragm in blue, the diaphragm moves down on inspiration, as expected, with a positive velocity. On the right-hand side in red, the hemi diaphragm inspirational motion and velocity during sniffing is negative. There is also eventual, but significantly impaired excursion during deep breathing, compared to a large change in position on the left blue side. Compare this to a graph of normal diaphragm motion, where there is uniform and orthodox motion during breathing maneuvers. We found the imaging easy to perform, even in relatively frail individuals, in whom fluoroscopy might be more challenging. Here's a woman in her 80s, in whom relying on standing spirometers is a limited use due to poor performance. We did manage to acquire DDR imaging in a seated position, and here are the images, again demonstrating paradoxical right hemi diaphragm movement upon sniffing. We've also used DDR to observe the change in diaphragm function associated with placation surgery. For example, in this gentleman with the palsy of a post-infective etiology. Again, you can see clear paradoxical motion on the right during sniffing, along with a full expansion, high quality PA imaging of the chest produced by the DDR machine. Series post-op. The first was acquired soon after elective hemi diaphragm placation, and the second, some months down the line. Again, we can quantify and chart the change in diaphragm motion between these studies. The first was actually acquired so soon after the procedure, and you can see an intercostal drain in situ. This wouldn't be possible with spirometry, and would be difficult in a fluoroscopy suite. Improvements in diaphragm position was consistent with patient-reported quality of life and symptoms post-procedure. We've now implemented a standard operating procedure to make DDR the choice exam for sniff tests at our centre. In a review of a couple of dozen cases, we found that DDR showed clear paradoxical motion in cases of paralysis, confirmed with other imaging modalities. The average effective dose of radiation was much lower than our fluoroscopy suite, and because it produces diagnostic chest radiograph quality images, we can combine it with the chest x-ray often required alongside fluoroscopy, meaning a further dose reduction. There was no need for radiologist oversight during image acquisition. We've published these results of our service review in the ERJ Open Respiratory Research. So LHH is also a large tertiary centre that care of people with cystic fibrosis. We wanted to use DDR to further our understanding of CF lung disease, specifically factors such as understanding of air trapping and CF lung disease, and how the musculature of breathing is affected by CF. We've been using DDR during CF Annual Review, the mandated yearly review of lung health in all people with CF in the UK, looking at factors such as change in lung area and diaphragm motion, automatically measured by DCR. Example of the kind of imaging we have acquired. On the left is a DDR of a 32-year-old female with CF bronchiosis. Compare this to a DDR of a similarly aged healthy individual on the right. The change in lung area is much less pronounced. Interestingly, in the individual with CF, when enlarged, you can actually see the change and end on bronchiola diameter during inspiration and expiration. Next, we looked at exacerbations of CF, during which chest symptoms get worse and lung function falls, which are a common feature of CF. We wanted to use DDR to see what changed following treatment of exacerbation. So we performed spirometry before and after pulmonary exacerbation in 20 cases. We found that, as expected, FEV1 improved with treatment. We also found that on DDR, the range of CF was much smaller than on DDR. So we were able to see that there was a change in lung function, which is a common feature of CF. The range of diaphragm excursion during deep breathing increased. And interestingly, the projected lung area, that is the borders of the lung, measured in the PA plane at full expiration, reduced significantly. And that the rates at which the projected lung area fell during expiration increased, suggesting a reduction in air trapping and an improvement in elastic recoil of the chest, with a reduction in inflammation after treatment with IV antibiotics and intensive physiotherapy. The results were published in Radiology earlier this year. We're now looking at further cases for calculation of lung volume subdivisions using the 2D projected lung areas calculated automatically from DDR images. On a similar note, here's some images from an individual after combination CFTR modulator therapy. You can see the range of chest wall area change and resting expiratory diaphragm position have both improved following initiation of triple combination CFTR modulators. So we observed similar results after modulator treatment in a further subgroup of individuals, suggesting that we can measure the effects of a reduction in inflammation and restoration of normal lung physiology using DDR. We suggest that this reduction in expiratory projected lung area represents a reduction in functional residual capacity of the lungs. The increased expiratory diaphragm speed, again, suggesting improvements in elastic recoil of the chest with a reduction of inflammation after modulator commencement. We published these results early this year in the Journal of Cystic Fibrosis. We've also started to branch out into other areas of assessment. We've started to look at cases of bronchoscopic lung volume reduction. So we need to understand the change in physiology with response to endobronchial valves. There is a need for firm outcome measures and predictors of success and complications in these procedures. And it can be difficult to acquire periprocedural pulmonary function tests. However, chest X-rays routinely performed both before and frequently after the procedures. We wanted to see if DDR could add a benefit as a diagnostic investigative tool in lung volume reduction, as it can measure moving structures such as the diaphragm and change in lung area, possibly proportional to change in lung volume with ease. As we've seen previously, it is very acceptable to patients, making periprocedural imaging possible. So here's a case of a woman in her 60s with advanced heterogeneous smoking-related emphysema. DDR can easily visualize the reduction in X-ray through projected lung area and the improvement or the high position of the hemidiaphragm position, consistent with restoration of lung and thoracic cavity dynamics after endobronchial valves have caused deflation of the hyperexpanded emphysematous lung. Interestingly, we observed improvements in these metrics on the contralateral hemidiaphragm and projected lung area dynamics as well. Here you can see the lung frames being tracked by the DDR software. The frame-by-frame lung area is indicated above each hemidthorax. These images are retained very shortly after lung volume reduction. This isn't possible with forced maneuvers such as body plethysmography. So as with post-application imaging, this kind of information might be extremely useful for prognostication and as a cost-saving, low-dose, quick and acceptable alternative to body plethysmography as CT, also producing quantifiable measures of diaphragm and lung area motion. In this individual, the reduction in air trapping we observed as a reduction in lung area is also confirmed later down the line by plethysmography. We think these changes might be useful for charting longitudinal change as well. There are plenty of other areas of interest to look into, which I've only touched on briefly here. Here's an example of an individual with significantly restrictive spirometry, but a normal transfer factor. A plain chest radiograph was unenlightening other than a right-sided effusion. DDR revealed a significantly limited range of chest expansion, suggesting extra thoracic restriction associated with chronic effusion and volume loss. Other areas of interest might include those with neuromuscular disease and DDR pre- and post-thoracic surgery. Overall, we have found DDR to be very useful. It represents a reduction in ionizing radiation dose compared to traditional fluoroscopy or CT. It has a good resolution as well. It also produces diagnostic imaging of the chest. We've improved our imaging workflow significantly when it comes to diaphragm sniff test imaging. The images can be seen in the following slides. The first slide is a sample of a chest imaging of a normal chest. The second slide is a sample of a chest imaging of a normal chest. The third slide is a sample of a normal chest. The fourth slide is a sample of a normal chest. The fifth slide is a sample of a normal chest. The sixth slide is a sample of a normal chest. The seventh slide is a sample of a normal chest. The eighth slide is a sample of a normal chest. The ninth slide is a sample of a normal chest. The twelfth slide is a sample of a normal chest. And those are the three activities I've talked about. Please feel free to drop me an email. Thank you, Dr. Fitzmaurice. As I mentioned, DDR is not just applicable to thoracic imaging, but can be used for all standard radiographic acquisitions. One of the areas that has seen the fastest adoption of DDR in the United States is replacing the lateral C-spine flexion extension static films with a dynamic acquisition. In addition to the lateral flexion extension images with DDR, you can also acquire all of the traditional cervical views, but with motion. This series of images shows a number of views all of the same patient. I'm very pleased to introduce Dr. Eric Wagner to talk about his clinical experience and research on dynamic imaging and the use of DDR in the traditional cervical spine dynamics. Eric, thank you for joining us today. Eric is a professor of clinical experience and research on dynamic imaging in the diagnosis and assessment of shoulder function. As a surgeon, he provides the perspective of the clinician using imaging directly in the care of his patients. Dr. Wagner is an assistant professor in the Department of Orthopedics at the Emory University School of Medicine. He has published and presented extensively and authored over 15 book chapters. He serves in numerous leadership capacities for several journals and professional societies. His specialty include common and complex pathologies from the shoulder through the hand. The Emory Orthopedics and Musculoskeletal Institute was the first site in the United States to use DDR for orthopedic imaging starting in the fall of 2019. Dr. Wagner. DDR. So what is it? It's basically multiple static images acquired at either six or 15 frames per second. That's a length of time of approximately eight to 10 seconds with an average dosage only about 1.3 times greater than the standard x-ray. I think that's important to realize. I mean, it's much less than a chest x-ray, much, much less than a shoulder CT. And thus, it's something that, at least from a patient standpoint, it really doesn't pose much extra risk. It's multifunctional. You can utilize it in multiple different joints. But more importantly, at least from my interest, it's the upper extremity that I care about. I'm an upper extremity surgeon. I operate from the shoulder to fingertip, really specialize in certain complex pathologies. And this dynamic DDR has really helped us to reevaluate a lot of these pathologies. One of my more interesting aspects that we've worked a lot on has been the shoulder. And as many of you know who treat shoulder pathologies, it's very difficult to assess scapular humoral rhythm and the interplay between the glenohumeral joint and the scapulothoracic joint. So here, modifying this to be more of a 3D-type motion, we started to look into how to actually capture this, how to capture it from an axial view or from a Gracie view. But I want to give you a couple case examples too that's been kind of eye-opening and very interesting to say the least. So I kind of showed you that massive cuff tear. I think it's kind of cool to see how the head shifts up as we kind of all assumed in these patients that have rotator cuff arthropathy. But even more so, let's say you have a patient that you do a reverse on. And so you have this massive cuff tear, you do a reverse. It looks pretty good from my standpoint, but ultimately, it's nice to know what's going on inside that reverse. So how much is their glenohumeral joint actually moving? How much is their scapulothoracic joint moving? How are they actually rotating? What's happening with the implant? Is there impingement on their chromium? Is there impingement inferiorly in adduction? Also, maybe you want to look at how your patient is doing after an arthroscopic lower trapezius transfer. So you had that massive cuff tear, you saw the superior subluxation. You can see with this lower trapezius transfer, we were able to pull the head back down and now it almost looks like a normal shoulder, both with regards to rotation in and around, as well as with regards to abduction. So you can see you've been able to re-center the humeral head, both on the axillary plane and on the gratia view. And you can see we've almost re-established a normal shoulder with this procedure. Scapula pathology is even one of the more interesting aspects and one of the things that I think is fascinating with this technology. So when you look at this, you can actually see how the scapula moves. And a normal shoulder on the left, you can see that the scapula externally rotates, as we all know, around the body and contributes a fair amount to that overall shoulder motion. But on the left, I mean, on the right, you can see how there's very little scapular motion. And despite the patient having basically full glenohumeral motion, their scapula is, in essence, paralyzed. So this is a patient with psoriasis anterior palsy. Here's another example, a 21-year-old swimmer. Limitation in shoulder function, no prior injury, collegiate swimmer, but very limited shoulder function. He woke up one day and couldn't move his shoulder. No prior injury, nothing else really to explain this. You can see his examination, he has scapular winging. This is the normal shoulder, so I'm testing the strength of his psoriasis anterior on the left. He has really good psoriasis anterior strength. So you can go to the right, though, look at how much he wings out. So he has no actual psoriasis anterior function, so it means no ability to hold his scapula to his chest wall. This markedly limits his ability to function, especially as a competitive athlete like a swimmer. And up until now, it's a clinical diagnosis. As you could see, as you'll see in a second on his DDR, you can actually make this as a more objective than it is. This is me stabilizing his scapula, and you can see I'm able to correct a lot of his glenohumeral motion by just keeping his scapula against his chest wall. So here's his DDR. So you can see how limited his scapula actually is moving. So his glenohumeral joint almost has full motion, but he has very limited scapular thoracic motion. That's because the psoriasis anterior is not holding his scapula against his chest wall, and he doesn't have the normal external rotation that most of us would be accustomed to. You can see how much more information you get on the right compared to just a static image on the left, which looks like, at least from my perspective, a very normal shoulder. Here are two other patients, also with scapular pathology, both with psoriasis anterior pathology paralysis as well. And once again, you can see how there is basically no scapular external rotation with either of these patients. So it's very limited in how much they can actually use your scapula, and thus, it's very limited how much they can actually use their shoulder. Shoulder instability is sort of the other, in addition to some of the ones I talked about, is the other one that I find very interesting, and especially in some of these more complex patients, and what actually is going on within the shoulder. So here's a 22-year-old gentleman, recurrent posterior shoulder instability, 100-plus dislocations, history of his seizures, or daily subluxations. And you can see how he is, I and he, are actively subluxing his shoulder in and out. So you can see I'm doing a posterior provocative maneuver, and you can see his shoulder subluxing in and out of the joint here. His shoulder should actually be very limited, and you can see how limited he is in his overall function. So static x-rays, you can see AP, or the gray sheet looks pretty normal, the scapula looks pretty normal. There is some posterior de-centering on the axillary, and you can see on the CT scan you can also see some posterior centering but I think when you see the DDR you can really get an understanding what's going on so you can legitimately see his shoulder subluxed from in the glenohumeral joint and then out posteriorly back into the glenohumeral joint and back out posteriorly where that bony bancard is. So you can see on these multiple views how his joint is legitimately subluxing from inside the glenohumeral joint out posteriorly to where that prior bony bancard was from you know probably one of his one of his hundred plus dislocations. You can also see this on the Gracie how he subluxed posteriorly and kind of gets caught when he does internal and external rotation. Here's another example of a patient who had posterior recurrent posterior shoulder instability daily subluxation very limited at multiple prior surgeries she did have some latissimus spasms scapular dyskinesia you can see she subluxed posteriorly she has glenoid retroversion in essence a pretty complex patient who was sent to me for a posterior wedge osteotomy in a 16 year old mind you. Because of her latissimus spasm this is not the purpose of this talk but because of the latissimus spasm and her scapular dyskinesia we did a latissimus transfer to her greater tracheostomy and a pec minor release and you're able to see we were able to recenter the her humeral head and gave her a pretty good overall function unfortunately on the right side the same problem started happening and she had basically the same imaging on the right side so posterior decentering this this example of not being able to move her shoulder and the cool thing was we got the DDR on the left was right so left inside we operate on did the latissimus spasm where you see you can see how we were able to recenter her head on the right you can see how she's posteriorly decentered and she's posteriorly subluxed and she's not able to move her shoulder because she's not actually in the glenohuman joint. Anterior shoulder instability is also kind of an interesting one there's a couple case examples for this I like this one just because it shows what happens after you treat these patients so this patient had recurrent anterior shoulder instability three prior surgeries daily subluxations and as you can see here she has a irreparable subscapularis tear and she has pretty significant anterior glenoid bone loss. So we did a distal tibia allograft to reconstruct that bone loss and we did a latissimus dorsi transfer than anterior capsule reconstruction to rebuild that irreparable latissimus transfer. You can see our post-op x-rays looks pretty good. Post-op release she was able to get back to fairly good motion she was able to return back to her work as a collegiate volleyball ref basically very limited limit very little limitations. The cool thing about the DDR is you can actually see what's going on how she actually stayed inside the joint and she's actually centered over that distal tibia allograft you can see in the upper right. On the x-ray view it also kind of shows how like legitimately what we did is we didn't necessarily recenter her that well it we what we did is we created a bigger surface area for her to to now function on a bigger platform. So in conclusion the reason why I like this technology and the reason why I get quite excited when thinking about its future is it really gives you some cool insight into what's going on besides what you sort of kind of try to interpret based off some static views. It's like looking at a picture versus looking at a video it's so you get so much more information from a video they say you know a picture is worth a thousand words but a video is worth a thousand pictures I mean you get so much more off these videos and as EA Kauffman 100 years ago started talking to us at least about the shoulder it just shows you know how slowly we've adapted some of these ideas of these giants that came before us but I mean at least in the shoulder I think it has some really cool potential. I'm excited about it and one of the other cool things is I've actually started bringing my laptop around my my clinics just so I can show the patients their DDR x-rays because they get really excited about it they think that I'm doing something novel that nobody else is doing that somehow I'm more I'm a you know more qualified or whatever because I'm doing these these these these dynamic images that actually get them some insight into what's going on in their shoulder. So thank you for your time please reach out to me if you have any questions via email or via this cell phone. Thank you Dr. Wagner. We'll now address as many of the questions as we can that you've raised in the chat. We'll start with one that I will take. What is the format of the images video or DICOM? The images are a standard DICOM object basically a stack of individual DICOM objects or images. They can be viewed as a cine loop or page through individually. Next question we'll take perhaps Dr. Benson you could take this. How is the patient instructed to breathe in these exams? We actually have a few different protocols we use and we just have a standard one if they're just kind of a routine like lung transplant follow a patient which they just do a few simple normal breaths and then a few deep breaths. That's kind of our basic standard. If we're looking for a sniff type test then we'll have them do a few deep breaths and then we ask them to do some sniffing like they would do during a routine sniff test. We do the same thing in laterals now on the patients that we do the sniffs on. So those are our two basic protocols. If we're interested in getting perfusion imaging then we have a separate six second breath hold that we can add on because we need that breath hold to really get good perfusion imaging. So we can add that on in addition to one of our two basic sets. So those are the basic breath hold that we use. Great thank you. Dr. Fitzmaurice can you talk about how long it took radiologists to learn how to read these studies? What is the learning process around trying to understand a DDR sequence and how to interpret it? Right so I mean we were very lucky to work quite closely with the radiologists particularly Caroline McCann at the Heart and Chest I think I mentioned at the beginning of my talk. I think as Don said in his talk a lot of it is just it's very nice to be able to just view the physiology and it's a learning curve for all of us just seeing these wide field of view images interpreted or making those interpretations as you go along. I guess in terms of the adoption we went through a process of presenting to our sort of local bodies and working with the radiologists to work out what they wanted in terms of the interpretation of those images in terms of the sequences requiring what we were asking of them and acquiring the acquiring set sequences and building those into a workflow allowed them to kind of answer the questions we were asking which was things like diaphragm motion but I think it was a it was a quick process all in all. Dr. Benson would you like to comment on that as well? Yeah I'm happy to comment. I feel like it's still kind of a learning process because we're not really you know used to seeing these things in motion so it's you know a constant learning process but I think to initially pick it up and start reading it if you're comfortable reading a chest x-ray and reading a sniff test then it's really you know nothing new technical that you really have to do. You know the other things like the perfusion and the ventilation those are kind of additional things that we're kind of still trying to figure out what to do with but in terms of just for clinical day-to-day reading it's not really a lot of additional work or additional learning. If you're comfortable reading a chest x-ray and looking at a sniff test then really it's just you know trying to figure out what the physiology is really going on. It's just a continued learning process but it's really not any more challenging than reading the basic chest x-ray. Excellent. Thanks a lot. And Dr. Benson do you want to kind of describe the process that you used at UAB to introduce DDR into the clinical workflow? Yeah so we started out primarily with the sniff tests. We were trying to get familiar with the technology and to build it into our workflow. So what we basically did is every patient that got a sniff test we would get them a DDR as well. And we kind of grew the practice from there trying to figure out other indications where it could be useful. We started growing it into looking at lung transplant patients, cardiac transplant patients. We've got some clinicians that are following up COVID patients that have some interest in it. So we've kind of just grown it from there but basically it all started with the sniff test because our goal ultimately like Dr. Pace-Morris is to replace the sniff test with the DDR since it's you know quite a bit easier to do technically. We don't have to walk over to the porosopy room you know the techs can just do it and send the images over to us. And then you kind of just built from there based on what the clinicians want. Dr. Pace-Morris anything to add to that? You know I'd agree. I mean I think in terms of the radiologists time and it's a time-saving. I think it takes probably a similar time to read as a standard porosopy would. And I think it yeah it does speed up the workflow for them. So yeah it's been a sort of easy adoption and I think it's just a case of being clear with the with the goal of what the the image is taken for. And then from that stem a load of different research questions, a load of different clinical questions you can ask after the fact. Excellent. Another question I think kind of building off that. Dr. Benson do you want to start with what were the challenges getting acceptance from the clinicians, the referring clinicians to adopting and starting to use DDR? Well I think our biggest issue was getting them to order it because we didn't starting out and we still are working on getting a specific orderable for the DDR. Currently clinicians just order chest x-rays and our you know we have set protocols that we tell the technicians to do, the technologists to do. But we don't have a specific order that yet that they can just order if they want it. So you know we're trying to get our lung transplant patients to do it but we you know they only want to know how do we order it. So the question is how do we order it. So I think when you start out this in your clinical practice it's good to have this as a separate portable that you can go to the clinician and show it. Because I think once you show them the images they're all interested in it and want to see it. They just need to know how to get it done and I think that's been our biggest obstacle. It's just making sure that it gets ordered correctly, getting protocol correctly. I think I'd second that. The biggest challenge we have is people say how long does this take? Is it going to be you know do we need to schedule this on a list two months down the line? And you say no actually we can we do it straight away if you want and it's going to take five minutes. Because it's new there's not as much knowledge of its advantages and how quick it is to do. So it sounds like the interest in adoption by the referring physicians is very high. There's some IT and back-office challenges to try to make it as efficient as possible in terms of getting those orders to take place. Sure absolutely. Another question we had here was can DDR be used for a lateral chest x-ray and I think you both showed examples of where that can happen. Do you just want to add any more comments on particular information that the lateral dynamic image can bring? I think for us we added it because we didn't do it at first and we noticed that there were some patients that you look their CT it looked like they didn't have complete paralysis. It looked more like an evitration type picture of the diaphragm. But sometimes you can't tell that just off of a frontal radiograph. So by adding the lateral you can really see if it's the entire diaphragm that's abnormal or if there's still portions of it that work. So we've started adding that on to all our DDRs that we do for diaphragm function just to see if we can differentiate between the totally dysfunctional diaphragm versus focal areas of the evitration. We've been using it as well I guess not so much for the diaphragm side of imaging but for for experimenting with lung volume calculation within within separate research studies. You can also get some really nice images. I think Don showed a couple of pictures of the sort of airway collapse. You can get some really nice images of the trachea with the with the lateral images as well. Excellent. Another question that we have here is are there any other applications beyond pulmonology or I assume thoracic applications? And I think Dr. Wagner showed some interesting cases in the upper extremity and there has been significant acceptance and adoption of this technology within the orthopedic and musculoskeletal imaging communities. In particular I'd point out cervical spine has been an area where the technology has been immediately adopted. It's just a great replacement similar to the sniff desk kind of paradigm. Replacing a standard flexion extension static images with a dynamic sequence provides all of the same information but then a lot more information as you can see the patient moving dynamically. Another application that's growing is the use of this in the sports medicine field. Be it to assess injuries, do all of the standard musculoskeletal imaging techniques but then also as a tool to communicate to the patient and to the allied health professionals who will be working with that patient exactly what these particular issues are that need to be resolved either through physical therapy or other interventions. So I think DDR really is a dynamic replacement for, not a replacement, but a dynamic utilization of any standard x-ray view. So it can be used across the board wherever you would get a traditional static film there's now the capability to do that dynamically. And one more question here, what is the impression of the technologists and the radiology staff? So probably two separate questions. Is DDR accepted by the technologists in your institutions or is it perceived as more work, more laborious to do these exams? Don, do you want to start? Sure, yeah I think it's improved over time. I think at the beginning when there was confusion about when to do it, how to do it, but now that we've got set protocols that we use and if we can get this orderable placed or set up then I think that's really going to help too because now it's just ordered as a chest x-ray and the technologists have to kind of decide how they want, you know, how we want it to be done and have to come ask us how it needs to be done. So I think once the order comes across as a DDR and what the indication is for, then I think it'll be easy in terms of the actual workflow since we have these protocols set up. It's not really that much more challenging than doing and acquiring a regular chest x-ray. It takes a little bit more time because you're having to do these breath holds but you know it's kind of automated now within the system. Then it just gets sent over to to the server and sent to PAX. It's not like there's any additional steps that have to go on beyond that. So I think, you know, once we've solved all the technical issues I think it's really not much work, much more work related to just doing a routine chest x-ray. Yeah, I'd just add that beyond the initial learning curve of instructing the radiographers in the breathing manoeuvres, what's expected, what constitutes a maximal breathing manoeuvre necessary to see whether, for example, the diaphragm's moving as it should, it's massively sped up our workflow with acquisition of sniff images certainly. And it's just kind of teaching that coaching much like a spirometry technician might do, making sure they know the language and the encouragement to use to get the most out of the breathing manoeuvres performed by the patient. Once that's achieved it's a real improvement in our workflow. Very good. And so I think that's all the time we have today for this webinar. Unfortunately, I'm sure the discussion could go on. This webinar will be available on the RS&A's Online Learning Centre and YouTube channel in the days to come. Please feel free to share it with your colleagues and if you have any additional questions, reach out to us. On behalf of Konica Minolta and our speakers today, I'd like to thank you for your attention and participation in this webinar. Have a great day.

Dynamic Digital Radiography

DDR

thoracic imaging

musculoskeletal imaging

Konica Minolta Healthcare

lung nodules

diaphragmatic function

cystic fibrosis

orthopedics

diagnostic capabilities