CT-Dual Energy - Coronary and Carotid CTA -Tutorial

Hi this is more stylish. Welcome back to our series of dual Energy City tutorials. Today we're going to talk about the coronary and carotid CDA. We already talked about more getic imaging in the last tutorials here. This slide shows that more energetic imaging office you a wide range of energies with specific contrast and noise properties. From 40K V up, 280 heavy and actually 190 KV, this is the maximum energy level possible you have. Higher contrast at low energies. And slightly improved noise properties, so you have sharper image impression and less noise in high energy levels. And it's important to understand that in clinical routine we are actually particularly interested in low. Energy. Images. From 40K via up to 80 KV for contrast optimization for enhance detection, better delineation. And so on. Whereas also the high energy levels. They are useful, but especially for artifact reduction. So when you have metal artifacts, blooming, artifacts from calcifications. Better choose high energy levels, but in routine. Almost everything focuses on. In terms of contrast on the lower energy levels. And the iron cage would be 33 KV, so with 40K V we are almost at the iron cage and these have the greatest intonation. A slight increase noise compared to 60 and 80 and higher energy levels, but the contrast increase outweighs this limitation by far. But in your clinical routine. You would probably sometimes choose energy levels from 50 and 60 KV just cause these images. They also have an. Increased contrast compared to the standard images, but from the overall image impressions. In our clinical experience, 1560 may be the better choice just for routine images. If you have a very poor contrast, of course always. The Ultra low cavey levels are useful. For artifact reduction, this is a nice case showing. That the lady here has highly. Calcified plaque burden. And. Do to blooming artifacts. It's very difficult here to diagnose the patency of the coronary artery, specially between those two classifications. You can see contrast enhanced Lumina left Bud Stenosis may be overestimated in this case, and when we reconstruct this with for instance 130 KV at this energy level, you will still have reasonable contrast. But you have significant. Blooming artifact reduction and see here that Please note that the Windows settings. Are kept equal. And you see that. This is actually no significant corner, either, stenosis. So majestic images are definitely helpful in reducing those artifacts. And for Artific direction, use levels above 100 KV. And also in 40K V we can widen the window with up to 2200 and we increase the level towards 1000 Hounsfield numbers. And also here. This may improve coronary artery assessment. In case of a higher calcium. Burn. The same strategy. Works also for coronary stents. When we have patients with prior standard surgeon, it's always important to assess the potential instant re stenosis, and in this standard image this was a 0.6. Image. Which is blended with 60% out of the low cavey spectrum and 40% of the high. Energy spectrum. It's actually. This is completely like with blooming artifacts, so we cannot see anything of the. Lumen within the send and cannot make any judgment on the patency of the stand, whereas 130 KV we can. Actually see a perfusion, understand and know instantly stenosis is present in this case. And also this energy levels and window settings are completely the same as in the slide before, so again with 40K V you probably also have an. Beneficial? Assessment in. Case of metal artifacts. So we would like to point out that it's beneficial to use both low and high cavey levels to fully exploit the potential of dual Energy Information. This is again or suggested. Dual Energy reconstruction protocol just to avoid an overwhelming amount of reconstruction series, and also of course in the packs like large datasets. This can cause problems, so to keep the reconstruction. Amount at a reasonable and efficient level. We would suggest. To have in cardiac imaging. Perfusion Maps and monogenic images. At 55 KV always available and reconstruct them routinely, whereas we optional reconstruct. Those free image data sets. And in this case for artifact reduction we would recommend 120KV. For enhanced assessment and less blooming artifacts. We already talked about the importance of adjustment of Windows settings, and this is another nice cake case example showing more new energetic. Images at 40K V. And for comparison, the same image with 100K V. Here on the right side and with different window settings. So for instance, for the ultra Low K vemana Getic image series on the left window width of 100,100 Hounsfield in the center of 500 Hounsfield. Maybe most appropriate and provide the best image. Impression and image quality, whereas this equals setting would just be insufficient 400. KVM on Attic plus reconstructions. The item signal gets too faint. This is way too dark. However, when we use these Windows settings for the 100K V image, we will have the best image impression, whereas for ultra low 40K V. Multiplus reconstructions then we could for instance notice anymore the Arctic valve and. Also, this is like. An overbearing item signal, so depending on the energy level you choose, manually adjust your Windows settings and this gets intuitively very quickly when you start working with more diegetic. Image series another. Very promising. Technique in the future, maybe calcium subtraction? In coronary artery imaging. So we have talked about overcoming blooming artifacts with monogenic reconstructions. And there are also. Very soon. There's an algorithm available which subtract the calcium accurately from the coronary arteries. And we know that severe calcification with again, scores about 1000 are a known limitation of standard coronary CTA and the cardiac imager has problems in deciding whether corner stenosis is significant or not because you just have too much blooming. And hampering thus the lumen assessment. For instance, in this particular case, high calcium burn here showing on the map models. For instance, here it's becomes very difficult to say something about the coronary lumen, especially in this area. And will energy calcium subtraction effectively removes the calcifications? Without affecting the contrast, Opacified Lumina, for instance. This is then the reconstruction you will get and you see that there is no significant coronary artery stenosis present. And this was not possible with traditional. Body bone removal applications. So we will talk about this later. In the hands-on cases. Body room bone removal is also very useful in geography imaging. Becaused you. Get a direct and review and Bones are automatically subtracted. However, in coronary arteries in tiny arteries this is not possible. To subject simply the calcium with the prior techniques cause you may be. You may have inaccurate removal and and over removal, so in the end you will remove also something from the iodine. This was true in the past. In the future. This algorithm may have very beneficial results in. Patients with higher eggertsen scores. Also virtual noncontrast. Imaging in Cardiff City has other applications beside the improved. Capabilities to always get an virtual Nonconnah image acquisition out of your contrast enhanced data. You can calculate from the virtual noncontrast images. Routinely calcium scores and they actually correlate very well. With the extra calcium scores, for instance, this patient we. Actually this was published agans score of 100. 78 was found the same magazine score as compared to the true. I get since scoring. Acquisition. And it has been stipulated that virtual noncontrast may obviate a dedicated Calcium score acquisition in the future. Thank you very much for your kind attention, and now let's analyze some clinical cases. This is our first case. Coronary CTA. City with a patient with high agates and score, the patient actually had and again score of 1500. And when we can overview over the coronary arteries, we can see this high, highly, and heavily calcified coronary artery circulation here. And. Really, to make an assessment of this. Highly. Calcified eladia it's barely impossible. Using the standard images. And when we for instance go here too. Or more logic plus workflow? We may reduce this blooming artifact with more using high energy levels. So. Let's go here to an energy level of. For instance, 110. And see if this is helpful and it definitely. It's still difficult to diagnose the coronary lumen, so this remains a challenging case. However, the blooming artifact here is. Definitely. Slightly reduced using quadratic images. When we go back to our standard image. It looked like that. With no possibility to diagnose the coronary perfusion itself. And in addition. Regarding the question whether this leads to a hypo perfusion in this patient. We could again go. Actually this is now. This is the majestic image acquisition we could go to. 40 and then again. Here, it's important to change the windows setting. And we don't see any perfusion deficit. Which would be suggestive for my cardial infarction or hypo perfusion? So we see in this patient to Landry monogenic imaging, provided you with enhanced capabilities to overcome this problem of. Hi calcifications. So as a briefly mentioned before, Dual Energy provides you with several possibilities to overcome. Challenging scenarios and to improve your diagnosis in difficult cases. For instance, in this patient, this patient was known to have severe. Peripheral artery disease had prior my cardial infarction. And now it was referred to be scanned. 2. Screen for vascular pathology of the carotid and cerebral arteries. The patient also had dementia, had only an Ivy axis with a very low possible flow rate. And was highly agitated, finally moved. During the contrast, Administration had a pair of isation, and this was actually the carotid CTA. That was acquired. And you can barely see contrast in this. CTA acquisition it's really. I would say this is a non diagnostic study. Let's remove the. Lines and also the dual energy field of view. In this case it's quite clearly so when you have carotid and cerebral scanning. Of course your field of view will cover the whole head, so there's still energy field of view, just as a side note is particularly relevant in abdominal and Jurassic imaging, but let's go back. It's already a quite a late. Material, almost Venus scan acquisition. And when? We would like to diagnose the carotid arteries, for instance, at this level, we see maybe a bit of hypoattenuation here. But this would still be nondiagnostic. And. Would be likely. Have the necessity of repeating the exam completely. And when you then go to. Monadic imaging you click monogenic plus. Now let's see if we can solve this problem with additional reconstructions. Our normal image compression from the standard M 0.6 would be. This image impression. Similar to a monogenic image at 75 KV, but now let's try to salvage this exam when going down to an ultra low energy level, and we see here finally we get. Contrast in the carotid circulation. And we can. Now reliably say OK, here there's an. Occlusion. And this was not possibly before using the standard images. When we go here from the common carotid artery. Here we see the carotid bifurcation severely affected with mixed calcified and soft flag. Then we go a bit more. Cranially and here the occlusion. Is present. Nicely shown here in this. Particular. Image and when we then. For instance, at this level, we had the suspicion that maybe an occlusion could be present, but we see it here really nicely shown in side comparison here. We have perfusion here. There's no lumen, no perfusion visible. And we. No issue needs those lines back. I would like to try if we can. Maybe angulatus better. Maybe on this level? That we have this in the car, so please focus here on the Coronas. Why? While I try to angulate this in a in a way that we have a side by side comparison. No, this is not working. Let's see here. Yeah, this is probably the best we can. We can get in on this Corona reconstruction you see nicely. The. Side comparison here, we have the perfusion of the internal carotid artery, whereas here we see a distinct delineation of thrombus occluding the vessel completely. Again, nicely shown that it helps in the delineation of traumatic material and perfusion defects. And finally also lead to an improved detection becausw before with low confidence. We were not able to make this diagnosis with motor plus 40K V. We could salvage this study and turn it into a diagnostic study so the patient does not have to go undergo further imaging to reliably make this diagnosis. And. We go more. Cranially we see actually that the circle of Willis is well perfused likely. Due to an increased. Perfusion of the vertebral arteries and basilar artery. Bud. I would like to show you another applications with this dental restoration implants. When we would like to, for instance, diagnose the mouth and the tongue and more the oral pharyngeal structures, we could go here. 2. 110 margetic images. And this at least helps a bit in. In the reduction of this. Of this artifacts, when we compare it. Two are actually standard images which would like would look like this. With more getic here, at least we have a bit of reduction of the central reservation. And just to. Have a look at the Venus phase of this patient of course. Also when you look for thrombo sis. No, actually let's. Focus on this level. Height those lines. Here, it's actually uncertain when I would look at those images alone. I would be not even sure if there is much contrast material inside the page and there the sign is Sigma videos. Here is a bit opacified, but. It almost is the impression of Anon. Contrast image acquisition and when we go to mono plus at 40K V. Again. Go here on the on this setting to 40. Now try to optimize the contrast and see here. You can actually have. Quite often I run single in the jugular veins. And make. At least analysis of. Venous perfusion, whereas in the normal image you would end up. Compared to 75 monogenic with this, or, let's go back completely. For comparison, this was actually our source image. With more getic. 40K V again. This would look like this. Can maybe also analyze it a bit better in the saddle this year. You can definitely reliably rule out traumas in this particular area. So this was on coronary and carotid CTA. I hope this was helpful. And thank you very much and see you next time.

Energy CT CT CT CT Dual Energy CT Dual Energy CT Dual Energy CALCIUM SUBTRACTION IWAYOVERCOMEBLOOMING CALCIUM SUBTRACTION MAY OVERCOME BLOOMING VIRTUAL NON-CONTRAST IN CARDIAC IMAGING DUAL-ENERGY CT IN CARDIAC IMAGING ADJUSTMENT OF WINDOW SETTINGS MONO+ FOR ARTIFACT REDUCTION MONO+ OFFERS A WIDE RANGE OF ENERGIES AND CONTRAST Cl. Energy Agatston score from calcium score Agatston score from virtual Step 1: DECT acquisition Step 2. Image reconstruction Step 3: Calcium subtraction Bilal-ener alcium subtraction Step r: calcium subtraction Comprehensive approach with enhanced capabilities PhV Plus Won oenergetlc Won oenergetlc Plus Mon oenergetlc pus vonoerergetlc Plus Vonoenergenc Plus Plus Plus Monoenergetic POS acquisition: 187 non-contrast (VNC): 187 DECT Data Acquisition Do not simply 1000 1500 MM Rearing MM Reaoing Rearing MM Reao•ng MM Reaong *eating MM Rearing Reading Reacing Rearing Reacng use the same Center 150 Center 150 HIJ Center HU MM Rearing 1000 window settings CT CTA for low and high Severe calcifications with Agatston energies 8 500 1000 1500 scores >1000 are a known limitation 10500 For artifact "30 keVVMl+ W600 LIT kev VMI+ 139key \jMl+ W600 L150 139key VMI+ w600 L150 139key VMI+ L150 139key VMI+ W600 L150 ev VMI+ w2250 LION .6 of standard coronary CTA reduction VGA MSS20 o Findings Navigator r u 20 r 420 Increase both Mono+ can effectively reduce blooming artifacts in heavily calcified Width 6100 Width 1100 Width The same strategy works in the scenario of coronary stents Routine Reconstruction Routine Routine Reconstruction Optional Reconstruction 1000 10500 window level Dual-energy calcium subtraction Bilal-energy calcium subtraction Dulal-energy calcium subtraction Center 500 1-ICJ Center coronary arteries echn018Å9 effectively removes Improved stent visualization for the assessment of in-stent restenosis technology effectively removes and width for Noize-optimized virtual monoenergetic imaging (Mono+) can be reconstructed at any VNC may obviate a Reduced risk for coronary stenosis overestimation calcifications without affecting Use both low and high kev levels to fully exploit the dual-energy potential low kev Mono+ energy level between 40 and 190 kev dedicated calcium score Higher energy levels (>100 keV) may be most useful contrast-opacified lumina 40 kev = close to the iodine k-edge (33 keV) = qreatest attenuation Virtual Linearly- Perfusion Virtual Non- acquisition acquisition: 187 VMI 55 VMI 40 VMI 120 VMI 40 120 Contrast Blended Map Tools Mono+ 400 Tools Albrecht, Schoepf, De Cecco, EJR, submitted De Santis, Albrecht, Schoepfet al, Investigative Radiology 2017 Kalisz, Albrecht, Schoepf, Rajiah et al, Radiographics 2017 Fuchs TA et al., Int J Cardiovasc Imaging 2014 Tools pu 00