Role of Dual Energy CT in MSK

Thank you for the kind introduction and thank you siebens for the invitation to speak. So just going through my goals and objectives, I'll just briefly go through Juliana geeked for evaluation of gout, 'cause I've already had an excellent review of this. I also mentioned some of the ultimate things we're doing for Mr and MSK. Trauma, particularly looking at tendons, ligaments, cartilage and particularly the virtual non calcium imaging. For looking at bone marrow adima. I'll briefly touch on metal reduction techniques and then just briefly again on fat quantification. So we've already heard a nice review of this, but just quickly. The incidence of gout is tripled over the last several decades and is now the most common form of inflammatory arthritis. And as we've heard, the gold standard is the aspiration and detection of uric acid crystals in joints. The in fact this is aspiration is done in a minority of cases. This Sinovel fluid aspiration may not reveal uric acid crystals an the patient certainly don't like you coming towards him with a needle to inject into their flame joint. So clinicians basically diagnosis on secondary criteria. And as we're food, then patients with GAL can have normal serum uric acid levels and hyperuricemia may be present patient without gout radio graphic changes may take years to develop and so Julian GCT is really come to the fore as a noninvasive technique for identification of mono sodium urate crystals in it certainly in our institution. It's the mainstay rheumatologists. To confirm the diagnosis of gout and we do several of these studies a day. So there's some early studies that showed excellent sensitivities and specificity's. We did a prospective accuracy study where we had 40 patients with active gout or suspicious for active gout compared to patients with other type of joint disease an we use joint aspiration's of the gold standard and had excellent sensitivity and specificity. We had three patients with false negative studies, and these are all in patients with very acute. An recent onset of gout, and we think this is because that they image few deposits were too small to register. We also did a diagnostic yield study, which I think is very interesting that we had duty patients with risk factors for gout but had negative aspiration's then went on to Joule Energy. See T 14 of these actually revealed evidence of in issue deposition and twelve of these agreed to have a repeat aspiration which was directed by the see T and these all proved to be positive for IMT issue crystals and this is just an example. Where a 50 year old man with severe pain and swelling of the elbow, he had an initial aspiration of the elbow joint which was negative. But as you can see on the CT the there's color pixelation actually in the triceps tendon, not within the joint, which explains why the initial aspiration was negative. Repeat aspiration within the triceps tendon did show in issue crystals. So we also use it for problem solving. This is not a subtle case, but this man was referred from outside hospital for potential 4 foot amputation for a large mass an the Joule energy CT with the 3D rendering shows a mass is obviously a very large tophus. This also shows what we often find with these cases. There's a lot of sub clinical. You miss you. Crystal deposition lies about the joints and also within tendons and you can see in the. Achilles tendon, and to be honest, posterior tendon so you can see why sometimes these aspirations are negative, 'cause they're not actually interrupt tacular. We tend to just use this technique for extremities. All those hendra's knees, feet and ankles. So occasionally we do do it in the spine and this is a case with severe pain. In the Don toyed axial region and you can see some erosions on the regular CT lissaman realization. But on the Joule energy, see T. This just shows purple of calcification, and so this is consistent with CPD or. Calcium pyrophosphate deposition. Even in this patient with hyperuricemia. This green here is just artifact from his metal fillings. Another nice thing about the jewel, NGC T is that we can have quantification of the amount of issue crystals and so we can get a volume metric measurement of the. Amount of crystals that we can see here. Before treatment he hid in the right hand 11 centimeters cubed amount of image you crystals following aggressive six months Ivy treatment we can see that there's a dramatic reduction in the volume. 90% volume reduction, so this is nice to show our response to therapy. So it's a very robust technique and we use it clinically all the time. Moving onto MSK trauma. Obviously this is a common thing coming through the ER an often radiographs can be inconclusive. Conventional city is helpful for assessing bone findings but is often limited for soft tissue assessment and Emma is considered the gold standard for marrow assessment in soft tissue evaluation. However, Julie Energy can be make up for some of the. Defekts unconventional CT's. You can have tendon specific color mapping. The bone removal can make the visualization of the soft tissue structures more obvious and importantly, virtual on calcium imaging can visualize and aerospace redeem a particularly occult fractures. For example, hip fractures and osteopenic patients. Also looking for marrow adima patterns which are associated with specific injuries such as ACL. Are tears acute or sub acute avian in middle static disease so the tendon and ligament specific color mapping uses 3 material decomposition, collagen, fat and soft tissue to color code the tendons and ligaments. An we did a study looking at 16 patients with proven ACL tears by Emma an. We did bilateral need jewel energy CTS with team control studies an this is just showing he actually angled the settle scan like we do for Emma to the lateral femoral condyle. So we've got the ACL and one slice an you can see that the normal ACL is very well scene. Text images The tendon specific images. You can see a very uniform coloration of a normal ACL tendon an we had full readers blindly read these studies and they all. Thought the Julie Nergy bone removal was superior to the single energy threshold. We could see the cartilage. Much better an the entire ACL. Example of an ACL tear you can see on the moderate proximal ACL tear and this is very nicely shown on the next image is the bone removal and then the color tendon specific. There's loss of the normal tendon color approximately and this is just to compare to the contralateral normal ACL which you can see very nicely. With the bone removal you can also identify soft tissue injuries. We could clearly see longitudinal tear of this procedure. Horn of the lateral meniscus. Here's the normal high signal of the posterior horn and the contralateral knee, and this was confirmed on Arthroscopy. We also had our first see T bucket handle tear with a double PCL sign. You can see the high. Help fill unit medical material within the Intercondylar notch with the EMA Coral it and then the double PCL sign of a bucket handle tear. On the cases we also did virtual on calcium, where we remove the calcium an the trabecula bone, which makes the marrow adima more conspicuous. An here you can see the characteristic bone contusion and the lateral femoral condyle. Here's the Emma Coral at, and this is high Association with ACL tears. So visional calcium. There's been several papers, and looking at an acute need for more and also an ankle trauma with using Emma's the gold standard with very high sensitivities and specificities, an good to excellent interobserver agreement. This paper by radio towel looked at virtual on calcium images and suspected hip fractures an they used clinical or imaging follow-up as a gold standard and again very high sensitivities and positive predictive value. This is a more recent paper by the same group and radiology, and they use the marrow. On the single via with the color to two day overlay and the black and white imaging. Showing them arrow Ademar for this occult an to truck and tarique fracture and subcapital fracture. So they found that there was increased sensitivity and detection of non displaced traumatic hip fractures and there was increased diagnostic confidence in the exclusion of furniture and this is certainly we've been doing this for a year or so. An hour ER an the residents really like when it's negative they feel much more confident in so. We really go on to get onimar in these cases. That just showing a couple of nice cases an is an image K radiologist like the black and white images 2 rather than necessary the color an, so we include a lot of the soft tissue anatomy as well, not just the marrow an these have a very similar appearance to the T2 MRI images, and that you can see the marrow edema within the black fatty marrow compared to the asymmetric asymptomatic side, and both the cronel. Sagittal and axial plane in this very subtle subcapital fracture. And here's another 197 year old who was knocked over by a car. Very subtle fracture not seen radiographically, but a little cortical break here, but you can clearly see the marrow adima in the Inter trochanteric region. She went on to fixation so our residents call these poor men's IMT are but I think they really very comparable to T2. We've recently added color and. We do the sort of more binary color than this theory. There's the bone marrow overlay, and we also do a volume rendered display where we rotate radially around so you can sort of get a 3 dimensional picture an obviously this is a clear fracture. It's not subtle that the clinical question was, did it go right through the Intertrochanteric region and require fixation? Or can if it's just the greater trochanteric a Volscian fracture, she can just be followed clinically. And I think you can see very nicely the marrow edema adjacent to the fracture, but the adima does not go to the medial quartics. This patient did get an Mr as well and I think personally I like the the version on calcium imaging. The patient was uncomfortable, couldn't hold still very well for the Mr in the. You know the marrow edema is there, but I think the see T shows it very elegantly as well. So just moving onto meter reduction techniques we've heard and seen some beautiful images from the single source scanner. These are study that we did on the 4th and these are total shoulder arthroplasties. We have a big practice where patients are referred for a vision of TSA and so these are all is a problem. Scanning of these vast amount of metal. And these TSA's and we're trying to look for subtle changes at the implant bone interface. And so we scanned these with Julie Energy. Did the standards reconstruction, the mono plus I'm a on the mixed images in then we also did Aymar with Mono plus which doesn't yet commercially available, but we were able to do these reconstructions. And all three blind agreed as felt that the I'm a with the dual energy mono plus was the first preference. So we from this image, but we felt that there was less bone loss at the implant bone interface, which sometimes you can get with. I'm are alone, so hopefully this will become commercially available soon with a sharp kernel to really look at those bone interface and not just the soft tissue. And so this is just some of the data showing that all readers preferred drink debtors number one, which was mono plus with I'm A and there was less out effect on with that combination compared to the standard. And even though I'm are. And then just in the last little. But this is just something we've started to do, but there certainly is. Interest in the orthopedic literature in Mr has been the. Modality that's been used to look at the set quantification. So fatty infiltration and atrophy of the right rotator cuff musculature does play a significant role in determining functional outcome after cut cuff repair, and so optimally, the rotator cuff tendon should be repaired before there is advanced fatty infiltration. His high grades of fatty infiltration this is associated with a higher rate of failure, repair failure and, as I've mentioned, MRI has been used to quantify the fatty atrophy. 'cause of the limited tissue contrast with conventional CT, though there have been some papers that have used just Hounsfield units to show muscle density and so these we do a lot of shoulder tsan this just couple of examples of type of patients we see so. This is a 76 year old man. He's only got advanced degenerative arthritis so he's not a rotator cuff appear candidate but with the shoulder arthroplasties we're looking at the. The glenoid bone stock, and also at the soft tissue components an you can see that he's got a very robust deltoid, but when we look at his super Spinedace infraspinatous, an even subscapularis is significant. Fatty atrophy with dual energy. We can actually do quantitative measurement of the fat component an there was 48% in this case, and so there will be no. Every of teendom the and so he went on to reverse TSA regular. TSA would not be very functional and listening. As opposed to this 40 year old woman, the see T beautifully demonstrates on the 3D imaging the subchondral defects in the glenoid. But you can see on her muscle an on her fat quantification that there's very low fat content and so suitable repair of her rotator cuff. Tendon tear is likely to have good outcome. In another era is sake penyo, which is progressive reduction and muscle mass and strength in elderly patients, and certainly with the aging population. This would be going to become a much more. Common problem and it causes physical impairment. Greater risk of falls, fractures, disability limited self sufficiency and and higher mortality. And so there's a lot of research going on. Detecting faka peynir an early stage. Measures to delay loss of muscle base and avoid or postpone the answer of functional impairment. In whole body dexa scanners certainly been in the forefront, but other imaging techniques, ultrasound, MRI and CT have been used. And see T is used for the measurement of my opinion. So there are various techniques where you can do segmentation of muscle using density threshold to quantify muscle muscle, cross sectional area and so you can either do all the muscles on a single see T abdominal's life. Just look at the source muscle or the paraspinal muscles. And another component is looking at muscle density for using the Hounsfield units to assess for fatty atrophy. But I'm wondering whether a more quantitative Julie Energy effect quantification may be more accurate than just Hounsfield units, but this is an area of very active research, so just keep an eye on this area. So in conclusion, the advantages of jyllinge ECT. And MSK imaging. Obviously in gout it's very well established. Technique and may replace the aspiration as a new gold standard as far as ER trauma, seating CT can not only provide ossias information, but also soft tissue. Information and I think the assessment of marrow edema is for radiography. Occult fractures may replace the need for urgent MRI. It certainly setes more available so she after hours, fast acquisition time and decreased cost for metal reduction technique on the force time are with the jewel energy seating mono plus it's very promising an then watch this space fit quantification may be useful. Technique. And thank you.

MAYO CLINIC MAYO CLINIC. MAYO CLINIC, MAYO CLINIC* MAYO Right Hand MAYO VNCa DECT for Gout DEC T Fat Quantification Fat quantification Intertrochanteric fracture Fat quantification DECT fat quantification DEC T Fat quantification DEC T fat quantification Virtual non-calcium imaging Conclusion Metal Reduction Techniques DECT metal reduction techniques DECT Alternative to MRI in MSK Trauma DECT alternate to MRI in MSK trauma DECT Gout DECT MSK Trauma DECT Gou DECT bon Gout Goals and Objectives DECT MSK DECT - DECT Gou DECT DECT bon False Negative DECT CLINIC VNCa marrow edema present up to 10 weeks after injury The incidence of gout has tripled over the last two VNCa observers) using MRI as gold standard: Up to 42% of patients with gout have normal serum uric Tendon specific color mapping for evaluation of tendons O Advantages of DECT: 16 patients with proven ACL tears by MRI had bilateral DECT O Fatty infiltration and atrophy of the rotator cuff Sarcopenia — progressive reduction in muscle mass decades and now represents the most common form of Knee Ri htKnee—Norm DECT for evaluation of gout -14 of the 30 DECT revealed evidence of MSU deposition 10 control subjects had bilateral DECT — Sensitivity 86.4/86.40/0 and specificity 94.4/95.5% — Sensitivity 85.4/86.496 and specificity 94.4/95.5% and ligaments acid levels preference Order inflammatory arthritis in men and women. and strength in elderly people musculature plays a significant role in the — Accurate assessment of gout without requiring aspiration — Good to excellent agreement -12 having positive repeat DECT guided aspiration Katrina Nesta Glazebrook DECT bone removal to better visualize the cartilage and DECT alternate to MRI in MSK trauma Demonstration of uric acid crystals within joint fluid determining functional outcome after cuff repair. Katrina Glazebrook • New gold standard SIEMENS .. SIEMENS Hyperuricemia may also be present in patients without — Physical impairment, greater risk of falls and fractures, Mayo Clinic Rochester • all were in patients with acute recent onset gout for soft tissue structures remains the diagnostic gold standard for diagnosis of gout Associate Professor, Radiographically occult gout. disability, limited self-sufficiency, higher mortality — Imaging of tendons, ligaments and cartilage. — Surgical repair of the RT tendons should be performed Mayo Clinic Rochester CT image — showed that VNCa images increased sensitivity for fractures • Provides detailed information about osseous and soft tissue gold standard: Synovial fluid aspiration may not reveal uric acid crystals in Virtual non-calcium (VNCa) imaging to visualize the Healthineers Contusion prior to advanced fatty infiltration, particularly of the — Virtual non calcium imaging (VNCa) of the bone for Detecting sarcopenia at an early stage can prompt Bony alterations occur only years into the illness and even imaging, but is often limited for soft tissue architecture Femoral Condyie — Visual grading patients had joint aspirations the acute setting and laboratory accuracy can vary marrow space for edema infraspinatus. 76 year old woman 40 year old woman marrow edema. Assessment of marrow edema to identify radiographically occult then only 45% of patients have radiographic findings. measures to delay loss of muscle mass to avoid or • Sensitivity 90/900/6 and specificity 80.5/81.6%, K = 0.66 assessment 40 year old woman swelling of the Clinicians may need to base diagnosis on secondary ECT fractures — Occult fractures e.g. hip in osteopenic patients — High grades of fatty infiltration are associated with higher VNCa DECT metal reduction techniques Metal Reduction Techniques postpone onset of functional impairment — Specificity remained the same. DECT non-invasive technique for identification of gout was 0.90 (95% a 0.76 to 0.97) and 0.83 (95% fractures. fractures fracture • Increased availability compared to MR particularly in the ER and criteria — Marrow edema patterns associated with specific injuries such as edema rates of repair failure — Diagnostic confidence in the exclusion of fracture was hyperuricemia a 0.68 to 0.93) monosodium urate crystals and has become the mainstay kissing contusions from ACL injury or transient patellar — Whole body DEXA scan DECT fat quantification 42 — MR has been used to quantify fatty atrophy due to the After treatment Before treatment negative for DECT DECT bone DECT Gout SECT DECT fractures fracture response to colchicine At arthroscopy, posterior hom lateral meniscus dislocation for Rheumatologists in our practice to confirm gout — Ultrasound mixed Tendon threshold crystals Apr. 09, 2008 Dec 18,2008 *.01ume decrease Apr. 09, 2008 Dec 18,2008 WIume decrease DECT DECT limited soft tissue contrast of conventional CT — rotator cuff musculature prior to shoulder surgery — Sensitivity 90% natural history — Acute or subacute Avascular necrosis (AVN) MAR with DECE MAR with DECTu iM ECT DECT SECT mixed Lt hand (cm3 tendon Tendon 90.957 9.57 iMARalone 1.09 88.61% radiological x-ray changes — CT studies use HU to show muscle density —EC T Fat quantification — Fat quantification DEC T Fat Quantification Fat quantification Mono+ 130 Mono+ 130 Mono+130 — sarcopenia — Metastatic disease specific Using black and white and color overlay DECT for ACL Tear: Display Techniques and Initial performance Estimates 11.27 1.02 SIEMENS 40 SIEMENS .. VNCa image MRI image Fx. left ? DECT fat quantification more accurate Boutin et al AIR 2015 DECT for ACL Tear: Display Techniques and Initial Performance Estimates (Case courtesy of Dr. Nisha J. Manek) Healthineers ECT CT