Feasibility of magnetic resonance elastography using myofascial phantom model Poster No.: C-0971 Congress: ECR 2013 Type: Scientific Exhibit Authors: H. J. Kang, J.-S. Yoon, S.-J. Hong, C.-H. Oh, S. H. Hong; Seoul/ KR Keywords: Image verification, Imaging sequences, MR, Elastography, Musculoskeletal system DOI: 10.1594/ecr2013/C-0971 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 8
Purpose Magnetic resonance elastography (MRE) is relatively advancement in MRI imaging, which includes phase contrast and tissue stiffness images. The concept of shear wave is used to produce images of MRE. The process is simple, just only needed external source like vibration. Myofascial taut band is the result of increased muscle tension, which is a typical finding to diagnose myofascial pain syndrome. Up to date, there is no definite imaging study for diagnosing myofascial pain syndrome. We hypothesis that MRE would be able to quantitate the differences of shear wave between myofascial taut band and other muscle fiber. The aim of this study is to prove and visualize the concept of myofascial taut band in model phantom by MRE. Methods and Materials Phantom muscle with taut band model was prepared using radiofrequency (RF) ablation of swine model (2 kg of flesh including skin). RF Catheter needle was inserted under ultrasonographic guidance, and RF ablation with 2.5cm-ablating-diameter was performed at the 30W intensity for 10 minutes (Figure 1). We directly monitored the change of echogenecity in the ablated area of the swine, and then stopped ablation before air bubbles appeared inside. The other phantom muscle, a bovine model which the thick visible tendon was penetrating into, was also prepared (Figure 2). 3.0T MRI machine (Magnetom Skyra, Siemens, Germany) was used to take images in swine and bovine phantom models. At first, anatomical T2 weighted image were obtained. Next, shear force was applied by a passive pneumatic driver (Figure 3). Shear wave propagation were obtained visually by MRE. Images for this section: Page 2 of 8
Fig. 1: RF (Radiofrequency) ablated swine. Blue painted area showed ablation site (2.5 cm). Page 3 of 8
Page 4 of 8
Fig. 2: Bovine model with thick visible tendon penetrating into the meat. Fig. 3: Pneumatic driver applying shear force. Page 5 of 8
Results In swine model, increased stiffness (red color, with range of) was found at needle ablation site which showed irregular round shape pattern with 1.5 cm diameter at coronal section (Figure 4). In bovine model, increased stiffness was observed at the longitudinal deep linear tendon site (Figure 5). To fix a pneumatic driver, some compression would be applied to subjects, which might result as false-increased stiffness. We thought that some areas with increased stiffness were induced by compression of pneumatic driver. Images for this section: Fig. 4: In swine model. Upper blue arrow indicates the ablated site, and lower indicates same area showing increased stiffness (red color, 1.5 cm) in MRE image. Left white arrow indicates false-increased stiffness by compression. Page 6 of 8
Fig. 5: In bovine model. Increased stiffness was observed following the longitudinal deep linear tendon site. Page 7 of 8
Conclusion The findings of this study in swine and bovine phantom model have significance of MRE for imaging taut band in muscles. Further research might be needed to detect the muscular trigger point using MRE technique in humans. References 1. Chen Q, Basford J, An K. Ability of magnetic resonance elastography to assess taut bands. Clinical Biomechanics 2008; 23: 623-629 2. Chen Q, Bensamoun S, Basford J, Thopson JM, An K. Identification and quantification of myofascial taut bands with magnetic resonance elastography. Arch Phys Med Rehabil 2007;88:1658-61 3. Huwart L, Sempoux C, Salameh N, Jamart J, Annet L, Sinkus R, Peeters F, Beek L, Horsmans Y, Beers B. Liver fibrosis: Noninvasive assessment with MR elastography versus aspartate aminotransferase-to-platelet ratio index Radiology 2007;245: 458-466 4. Carrion JA, Navasa M, et al. MR elastography to assess liver fibrosis Radiology May 2008 248:591-592 Personal Information Page 8 of 8