1. Ioannis Karakitsios, Timur Saliev, Helen McLeod, Sarfraz Ahmad, Andreas Melzer Ioannis Karakitsios, Timur Saliev, Helen McLeod, Sarfraz Ahmad, Andreas Melzer Institute for Medical Science & Technology, University of Dundee, United Kingdom Methods: Four explanted livers: two fresh sheep livers and two Thiel embalmed human livers were scanned with MRI (1.5 T HDxt, GE Healthcare, USA) using Fast Spoiled Gradient Echo (FSPGR) imaging with TE: Minimum, TR: 60 msec, Flip Angle: 30 o and acquisition matrix 256x256. The organs were heated for 20 sec with Focused Ultrasound (FUS) (ExAblate 2000, InSightec Ltd., Israel) at various acoustic energies: 253, 506 and 709 Joules. Proton Resonance Frequency (PRF) MR Thermometry was applied for temperature monitoring. Post-sonication maximum temperature values of the animal liver and Thiel human liver were compared. Acknowledgements: Project FUSIMO (“Patient specific modelling and simulation of focused ultrasound in moving organs”) funded under the EU's 7th Framework Programme for Research and Technological Development. Explanted Thiel Embalmed Human Liver as a Model to Study MR-guided Focused Ultrasound Surgery Results: Table shows the average value of the maximum temperatures after MRgFUS treatment of fresh animal liver and Thiel embalmed human liver at various acoustic energies, and their difference Conclusions: MRgFUS treatment of Thiel embalmed human liver at energies >506 J can induce tumour ablation with temperatures >56 o C. There was a good correlation between temperatures achieved in the Thiel embalmed tissue and the temperatures in the fresh animal tissue. In overall, Thiel embalmed human liver constitutes a feasible, safe and reliable model to study MRgFUS treatment, ex vivo. Acoustic Energy253 J506 J709 J Thiel liver temperature, C58.0 ± 0.81671.7 ± 1.24787 ± 0.816 Fresh liver temperature, C58.0 ± 0.81671.3 ± 1.88686 ± 0.816 Temperature difference00.32 References [1] Cline HE, Schenck JF, Hynynen K, et al MR-guided Focused Ultrasound Surgery. Journal of Computer Assisted Tomography 1996;16:956-965.[2] Jolesz FA. MRI-Guided Focused Ultrasound Surgery. Annual Revew of Medicine 2009;60:417-430. [3] Fischer K, Gedroyc W, and Jolesz FA. Focused Ultrasound as a Local Therapy for Liver Cancer. Cancer Journal 2010;16:118-124. [4] Kopelman D, Inbar Y, Hanannel A, Freundlich D, Vitek S, Schmidt R, Sokolov A, Hatoum OA, and Rabinovici J. MR-guided Focused Ultrasound Surgery Using an enhanced SonicationTechnique in a Pig Muscle model. European Journal of Radiology 2006;59:190-197. [5] Gedroyc WM. New Clinical Applications of Magnetic Resonance-Guided Focused Ultrasound. Topics in Magnetic Resonance Imaging 2006;17:189-194. [6] Thiel W. The Preservation of the Whole Corpse with Natural Color. Annual Journal of Anatomy 1992;174:185-195. Absorber Background: MR-guided Focused Ultrasound Surgery (MRgFUS) is a useful method to ablate tumours noninvasively [1,2]. Treatment of liver disease is a very demanding treatment process with high death rates [3]. Studies on animals and human patients under general anaesthesia have reported the feasibility and accuracy of MRgFUS to coagulate tumour [4,5]. Thiel embalming is used to preserve human cadavers, giving the bodies a high degree of flexibility and life-like characteristics. Objectives: The focus of our study was to determine whether explanted Thiel embalmed human liver constitutes a reliable model for studying MRgFUS. For that purpose, the temperatures of the heated Thiel tissue were compared to the temperatures of fresh animal tissue. HIFU transducer Liver Gel Pad