Traditional Posters: Interventional - ismrm

1815. MR Guided High Intensity Focused Ultrasound for Tumor Ablation in Brain:
Preliminary Results
Najat Salameh 1 , Line Souris 1 , Laurent Marsac 2 , Jean-François Aubry 3 , Mathieu Pernot 3 ,
Benjamin Robert 2 , Mathias Fink 3 , Luc Darrasse 1 , Mickaël Tanter 3
1 Imagerie par Résonance Magnétique Médicale et MultiModalité (UMR 8081), Université Paris-Sud, CNRS,
Orsay, Iles-de-France, France; 2 SuperSonic Imagine, Aix-en-Provence, France; 3 Institut Langevin, ESPCI
ParisTech, CNRS UMR 7587 INSERM U979, Paris, France
A novel prototype for brain therapy with transcranial focused ultrasound is presented here. The first part of this study showed that this
new HIFU system was fully MR-compatible. Secondly, we optimized a sequence for MR thermometry, and followed the increase in
temperature in a gel heated with increasing power (from 125 to 500 Wac). Finally, we showed it is possible to heat veal brains through
a human skull at a high frequency and monitor the heating process with MRI. After validation on cadaver heads, this work will open
new horizons to tumor brain therapy in animals and then in humans.
1816. Brain Tissue Flow Measurement Using Arterial Spin Labeling with Flow
Discrimination by Cumulative Readout Pulses
Yi Wang 1 , Allison Payne 2 , Seong-Eun Kim 2 , Edward DiBella 2 , Dennis L. Parker 2
1 Bioengineering, University of Utah, Salt Lake City, UT, United States; 2 Utah Center for Advanced Imaging
Research, University of Utah, Salt Lake City, UT, United States
The Pennes' perfusion term in the Pennes bioheat transfer equation depicts the rate at which blood flow removes heat from a point and
can play an important role in tissue heat dissipation. Because tissue perfusion is known to change over the course of a thermal therapy
treatment, the ability to perform multiple flow assessments to detect perfusion changes during magnetic resonance-guided highintensity
focused ultrasound treatment is of high importance. In this work, we present a method to use arterial spin labeling to
determine the Pennes' perfusion term in brain tissue and evaluate performance as a function of various imaging parameters, such as
flip angle , bandwidth, and resolution. The results indicate that the proposed technique could be applied in MRgHIFU to provide an
efficient estimate of the Pennes' perfusion term. Although demonstrated on brain tissue, this technique could be applied to other tissue
types.
Thermotherapy
Hall B Wednesday 13:30-15:30
1817. Dual-Echo Sequence for MR Thermometry in Moving Objects
Bruno Madore 1 , Lawrence P. Panych 1 , Chang-Sheng Mei 1,2 , Renxin Chu 1
1 Radiology Department, Brigham and Women's Hospital, Harvard Medical School , Boston, MA, United States;
2 Department of Physics, Boston College, Chestnut Hill, MA, United States
An MR thermometry dual-echo sequence is proposed here that offers advantages both in terms of temperature-to-noise ratio and
image contrast, as compared to typically-used sequences. For thermometry in moving organs, the contrast properties of the proposed
sequence allow blood vessels to be readily detected, for motion tracking purposes.
1818. Fat Temperature Imaging with T1 of Fatty Acid Species Using Multiple Flip Angle
Multipoint Dixon Acquisitions
Kagayaki Kuroda 1,2 , Taku Iwabuchi, Mie Kee Lam 3 , Makoto Obara 4 , Masatoshi Honda 5 ,
Kensuke Saito, Marc Van Cauteren 4 , Yutaka Imai 5
1 Graduate School of Engineering, Tokai University, Hiratsuka, Kanagawa, Japan; 2 Medical Device
Development Center, Foundation for Biomedical Research and Innovation, Kobe, Hyogo, Japan; 3 Image
Sciences Institute, University Medical Center Utrecht, Utrecht, Netherlands; 4 MR Marketing, Philips
Electronics Japan Medical Systems, Shinagawa, Tokyo, Japan; 5 Department of Radiology, Tokai University,
Isehara, Kanagawa, Japan
A fat temperature imaging technique based on multiple flip angle, multipoint Dixon acquisitions and a least square estimation scheme
is proposed. Gradient recalled acquisition of 5 echo times with 3 different flip angles were obtained to separate the signals of
methylene and methyl protons and to estimate T1's of these fatty acid species. Temperature images of a water-oil phantom were
successfully obtained with previously obtained temperature coefficients demonstrating the feasibility of quantitative thermometry of
fat. Since the acquisition time was 4-6 second, the technique seemed to be practical for temperature monitoring of fat-water tissues
like breast under thermal therapies.
1819. Novel Body Coil Driven Radio Frequency Ablation Device
Yik-Kiong Hue 1 , Jerome L. Ackerman 1 , Erez Nevo 2
1 Martinos Center, Department of Radiology, Massachusetts General Hospital, Boston, MA, United States;
2 Robin Medical, Inc., Baltimore, MD, United States
A novel body coil driven radiofrequency ablation (RFA) device is proposed. It provides an alternative to commercial available RFA
device which required external power generator and large grounding pad. It allowed MR scanner as the sole modality to localize
tumor, probe placement, RF power control, temperature mapping and tissue monitoring.