Table of Contents Author Guidelines Submit a Manuscript
BioMed Research International
Volume 2014, Article ID 421726, 9 pages
http://dx.doi.org/10.1155/2014/421726
Research Article

Respiratory-Gated MRgHIFU in Upper Abdomen Using an MR-Compatible In-Bore Digital Camera

1Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
2Clinatec/LETI/CEA, 38054 Grenoble, France
3Department of Radiology, University Hospitals of Geneva, 1211 Geneva, Switzerland
4Radiology Department, Lyon-Sud Hospital, University Hospitals of Lyon, 69495 Pierre Bénite, France
5CREATIS, CNRS UMR5220, INSERM U1044, University of Lyon, INSA Lyon, 69621 Villeurbanne, France

Received 23 August 2013; Revised 25 November 2013; Accepted 26 November 2013; Published 29 January 2014

Academic Editor: Tosiaki Miyati

Copyright © 2014 Vincent Auboiroux et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. To demonstrate the technical feasibility and the potential interest of using a digital optical camera inside the MR magnet bore for monitoring the breathing cycle and subsequently gating the PRFS MR thermometry, MR-ARFI measurement, and MRgHIFU sonication in the upper abdomen. Materials and Methods. A digital camera was reengineered to remove its magnetic parts and was further equipped with a 7 m long USB cable. The system was electromagnetically shielded and operated inside the bore of a closed 3T clinical scanner. Suitable triggers were generated based on real-time motion analysis of the images produced by the camera (resolution pixels, 30 fps). Respiratory-gated MR-ARFI prepared MRgHIFU ablation was performed in the kidney and liver of two sheep in vivo, under general anaesthesia and ventilator-driven forced breathing. Results. The optical device demonstrated very good MR compatibility. The current setup permitted the acquisition of motion artefact-free and high resolution MR 2D ARFI and multiplanar interleaved PRFS thermometry (average SNR 30 in liver and 56 in kidney). Microscopic histology indicated precise focal lesions with sharply delineated margins following the respiratory-gated HIFU sonications. Conclusion. The proof-of-concept for respiratory motion management in MRgHIFU using an in-bore digital camera has been validated in vivo.