title: Development of a hybrid magnetic resonance and ultrasound imaging system.
abstract: A system which allows magnetic resonance (MR) and ultrasound (US) image data to be acquired simultaneously has been developed. B-mode and Doppler US were performed inside the bore of a clinical 1.5 T MRI scanner using a clinical 1-4 MHz US transducer with an 8-metre cable. Susceptibility artefacts and RF noise were introduced into MR images by the US imaging system. RF noise was minimised by using aluminium foil to shield the transducer. A study of MR and B-mode US image signal-to-noise ratio (SNR) as a function of transducer-phantom separation was performed using a gel phantom. This revealed that a 4 cm separation between the phantom surface and the transducer was sufficient to minimise the effect of the susceptibility artefact in MR images. MR-US imaging was demonstrated in vivo with the aid of a 2 mm VeroWhite 3D-printed spherical target placed over the thigh muscle of a rat. The target allowed single-point registration of MR and US images in the axial plane to be performed. The system was subsequently demonstrated as a tool for the targeting and visualisation of high intensity focused ultrasound exposure in the rat thigh muscle.
authors.affiliation: Division of Radiotherapy and Imaging, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, 123 Old Brompton Road, London SW7 3RP, UK.
authors.forename: Victoria
authors.initials: V
authors.lastname: Sherwood
authors.affiliation: Division of Radiotherapy and Imaging, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, 123 Old Brompton Road, London SW7 3RP, UK.
authors.forename: John
authors.identifier: 0000-0002-9014-9292
authors.initials: J
authors.lastname: Civale
authors.affiliation: Division of Radiotherapy and Imaging, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, 123 Old Brompton Road, London SW7 3RP, UK.
authors.forename: Ian
authors.initials: I
authors.lastname: Rivens
authors.affiliation: Department of Clinical Magnetic Resonance, CRUK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, 123 Old Brompton Road, London SW7 3RP, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Collins
authors.affiliation: Department of Clinical Magnetic Resonance, CRUK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, 123 Old Brompton Road, London SW7 3RP, UK.
authors.forename: Martin O
authors.initials: MO
authors.lastname: Leach
authors.affiliation: Division of Radiotherapy and Imaging, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, 123 Old Brompton Road, London SW7 3RP, UK.
authors.forename: Gail R
authors.initials: GR
authors.lastname: ter Haar
mesh_terms: D000818:Animals; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D007089:Image Enhancement / Q000295:instrumentation*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D064847:Multimodal Imaging / Q000295:instrumentation*; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D019047:Phantoms, Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018511:Systems Integration; D013848:Thigh / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D018608:Ultrasonography, Doppler / Q000295:instrumentation*