Fast Magnetic-Resonance Temperature Imaging

✍ Scribed by Jacco A. de Zwart; Peter van Gelderen; Dan J. Kelly; Chrit T.W. Moonen

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 169 KB
• Volume: 112
• Category: Article
• ISSN: 1064-1866
• DOI: 10.1006/jmrb.1996.0115

✦ Synopsis

It has long been realized that local temperature elevation using focused ultrasound (FUS) can have medical benefits, for example, in cancer therapy (1, 2). However, problems with the evaluation of power dosage and with focusing the ultrasound power at the target location have prevented widespread use. Magnetic-resonance imaging can be used, not only to provide detailed anatomical images, but also to provide temperature images (3). Therefore, the combination of FUS and MRI appears to be promising for medical interventions (4, 5). Ideally, pulsed, low-dose ultrasound would be used to elevate temperature by at most a few degrees Celsius. MR temperature imaging would then be used for dosimetry and for focusing the ultrasound interactively at the target location. Then, the therapeutic dose of ultrasound would be FIG. 1. Theoretical signal-to-noise ratio of PRF-based MRI thermometry (SNR T ) as a function of TE (dashed curve, left axis), together with delivered. The interactive FUS adjustment necessitates a variance of the temperature as a function of TE (solid line, right axis) for high temporal resolution in temperature imaging because of a sample with T * 2 of 100 ms and initial image SNR of 100. Simulation was two reasons: (1) to avoid problems due to patient motion; performed for a temperature increase of 1ЊC.