[MRI for monitoring of high intensity focused ultrasound: current developments]

Radiologe. 2013 Nov;53(11):1001-8. doi: 10.1007/s00117-012-2463-4.
[Article in German]

Abstract

With respect to monitoring of high intensity focused ultrasound (HIFU), synonym focused ultrasound (FUS) treatment, magnetic resonance imaging (MRI) is characterized by several advantageous properties: the precise definition and morphological characterization of the target area (before and after the intervention), the real-time visualization of the treatment effect by thermal imaging (during the intervention) and in the sense of a stereotactic system, the 3-dimensional localization of the target lesion, planning of the target volume and assessment of the achieved ablation volume (before and during the intervention). Non-enhanced T2-weighted multislice MR images are acquired for planning of the intervention. For temperature monitoring (comprising thermometry and thermodosimetry), the temperature-dependent shift of proton resonance frequency (PRFS) is most frequently employed. This method is independent of the treated tissue type or thermally induced tissue changes and facilitates a relative measurement of the temperature change based on a reference value. Future MRI applications include diffusion-weighted MRI (DWI-MRI; for the intrainterventional estimation of treatment efficacy), dynamic contrast-enhanced MRI (DCE-MRI, for the prediction of the potential and assessment of the treatment effect achieved) and motion-corrected temperature monitoring (referenceless and multibaseline thermometry).

Publication types

  • English Abstract

MeSH terms

  • High-Intensity Focused Ultrasound Ablation / methods*
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Monitoring, Intraoperative / methods*
  • Surgery, Computer-Assisted / methods*