Abstract
Background: Magnetic Resonance Imaging (MRI)-guided Focused Ultrasound Surgery (MRgFUS) is a non-invasive thermal ablation method utilizing high-intensity focused ultrasound (HI-FU) energy for tissue ablation under MRI with real-time thermal mapping. Ablating to a dynamic target as in the liver is very challenging, requiring approval. A novel quality-assured liver tumor ablation system has been proposed for clinics. The paper reports the evaluation of conventional and new MR-receiving coils.
Purpose: To evaluate the suitability of MR coils as part of the MRgFUS treatment system for liver, while simulating breathing motion in pre-clinical settings.
Material and Methods: The novel software communicates with the MR scanner and the transducer. To monitor the temperature via proton resonance frequency (PRF) methodology echo planar imaging (EPI) sequence was used while the algorithms of static, static and dynamic tracking were tested with sonications of 100 W for 30 s on tissue-mimicking phantoms. Different coil sets were used to assess the performance of the system for fitness for dynamic thermometry. Finally, in vivo experiments were performed over a porcine model.
Results: Single-loop four-channel Duoflex and Gem coils provided adequate signal-to-noise ratio and contrast with consistent thermal readings. Body array coils showed severe loss of signal in dynamic cases since the integration of tracking algorithm causes low efficiency.
Conclusion: Body array coils are unsuitable for MRgFUS of the liver due to signal loss. The dedicated coil set with a single loop around the FUS transducer combined with four-channel arrays might be the best option for liver treatment using dynamic MRgFUS applications.
Purpose: To evaluate the suitability of MR coils as part of the MRgFUS treatment system for liver, while simulating breathing motion in pre-clinical settings.
Material and Methods: The novel software communicates with the MR scanner and the transducer. To monitor the temperature via proton resonance frequency (PRF) methodology echo planar imaging (EPI) sequence was used while the algorithms of static, static and dynamic tracking were tested with sonications of 100 W for 30 s on tissue-mimicking phantoms. Different coil sets were used to assess the performance of the system for fitness for dynamic thermometry. Finally, in vivo experiments were performed over a porcine model.
Results: Single-loop four-channel Duoflex and Gem coils provided adequate signal-to-noise ratio and contrast with consistent thermal readings. Body array coils showed severe loss of signal in dynamic cases since the integration of tracking algorithm causes low efficiency.
Conclusion: Body array coils are unsuitable for MRgFUS of the liver due to signal loss. The dedicated coil set with a single loop around the FUS transducer combined with four-channel arrays might be the best option for liver treatment using dynamic MRgFUS applications.
| Original language | English |
|---|---|
| Pages (from-to) | 3-11 |
| Number of pages | 9 |
| Journal | Acta Radiologica |
| Volume | 62 |
| Issue number | 1 |
| Early online date | 10 Apr 2020 |
| DOIs | |
| Publication status | Published - Jan 2021 |
Keywords
- Coils
- Magnetic resonance thermometry
- tracking
- echo planar imaging
- magnetic resonance-guided focused-ultrasounds surgery
- CE marking
- validation
- verification
- magnetic resonance-guided focused-ultrasound surgery
- magnetic resonance thermometry
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging