Dataset Information

Update on Clinical Magnetic Resonance-Guided Focused Ultrasound Applications.

ABSTRACT: In this review, several clinical applications of magnetic resonance (MR)-guided focused ultrasound (FUS) are updated. MR-guided FUS is used clinically for thermal ablation of uterine fibroids and bone metastases. Thousands of patients have successfully been treated. Transcranial MR-guided FUS has received CE certification for ablation of deep, central locations in the brain. Thermal ablation of specific parts of the thalamus can result in relief of the symptoms in a number of neurological disorders. Several approaches have been proposed for ablation of prostate and breast cancer and clinical trials should show the potential of MR-guided FUS for these and other applications.

SUBMITTER: Kobus T

PROVIDER: S-EPMC4621790 | biostudies-literature | 2015 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Update on Clinical Magnetic Resonance-Guided Focused Ultrasound Applications.

Kobus Thiele T McDannold Nathan N

Magnetic resonance imaging clinics of North America 20150707 4

In this review, several clinical applications of magnetic resonance (MR)-guided focused ultrasound (FUS) are updated. MR-guided FUS is used clinically for thermal ablation of uterine fibroids and bone metastases. Thousands of patients have successfully been treated. Transcranial MR-guided FUS has received CE certification for ablation of deep, central locations in the brain. Thermal ablation of specific parts of the thalamus can result in relief of the symptoms in a number of neurological disord ...[more]

PMID: 26499282

Similar Datasets

Project description:BACKGROUND:MR-guided focused ultrasound or high-intensity focused ultrasound (MRgFUS/MRgHIFU) is a non-invasive therapeutic modality with many potential applications in areas such as cancer therapy, drug delivery, and blood-brain barrier opening. However, the large financial costs involved in developing preclinical MRgFUS systems represent a barrier to research groups interested in developing new techniques and applications. We aim to mitigate these challenges by detailing a validated, open-source preclinical MRgFUS system capable of delivering thermal and mechanical FUS in a quantifiable and repeatable manner under real-time MRI guidance. METHODS:A hardware and software package was developed that includes closed-loop feedback controlled thermometry code and CAD drawings for a therapy table designed for a preclinical MRI scanner. For thermal treatments, the modular software uses a proportional integral derivative controller to maintain a precise focal temperature rise in the target given input from MR phase images obtained concurrently. The software computes the required voltage output and transmits it to a FUS transducer that is embedded in the delivery table within the magnet bore. The delivery table holds the FUS transducer, a small animal and its monitoring equipment, and a transmit/receive RF coil. The transducer is coupled to the animal via a water bath and is translatable in two dimensions from outside the magnet. The transducer is driven by a waveform generator and amplifier controlled by real-time software in Matlab. MR acoustic radiation force imaging is also implemented to confirm the position of the focus for mechanical and thermal treatments. RESULTS:The system was validated in tissue-mimicking phantoms and in vivo during murine tumor hyperthermia treatments. Sonications were successfully controlled over a range of temperatures and thermal doses for up to 20 min with minimal temperature overshoot. MR thermometry was validated with an optical temperature probe, and focus visualization was achieved with acoustic radiation force imaging. CONCLUSIONS:We developed an MRgFUS platform for small-animal treatments that robustly delivers accurate, precise, and controllable sonications over extended time periods. This system is an open source and could increase the availability of low-cost small-animal systems to interdisciplinary researchers seeking to develop new MRgFUS applications and technology.

Project description:PurposeHigh intensity focused ultrasound (HIFU) is a non-invasive therapeutic technique that can thermally ablate tumors. Boiling histotripsy (BH) is a HIFU approach that can emulsify tissue in a few milliseconds. Lesion volume and temperature effects for different BH sonication parameters are currently not well characterized. In this work, lesion volume, temperature distribution, and area of lethal thermal dose were characterized for varying BH sonication parameters in tissue-mimicking phantoms (TMP) and demonstrated in ex vivo tissues.MethodsThe following BH sonication parameters were varied using a clinical MR-HIFU system (Sonalleve V2, Philips, Vantaa, Finland): acoustic power, number of cycles/pulse, total sonication time, and pulse repetition frequency (PRF). A 3×3×3 pattern was sonicated inside TMP's and ex vivo tissues. Post sonication, lesion volumes were quantified using 3D ultrasonography and temperature and thermal dose distributions were analyzed offline. Ex vivo tissues were sectioned and stained with H&E post sonication to assess tissue damage.ResultsSignificant increase in lesion volume was observed while increasing the number of cycles/pulse and PRF. Other sonication parameters had no significant effect on lesion volume. Temperature full width at half maximum at the end of sonication increased significantly with all parameters except total sonication time. Positive correlation was also found between lethal thermal dose and lesion volume for all parameters except number of cycles/pulse. Gross pathology of ex vivo tissues post sonication displayed either completely or partially damaged tissue at the focal region. Surrounding tissues presented sharp boundaries, with little or no structural damage to adjacent critical structures such as bile duct and nerves.ConclusionOur characterization of effects of HIFU sonication parameters on the resulting lesion demonstrates the ability to control lesion morphologic and thermal characteristics with a clinical MR-HIFU system in TMP's and ex vivo tissues. We demonstrate that this system can produce spatially precise lesions in both phantoms and ex vivo tissues. The results provide guidance on a preliminary set of BH sonication parameters for this system, with a potential to facilitate BH translation to the clinic.

Dataset Information

Update on Clinical Magnetic Resonance-Guided Focused Ultrasound Applications.

Publications

Update on Clinical Magnetic Resonance-Guided Focused Ultrasound Applications.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets