Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Jan;73(1):417-26.
doi: 10.1002/mrm.25099. Epub 2014 Jan 29.

Endoluminal MR-guided ultrasonic applicator embedding cylindrical phased-array transducers and opposed-solenoid detection coil

Affiliations
Free article

Endoluminal MR-guided ultrasonic applicator embedding cylindrical phased-array transducers and opposed-solenoid detection coil

Mihaela Rata et al. Magn Reson Med. 2015 Jan.
Free article

Abstract

Purpose: MR-guided high-intensity contact ultrasound (HICU) was suggested as an alternative therapy for esophageal and rectal cancer. To offer high-quality MR guidance, two prototypes of receive-only opposed-solenoid coil were integrated with 64-element cylindrical phased-array ultrasound transducers (rectal/esophageal).

Methods: The design of integrated coils took into account the transducer geometry (360° acoustic window within endoluminal space). The rectal coil was sealed on a plastic support and placed reversibly on the transducer head. The esophageal coil was fully embedded within the transducer head, resulting in one indivisible device. Comparison of integrated versus external coils was performed on a clinical 1.5T scanner.

Results: The integrated coils showed higher sensitivity compared with the standard extracorporeal coil with factors of up to 7.5 (rectal applicator) and 3.3 (esophageal applicator). High-resolution MR images for both anatomy (voxel 0.4 × 0.4 × 5 mm(3)) and thermometry (voxel 0.75 × 0.75 × 8 mm(3), 2 s/image) were acquired in vivo with the rectal endoscopic device. The temperature feedback loop accurately controlled multiple control points over the region of interest.

Conclusion: This study showed significant improvement of MR data quality using endoluminal integrated coils versus standard external coil. Inframillimeter spatial resolution and accurate feedback control of MR-guided HICU thermotherapy were achieved.

Keywords: MRI-guided contact ultrasound; RF receiver coil; active temperature control; cancer therapy; opposite solenoid; phased-array transducer.

PubMed Disclaimer

Publication types

MeSH terms

LinkOut - more resources