Work

Dual-mode IVUS catheter for intracranial image-guided hyperthermia: Feasibility study

Year: 2010

Type: article

Abstract: In this study, we investigated the feasibility of modifying 3-Fr IVUS catheters in several designs to potentially achieve minimally-invasive, endovascular access for image-guided ultrasound hyperthermia treatment of tumors in the brain. Using a plane wave approximation, target frequencies of 8.7 and 3.5 MHz were considered optimal for heating at depths (tumor sizes) of 1 and 2.5 cm, respectively. First, a 3.5-Fr IVUS catheter with a 0.7-mm diameter transducer (30 MHz nominal frequency) was driven at 8.6 MHz. Second, for a low-frequency design, a 220-μm-thick, 0.35 x 0.35-mm PZT-4 transducer--driven at width-mode resonance of 3.85 MHz--replaced a 40-MHz element in a 3.5-Fr coronary imaging catheter. Third, a 5 x 0.5-mm PZT-4 transducer was evaluated as the largest aperture geometry possible for a flexible 3-Fr IVUS catheter. Beam plots and on-axis heating profiles were simulated for each aperture, and test transducers were fabricated. The electrical impedance, impulse response, frequency response, maximum intensity, and mechanical index were measured to assess performance. For the 5 x 0.5-mm transducer, this testing also included mechanically scanning and reconstructing an image of a 2.5-cm-diameter cyst phantom as a preliminary measure of imaging potential.

Source: IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control

DOI: 10.1109/tuffc.2010.1723

Authors: Carl D Herickhoff, Gerald A Grant, Gavin W Britz, Stephen W Smith

Institutions: Duke University, Duke Medical Center

Language: English

Topic: Ultrasound and Hyperthermia Applications

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: green

Funder: National Heart, Lung, and Blood Institute