TY - JOUR
T1 - Dual-mode IVUS catheter for intracranial image-guided hyperthermia
T2 - Feasibility study
AU - Herickhoff, Carl D.
AU - Grant, Gerald A.
AU - Britz, Gavin W.
AU - Smith, Stephen W.
N1 - Funding Information:
manuscript received october 20, 2009; accepted July 8, 2010. This research was supported by a 2008 chandran Family Foundation research award, and nIH grant Hl089507. c. d. Herickhoff and s. W. smith are with the department of biomedical Engineering, duke University, durham, nc (e-mail: carl.herick-hoff@duke.edu). G. a. Grant and G. W. britz are with the division of neurosurgery, duke University medical center, durham, nc. digital object Identifier 10.1109/TUFFc.2010.1723
PY - 2010/11
Y1 - 2010/11
N2 - In this study, we investigated the feasibility of modifying 3-Fr IVUS catheters in several designs to potentially achieve minimally-invasive, endovascular access for imageguided 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-m-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.
AB - In this study, we investigated the feasibility of modifying 3-Fr IVUS catheters in several designs to potentially achieve minimally-invasive, endovascular access for imageguided 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-m-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.
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U2 - 10.1109/TUFFC.2010.1723
DO - 10.1109/TUFFC.2010.1723
M3 - Article
C2 - 21041144
AN - SCOPUS:78149242369
SN - 0885-3010
VL - 57
SP - 2572
EP - 2584
JO - IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
JF - IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
IS - 11
M1 - 5611704
ER -