Angled-focused 45 MHz PMN-PT single element transducer for intravascular ultrasound imaging.
A transducer with an angled and focused aperture for intravascular ultrasound imaging has been developed. The acoustic stack for the angled-focused transducer was made of PMN-PT single crystal with one matching layer, one protective coating layer, and a highly damped backing layer. It was then press-focused to a desired focal length and inserted into a thin needle housing with an angled tip. A transducer with an angled and unfocused aperture was also made, following the same fabrication procedure, to compare the performance of the two transducers. The focused and unfocused transducers were tested to measure their center frequencies, bandwidths, and spatial resolutions. Lateral resolution of the angled-focused transducer (AFT) improved more than two times compared to that of the angled-unfocused transducer (AUT). A tissue-mimicking phantom in water and a rabbit aorta tissue sample in rabbit blood were scanned using AFT and AUT. Imaging with AFT offered improved contrast, over imaging with AUT, of the tissue-mimicking phantom and the rabbit aorta tissue sample by 23 dB and 8 dB, respectively. The results show that AFT has strong potential to provide morphological and pathological information of coronary arteries with high resolution and high contrast.
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
Sangpil
S
Yoon
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
Jay
J
Williams
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
Bong Jin
BJ
Kang
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
Changhan
C
Yoon
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
Nestor
N
Cabrera-Munoz
Department of Medical Biotechnology, Dongguk University, Seoul 100-715, Republic of Korea.
Jong Seob
JS
Jeong
IBULE Photonics Co., Ltd., Incheon, Republic of Korea.
Sang Goo
SG
Lee
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA.
K Kirk
KK
Shung
Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA ; Analogic Corporation, Peabody, MA 01960, USA.
Hyung Ham
HH
Kim
Angled-focused transducer; Contrast; Coronary stenosis evaluation; High frequency transducer; Intravascular ultrasound (IVUS) imaging; Rabbit aorta