TY - GEN
T1 - Quadratic B-mode and pulse inversion imaging of thermally-induced lesions In Vivo
AU - Ebbini, Emad S
AU - Bischof, John C
AU - Visaria, Rachana K.
AU - Shrestha, Ajay
PY - 2007/11/27
Y1 - 2007/11/27
N2 - Ultrasound is a leading image-guidance modality for noninvasive surgery using high intensity focused ultrasound (HIFU). Its low cost and portability, together with its high frame rates, are among its well-known advantages. However, ultrasound's poor soft-tissue contrast continues to limit the specificity of image feedback on local tissue changes due to the application of HIFU beams. This limitation is being addressed by developing nonlinear pulse-echo imaging methods for monitoring of lesion formation with HIFU. In this paper, we provide the first in vivo results from an investigation of two nonlinear methods for this purpose. Specifically, pulse inversion (PI) and quadratic B-mode (QB-mode) are compared with standard B-mode imaging. An integrated system employing a HIFU transducer and a diagnostic scanner was used. Beam-formed RF data was acquired in real-time before, during, and after HIFU-lesion formation and processed off-line to produce B-mode, PI-mode, and QB-mode images for comparison. The imaging target was a LNCaP Pro 5 human prostate tumor implanted in the hind limb of nude mice and carefully positioned at the intersection of the imaging plane and the HIFU focus. The results show clearly that both QB-mode and PI-mode improve the lesion contrast compared to standard B-mode (6 dB or more for typical lesions). The results also show that QB-mode offers the advantage of improved dynamic range when compared to PI-mode imaging (by 30 dB or higher). These in vivo results show that QB-mode imaging offers a guidance modality with high sensitivity and specificity to tissue changes at the therapeutic HIFU focus without loss in spatial resolution.
AB - Ultrasound is a leading image-guidance modality for noninvasive surgery using high intensity focused ultrasound (HIFU). Its low cost and portability, together with its high frame rates, are among its well-known advantages. However, ultrasound's poor soft-tissue contrast continues to limit the specificity of image feedback on local tissue changes due to the application of HIFU beams. This limitation is being addressed by developing nonlinear pulse-echo imaging methods for monitoring of lesion formation with HIFU. In this paper, we provide the first in vivo results from an investigation of two nonlinear methods for this purpose. Specifically, pulse inversion (PI) and quadratic B-mode (QB-mode) are compared with standard B-mode imaging. An integrated system employing a HIFU transducer and a diagnostic scanner was used. Beam-formed RF data was acquired in real-time before, during, and after HIFU-lesion formation and processed off-line to produce B-mode, PI-mode, and QB-mode images for comparison. The imaging target was a LNCaP Pro 5 human prostate tumor implanted in the hind limb of nude mice and carefully positioned at the intersection of the imaging plane and the HIFU focus. The results show clearly that both QB-mode and PI-mode improve the lesion contrast compared to standard B-mode (6 dB or more for typical lesions). The results also show that QB-mode offers the advantage of improved dynamic range when compared to PI-mode imaging (by 30 dB or higher). These in vivo results show that QB-mode imaging offers a guidance modality with high sensitivity and specificity to tissue changes at the therapeutic HIFU focus without loss in spatial resolution.
KW - Biomedical acoustic imaging
KW - Contrast enhancement
KW - Nonlinear acoustics
KW - Nonlinear filters
UR - http://www.scopus.com/inward/record.url?scp=36349003518&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=36349003518&partnerID=8YFLogxK
U2 - 10.1109/ISBI.2007.357053
DO - 10.1109/ISBI.2007.357053
M3 - Conference contribution
AN - SCOPUS:36349003518
SN - 1424406722
SN - 9781424406722
T3 - 2007 4th IEEE International Symposium on Biomedical Imaging: From Nano to Macro - Proceedings
SP - 1120
EP - 1123
BT - 2007 4th IEEE International Symposium on Biomedical Imaging
T2 - 2007 4th IEEE International Symposium on Biomedical Imaging: From Nano to Macro; ISBI'07
Y2 - 12 April 2007 through 15 April 2007
ER -