Design considerations for ultrasound detectors in photoacoustic breast imaging

TY - CHAP

T1 - Design considerations for ultrasound detectors in photoacoustic breast imaging

AU - Xia, Wenfeng

AU - Piras, Daniele

AU - Singh, Mithun K.A.

AU - Van Hespen, Johan C.G.

AU - Van Veldhoven, Spiridon

AU - Prins, Christian

AU - Van Leeuwen, Ton G.

AU - Steenbergen, Wiendelft

AU - Manohar, Srirang

PY - 2013/5/28

Y1 - 2013/5/28

N2 - The ultrasound detector is the heart of a photoacoustic imaging system. In photoacoustic imaging of the breast there is a requirement to detect tumors located a few centimeters deep in tissue, where the light is heavily attenuated. Thus a sensitive ultrasound transducer is of crucial importance. As the frequency content of photoacoustic waves are inversely proportional to the dimensions of the absorbing structures, and in tissue can range from hundreds of kHz to tens of MHz, a broadband ultrasound transducer is required centered on an optimum frequency. A single element piezoelectric transducer structurally consists of the active piezoelectric material, front- and back-matching layers and a backing layer. To have both high sensitivity and broad bandwidth, the materials, their acoustic characteristics and their dimensions should be carefully chosen. In this paper, we present design considerations of an ultrasound transducer for imaging the breast such as the detector sensitivity and frequency response, which guides the selection of active material, matching layers and their geometries. We iterate between simulation of detector performance and experimental characterization of functional models to arrive at an optimized implementation. For computer simulation, we use 1D KLM and 3D finite-element based models. The optimized detector has a large-aperture possessing a center frequency of 1 MHz with fractional bandwidth of more than 80%. The measured minimum detectable pressure is 0.5 Pa, which is two orders of magnitude lower than the detector used in the Twente photoacoustic mammoscope.

AB - The ultrasound detector is the heart of a photoacoustic imaging system. In photoacoustic imaging of the breast there is a requirement to detect tumors located a few centimeters deep in tissue, where the light is heavily attenuated. Thus a sensitive ultrasound transducer is of crucial importance. As the frequency content of photoacoustic waves are inversely proportional to the dimensions of the absorbing structures, and in tissue can range from hundreds of kHz to tens of MHz, a broadband ultrasound transducer is required centered on an optimum frequency. A single element piezoelectric transducer structurally consists of the active piezoelectric material, front- and back-matching layers and a backing layer. To have both high sensitivity and broad bandwidth, the materials, their acoustic characteristics and their dimensions should be carefully chosen. In this paper, we present design considerations of an ultrasound transducer for imaging the breast such as the detector sensitivity and frequency response, which guides the selection of active material, matching layers and their geometries. We iterate between simulation of detector performance and experimental characterization of functional models to arrive at an optimized implementation. For computer simulation, we use 1D KLM and 3D finite-element based models. The optimized detector has a large-aperture possessing a center frequency of 1 MHz with fractional bandwidth of more than 80%. The measured minimum detectable pressure is 0.5 Pa, which is two orders of magnitude lower than the detector used in the Twente photoacoustic mammoscope.

KW - breast imaging

KW - finite-element method

KW - photoacoustic

KW - ultrasound transducer

UR - http://www.scopus.com/inward/record.url?scp=84878092666&partnerID=8YFLogxK

U2 - 10.1117/12.2004329

DO - 10.1117/12.2004329

M3 - Conference paper

AN - SCOPUS:84878092666

SN - 9780819493507

VL - 8581

BT - Photons Plus Ultrasound

T2 - Photons Plus Ultrasound: Imaging and Sensing 2013

Y2 - 3 February 2013 through 5 February 2013

ER -