SOUND-SPEED TOMOGRAPHY USING FIRST-ARRIVAL TRANSMISSION ULTRASOUND FOR A RING ARRAY

Conference · Wed Jan 31 04:00:00 EST 2007

OSTI ID:985880

HUANG, LIANJIE ^[1]; QUAN, YOULI ^[1]

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1. Los Alamos National Laboratory

Sound-speed tomography images can be used for cancer detection and diagnosis. Tumors have generally higher sound speeds than the surrounding tissue. Quality and resolution of tomography images are primarily determined by the insonification/illumination aperture of ultrasound and the capability of the tomography method for accurately handling heterogeneous nature of the breast. We investigate the capability of an efficient time-of-flight tomography method using transmission ultrasound from a ring array for reconstructing sound-speed images of the breast. The method uses first arrival times of transmitted ultrasonic signals emerging from non-beamforming ultrasound transducers located around a ring. It properly accounts for ray bending within the breast by solving the eikonal equation using a finite-difference scheme. We test and validate the time-of-flight transmission tomography method using synthetic data for numerical breast phantoms containing various objects. In our simulation, the objects are immersed in water within a ring array. Two-dimensional synthetic data are generated using a finite-difference scheme to solve acoustic-wave equation in heterogeneous media. We study the reconstruction accuracy of the tomography method for objects with different sizes and shapes as well as different perturbations from the surrounding medium. In addition, we also address some specific data processing issues related to the tomography. Our tomography results demonstrate that the first-arrival transmission tomography method can accurately reconstruct objects larger than approximately five wavelengths of the incident ultrasound using a ring array.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 985880
• Report Number(s): LA-UR-07-0702
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ACCURACY
APERTURES
BENDING
DATA PROCESSING
DETECTION
DIAGNOSIS
MAMMARY GLANDS
NEOPLASMS
PHANTOMS
RESOLUTION
SIMULATION
TOMOGRAPHY
TRANSDUCERS
ULTRASONIC WAVES
WATER
WAVELENGTHS