Error analysis of speed of sound reconstruction in ultrasound limited angle transmission tomography

Rungroj Jintamethasawat; Won-Mean Lee; Paul L Carson; Fong Ming Hooi; J Brian Fowlkes; Mitchell M Goodsitt; Richard Sampson; Thomas F Wenisch; Siyuan Wei; Jian Zhou; Chaitali Chakrabarti; Oliver D Kripfgans

doi:10.1016/j.ultras.2018.03.016

Error analysis of speed of sound reconstruction in ultrasound limited angle transmission tomography

Ultrasonics. 2018 Aug:88:174-184. doi: 10.1016/j.ultras.2018.03.016. Epub 2018 Apr 7.

Authors

Affiliations

¹ Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address: rungroj@umich.edu.
² Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA; GE Healthcare, 447 Indio Way, Sunnyvale, CA 94085, USA.
³ Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
⁴ Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA; Siemens Medical Solutions USA, Inc., 22010 South East 51st Street, Issaquah, WA 98029-7002, USA.
⁵ Department of Radiology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109, USA.
⁶ Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI 48109, USA.
⁷ School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287, USA.

PMID: 29674228
DOI: 10.1016/j.ultras.2018.03.016

Abstract

We have investigated limited angle transmission tomography to estimate speed of sound (SOS) distributions for breast cancer detection. That requires both accurate delineations of major tissues, in this case by segmentation of prior B-mode images, and calibration of the relative positions of the opposed transducers. Experimental sensitivity evaluation of the reconstructions with respect to segmentation and calibration errors is difficult with our current system. Therefore, parametric studies of SOS errors in our bent-ray reconstructions were simulated. They included mis-segmentation of an object of interest or a nearby object, and miscalibration of relative transducer positions in 3D. Close correspondence of reconstruction accuracy was verified in the simplest case, a cylindrical object in homogeneous background with induced segmentation and calibration inaccuracies. Simulated mis-segmentation in object size and lateral location produced maximum SOS errors of 6.3% within 10 mm diameter change and 9.1% within 5 mm shift, respectively. Modest errors in assumed transducer separation produced the maximum SOS error from miscalibrations (57.3% within 5 mm shift), still, correction of this type of error can easily be achieved in the clinic. This study should aid in designing adequate transducer mounts and calibration procedures, and in specification of B-mode image quality and segmentation algorithms for limited angle transmission tomography relying on ray tracing algorithms.

Keywords: Breast ultrasound; Medical imaging; Medical transducers.

MeSH terms

Algorithms
Breast Neoplasms / diagnostic imaging*
Calibration
Computer Simulation
Equipment Design
Humans
Image Enhancement / methods
Image Interpretation, Computer-Assisted / methods
Multimodal Imaging*
Phantoms, Imaging
Sensitivity and Specificity
Tomography, X-Ray / methods*
Transducers
Ultrasonography, Mammary / methods*