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PubMed · 11367797

Continuous wave ultrasonic tomography.

H D Liang·M Halliwell·P N Wells
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Abstract

As an object rotates with respect to a stationary ultrasonic beam, the scattering centers within the object return echoes that are Doppler-shifted in frequency by amounts depending on the velocities of the individual scatterers. The scattering centers that lie on a line of constant cross-range all have the same effective velocity in the direction pointing toward the transducer; therefore, the backscattered echo amplitude at any particular frequency is the line integral of the scattered radiation at the cross-range corresponding to that frequency. The amplitudes of the returned signals at other frequencies give the line integrals for the scatterers at the corresponding cross-ranges. The amplitude as a function of frequency can be interpreted as a tomographic projection. A continuum of the projections at different positions is generated while the object is rotating. A tomographic reconstruction algorithm can produce an image of the distribution of scattering centers in the insonified object from these projections. A microscanner was developed to investigate the approach of using continuous wave (CW) ultrasound for cross-sectional imaging. The resolution is limited by the target size and the ultrasonic wavelength.

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AlgorithmsAnatomy, Cross-SectionalImage Processing, Computer-AssistedPhantoms, ImagingTomography, X-Ray ComputedTransducersUltrasonography, DopplerJournal ArticleResearch Support, Non-U.S. Gov't

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BibTeXRIS

H D Liang, M Halliwell, P N Wells. 2001. Continuous wave ultrasonic tomography.. https://doi.org/10.1109/58.896141

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