Liang, Hai-Dong, Halliwell, M. and Wells, Peter Neil Temple ![]() |
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.
Item Type: | Article |
---|---|
Date Type: | Publication |
Status: | Published |
Schools: | Engineering |
Subjects: | Q Science > QC Physics R Medicine > R Medicine (General) T Technology > TK Electrical engineering. Electronics Nuclear engineering |
Uncontrolled Keywords: | INSPEC Controlled Indexing Doppler shift; acoustic tomography; biomedical ultrasonics; computerised tomography; image reconstruction; medical image processing; ultrasonic equipment; ultrasonic imaging; ultrasonic materials testing; ultrasonic scattering Non Controlled Indexing CW Doppler ultrasound; CW ultrasonic tomography; Doppler-shifted echoes; backscattered echo amplitude; continuous wave US tomography; cross-sectional imaging; line integral; microscanner; resolution limitation; scattering centers; stationary ultrasonic beam; target size; tomographic projection; tomographic reconstruction algorithm; ultrasonic wavelength Medical Subject Heading (MeSH Terms) Algorithms; Anatomy; Cross-Sectional; Image Processing; Computer-Assisted; Phantoms; Imaging; Tomography; X-Ray Computed; Transducers; Ultrasonography; Doppler |
ISSN: | 0885-3010 |
Last Modified: | 17 Oct 2022 09:07 |
URI: | https://orca.cardiff.ac.uk/id/eprint/2114 |
Citation Data
Cited 16 times in Scopus. View in Scopus. Powered By Scopus® Data
Actions (repository staff only)
![]() |
Edit Item |