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- Jansson, Tomas, et al.
(author)
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Ultrasound Doppler Vector Tomography - Measurements of Directional Blood Flow
- 1997
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In: Ultrasound in Medicine and Biology. - 0301-5629. ; 23:1, s. 47-57
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Journal article (peer-reviewed)abstract
- An experimental system has been developed to verify the possibility of detecting flow activity using a technique called ultrasound Doppler vector tomography. A tomography algorithm is used to reconstruct blood flow vector fields using data from computer-controlled ultrasound continuous-wave Doppler scanning equipment. The result is a picture in which the brightness variations represent the reconstructed values of the curl of the velocity field (del x v). Continuous ultrasound is transmitted into a region with flow activity and the Doppler-shifted signals are received. To obtain measurement data suited for fan beam tomography, the scanning is performed in a plane from points encircling the region. Reconstructions have been achieved using measurement data from two different flow phantoms. A comparison between the experimental results and simulations shows good conformity. Copyright (C) 1997 World Federation for Ultrasound in Medicine & Biology.
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| 2. |
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| 3. |
- Stråhlén, Kent, et al.
(author)
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Exponential Vector Field Tomography
- 1997
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In: Lecture Note in Computer Science. V. 1311. - 3 540 63508 4 ; 2, s. 348-355
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Conference paper (other academic/artistic)abstract
- In the exponential Radon transform in R2, the integrals of a scalar function f over lines, with exponential weight functions, are determined. We demonstrate how to define two different kinds of exponential Radon transforms for vector fields in R2 in a natural way. It is shown that having data from these transforms it is possible to reconstruct the vector field uniquely. The motivation for the study of this problem is ultrasound measurements of flows, from which velocity spectra along lines can be determined. The first moment of these can be interpreted by means of one of the exponential vectorial Radon transforms
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