Journal article
Compounding in synthetic aperture imaging
A method for obtaining compound images using synthetic aperture data is investigated using a convex array transducer. The new approach allows spatial compounding to be performed for any number of angles without reducing the frame rate or temporal resolution. This important feature is an intrinsic property of how the compound images are constructed using synthetic aperture data and an improvement compared with how spatial compounding is obtained using conventional methods.
The synthetic aperture compound images are created by exploiting the linearity of delay-and-sum beamformation for data collected from multiple spherical emissions to synthesize multiple transmit and receive apertures, corresponding to imaging the tissue from multiple directions. The many images are added incoherently, to produce a single compound image.
Using a 192-element, 3.5-MHz, λ-pitch transducer, it is demonstrated from tissue-phantom measurements that the speckle is reduced and the contrast resolution improved when applying synthetic aperture compound imaging. At a depth of 4 cm, the size of the synthesized apertures is optimized for lesion detection based on the speckle information density.
This is a performance measure for tissue contrast resolution which quantifies the tradeoff between resolution loss and speckle reduction. The speckle information density is improved by 25% when comparing synthetic aperture compounding to a similar setup for compounding using dynamic receive focusing.
The cystic resolution and clutter levels are measured using a wire phantom setup and compared with conventional application of the array, as well as to synthetic aperture imaging without compounding. If the full aperture is used for synthetic aperture compounding, the cystic resolution is improved by 41% compared with conventional imaging, and is at least as good as what can be obtained using synthetic aperture imaging without compounding.
Language: | English |
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Publisher: | IEEE |
Year: | 2012 |
Pages: | 2054-2065 |
ISSN: | 15258955 and 08853010 |
Types: | Journal article |
DOI: | 10.1109/TUFFC.2012.2427 |
ORCIDs: | Jensen, J. A. |
Apertures Artifacts Compounds Focusing Image Processing, Computer-Assisted Models, Biological Phantoms, Imaging Signal-To-Noise Ratio Speckle Transducers Ultrasonography biological tissues biomedical transducers biomedical ultrasonics clutter levels conventional methods convex array transducer cystic resolution delay-and-sum beamformation depth 4 cm frame rate frequency 3.5 MHz image resolution medical ultrasound multiple spherical emissions multiple transmit aperture phantoms receive aperture spatial compounding speckle information density synthetic aperture imaging data temporal resolution tissue contrast resolution tissue imaging tissue-phantom measurements wire phantom setup λ-pitch transducer