Abstract
Magnetic Resonance Elastography (MRE) quantitatively maps the stiffness of tissues by imaging propagating shear waves induced by mechanical transducers. It has been shown that by using multiple drivers, certain limitations of conventional single driver MRE can be reduced, and that by suitably adjusting the waveforms applied to these drivers, any arbitrary region of interest can be optimally illuminated (wave optimization). Typically these adjustments were derived from wave response data collected for each transducer individually, which increases the total scan time. To address this issue, we investigated the use of time reversal principles to calculate the appropriate waveforms and their potential advantages in MRE exams. A phased array acoustic driver system with four independent 'daughter' transducers was used. An additional shear 'parent' transducer was used to create shear waves at the ROI, and wave propagation data was collected with MRE both in continuous and transient wave mode. From these single source wave data, the appropriate phase and time offset relationships between the daughter transducers were derived. Separate experiments were then carried out driving the daughter transducers with these calculated motions, and wave optimization was achieved in both continuous and transient wave MRE. We conclude that time reversal principles could be used for wave optimization with multiple drivers and could potentially reduce the total scan time.
| Original language | English (US) |
|---|---|
| Title of host publication | Progress in Biomedical Optics and Imaging - Proceedings of SPIE |
| Volume | 6511 |
| Edition | PART 1 |
| DOIs | |
| State | Published - 2007 |
| Event | Medical Imaging 2007: Physiology, Function, and Structure from Medical Images - San Diego, CA, United States Duration: Feb 18 2007 → Feb 20 2007 |
Other
| Other | Medical Imaging 2007: Physiology, Function, and Structure from Medical Images |
|---|---|
| Country | United States |
| City | San Diego, CA |
| Period | 2/18/07 → 2/20/07 |
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Keywords
- Elasticity
- Elastography
- Magnetic resonance elastography
- Shear modulus
- Time reversal
ASJC Scopus subject areas
- Engineering(all)
Cite this
Time reversal principles for wave optimization in multiple driver magnetic resonance elastography. / Mariappan, Yogesh K.; Manduca, Armando; Ehman, Richard Lorne.
Progress in Biomedical Optics and Imaging - Proceedings of SPIE. Vol. 6511 PART 1. ed. 2007. 651119.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Time reversal principles for wave optimization in multiple driver magnetic resonance elastography
AU - Mariappan, Yogesh K.
AU - Manduca, Armando
AU - Ehman, Richard Lorne
PY - 2007
Y1 - 2007
N2 - Magnetic Resonance Elastography (MRE) quantitatively maps the stiffness of tissues by imaging propagating shear waves induced by mechanical transducers. It has been shown that by using multiple drivers, certain limitations of conventional single driver MRE can be reduced, and that by suitably adjusting the waveforms applied to these drivers, any arbitrary region of interest can be optimally illuminated (wave optimization). Typically these adjustments were derived from wave response data collected for each transducer individually, which increases the total scan time. To address this issue, we investigated the use of time reversal principles to calculate the appropriate waveforms and their potential advantages in MRE exams. A phased array acoustic driver system with four independent 'daughter' transducers was used. An additional shear 'parent' transducer was used to create shear waves at the ROI, and wave propagation data was collected with MRE both in continuous and transient wave mode. From these single source wave data, the appropriate phase and time offset relationships between the daughter transducers were derived. Separate experiments were then carried out driving the daughter transducers with these calculated motions, and wave optimization was achieved in both continuous and transient wave MRE. We conclude that time reversal principles could be used for wave optimization with multiple drivers and could potentially reduce the total scan time.
AB - Magnetic Resonance Elastography (MRE) quantitatively maps the stiffness of tissues by imaging propagating shear waves induced by mechanical transducers. It has been shown that by using multiple drivers, certain limitations of conventional single driver MRE can be reduced, and that by suitably adjusting the waveforms applied to these drivers, any arbitrary region of interest can be optimally illuminated (wave optimization). Typically these adjustments were derived from wave response data collected for each transducer individually, which increases the total scan time. To address this issue, we investigated the use of time reversal principles to calculate the appropriate waveforms and their potential advantages in MRE exams. A phased array acoustic driver system with four independent 'daughter' transducers was used. An additional shear 'parent' transducer was used to create shear waves at the ROI, and wave propagation data was collected with MRE both in continuous and transient wave mode. From these single source wave data, the appropriate phase and time offset relationships between the daughter transducers were derived. Separate experiments were then carried out driving the daughter transducers with these calculated motions, and wave optimization was achieved in both continuous and transient wave MRE. We conclude that time reversal principles could be used for wave optimization with multiple drivers and could potentially reduce the total scan time.
KW - Elasticity
KW - Elastography
KW - Magnetic resonance elastography
KW - Shear modulus
KW - Time reversal
UR - http://www.scopus.com/inward/record.url?scp=35148816661&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=35148816661&partnerID=8YFLogxK
U2 - 10.1117/12.710717
DO - 10.1117/12.710717
M3 - Conference contribution
AN - SCOPUS:35148816661
SN - 0819466298
SN - 9780819466297
VL - 6511
BT - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
ER -