CONTACT

urvivyas[at]stanford.edu

Department of Radiology
Stanford University
1201 Welch Road
Palo Alto, CA


RESEARCH INTERESTS

Biomedical Engineering, Medical Devices, Medical Imaging, Image Processing and Analysis, Ultrasound, MRI, Mathematical Modeling, Algorithms, Optimization, Simulations, Medical Physics

SUMMARY

My research focuses on developing algorithms for pre and post treatment planning for MR-guided focused ultrasound surgery. For my PhD work at the University of Utah, I developed rapid techniques for modeling ultrasound beam simulation in 3D inhomogeneous tissue geometries. These fast and accurate beam simulation techniques were used to develop treatment plans for MRgFUS, investigate effects of spatial sampling choices on MR temperature measurements, and to develop improved methods for monitoring MR-guided treatments. Further, I developed a parameter estimation technique using optimization routines to probe changes in acoustic properties of tissues after MRgFUS treatments and demonstrated this non-invasive technique for the first time in-vivo. My dissertation work thus involved building broad expertise on MR-guided focused ultrasound treatment. As a postdoctoral research fellow at Stanford University, I have combined my skills in beam modeling, imaging and optimization with complementary techniques in MR-ARFI applications to develop techniques for phase aberration correction. Recently we demonstrated a technique that used simulations and MR-ARFI with pre-treatment imaging-derived aberrations to achieve phase correction with the overall goal of reducing both pre-treatment ultrasound and CT dose. Combining information from simulations with experimental measurements and guidance from MR images (like MR-ARFI and UTE) has the potential of improving pre- and post-treatment planning, reducing CT dose to patients and thus significantly improving the safety and accessibility of MRgFUS treatments.

EXPERIENCE

June 2013- Present           Research Associate
                                            Department of Radiology, Stanford University

Oct 2011-June 2013          Post Doctoral Research Fellow
                                           Department of Radiology, Stanford University

June 2012- Dec 2012        Project Manager
                                           
 Quality Improvement, Stanford Hospital and Clinics

Aug 2006-2011                Graduate Research Assistant
                                            Department of Bioengineering, University of Utah


EDUCATION 

2011-2013                        Post-Doctoral Research Fellow, Stanford University
                                            Department of Radiology
2006-2011                        PhD in Bioengineering, University of Utah 
                                            Bioinstrumentation and Imaging Track 
2002-2006                        Bachelor of Engineering in Biomedical Engineering
                                             Shree Govindram Sekseria Institute of Technology and Science (SGSITS), Indore,India

AWARDS 

2013- Highly Cited Article IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, Ultrasound Beam Simulations in Inhomogeneous Tissue Geometries Using the Hybrid Angular Spectrum Method, November

2013- Editor’s Selection of Highly Cited Articles in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, July

2013- Recipient of the Brain Program Contract Award ($100,000) from the Focused Ultrasound Surgery Foundation for work on Phase Aberration Correction for Transcranial Ultrasound Surgery

2011-Finalist Graduate Student Paper Award, International Society of Therapeutic Ultrasound 

2010-Recipient of the Young Investigator Award at the 2nd International Symposium on MR-guided Focused Ultrasound, Washington, DC, USA

2010-Recipient of the New Investigator Award at the Society of Thermal Medicine Annual Meeting in Clearwater, Florida.

2008-Recipient of the Best Poster Award at the 4th Annual Mountain West Biomedical Engineering Conference, Park City, Utah.


TEACHING AND PROFESSIONAL SERVICE

2011-Present                   Reviewer: Journal of Acoustical Society of America (JASA), IEEE Signal Processing                                                       Society and Focused Ultrasound Surgery Foundation
Fall 2012, 2013                Lecturer, Ultrasound Imaging and Therapeutic Applications
                                            Stanford University, Department of  Radiology/Bioengineering (RAD 225, BIOEN 224)
Spring 2013, 2014            Guest Lecturer, Interventional MRI Diagnostic Devices
                                            Stanford University, Department of Bioengineering (BIOE301C)
Aug 2009- Dec 2009          Graduate Teaching Assistant, Ultrasound Physics
                                            University of Utah, Department of Bioengineering/Electrical Engineering (BIOEN 5490)

PEER-REVIEWED PUBLICATIONS (updated list and citation index at the Google Scholar Link)

1. U Vyas, E Kaye, KB Pauly, "Transcranial phase aberration correction using beam simulations and MR-ARFI", Medical Physics, 2014 Mar;41(3):032901. doi: 10.1118/1.4865778

2. U Vyas, DA Christensen, "Ultrasound beam simulation in inhomogeneous tissue geometries using the hybrid angular spectrum method", Ultrasonics, Ferroelectrics and Frequency Control, IEEE Transactions on, 59 (6): 1093-100, 2012

3. U Vyas, DA Christensen, "Extension of the angular spectrum method to calculate pressure from a spherically curved acoustic source" The Journal of the Acoustical Society of America 134 (5), 4183-4183, 2011

4. U Vyas, E Kaye, KB Pauly, "Transcranial phase aberration correction using beam simulations and MR-ARFI", AIP Conference Proceedings 1503, 185, 2012 

5. A Payne, R Merrill , E Minalga, U Vyas, J Bever, N Todd, R Hadley, E Dumont, L Neumayer, DA Christensen, R Roemer, DL Parker, "Design and characterization of a laterally mounted phased-array transducer breast-specific MRgHIFU device with integrated 11-channel receiver array." Medical Physics, 39, 1552, 2012

6. U Vyas, A Payne, N Todd, DL Parker, RB Roemer, DA Christensen, "Non-invasive patient-specific acoustic property estimation for MR-guided focused ultrasound surgery", AIP Conference Proceedings 1481, 419, 2012

7. N. Todd, U Vyas, J Bever, A Payne, DL Parker, "Reconstruction of fully 3-D high spatial and temporal resolution MR temperature maps for retrospective applications", Magnetic Resonance in Medicine, 67(3), 724-730, 2012

8. CR Dillon, U Vyas, A Payne, DA Christensen, RB Roemer, "An analytical solution for improved HIFU SAR estimation", Physics in Medicine and Biology 57 (14), 4527, 2012

9. A Payne, U Vyas, N Todd, J Bever, DA Christensen, DL Parker, "The effect of electronically steering a phased array ultrasound transducer on near-field tissue heating", Medical Physics 38, 4971, 2011

10.  N Todd, U Vyas, J Bever, A Payne, DL Parker, "The Effects of Spatial Sampling Choices on MR Temperature Measurements", Magnetic Resonance in Medicine, 65(2):515-521. 2011

11.U Vyas, A Payne, N Todd, DL Parker, RB Roemer, DA Christensen, "Changes in attenuation coefficient in MRgFUS treatments of in-vivo rabbit thigh estimated using MRTI-derived specific absorption rate patterns", International Society of Magnetic Resonance in Medicine Conference Proceedings, 19, 2011

12. A Payne, U Vyas, A Blankespoor, DA Christensen, RB Roemer, "Minimization of HIFU Pulse Heating and Inter-pulse Cooling Times", International Journal of Hyperthermia, 26(2):198-208. 2010

13. U Vyas, DA Christensen, "Ultrasound beam propagation using the hybrid angular spectrum method", Engineering in Medicine and Biology Society, 2008

14. Todd N, Vyas U, de Bever J, Payne A, Parker DL, “3D volume MR temperature mapping for HIFU heating trajectory comparisons”, AIP Conf Proc, 1481, 388

15. Todd N, Vyas U, Payne A, Christensen DA, Parker DL, “Combining thermal and ultrasound modeling techniques for improved monitoring of MR-guided HIFU treatments” AIP Conf Proc, 1215, 375-378. 2010

16.Payne A, Vyas U, Todd N, de Bever J, Christensen DA, Parker DL, “The Effect of Electronically Steering a Phased Array on Proximal Tissue Heating”, AIP Conf Proc, 1215, 145-148. 2010


SELECTED CONFERENCE PRESENTATIONS

Urvi Vyas, Ethan M Johnson, John Pauly and Kim Butts Pauly, " 3D UTE Imaging for Phase Aberration Correction for Transcranial MR-guided Focused Ultrasound Surgery: Comparison of the segmented bone contours and corrected phases with CT", International Society of Magnetic Resonance in Medicine, Milan, 2014

Urvi Vyas and Kim Butts Pauly, " Rapid aberration correction for transcranial magnetic resonance-guided focused ultrasound surgery using a hybrid simulation and magnetic resonance-acoustic radiation force imaging method" Acoustic Society of America, San Francisco, 2013

Urvi Vyas, Ethan Johnson, Micheal Marx, John Pauly, Kim Butts Pauly, " Effect of additional anatomical features of the head from high resolution 3D UTE images on focal intensity and location for Transcranial MR-guided Focused Ultrasound Surgery", International Society of Magnetic Resonance in Medicine, Salt Lake City, 2013

Urvi Vyas, Elena Kaye, Kim Butts Pauly, " Phase aberration correction for transcranial MRgFUS using a hybrid simulation and MR-ARFI method" 
International Society for Therapeutic Ultrasound, Germany, 2012

Urvi Vyas, Allison Payne, Nick Todd, Dennis L. Parker, Bob Roemer, Douglas A. Christensen, "Urvi Vyas, Allison Payne, Nick Todd, Dennis L. Parker, Bob Roemer, Douglas A. Christensen", Abstract 107, Focused Ultrasound Surgery Foundation Symposium, 2011

Urvi Vyas, Allison Payne, Nick Todd, Dennis L. Parker, Bob Roemer, Douglas A. Christensen," Change in attenuation coefficient with MRgFUS treatment in in-vivo rabbit thigh with MRTI derived specific absorption rate patterns", 
International Society of Magnetic Resonance in Medicine, Montreal, 2011

Urvi Vyas, Allison Payne, Nick Todd, Dennis Parker, Bob Roemer and Douglas Christensen, "A new technique for measuring changes in tissue acoustic properties using MR temperature mapping", Society for Thermal Medicine, Clearwater Beach, Florida, April, 2010.

Urvi Vyas, Douglas Christensen, "Fast ultrasound beam simulation in inhomogeneous tissue geometries for MRI-guided HIFU," International Society for Therapeutic Ultrasound, Aix-en-Provence, France, 2009.

Urvi Vyas, Christensen DA, “Ultrasound Beam Propagation using the Hybrid Angular Spectrum Method”, Conf Proc IEEE Eng Med Biol Soc, 2526-9. 2008

Urvi Vyas, Robert Roemer, Dennis Parker, Douglas Christensen, "Beam Propagation for HIFU Using the Hybrid Angular Spectrum Method", International Society for Therapeutic Ultrasound, Minneapolis, 2008.

Allison Payne, Urvi Vyas, Douglas Christensen, Dennis Parker, Robert Roemer, "Optimization of HIFU treatments for use in model predictive control", International Society for Therapeutic Ultrasound, Minneapolis, 2008.

Urvi Vyas, Douglas Christensen, "Extending Angular Spectrum to Curved Surfaces", 4th Annual Mountain West Biomedical Engineering Conference September, 2008, Park City, Utah.



Department of RadiologyRichard M. Lucas Center for Imaging, Stanford University, CA