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Rizwan Ahmad

  • Assistant Professor, Biomedical Engineering
  • Assistant Professor, Electrical & Computer Engr.
  • 1080 Carmack Rd
    Columbus, OH 43210

About

Education

PhD: Ohio State University, Department of Electrical and Computer Engineering, 2007

MS: Electrical and Computer Engineering, The Ohio State University, March 2004

BS: (with honors) in Electrical Engineering, University of Engineering & Tech., Lahore, Pakistan, December 2000

Areas of Interest

Ahmad's research aims to bring engineering innovations to biomedical imaging. He is particularly interested in developing data acquisition and image reconstruction methods that improve diagnostic accuracy of established or emerging imaging modalities. His research expertise encompasses digital signal and image processing, tomographic reconstruction, linear and nonlinear inverse problems, statistical sensitivity analysis, multimodal imaging, and biomedical instrumentation, with application to magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) spectroscopy and imaging.

Office

126A Tzagournis Medical Research Facility, 420 W 12th Avenue, Columbus OH, 43210

 

Honors

  • 20170401

    Power pitch (awarded to top 2.7% abstracts).

  • 20170401

    Lumley Research Award.

  • 20160201

    Power pitch (awarded to top 2.7% abstracts).

  • 20150601

    Show and Tell (top 10% of the conference papers).

  • 20150501

    Distinguished reviewer.

  • 20150201

    Power pitch (awarded to top 2.7% abstracts).

  • 20140501

    Distinguished reviewer.

  • 20121001

    Poster competition at annual research retreat (1st place).

  • 20110401

    Lumley Interdisciplinary Research Award.

  • 20091001

    Poster competition at annual research retreat (2nd place).

  • 20050401

    Young researcher award.

  • 20001201

    Top-ten student in the department.

Chapters

2017

  • 2017. "Recovering Signals with Unknown Sparsity in Multiple Dictionaries." In Compressed Sensing and its Applications. Applied and Numerical Harmonic Analysis, edited by Boche, H.; Caire, G.; Calderbank, R.; März, M.; Kutyniok, G.; Mathar, R.,

2011

  • Ahmad, R.; Kuppusmay, P.. 2011. "EPR Imaging: Theory and Instrumentation." edited by Misra, S.K.; Misra, S.K.,

2010

  • Ahmad, R.; Khan, M.; Vikram, D.S.; Bratasz, A. et al.. 2010. "EPR Oximetry: Method and Application." edited by Das, D.K.; Das, D.K.,

Journal Articles

2018

  • Ahmad, R.; Hu, H.H.; Krishnamurthy, R.; Krishnamurthy, R., 2018, "Reducing sedation for pediatric body MRI using accelerated and abbreviated imaging protocols.." Pediatric radiology 48, no. 1, 37-49 - 37-49.
  • Ebersole, C.; Ahmad, R.; Rich, A.V.; Potter, L.C. et al., 2018, "A bayesian method for accelerated magnetic resonance elastography of the liver." Magnetic Resonance in Medicine

2017

  • da Silveira, J.S.; Smyke, M.; Rich, A.V.; Liu, Y. et al., 2017, "Quantification of aortic stenosis diagnostic parameters: comparison of fast 3 direction and 1 direction phase contrast CMR and transthoracic echocardiography.." Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance 19, no. 1, 35 - 35.
  • Ting, S.T.; Ahmad, R.; Jin, N.; Craft, J. et al., 2017, "Fast implementation for compressive recovery of highly accelerated cardiac cine MRI using the balanced sparse model." Magnetic Resonance in Medicine 77, no. 4, 1505-1515 - 1505-1515.
  • Simonetti, O.P.; Ahmad, R., 2017, "Low-Field Cardiac Magnetic Resonance Imaging: A Compelling Case for Cardiac Magnetic Resonance's Future.." Circulation. Cardiovascular imaging 10, no. 6,
  • Varghese, J.; Potter, L.C.; LaFountain, R.; Pan, X. et al., 2017, "CMR-based blood oximetry via multi-parametric estimation using multiple T2 measurements.." Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance 19, no. 1, 88 - 88.

2016

  • Rich, A.V.; Potter, L.C.; Jin, N.; Ash, J. et al., 2016, "A Bayesian model for highly accelerated phase-contrast MRI.." Magnetic resonance in medicine 76, no. 2, 689-701 - 689-701.
  • Ahmad, R.; Samouilov, A.; Zweier, J.L., 2016, "Accelerated dynamic EPR imaging using fast acquisition and compressive recovery.." Journal of magnetic resonance (San Diego, Calif. : 1997) 273, 105-112 - 105-112.

2015

  • Ding, Y.; Xue, H.; Ahmad, R.; Chang, T. et al., 2015, "Paradoxical effect of the signal-to-noise ratio of GRAPPA calibration lines: A quantitative study." Magnetic Resonance in Medicine 74, no. 1, 231-239 - 231-239.
  • Wolfson, H.; Ahmad, R.; Twig, Y.; Wiliams, B. et al., 2015, "A magnetic resonance probehead for evaluating the level of ionizing radiation absorbed in human teeth.." Health Physics 108, no. 3, 326-335 - 326-335.
  • Ahmad, R.; Schniter, P., 2015, "Iteratively Reweighted L1 Approaches to Sparse Composite Regularization." IEEE Transactions on Computational Imaging 1, no. 4, 220-235 - 220-235.
  • Ahmad, R.; Xue, H.; Giri, S.; Ding, Y. et al., 2015, "Variable density incoherent spatiotemporal acquisition (VISTA) for highly accelerated cardiac MRI.." Magnetic resonance in medicine 74, no. 5, 1266-78 - 1266-78.
  • Serafim, J.; Smyke, M.; Jin, N.; Ahmad, R. et al., 2015, "Aortic Stenosis assessment with a 3-directional phase contrast magnetic resonance technique . Comparison to transthoracic echocardiography." Journal of Cardiovascular Magnetic Resonance 17, no. Suppl 1, P381-P381 - P381-P381.
  • Ahmad, R.; Ding, Y.; Simonetti, O.P., 2015, "Edge Sharpness Assessment by Parametric Modeling: Application to Magnetic Resonance Imaging.." Concepts in magnetic resonance. Part A, Bridging education and research 44, no. 3, 138-149 - 138-149.

2014

  • Johnson, D.H.; Ahmad, R.; Liu, Y.; Chen, Z. et al., 2014, "Uniform spinning sampling gradient electron paramagnetic resonance imaging." Magnetic Resonance in Medicine 71, no. 2, 893-900 - 893-900.
  • Johnson, D.H.; Ahmad, R.; He, G.; Samouilov, A. et al., 2014, "Compressed sensing of spatial electron paramagnetic resonance imaging.." Magnetic Resonance in Medicine 72, no. 3, 893-901 - 893-901.
  • Gungor, D.; Ahmad, R.; Potter, L.C., 2014, "A subspace approach to blind coil sensitivity estimation in parallel MRI." Journal of Cardiovascular Magnetic Resonance 16, no. Suppl 1, W1-W1 - W1-W1.
  • Wolfson, H.; Ahmad, R.; Twig, Y.; Kuppusamy, P. et al., 2014, "A Miniature Electron Spin Resonance Probehead for Transcutaneous Oxygen Monitoring." Applied Magnetic Resonance 45, no. 10, 955-967 - 955-967.

2013

  • Golub, F.; Potter, L.C.; Ash, J.N.; Blank, A. et al., 2013, "Estimation of spin-echo relaxation time.." Journal of magnetic resonance (San Diego, Calif. : 1997) 237, 17-22 - 17-22.
  • Bender, J.A.; Ahmad, R.; Simonetti, O.P., 2013, "The importance of k -space trajectory on off-resonance artifact in segmented echo-planar imaging." Concepts in Magnetic Resonance Part A 42A, no. 2, 23-31 - 23-31.
  • 2013, "Estimation of Spin-Echo Relaxation Time." Journal of Magnetic Resonance 237,

2012

  • Ahmad, R.; Potter, L.C.; Khramtsov, V.V., 2012, "Spectral modeling for accelerated pH spectroscopy using EPR.." Journal of magnetic resonance (San Diego, Calif. : 1997) 218, 86-92 - 86-92.
  • 2012, Multisite EPR oximetry from multiple quadrature harmonics. Journal of Magnetic Resonance 214, no. 1,
  • 2012, Spectral modeling for accelerated pH spectroscopy using EPR. Journal of Magnetic Resonance 218,
  • Palmer, J.; Potter, L.C.; Johnson, D.H.; Zweier, J.L. et al., 2012, "Dual-scan acquisition for accelerated continuous-wave EPR oximetry.." Journal of magnetic resonance (San Diego, Calif. : 1997) 222, 53-58 - 53-58.
  • Ahmad, R.; Som, S.; Johnson, D.H.; Zweier, J.L. et al., 2012, "Multisite EPR oximetry from multiple quadrature harmonics.." Journal of magnetic resonance (San Diego, Calif. : 1997) 214, no. 1, 135-143 - 135-143.
  • Ding, Y.; Xue, H.; Ahmad, R.; Ting, S.T. et al., 2012, "SC-GRAPPA: Self-constraint noniterative GRAPPA reconstruction with closed-form solution." Medical Physics 39, no. 12, 7686-7693 - 7686-7693.
  • 2012, Dual-scan acquisition for accelerated continuous-wave EPR oximetry. Journal of Magnetic Resonance 222,

2011

  • Palmer, J.; Potter, L.C.; Ahmad, R., 2011, "Optimization of magnetic field sweep and field modulation amplitude for continuous-wave EPR oximetry.." Journal of magnetic resonance (San Diego, Calif. : 1997) 209, no. 2, 337-340 - 337-340.
  • 2011, "Optimization of magnetic field sweep and field modulation amplitude for CW EPR oximetry." Journal of Magnetic Resonance 209, no. 2,

2010

  • Ahmad, R.; Som, S.; Kesselring, E.; Kuppusamy, P. et al., 2010, "Digital detection and processing of multiple quadrature harmonics for EPR spectroscopy.." Journal of magnetic resonance (San Diego, Calif. : 1997) 207, no. 2, 322-331 - 322-331.
  • Ahmad, R.; Caia, G.; Potter, L.C.; Petryakov, S. et al., 2010, "In vivo multisite oximetry using EPR-NMR coimaging.." Journal of magnetic resonance (San Diego, Calif. : 1997) 207, no. 1, 69-77 - 69-77.
  • 2010, Digital detection and processing of multiple quadrature harmonics for EPR spectroscopy. Journal of Magnetic Resonance 207, no. 2,
  • Ahmad, R.; Kuppusamy, P., 2010, "Theory, instrumentation, and applications of electron paramagnetic resonance oximetry." Chemical Reviews 110, no. 5, 3212-3236 - 3212-3236.
  • 2010, In vivo multisite oximetry using EPR-NMR coimaging. Journal of Magnetic Resonance 207, no. 1,

2008

  • Ahmad, R.; Vikram, D.S.; Potter, L.C.; Kuppusamy, P., 2008, "Estimation of mean and median pO2 values for a composite EPR spectrum.." Journal of magnetic resonance (San Diego, Calif. : 1997) 192, no. 2, 269-274 - 269-274.
  • Som, S.; Potter, L.C.; Ahmad, R.; Vikram, D.S. et al., 2008, "EPR oximetry in three spatial dimensions using sparse spin distribution.." Journal of magnetic resonance (San Diego, Calif. : 1997) 193, no. 2, 210-217 - 210-217.
  • 2008, Estimation of mean and median pO2 values for a composite EPR spectrum. Journal of Magnetic Resonance 192, no. 2,
  • Vikram, D.S.; Ahmad, R.; Rivera, B.K.; Kuppusamy, P., 2008, "Mapping of oxygen concentration in biological samples using EPR imaging." Israel Journal of Chemistry 48, no. 1,
  • Vikram, D.S.; Ahmad, R.; Pandian, R.P.; Petryakov, S. et al., 2008, "Evaluation of oxygen-response times of phthalocyanine-based crystalline paramagnetic spin probes for EPR oximetry." Journal of Magnetic Resonance 193, no. 1, 127-132 - 127-132.
  • Vikram, D.S.; Ahmad, R.; Rivera, B.K.; Kuppusamy, P., 2008, "Mapping of Oxygen Concentration in Biological Samples Using EPR Imaging." Israel Journal of Chemistry 48, no. 1, 39-43 - 39-43.
  • 2008, EPR oximetry in three spatial dimensions using sparse spin distribution. Journal of Magnetic Resonance 193, no. 2,

2007

  • Ahmad, R.; Clymer, B.; Vikram, D.S.; Deng, Y. et al., 2007, "Enhanced resolution for EPR imaging by two-step deblurring.." Journal of magnetic resonance (San Diego, Calif. : 1997) 184, no. 2, 246-257 - 246-257.
  • Ahmad, R.; Deng, Y.; Vikram, D.S.; Clymer, B. et al., 2007, "Quasi Monte Carlo-based isotropic distribution of gradient directions for improved reconstruction quality of 3D EPR imaging.." Journal of magnetic resonance (San Diego, Calif. : 1997) 184, no. 2, 236-245 - 236-245.
  • 2007, Uniform distribution of projection data for improved reconstruction quality of 4D EPR imaging. Journal of Magnetic Resonance 187, no. 2,
  • Som, S.; Potter, L.C.; Ahmad, R.; Kuppusamy, P., 2007, "A parametric approach to spectral-spatial EPR imaging.." Journal of magnetic resonance (San Diego, Calif. : 1997) 186, no. 1, 1-10 - 1-10.
  • 2007, A parametric approach to spectral-spatial EPR imaging. Journal of Magnetic Resonance 186, no. 1,
  • Vikram, D.S.; Bratasz, A.; Ahmad, R.; Kuppusamy, P., 2007, "A comparative evaluation of EPR and OxyLite oximetry using a random sampling of pO(2) in a murine tumor." Radiation Research 168, no. 3, 308-315 - 308-315.
  • 2007, Quasi Monte Carlo-based isotropic distribution of gradient directions for improved reconstruction quality of 3D EPR imaging. Journal of Magnetic Resonance 184, no. 2,
  • Ahmad, R.; Vikram, D.S.; Clymer, B.; Potter, L.C. et al., 2007, "Uniform distribution of projection data for improved reconstruction quality of 4D EPR imaging.." Journal of magnetic resonance (San Diego, Calif. : 1997) 187, no. 2, 277-287 - 277-287.
  • 2007, Enhanced resolution for EPR imaging by two-step deblurring. Journal of Magnetic Resonance 184, no. 2,

2006

Presentations

  • "Accelerated Cardiac MRI." 2016, Presented at Meeting with GE MRI Research Team,

Papers in Proceedings

2018

  • Bush, M.; Ahmad, R.; Liu, Y.; Jin, N. et al. "Prospective correction of patient-specific respiratory motion in T1 and T2 mapping." (1 2018).
  • Liu, Y.; Ahmad, R.; Jin, N.; Tani, D. et al. "Strain Encoding (SENC) Using EPI Readout." (1 2018).
  • Bush, M.; Simonetti, O.; Ahmad, R.; Liu, Y. et al. "Patient specific prospective respiratory motion correction for efficient, free-breathing cardiovascular MRI." (1 2018).
  • Varghese, J.; Liu, Y.; Jin, N.; Armstrong, A. et al. "Comparison of Intra-Cardiac Magnetic Resonance Blood Oximetry to Invasive Catheterization in Pediatric Patients with Congenital Heart Disease." (1 2018).
  • Rich, A.; Liu, Y.; Jin, N.; Potter, L. et al. "Single Breath Hold 4D Flow Acquisition of the Aortic Valve." (1 2018).
  • Simonetti, O.; Ahmad, R. "The Potential for Cardiovascular MRI at Low Field." (1 2018).
  • Chen, C.; Liu, Y.; Simonetti, O.; Ahmad, R. "Reconstructing real-time exercise stress cine images with multiple sets of sensitivity maps." (1 2018).
  • Bush, M.A.; Simonetti, O.; Ahmad, R.; Liu, Y. et al. "Prospective correction of patient-specific respiratory motion in T1 mapping." (1 2018).
  • Varghese, J.; Cardona, A.; Raman, S.; Ahmad, R. et al. "Comparison of Cardiac Magnetic Resonance-Derived Blood Oximetry to Invasive Catheterization in Heart Transplant Recipients." (1 2018).
  • Rich, A.; Jin, N.; Liu, Y.; Potter, L. et al. "CArtesian sampling with Variable density and Adjustable temporal resolution (CAVA)." (1 2018).
  • Pruitt, A.; Jin, N.; Liu, Y.; Simonetti, O. et al. "Background phase correction in the presence wrap-around artifact: Application in 4D flow imaging." (1 2018).
  • Rich, A.; Ahmad, R. "MR Image Reconstruction via Denoising (MR-RED)." (1 2018).
  • Varghese, J.; Desai, L.; Ahmad, R.; Potter, L.C. et al. "Non-invasive MR-based blood oximetry via multi-parametric, non-linear estimation: initial multi-center experience in adult and pediatric patients." (1 2018).
  • Dong, H.; Ahmad, R.; Kolipaka, A. "Helmholtz Inversion Using Unconstrained Optimization for MR Elastography." (1 2018).
  • Zhao, S.; Potter, L.; Jin, N.; Liu, Y. et al. "PC-MRI with Phase Recovery from Multiple Wrapped Measurements (PRoM)." (1 2018).
  • Pruitt, A.; Liu, Y.; Jin, N.; Simonetti, O. et al. "Automatic Image-Based Background Phase Correction in the Presence of Wrap-Around Artifact." (1 2018).
  • Varghese, J.; Ahmad, R.; Raman, S.; Potter, L. et al. "Non-invasive quantitative estimation of blood oxygen saturation with MRI: feasibility of machine learning." (1 2018).

2017

  • Varghese, J.; Ahmad, R.; Raman, S.; Potter, L.C. et al. "Intracardiac MR Oximetry in Patients with Cardiovascular Disease: Preliminary Comparison with Right Heart Catheterization." (1 2017).
  • Rich, A.V.; Potter, L.C.; Jin, N.; Liu, Y. et al. "A Bayesian Approach to Enable Single Breath-hold 4D Flow MRI." (1 2017).
  • Liu, Y.; Ting, S.; Jin, N.; Simonetti, O.P. et al. "Fully Automated Online Compressive Recovery for Real-Time, Free-Breathing CINE." (1 2017).
  • Pruitt, A.; Jin, N.; Simonetti, O.; Liu, Y. et al. "An Outlier Rejection Scheme to Improve Background Phase Correction in PC-MRI." (1 2017).
  • Bush, M.; Ahmad, R.; Simonetti, O.P. "Respiratory motion compensation for efficient, free-breathing cardiovascular MRI." (1 2017).
  • Dong, H.; Joseph, M.; Kalra, P.; Mo, X. et al. "In Vivo Magnetic Resonance Elastography of Abdominal Aortic Aneurysm in a Porcine Model." (1 2017).
  • Ebersole, C.; Ahmad, R.; Rich, A.; Potter, L. et al. "Highly Accelerated Magnetic Resonance Elastography Via Bayesian Modeling." (1 2017).

2016

  • Serafim da Silveira, J, Smyke, ME, Ahmad, R, Jin, N, Scandling, D, Dickerson, JA, Rochitte, CE, Raman, SV, Simonetti, OP "Peak velocity estimation in aortic stenosis patients using a fast three-directional two-dimensional phase contrast technique in a single breath-hold: comparison to unidirectional phase contrast MRI and transthoracic echocardiography." in SCMR 19th Annual Scientific Sessions. (1 2016).
  • Varghese, J, Ahmad, R, Jin, N, Potter, LC, Simonetti, OP "Venous Oxygen Saturation Estimation from Multiple T2 Maps with Varying Inter-Echo Spacing." in Annual SCMR Workshop: Quantitative CMR: From Technique Development to Practical Implementation. (1 2016).
  • Serafim da Silveira, J, Rich, A, Liu, Y, Smyke, M, Jin, N, Scandling, D, Dickerson, JA, Rochitte, CE, Raman, S, Potter, LC, Ahmad, R, Simonetti, OP "Highly Accelerated Phase-Contrast Mri-Based Multi-Directional Flow Imaging for Peak Velocity Estimation in Aortic Stenosis Patients." in Annual SCMR Workshop: Quantitative CMR: From Technique Development to Practical Implementation. (1 2016).
  • Ahmad R, Schroeder SA, White RD, Kolipaka A. "Accelerated MR Elastography for Quantitative Measurement of Myocardial Stiffness.." in ISMRM. (5 2016).
  • Ting, S.T.; Ahmad, R.; Jin, N.; Simonetti, O.P. "Patch-based, iteratively-reweighted compressive recovery for reconstruction of highly accelerated exercise stress cardiac cine." (1 2016).
  • Ahmad, R.; Jin, N.; Simonetti, O.P. "Background Phase Correction for Quantitative Phase-Contrast MRI." (1 2016).
  • Adam, R.; Potter, L.C.; Jin, N.; Silveira, J.S.D. et al. "Joint processing of highly accelerated multi-directional phase-contrast MRI using ReVEAL." (1 2016).

2015

  • Ting, ST, Ahmad, R, Jin, N, Serafim da Silveira, J, Simonetti, OP "Low Latency Reconstruction of Free-breathing Real-time Cardiac Cine with VISTA and SENSE." in ISMRM 23rd Annual Meeting & Exhibition. (1 2015).
  • Wolfson, H.; Ahmad, R.; Twig, Y.; Blank, A. et al. "A hand-held EPR scanner for transcutaneous oximetry." (1 2015).
  • Ahmad, R, Schniter, P, Simonetti, OP "Parameter-Free Sparsity Adaptive Compressive Recovery (SCoRe)." in ISMRM 23rd Annual Meeting & Exhibition. (1 2015).
  • Rich, A, Potter, LC, Ash, J, Ahmad, R "Factor Graphs for Inverse Problems: Accelerated Phase Contrast Magnetic Resonance Imaging." in 2015 IEEE International Conference on Image Processing (ICIP). (1 2015).
  • Rich, A, Potter, LC, Jin, N, Ash, J, Simonetti, OP, Ahmad, R "A Bayesian Approach for Accelerated Phase Contrast MRI." in ISMRM 23rd Annual Meeting & Exhibition. (1 2015).

2014

  • Ahmad, R, Jin, N, Ding, Y, Simonetti, OP "An Adaptive Phase Recovery Method for 4D Phase-Contrast MRI." in ISMRM 22nd Annual Meeting & Exhibition. (1 2014).
  • Ting, S.T.; Ding, Y.; Giri, S.; Jin, N. et al. "Sub-30 ms real-time, free-breathing cardiac imaging with SPIRiT." (1 2014).
  • Ting, ST, Ding, Y, Giri, S, Jin, N, Simonetti, OP, Ahmad, R Sub-30 ms real-time, free-breathing cardiac imaging with SPIRiT. http://www.jcmr-online.com/content/16/S1/W2, (1 2014).
  • Ting, Samuel, Ding, Yu, Xue, Hui, Giri, Shivraman, Jin, Ning, Ahmad, Rizwan, Simonetti, Orlando P "Sub-30ms Real-Time, Free-Breathing Cardiac Cine with VISTA Sampling and SPIRiT Reconstruction: A Comparison with Conventional Segmented Cine." in ISMRM 22nd Annual Meeting & Exhibition. (1 2014).
  • Ding, Y, Ahmad, R, Jin, N, Simonetti, OP "A New Perspective on the 4-point Balanced Velocity-encoding." in ISMRM 22nd Annual Meeting & Exhibition. (1 2014).
  • Ahmad, R, Ting, ST, Craft, J, Giri, S, Jin, N, Raman, SV, Simonetti, OP High-resolution, real-time exercise stress cine. http://www.jcmr-online.com/content/16/S1/W14, (1 2014).
  • Rich, A.; Potter, L.; Jin, N.; Ash, J. et al. "A Factor Graph Approach for Accelerated Phase Contrast MRI." (1 2014).

2013

  • Ahmad, R.; Jin, N.; Ding, Y.; Simonetti, O.P. "Direct Reconstruction (DiR) for PC-MRI." (1 2013).
  • Ding, Y, Ahmad, R, Xue, H, Potter, LC, Ting, S, Jin, N, Simonetti, OP "A Bilinear Noise Transfer Model for SENSE Reconstruction." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).
  • Ding, Y, Ahmad, R, Xue, H, Ting, ST, Jin, N, Simonetti, OP "Comparing Boundary Sharpness of SENSE and GRAPPA." in ISMRM Workshop on Data Sampling and Image Reconstruction. (1 2013).
  • Golub, F, Potter, LC, Ahmad, R "Characterization of EPR spin-echo data for accelerated oximetry." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).
  • Jin, N, Ahmad, R, Ding, Y, Zuehlsdorff, S, Simonetti, OP "High temporal-resolution three-directional velocity measurements in a single breath-hold using EPI and direct inversion." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).
  • Ahmad, R, Jin, N, Ding, Y, Simonetti, OP "A direct reconstruction method for blood velocity estimation from phase-contrast MRI data." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).
  • Palmer, J, Potter, LC, Kuppusamy, P, Ahmad, R "Application-specific evaluation of oxygen measurement accuracy of EPR probes." in 41st Annual ISOTT/EPR 2013 Conference. (1 2013).
  • Ahmad, R, Xue, H, Ding, Y, Simonetti, OP Variable Density Incoherent Spatial-Temporal Acquisition (VISTA) for Cardiac MRI. in ISMRM Workshop on Data Sampling and Image Reconstruction. http://www.ismrm.org/workshops/Data13/program.htm, (1 2013).
  • Ting, Samuel T, Ahmad, Rizwan, Ding ,Yu, Xue, Hui, Potter, Lee C, Simonetti, Orlando P "S-SPIRiT: An Iterative/Shrinkage Approach to SPIRiT for Real-Time Cardiac MRI." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).
  • Ding, Y, Ahmad, R, Xue, H, Ting, ST, Jin, N, Simonetti, OP "L1-Regularized GRAPPA Kernel Estimate." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).
  • Johnson, DH, Ahmad, R, Samouilov, A, Zweier, JL "Spatial 3D EPR Imaging with Compressed Sensing Reconstruction." in 41st Annual ISOTT/EPR 2013 Conference. (1 2013).
  • Johnson, DH, Ahmad, R, Samouilov, A, Zweier, JL "Uniform Spinning Sampling Gradient Electron Paramagnetic Resonance Imaging." in 41st Annual ISOTT/EPR 2013 Conference. (1 2013).
  • Golub, F, Potter, LC, Ash, JN, Ahmad, R T2 Estimation for Spin-Echo EPR. in 41st Annual ISOTT/EPR 2013 Conference. http://isott.org/index.php/news-reader/items/isott-2013-hanover-nh-usa.html, (1 2013).
  • Ding, Y, Xue, H, Ahmad, R, Ting, ST, Jin, N, Potter, LC, Simonetti, Orlando P "A Bilinear Noise Transfer Model for GRAPPA Reconstruction." in ISMRM Workshop on Data Sampling and Image Reconstruction. (1 2013).
  • Ting, ST, Ding, Y, Ahmad, R, Xue, H, Simonetti, OP "Taming an Ill-Conditioned SPIRiT: Improved Iterative Image Reconstruction for Real-Time Cardiac MRI." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).
  • Johnson, DH, Chen, Z, Ahmad, R, Samouilov, A, Zweier, JL "Uniform Spinning Sampling Gradient Electron Paramagnetic Resonance Imaging." in ISMRM 21st Annual Meeting & Exhibition. (1 2013).

2012

  • Ahmad, R.; Xue, H.; Ding, Y.; Simonetti, O.P. "Variable Density Incoherent Spatial-Temporal Acquisition for Cardiac MR." (1 2012).
  • Johnson, D, Chen, Z, Ahmad, R, Samouilov, A, Zweier, JL "Temporal Tomographic Imaging By Greedy Feteke and Golden Means Sampling." in ISMRM 20th Annual Meeting & Exhibition. (1 2012).
  • Palaniappan, P, Simonetti, OP, Ding, Y, Ahmad, R, Xue, H, Chang, TC, Guetter, C "KLT and Wavelet Filtering: Reducing Noise in Highly Accelerated Dynamic Images." in ISMRM 20th Annual Meeting & Exhibition. (1 2012).

2011

  • Ahmad, R.; Austin, C.D.; Potter, L.C. "Toeplitz embedding for fast iterative regularized imaging." (5 2011).
  • Ahmad, R, Austin, C, Potter, LC "Toeplitz embedding for fast iterative regularized imaging." in Proceedings SPIE: Algorithms for Synthetic Aperture Radar Imagery XVIII. (1 2011).
  • Ahmad, R "Multisite EPR Oximetry using Multiple Field Modulation Harmonics." in 53rd Rocky Mountain Conference on Analytical Chemistry, 34th International EPR Symposium. (1 2011).
  • Ahmad, R. "Accelerated pH Imaging using electron paramagnetic resonance." (1 2011).

2010

  • Ahmad, R, Kuppusamy, P, Potter, LC "Nested Uniform Sampling for Multiresolution 3-D Tomography." in 2010 IEEE International Conference on Acoustics, Speech and Signal Processing. (1 2010).
  • Som, S, Ahmad, R, Potter, LC, Kesselring, E, Kuppusamy, P, Zweier JL "A digital receiver for EPR spectroscopy." in A Joint Conference of 14th In Vivo ESR/EPR Spectroscopy & Imaging and the 11th International EPR Spin Trapping/Spin Labeling. (1 2010).
  • Ahmad, R, Caia, G, Potter, LC, Petryakov, S, Kuppusamy, P, Zweier JL "In vivo oximetry using EPR-NRM coimaging." in A Joint Conference of the 14th In Vivo ESR/EPR Spectroscopy & Imaging and the 11th International EPR Spin Trapping/Spin Labeling. (1 2010).

2009

  • Ahmad, R, Potter, LC, Kuppusamy, P "Oscillating Radial Trajectories for Reduced Undersampling Artifacts." in ISMRM 17th Annual Meeting & Exhibition. (1 2009).

2007

  • Som, S, Potter, LC, Ahmad, R, Kuppusamy, P "Reduced Acquisition Spectral-Spatial EPR Oximetry." in A Joint Conference of 12th In Vivo EPR Spectroscopy and Imaging 9th International EPR Spin Trapping/Spin Labeling. (1 2007).
  • Ahmad, R, Vikram, DS, Clymer, B, Potter, LC, Srinivasan, P, Zweier, Jay L, Kuppusamy, P "Uniform Sampling for 4D Spectral-Spatial EPR Imaging." in A Joint Conference of 12th In Vivo EPR Spectroscopy and Imaging 9th International EPR Spin Trapping/Spin Labeling. (1 2007).
  • Ahmad, R, Potter, LC, Clymer, B, Zweier, JL, Kuppusamy, P "Progressive uniform distribution of EPR data." in 49th Rocky Mountain Conference for Analytical Chemistry. (1 2007).

2006

  • Ahmad, R, Clymer, B, Deng, Y, Petryakov, S, Vikram, DS, Kuppusamy, P, Zweier, JL "An Automated On-The-Fly Detection and Correction Procedure for EPR Imaging Data Acquisition." in ISMRM 14th Annual Meeting & Exhibition. (1 2006).

2005

  • Ahmad, R, Clymer, B, Deng, Y, He, G, Vikram, DS, Kuppusamy, P, Zweier, JL "Adaptive sampling for in vivo EPRI." in International Conference on Electron Paramagnetic Resonance Spectroscopy and Imaging of Biological Systems. (1 2005).
  • Ahmad, R, Zweier, JL, Kuppusamy, P, Clymer, B "Adaptive Image Reconstruction for EPR." in ISMRM 13th Annual Meeting & Exhibition. (1 2005).

Unknown

  • Ahmad, R, Schroede, SA, White, RD, Kolipaka, A "Accelerated MR Elastography for Quantitative Measurement of Myocardial Stiffness." in ISMRM 24th Annual Meeting & Exhibition.
  • Ahmad, R, Jin, N, Simonetti, OP "Background Phase Correction for Quantitative Phase-Contrast MRI." in ISMRM 24th Annual Meeting & Exhibition.
  • Rich, A, Potter, LC, Jin, N, Serafim da Silveira, J, Simonetti, OP, Ahmad, R "Joint processing of highly accelerated multi-directional phase-contrast MRI using ReVEAL." in ISMRM 24th Annual Meeting & Exhibition.

Patents

  • Kolipaka A, Ahmad R. "METHODS FOR CO-IMAGING TISSUE STIFFNESS AND BLOOD FLOW IN AN MRI SCAN."
  • Ahmad, R, Ding, Y, Simonetti, OP. "Variable Density Incoherent Constrained Sampling (VICS) for Highly Accelerated Magnetic Resonance Imaging."
  • Ahmad, R, Jin, N, Simonetti, OP. "Background Phase Correction for Quantitative Cardiovascular MRI."
  • Ding, Y, Ahmad, R, Simonetti, OP, Ting, S, Xue, H,. "Self-Constraint Non-Iterative GRAPPA Reconstruction with Closed-Form Solution."
  • Ahmad, R, Ding, Y, Ning, J, Simonetti, OP. "Direct Inversion for Phase-Based Dynamic Magnetic Resonance Measurement."
  • Simonetti, OP, Ahmad, R, Potter, LC, Varghese, J. "A Magnetic Resonance Imaging Method to Non-Invasively Measure Blood Oxygen Saturation."
  • Ahmad, R, Simonetti, OP, Potter, LC, Rich, A, Ting, ST. "Low-Field MRI Scanner for Cardiac Imaging." Patent number: 9,874,620
  • "A Bayesian model for highly accelerated phase-contrast MRI."
  • "Magnetic Resonance Imaging Method to Non-Invasively Measure Blood Oxygen Saturation."
  • Simonetti, OP, Ahmad, R, Potter, LC, Varghese, J. "Magnetic Resonance Imaging Method to Non-Invasively Measure Blood Oxygen Saturation."
  • Kolipaka A, Ahmad R. "Methods for Co-Imaging Tissue Stiffness and Blood Flow in an MRI."
  • "Methods for Co-Imaging Tissue Stiffness and Blood Flow in an MRI Scan."
  • Ahmad, R, Jin, N, Simonetti, OP. "Background Phase Correction for Quantitative Cardiovascular MRI." Patent number: 9,911,062
  • "Low-Field MRI Scanner for Cardiac Imaging."
  • "A Bayesian Model for Highly Accelerated Phase-Contrast MRI."
  • Ahmad, R, Ding, Y, Simonetti, OP. "Variable Density Incoherent Constrained Sampling (VICS) for Highly Accelerated Magnetic Resonance Imaging." Patent number: 9,939,509
  • "Variable Density Incoherent Costrained Sampling (VICS) for Highly Accelerated Magnetic Resonance Imaging."
  • "Variable Density Incoherent Spatial-Temporal Acquisition (VISTA) for Cardiac MR."
  • "Self-Constraint Non-Iterative GRAPPA Construction with Closed-Form Solution."
  • "Direct Inversion for Phase-Based Dynamic Magnetic Resonance Measurements."
  • "Electron Paramagnetic Resonance Systems and Methods for Transcutaneous and Subcutaneous Oxygen."
  • "METHOD AND SYSTEM FOR ELECTRON PARAMAGNETIC RESONANCE."
  • "Background Phase Correction for Quantitative Cardiovascular MRI."