Florian Knoll

Florian Knoll, PhD

Faculty Profile ↗

Assistant Professor of Radiology

Function:

Key Personnel

Affiliation:

CAI²R

Email:

florian.knoll@nyumc.org

Phone:

(212) 263 0335

Fax:

212-263-7541

Address:

4th Floor 660 First Avenue New York, NY 10016

Educational Details:

2007 – 2011 PhD Studies, Electrical Engineering, Graz University of Technology
2001 – 2006 Studies of Electrial Engineering, Graz University of Technology

Research Interest:

Iterative Image Reconstruction including Parallel Imaging and Compressed Sensing
Non-Cartesian Imaging
Inverse Problems
High Performance Computing using GPUs

Selected Publications:

Journal publications

Cloos, M.; Knoll F.; Zhao T.; Wiggins G.; Bruno M.; Block KT.; Sodickson DK. Multiparametric Imaging with Heterogeneous Radiofrequency Fields. Nature communications: 7:12445, (2016).
Knoll F.; Holler M.; Koesters T.; Otazo R.; Bredies K.; Sodickson DK. Joint MR-PET reconstruction using a multi-channel image regularizer. IEEE Transactions on Medical Imaging 76: 301-314 (2016).
Benning M.; Knoll F.; Schönlieb CB.; Valkonen T. Preconditioned ADMM with nonlinear operator constraint. IFIP 2015 Systems Modelling and Optimization (in press, arXiv preprint arXiv:1511.00425).
Veraart J.;, Fieremans E.; Jelescu O I.; Knoll F.; Novikov S D: Gibbs ringing in diffusion MRI. Magnetic Resonance in Medicine 76: 301-314 (2016).
Knoll F.; Raya JG.; O. Halloran R.; Baete S.; Sigmund E.; Bammer R.; Block T.; Otazo R and SodicksonDK.: A model-based reconstruction for undersampled radial spin-echo DTI with variational penalties on the diffusion tensor. NMR in Biomedicine: 28: 353–366 (2015).
Diwoky C.; Liebmann D.; Neumayer B.; Reinisch A.; Knoll F.; Strunk D. and Stollberger R.: Positive contrast of SPIO-labeled cells by off-resonant reconstruction of 3D radial half-echo bSSFP. NMR in Biomedicine: 28: 79-88 (2015).
Sumpf, T.; Petrovic, A.; Uecker, M.; Knoll, F.; Frahm, J.: Fast T2 Mapping with Improved Accuracy Using Undersampled Spin-echo MRI and Model-based Reconstructions with a Generating Function. IEEE Transactions on Medical Imaging: 33: 2212-2222 (2014).
Knoll F.; Schultz, G.; Bredies, K.; Gallichan, D.; Zaitsev, M.; Hennig, J.; Stollberger, R.: Reconstruction of undersampled radial PatLoc imaging using Total Generalized Variation. Magnetic Resonance in Medicine: 70: 40-52 (2013).
Valkonen T.; Bredies K.; Knoll F.: Total generalised variation in diffusion tensor imaging. SIAM Journal on Imaging Sciences 6: 487-525 (2013).
Freiberger,M.; Knoll, F.; Bredies, K.; Scharfetter, H.; Stollberger, R.: The AGILE library for image reconstruction in biomedical sciences using graphics card hardware acceleration. Computing in Science and Engineering 15: 34 - 44 (2013).
Knoll, F.; Clason, C.; Bredies, K.; Uecker, M.; Stollberger R.: Parallel Imaging With Nonlinear Reconstruction Using Variational Penalties. Magnetic Resonance in Medicine, 67: 34-41 (2012).
Keeling, S.; Clason, C.; Hintermüller, M.; Knoll, F.; Laurain, A.; Von Winckel, G.: An Image Space Approach to Cartesian based Parallel MR Imaging with Total Variation Regularization. Medical Image Analysis, 16: 189-200 (2012).
Knoll, F.; Bredies, K.; Pock, T.; Stollberger, R.: Second Order Total Generalized Variation (TGV) for MRI. Magnetic Resonance in Medicine, 65: 480-491 (2011).
Knoll, F.; Clason, C.; Diwoky, C.; Stollberger, R.: Adapted Random Sampling Patterns for Highly Accelerated MRI. Magnetic resonance materials in physics, biology and medicine, 24: 43-50 (2011).
Keeling, S.; Hintermüller, M.; Knoll, F.; Kraft, D.; Laurain, A.: A Total Variation Based Approach to Correcting Surface Coil Magnetic Resonance Images. Applied Mathematics and Computation 218: 219-232 (2011).
Knoll, F.; Unger, M.; Diwoky, C.; Clason, C.; Pock, T.; Stollberger, R.: Fast reduction of undersampling artifacts in radial MR angiography with 3D total variation on graphics hardware. Magnetic resonance materials in physics, biology and medicine 23: 103-114 (2010).

Conference Proceedings

Knoll F, Holler M, Koesters T, Cloos M, Otazo R, Bredies K, Sodickson D: Simultaneous Multi-Modality/multi-Contrast Image Reconstruction with Nuclear-Norm TGV. Proc. Intl. Soc. Mag. Reson. Med. 24:873 (2016).
Hammernik K, Knoll F, Sodickson D, Pock, T: Learning a Variational Model for Compressed Sensing MRI Reconstruction. Proc. Intl. Soc. Mag. Reson. Med. 24:1088 (2016).
Cloos M, Zhao T, Knoll F, Sodickson D: Online Radial Multiband Magnetic Resonance Fingerprinting. Proc. Intl. Soc. Mag. Reson. Med. 24:608 (2016).
Knoll F, Holler M, Koesters T, Bredies K, Sodickson D: Simultaneous PET-MRI reconstruction with vectorial second order total generalized variation. 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference (in press).
Rasch J, Brinkmann EM, Wuebbeling F, Knoll F, Koesters T, Burger M. PET-MRI Joint Reconstruction via Multichannel
Bregman-TV. 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference (in press).
Raya J.G.; Knoll, F.: Non-Linear Phase Correction in Model-Based Reconstruction of the Diffusion Tensor. Proc. Intl. Soc. Mag. Reson. Med. 23:81 (2015).
Cloos M.; Zhao T.; Knoll F.; Alon L.; Lattanzi R.; Sodickson D. K.: Magnetic Resonance Fingerprint Compression. Proc. Intl. Soc. Mag. Reson. Med. 23:330 (2015).
Veraart J.; Knoll F.; Sijbers J.; Fieremans E.; Novikov D. S.: Gibbs Ringing Removal in Diffusion MRI Using Second Order Total Variation Minimization. Proc. Intl. Soc. Mag. Reson. Med. 23:2809 (2015).
Baete S.; Raya J. G.; Knoll F.; Cho G. Y.; Parasoglou P.; Brown R.; Block K. T.; Otazo R.; Bencardino J.; Sigmund E.: Feasibility of In Vivo Dynamic Diffusion Tensor Imaging on a 3T Clinical Scanner with a Multi Echo Sequence and Compressed Sensing Reconstruction. Proc. Intl. Soc. Mag. Reson. Med. 23:2889 (2015).
Knoll F.; Holler M. Koesters T.; Sodickson D. K.: Joint MR-PET Reconstruction Using Vector Valued Total Generalized Variation. Proc. Intl. Soc. Mag. Reson. Med. 23:3424 (2015).
Knoll F.; Cloos M.; Koesters T.; Zenge M.; Otazo R.; Sodickson D. K.: PET-MRF: One-Step 6-Minute Multi-Parametric PET-MR Imaging Using MR Fingerprinting and Multi-Modality Joint Image Reconstruction. Proc. Intl. Soc. Mag. Reson. Med. 23:3391 (2015).
Sodickson DK; Feng L; Knoll F; Cloos M; Ben-Eliezer N; Axel L; Chandarana H; Block T; Otazo R. The rapid imaging renaissance: sparser samples, denser dimensions, and glimmerings of a grand unified tomography. Proc. SPIE Medical Imaging, 94170G-1 - 94170G-14 (2015).
Knoll, F.; Koesters, T.; Otazo, R.; Block, K.T.; Feng, L.; Vunckx, K.; Faul, D.; Nuyts, J.; Boada, F.; Sodickson, D.K.: Simultaneous MR-PET Reconstruction using Multi Sensor Compressed Sensing and Joint Sparsity. Proc. Intl. Soc. Mag. Reson. Med. 22:82 (2014) (ISMRM Magna Cum Laude Award).
Knoll, F.; Raya, J.; O'Halloran, R.; Baete, S.; Sigmund, E.; Bammer, R.; Block, K.T.; Otazo, R.; Sodickson, D.K.: Model-based DTI reconstruction with sparsity constraints on the diffusion tensor. Proc. Intl. Soc. Mag. Reson. Med. 22:4466 (2014).
Knoll, F.; Schwarzl, A.; Diwoky, C.; Sodickson, D.K.: gpuNUFFT - An open source GPU library for 3D regridding with direct Matlab interface. Proc. Intl. Soc. Mag. Reson. Med. 22:4297 (2014).
Raya, J.; Knoll, F.; Burcaw, L.; Milani, S.; Sodickson, D.K.; Block, K.T.: Combination of a Radial Sequence for In Vivo DTI of Articular Cartialge with an Iterative Model-Based Reconstruction. Proc. Intl. Soc. Mag. Reson. Med. 22:152 (2014).
Xu, J.; Feng, L.; Piccine, D.; Otazo, R.; Bonanno, G.; Knoll, F.; Wong, E.K.; Sodickson, D.K.: Feasibility of Free-Breathing Whole Heart Coronary MRA in Less Than 3 Minutes Using Combination of Compressed Sensing, Parallel Imaging and a 3D Radial Phyllotaxis Trajectory. Proc. Intl. Soc. Mag. Reson. Med. 22:937 (2014).
Carluccio, G.; Knoll, F.; Deniz, C.M.; Alon, L.; Collins, C.: A Fast Method to Estimate SAR Distribution from Temperature Images Highly Affected by Noise. Proc. Intl. Soc. Mag. Reson. Med. 22:4904 (2014).
Kroboth S.; Knoll F.; Bredies K.: Fast Regularized Reconstruction for PatLoc MR Imaging using Total Generalized Variation and GPUs. 16 Ann. Meet. Ger. Chapter Int. Soc. Magn. Reson. Med. 2013, Freiburg.
Knoll, F.; Block, K.T.; Bredies, K.; Diwoky, C.; Axel, L.; Sodickson, D.K.; Stollberger, R.: Accelerated 3D radial imaging with 3D variational regularization. Proc. Intl. Soc. Mag. Reson. Med. 21:2636 (2013) (ISMRM Magna Cum Laude Award).
Knoll, F.; Valkonen, T.; Bredies, K.; Stollberger, R.: Higher order variational denoising for diffusion tensor imaging. Proc. Intl. Soc. Mag. Reson. Med. 21:2078 (2013) (ISMRM Magna Cum Laude Award).
Knoll, F.; O'Halloran, R.; Bredies, K.; Stollberger, R.; Bammer, R.: Quantitative Evaluation of 3D Variational Regularized Reconstruction of Undersampled Diffusion Tensor Imaging. Proc. Intl. Soc. Mag. Reson. Med. 21:2615 (2013).
Schloegl, M.; Knoll, F.; Gruber, K.; Ebner, F.; Stollberger, R.: Quantitative Evaluation of non-linear Reconstruction Methods in MRI. Proc. Intl. Soc. Mag. Reson. Med. 21:2665 (2013).
O'Halloran, R.; Knoll, F.; Bredies, K.; Stollberger, R.; Bammer, R.: Scan time reduction in 3D Diffusion-Weighted Steady-State Free Precession Imaging using Constrained Reconstruction. Proc. Intl. Soc. Mag. Reson. Med. 21:3182 (2013).
Kroboth, S.; Testud, F.; Bredies, K.; Layton, K.J.; Gallichan, D.; Cocosco, C.A.; Schultz, G.; Knoll, F.; Barmet, C.; Pruessmann, K.P.; Zaitsev, M.; Stollberger R.: Image Reconstruction of Single-Shot North West EPI Data acquired with PatLoc Gradients using Magnetic Field Monitoring and Total Generalized Variation – Conjugate Gradient. Proc. Intl. Soc. Mag. Reson. Med. 21:3827 (2013).
Kristian Bredies, Florian Knoll and Christian Langkammer. TGV regularization for variational approaches to quantitative susceptibility mapping. Proceedings of the 2nd International Workshop on MRI Phase Contrast & Quantitative Susceptibility Mapping (QSM). Ithaca, New York (USA), pp. 45-48, 2013.
Knoll, F.; Clason, C.; Bredies, K.; Stollberger, R.: Iterative Image reconstruction for accelerated MR-Imaging: Mathematics meets Radiology: Strahlentherapie und Onkologie 189 (2), 184-185 (2013).
Valkonen T., Knoll F; Bredies K.: TGV for diffusion tensors: A comparison of fidelity functions, in: Journal of Inverse and Ill-posed Problems, Special issue for IP:M&S 2012, Antalya, Turkey, 21 (2013), 355–377.
Kroboth S.; Gallichan D.; Knoll F.; Cocosco C.A.; Schultz G.; Zaitsev M.; Stollberger R.: Effect of miscalibration of gradient fields and RF coil sensitivities in PatLoc imaging. Proc. ESMRMB 152-153 (2012).
Knoll F.; Schultz, G.; Bredies, K.; Gallichan, D.; Zaitsev, M.; Hennig, J.; Stollberger, R.: Reconstruction of undersampled radial PatLoc imaging using Total Generalized Variation. Proc. Intl. Soc. Mag. Reson. Med. 20:3345 (2012).
Sumpf, T.; Knoll, F.; Frahm, J.; Stollberger, R.; Petrovic, A.: Nonlinear inverse reconstruction for T2 mapping using the generating function formalism on undersampled Cartesian data. Proc. Intl. Soc. Mag. Reson. Med. 20:5578 (2012).
Knoll, F.; Clason, C.; Bredies, K.; Uecker, M.; Stollberger, R.: Parallel Imaging with Nonlinear Reconstruction using Variational Penalties. Proc. Intl. Soc. Mag. Reson. Med. 19:485 (2011).
Knoll, F.; Bredies, K.; Stollberger, R.: Iterative parallel imaging reconstruction of time-resolved data using 3D variational regularization. Proc. Intl. Soc. Mag. Reson. Med. 19:2883 (2011).
Knoll, F.; Freiberger, M.; Bredies, K.; Stollberger, R.: AGILE: An open source library for image reconstruction using graphics card hardware acceleration. Proc. Intl. Soc. Mag. Reson. Med. 19:2554 (2011).
Knoll, F.; Dong, Y.; Hintermüller, M.; Stollberger, R.: Total Variation Denoising with Spatially Dependent Regularization. Proc. Intl. Soc. Mag. Reson. Med. 18:5088 (2010).
Buchgraber, G.; Knoll, F.; Freiberger, M.; Clason, C.; Grabner, M.; Stollberger, R.: Fast Regridding using LSQR on Graphics Hardware. Proc. Intl. Soc. Mag. Reson. Med. 18:4959 (2010).
Knoll, F.; Bredies, K.; Pock, T.; Stollberger, R.: Total Generalized Variation (TGV) for MRI. Proc. Intl. Soc. Mag. Reson. Med. 18:4855 (2010).
Knoll, F.; Clason, C.; Aschauer, M.; Ebner, F.; Stollberger, R.: Adapted Random 3D Sampling Patterns for CE-MRA. Proc. Intl. Soc. Mag. Reson. Med. 18:3763 (2010).
Knoll, F.; Clason, C.; Stollberger, R.: Tailored 3D Random Sampling Patterns for Nonlinear Parallel Imaging. Proc. Intl. Soc. Mag. Reson. Med. 18:2876 (2010).
Diwoky, C.; Reinisch, A.; Knoll, F.; Neumayer, B.; Strunk, D.; Stollberger, R.: On Possible Pitfalls in Working on SPIO Labelled Cells with 2D UTE Sequences. Proc. Intl. Soc. Mag. Reson. Med. 18:1875 (2010).
Kraiger, M.; Knoll, F.; Clason, C.; Stollberger, R.: Quantification of Transversal Relaxation Time T2 using an Iterative Regularized Parallel Imaging Reconstruction. Proc. Intl. Soc. Mag. Reson. Med. 18:2954 (2010).
Knoll, F.; Bredies, K.; Stollberger, R.: MR Image Reconstruction of Subsampled Spiral Data from Multiple Coils using Total Generalized Variation. Biomed Tech 55 (Suppl. 1): 184 - 188 (2010).
Knoll, F.; Dong, Y.; Hintermüller, M.; Stollberger, R.: Automatic Spatially Dependent Parameter Selection for TV Denoising of MR Images with Non-Uniform Noise Distribution. Biomed Tech 55 (Suppl. 1): 198 - 202 (2010).
Kraiger, M.; Knoll, F.; Clason, C.; Stollberger, R.: Assessment of Iterative Regularized Parallel Imaging Reconstruction for Quantitative Magnetic Resonance Imaging. BMT 2010: Biomed Tech 55 (Suppl. 1): 234 - 237 (2010).
Knoll, F.; Clason, C.; Uecker, M.; Stollberger, R.: Improved Reconstruction in Non-Cartesian Parallel Imaging by Regularized Nonlinear Inversion. Proc. Intl. Soc. Mag. Reson. Med. 17:2721 (2009).
Knoll, F.; Unger, M.; Ebner, F.; Stollberger, R.: Real-Time Elimination of Undersampling Artifacts using 3D Total Variation on Graphics Hardware. Proc. Intl. Soc. Mag. Reson. Med. 17:2838 (2009).
Knoll, F.; Clason. C.; Ebner, F.; Aschauer, M.; Stollberger, R.: CE-MRA with tailored 3D random sampling patterns and nonlinear parallel imaging reconstruction, 21th annual international conference on magnetic resonance angiography, East Lansing, Michigan, USA, September 29 - Oktober 1 (2009).
Knoll, F.: Towards real-time MR imaging: Data acquisition strategies and image reconstruction, Conference on applied Inverse Problems, Minisymposium: Magnetic Resonance and Magnetic Induction Tomography; Vienna, July 20 - July 24 (2009).
Knoll, F.; Unger, M.; Ebner, F.; Stollberger, R.: Real time elimination of undersampling artifacts in CE MRA using variational denoising on graphics hardware, 20th annual international conference on magnetic resonance angiography: p71, Graz, Austria, October 15 - October 18 (2008).
Knoll, F.; Ebner, F.; Keeling, S.; Stollberger, R.: Assessment of image reconstruction methods for subsampled DCE-MRI. Proc. Intl. Soc. Mag. Reson. Med. 16:3263 (2008).