On the Impact of Artifacts Induced by Mismatches Between Auto‐Calibration Signal and Accelerated 3D GRE Data at 11.7T
2025-10-18 Joseph Obriot, Franck Mauconduit, Vincent Gras, et al. Magnetic Resonance in Medicine

PURPOSE: field inhomogeneity artifacts arising from remote locations in the FOV and encountered in accelerated 3D gradient-recalled echo (GRE) sequences at ultra-high field, and at providing mitigation strategies. METHODS: Measurements were conducted at 11.7T using a head-shaped phantom and an accelerated 3D GRE…

Benchmarking common and advanced non-Cartesian trajectories with high acceleration and static off-resonance effects
2024-08-14 Guillaume Daval-Frérot, Chaithya Giliyar Radhakrishna, Fernanda Ponce, et al. ISMRM & ISMRT Annual Meeting & Exhibition

Non-Cartesian sampling patterns allow for highly accelerated MRI exams at the cost of exacerbated and more complex artifacts, each impacting image quality in unique ways. Patient-induced B0 field inhomogeneities can notably cause distortions and blurring, but some trajectories are by design more robust to them.

More-sparkling: non-Cartesian trajectories with minimized off-resonance effects
2023-08-03 Chaithya Giliyar Radhakrishna, Guillaume Daval-Frérot, Aurélien Massire, et al. Proceedings of the 30th Annual Meeting of ISMRM

We augment the recently introduced SPARKLING algorithm and propose an improved mathematical formulation that takes the temporal dependence of the MR signal into account. This prevents the trajectories from sampling similar portions of k-space at different times, thereby reducing distortions and blurring induced by (B0…

Improving spreading projection algorithm for rapid k-space sampling trajectories through minimized off-resonance effects and gridding of low frequencies
2023-05-22 Chaithya Giliyar Radhakrishna, Guillaume Daval-Frérot, Aurélien Massire, et al. Magnetic Resonance in Medicine

Purpose Non‐Cartesian MRI with long arbitrary readout directions are susceptible to off‐resonance artifacts due to patient induced inhomogeneities. This results in degraded image quality with strong signal losses and blurring.

Designing and learning non-Cartesian k-space sampling trajectories for accelerated 3D MRI
2023-04-25 Chaithya Giliyar Radhakrishna theses.fr (ABES)

Conception et apprentissage de trajectoires d'échantillonnage non cartésiennes dans l'espace k pour l'IRM 3D accélérée L'imagerie par résonance magnétique (IRM) est une technique d'imagerie médicale non invasive très répandue qui permet de comprendre les structures des tissus du corps humain. Cependant, sa portée et…