K. V. S. Hari

Hemant Kumar Aggarwal, Sudhanya Chatterjee, Dattesh Shanbhag et al.

Single-shot magnetic resonance (MR) imaging acquires the entire k-space data in a single shot and it has various applications in whole-body imaging. However, the long acquisition time for the entire k-space in single-shot fast spin echo (SSFSE) MR imaging poses a challenge, as it introduces T2-blur in the acquired images. This study aims to enhance the reconstruction quality of SSFSE MR images by (a) optimizing the trajectory for measuring the k-space, (b) acquiring fewer samples to speed up the acquisition process, and (c) reducing the impact of T2-blur. The proposed method adheres to physics constraints due to maximum gradient strength and slew-rate available while optimizing the trajectory within an end-to-end learning framework. Experiments were conducted on publicly available fastMRI multichannel dataset with 8-fold and 16-fold acceleration factors. An experienced radiologist's evaluation on a five-point Likert scale indicates improvements in the reconstruction quality as the ACL fibers are sharper than comparative methods.

Dinesh Dileep Gaurav, K. V. S. Hari

We consider a two-hop Multiple-Input Multiple-Output channel with a source, a single Amplify and Forward relay, and the destination. We consider the problem of designing precoders at the source and the relay, and the receiver matrix at the destination. In particular, we address the problem of optimal power allocation scheme at the source which minimizes the source transmit power while satisfying a given Quality of Service requirement at the destination, and a power constraint at the relay. We consider two types of receiver at the destination, a Zero Forcing receiver and an Minimum Mean Square Error receiver. Simulation Results are provided in the end which compare the performance of both the receivers.