MedTech West seminar with Dr. Ashkan Panahi- From sparsity-based estimation to compressive magnetic resonance imaging: Challenges and solutions

Ashkan Panahi
Welcome to a MedTech West seminar on Oct 15 at 13:00-14:00 (14:30 incl. coffee)!

Dr. Ashkan Panahi received his PhD degree in signal processing at Chalmers university of technology (Mats Viberg), Sweden, in 2015.

In this seminar, Dr. Panahi will speak about Compressed Sensing (CS), which is a new paradigm for acquiring large data sets. Relying on the premise that the natural sources of data are compressible, CS emphasizes on simplifying the costly physical process of sensing at the expense of higher effort in the digital signal processing domain. Due to the costly and inconvenient process of imaging, Magnetic resonance imaging (MRI) is one of the areas, where CS may have a great advantage. This is mainly provided by the fact that the MR images, similar to other natural image sources, are compressible. However, previous attempts to apply CS into the MRI context have confronted with practical obstacles. Numerical difficulties and the high resolution requirement are among the prominent issues. Moreover, the application of random sampling has been found to be inappropriate, because of the field variations introduced by the imaging gradients. This presentation further investigates these issues from a signal processing point of view.

We will first introduce and discuss sparsity-based estimation techniques, which are the essential parts of the conventional compressed sensing. We then develop a rigorous statistical framework to study these techniques and discuss different dimensions, in which the sparsity-based techniques may be modified based on our statistical framework. Then, we show that these modifications are useful to bridge the gap between CS and MR imaging. In particular, we propose and discuss an adaptive method of signal acquisition, based on CS. We also discuss the compressibility of MR images and briefly study the different possibilities, in accordance with the CS statistical framework.

Where? MedTech West Conference Room, Röda stråket 10B, Sahlgrenska University Hospital
When? Oct 15, 13:00-14:00 (14:30 incl. coffee)

Coffee will be served to those who have registered. Email your registration to: seminars@medtechwest.se. Write “Seminar Oct 15″ in the subject.

Welcome!