Medical Image Computing and Signal Processing Lab

• Contact Details :
  • Email Address : sreekanth.m@iiitmk.ac.in
  • Phone no. (M): +91-9961942368
  
  
• Research Focus : Parallel MRI Reconstruction.

Parallel MRI was established in 1980s. In conventional MR imaging, the phase-encoding steps are performed in sequential order by switching the magnetic field gradient step-by step, which in turn determines the speed of acquisition. Since the switching is expensive, acceleration is achieved by skipping alternate phase encoding lines. This was first implemented in 1989 by under sampling the k-space in PE direction. GRAPPA is a more generalized and improved version where acquired lines are linearly combined to estimate the missing line. The unacquired PE lines are then estimated from a linear combination of the acquired PE lines using one or more kernels computed using the calibrating signals.

My work emphasizes quality improvement of stroke and DTI images obtained after GRAPPA reconstruction. GRAPPA performance is analyzed in various non-ideal conditions. The non-ideal conditions include higher acceleration factor, increase in sensitivity noise and reduced number of calibration lines. For rapid acquisition of stroke images, higher acceleration factors and reduced number of calibration lines are needed. However aliasing artifacts in the reconstructed image increase with acceleration factor. The same thing also happens when the calibration lines are decreased. When more number of coils are used to add more data content, the sensitivity noise will also increase. The overall effect is the reduction in SNR and CNR, with increased artifact and blurring. Goal of my work is to overcome these difficulties and improve GRAPPA reconstruction in stroke imaging.

• Madhusoodhanan, S. Kesavadas, C. and Paul, J. S., SWI post processing using granularity controlled edge-preserved denoising of multichannel GRE images. International Journal of Imaging Systems and Technology, March 2019. In press.


• Madhusoodhanan, S. Kesavadas, C. and Paul, J. S., SWI processing using a local phase difference modulated venous enhancement filter with noise compensation. Magnetic resonance imaging, 2019 Jun 1;59:17-30.


• Madhusoodhanan, S. and Paul, J. S., A quantitative survey of GRAPPA reconstruction in parallel MRI: impact on noise reduction and aliasing. Concepts in Magnetic Resonance part-A, 2015; 44(6), 287-305.

• S. Madhusoodhanan, J. S. Paul. "A Phase Noise Correction Scheme for Multi-channel Multi-echo SWI processing." In the proceedings of the International Conference on Machine Intelligence and Signal Processing (MISP-2019), Allahabad, September 2019.


• S. Madhusoodhanan, J. S. Paul. "On the Choice of Coil Combination Weights for Phase-Sensitive GRAPPA Reconstruction in multi-channel SWI." In Proceedings of 3rd International Conference on Computer Vision & Image Processing (CVIP), Jabalpur, India, September 2018.