Accelerated CEST MRI Using Compressive Sensing and Multishot Spiral Acquisitions

Sampada Bhave¹, Jinsuh Kim¹, Casey P. Johnson¹, Mathews Jacob¹

A novel method based on multishot variable density spiral acquisitions and compressive sensing is introduced to reduce the scan time in high spatial resolution quantitative CEST imaging. Variable density acquisitions provide acceptable signal to noise ratio, even when high resolution acquisitions are used. The k-space data of each of the z-planes is undersampled by skipping the interleaves of the spiral trajectory. The recovery of the entire spatial spectral dataset is posed as a sparse optimization scheme. The total variation prior is used for spatial regularization, while the l1 norm of the second order temporal derivatives are used to exploit the smoothness of z-spectra.