Accelerating chemical exchange saturation transfer (CEST) MRI by combining compressed sensing and sensitivity encoding techniques

Purpose To evaluate the feasibility of accelerated chemical‐exchange‐saturation‐transfer (CEST) imaging using a combination of compressed sensing (CS) and sensitivity encoding (SENSE) at 3 Tesla. Theory and Methods Two healthy volunteers and six high‐grade glioma patients were recruited. Raw CEST image k‐space data were acquired (with varied radiofrequency saturation power levels for the healthy volunteer study), and a sequential CS and SENSE reconstruction (CS‐SENSE) was assessed. The MTR asym (3.5 ppm) signals were compared with varied CS‐SENSE acceleration factors. Results In the healthy volunteer study, a CS‐SENSE acceleration factor of R = 2 × 2 (CS × SENSE) was achieved without compromising the reconstructed MTR asym (3.5 ppm) image quality. The MTR asym (3.5 ppm) signals obtained from the CS‐SENSE reconstruction with R = 2 × 2 were well preserved compared with the reference image (R = 2 for only SENSE). In the glioma patient study, the MTR asym (3.5 ppm) signals were significantly higher in the tumor region (Gd‐enhancing tumor core) than in the normal‐appearing white matter ( P < 0.001). There was no significant MTR asym (3.5 ppm) difference between the reference image and CS‐SENSE‐reconstructed image in the acceleration factor of R = 2 × 2. Conclusion Combining the SENSE technique with CS (R = 2 × 2) enables considerable acceleration of CEST image acquisition and potentially has a wide range of clinical applications. Magn Reson Med 77:779–786, 2017.