An off‐resonance insensitive orthogonal CSPAMM sequence (ORI‐O‐CSPAMM) for the acquisition of CSPAMM and MICSR grids in half scan time

PURPOSE: To develop an Off-Resonance Insensitive Orthogonal CSPAMM sequence (ORI-O-CSPAMM) for the acquisition of CSPAMM and MICSR grids in half of the acquisition time. METHODS: Phantom and mid-level left ventricle short-axis tagged images were acquired using CSPAMM, ORI-CSPAMM, O-CSPAMM, and the proposed ORI-O-CPAMM sequences to interrogate and compare its behavior under off-resonance effects produced by vegetable oil and subcutaneous and epicardial fat. The images were compared in terms of signal and the capacity to obtain complex difference and MICSR images. RESULTS: Like ORI-CSPAMM, the proposed ORI-O-CSPAMM sequence removed almost completely the off-resonance artifacts produced during the tagging preparation. Tagging grids without DC components were obtained with ORI-O-CSPAMM using complex difference and MICSR from only two complementary images, which reduced the scan time to a half compared to CSPAMM and ORI-CSPAMM. The removal of off-resonance effects and the capacity to obtain MICSR images are advantages of ORI-O-CSPAMM over the O-CSPAMM sequence. CONCLUSION: We developed a novel and fast tagging sequence designed to remove off-resonance effects during the tagging preparation, and to obtain complex difference and MICSR grids in half of the scan time compared to CSPAMM and ORI-CSPAMM sequences, which could allow its application to clinical protocols.