Mark Jason Hamamura1, Seunghoon Ha1,
Werner
1Tu & Yuen Center for
Functional Onco-Imaging, University of California, Irvine, CA, United States;
2Department of Cogno-Mechatronics Engineering, Pusan National
University, Pusan, Republic of Korea
In a combined MRI and SPECT system (MR-SPECT), metallic components of the SPECT hardware distort the B0 field for MR imaging. Rotation of the SPECT hardware for tomographic imaging thus alters the B0 field and requires re-shimming. To perform rapid re-shimming, pre-determined field maps were utilized to calculate the optimum currents to apply to the shim channels. These calculations do not require any additional MRI acquisitions, allowing for re-shimming immediately after any rotation.