(A) multi-contrast imaging method using steady-state free precession with alternating RF flip angles

Abstract

To obtain multi-contrast images including fat-suppressed contrast image, a novel multi-contrast imaging method using a steady-state free precession sequence with alternating RF flip angles is proposed.

The proposed method uses the balanced steady-state free precession (bSSFP) sequence with two flip angles. In general, the conventional bSSFP sequence has its own unique contrast, which combines both FID signal and echo signal under a steady state condition. By using alternating RF flip angles and RF phase cycling, various image contrasts weighted by PD, T1, and T2 can be obtained. The proposed method offers multi-contrast images with fat suppression by using the combination of two images obtained just after alternating RF pulses, respectively.

As demonstrated by simulations, phantom and in-vivo experiments, the proposed method provides multi-contrast knee images including fat-suppressed contrast images. The proposed method can be a useful tool for clinical diagnosis, such as the cartilage segmentation and the fast screening of lesions.