Significance of phase compensation in cine magnetic resonance imaging

To evaluate the usefulness of cine magnetic resonance (MR) imaging in a quantitative study of valvular regurgitation, we applied modified cine MR pulse sequences on the 5 healthy volunteers and 15 patients with valvular regurgitation. We obtained cine MR images in two patients with valvular regurgitation using the pulse sequences with different echo time (12, 10, 8 msec) and with extra gradients for phase compensation. Another 13 patients and 5 healthy volunteers were imaged by both of conventional (non-rephased, NR) and phase-compensated (rephased, R) cine MR sequences for the evaluation of the ability of cine MR imaging in a quantitation of valvular regurgitation. The streaking artifacts were diminished and intracavity flow signal was higher in the images with shorter TE. Namely, a cut down of echo time improved the image quality of cine MR, while the improvement was much greater in rephased image. R images were better in quality than the NR images. Meanwhile the extent of signal void in cine MR images caused by valvular regurgitation were correlated with the extent of regurgitant signal estimated by Doppler color flow mapping. The area of signal void in R images were smaller than that in NR images in all patients, and the correlation between the length of regurgitant flow in cine MR imaging and that in color flow mapping was better on R than NR images [NR; r=0.7889 (p<0.01), R; r=0.9183 (p<0.001)]. Intracavity signal void observed in NR images in healthy volunteers were suppressed in R images. Thus cine MR imaging with phase compensation is useful for the quanatitation of regurgitant flow. (author)