| Abstract: | The RARE method and its variants have become popular, rapid-imaging alternatives to conventional spin-echo imaging, particularly for long repetition time proton density and T2-weighted imaging. One variant is to generate both early and late echo images using the same pulse sequence, which has the added benefit of reduced edge artifacts and blurring. Described in this paper is variable-averaging RARE (VARARE), a method by which independent amounts of averaging can be set for the early and late echo images generated by a single scanning sequence. Through the use of this method, the signal-to-noise ratio (SNR) of late echo images can be improved without unnecessarily increasing the number of averages for the early echo image, thus saving scanning time. Comparisons to various alternatives are made with respect to scanning time and image quality. Phantom measurements and in vivo images are given to demonstrate the effectiveness of VA-RARE as an efficient method for improving SNR of late echo time images in RARE imaging. |
