Fast-spin Echo, Echo Planar, Inversion Recovery, and Short-T1 Inversion Recovery Imaging

This chapter covers other pulse sequences used for breast MRI. Most sites use fast spin-echo (FSE), also sometimes called turbo spin-echo (TSE), in place of normal spin-echo (SE) sequences for both T1- and T2-weighted imaging, as FSE speeds image acquisition compared to SE.^1,2 Echo-planar imaging is an extremely fast imaging technique that has been used for cardiac imaging and in breast imaging research applications requiring very high temporal resolution at the cost of lower spatial resolution.^2,3 Echo-planar imaging has not found clinical application in breast imaging but may in the future as echo-planar techniques become more refined. Inversion-recovery has been used since the earliest days of clinical MRI to provide heavily T1-weighted images.^4,5 Short-TI inversion recovery (STIR) imaging is used by some breast MRI sites in place of T2-weighted SE or FSE, as STIR can provide more resilient fat-suppression than the chemical-shift techniques used in SE and FSE.^5–7 STIR has the added benefit of being the only pulse sequence in which T1, T2, and spin-density effects of diseased tissues add constructively to enhance image contrast. Each of these techniques will be described in this chapter.