Multislice double inversion-recovery black-blood imaging with simultaneous slice reinversion.

Abstract

To develop a technique for time-efficient multislice double inversion-recovery (DIR) black-blood imaging and to test its applicability and limitations for high-resolution imaging of carotid arteries. A multislice DIR pulse sequence with fast spin-echo (FSE) readout was implemented on a 1.5 T magnetic resonance (MR) scanner. The principle of the method is that a slice-selective inversion in a DIR preparation reinverts an entire slice pack, and all slices are imaged within repetition time (TR). The number of slices acquired per TR (N) controls the inversion time (TI) to execute the readout for each slice at the zero-crossing point of blood. Multislice DIR images (TR/TE = 2500/9 msec) of carotid arteries were obtained with variable N = 2-8 from four subjects. The method was compared with the standard single-slice DIR and inflow saturation techniques. Multislice DIR with N = 2-6 provided similar flow suppression in carotid arteries as single-slice DIR. At all N = 1-8, blood suppression by DIR was significantly better than by inflow saturation. An additional limitation of multislice DIR was saturation of the signal from stationary tissues that worsened visualization of the vessel wall at N >or= 6. Multislice DIR provides up to eight-fold improvement of time-efficiency relative to single-slice DIR and high-quality blood suppression.