FIG. 1.

Real-time interactive adjustment of temporal resolution is shown schematically. Imaging can be performed using any Np, during uninterrupted scanning. The Np is increased or decreased using a simple keyboard command. Here 32 projections and a 4-ms TR were used to acquire a number of short-axis cardiac images rapidly; Np was then increased to 40, and a 64-Np frame was obtained. During the 40-ms interscan delays, all of the necessary updates to gradient waveforms, and receiver phase and frequency tables were performed for acquisition with an adjusted Np.