TE interleaving: New multisection imaging technique

A new pulse sequence that increases the number of sections that can be acquired with a T2-weighted multisection imaging prescription is presented. The sequence achieves a higher efficiency in section acquisition per unit time by interleaving excitation and data collection for up to three separate sections during the long TE (greater than or equal to 80 msec) of a T2-weighted spin-echo pulse sequence. The necessary modifications of the section-select and readout gradient waveforms for the implementation of TE-interleaved (TEI) sequences, with and without flow compensation, are described. Secondary- and stimulated-echo artifacts are present on some TEI images, but these can be controlled with appropriate spoiler gradients. The signal-to-noise ratio for contiguous sections is slightly reduced compared with that of a standard multisection pulse sequence. These observations indicate that the effects of radio-frequency section interference are enhanced by the TEI sequence.