T2-weighted spin-echo pulse sequence with variable repetition and echo times for reduction of MR image acquisition time

R. Kim Butts, Farhad Farzaneh, Stephen J. Riederer, John N. Rydberg, Roger C. Grimm

Research output: Contribution to journalArticle

16 Scopus citations


Use of intraacquisition modification of pulse-sequence parameters to reduce acquisition time for conventional T2-weighted spin-echo images was evaluated. With this technique (variable-rate spin-echo pulse sequence), the repetition time and echo time (TR msec/TE msec) were reduced during imaging as a function of the phase-encoding view. To maintain T2-based contrast, TR and TE for the low-spatial-frequency views were left at their prescribed values (eg, 2,000/80). TR and TE for the highspatial-frequency views were pro gressively reduced during imaging(eg, to 1,000/20). Acquisition time was reduced by as much as 25%. In one pulse sequence, the duration of multisection imaging nominally performed at TR 2,000 and with 256 phase-encoding views was reduced from 9 minutes 30 seconds to 6 minutes 30 seconds. In all sequences, edges and small structures were enhanced, and T2 contrast was somewhat decreased in high spatial frequencies. Filtering of the raw data before reconstruction can suppress these effects and provide a net increase in contrast-to-noise ratio.

Original languageEnglish (US)
Pages (from-to)551-556
Number of pages6
Issue number2
StatePublished - Aug 1991



  • Magnetic resonance (MR), pulse sequences
  • Magnetic resonance (MR), rapid imaging
  • Magnetic resonance (MR), technology

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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