✦ LIBER ✦

Frequency response of prospectively gated phase-contrast MR velocity measurements

✍ Scribed by Richard Frayne; Brian K. Rutt

Publisher: John Wiley and Sons
Year: 1995
Tongue: English
Weight: 911 KB
Volume: 5
Category: Article
ISSN: 1053-1807
DOI: 10.1002/jmri.1880050114

No coin nor oath required. For personal study only.

✦ Synopsis

The authors developed and experimentally verifled expressions that describe the frequency response of prospectively gated phase-contrast magnetic resonance velocity measurements. Both interleaved and noninterleaved phase-contrast techniques were evaluated. The primary determinants of the frequency response were (a) the number of interleaved acquisitions (N), @] the time between acquisitions (AT], and [c) the degree of balance between the flrst moments of the velocity-encoding gradients. To quantiPg the last factor, an imbalance parameter (v) was defined. Depending on the chosen implementation and U, deviations from the ideal frequency responses were predicted and observed. The expressions also revealed an advantage of interleaved acquisitions that use a one-sided gradient configuration: no changes in the frequency response. The effects of concurrently encoding orthogonal velocity components with a Hadamard four-point scheme were examined. Index t e r n : Gatlng studles -Image processlng * Phase Imag-Ing * Veloclty studles JMRl 1995 5:65-73 ' From the Departments of Medlcal Blophyslcs and Dlagnostlc Radlologv.

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