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. Author manuscript; available in PMC: 2024 Jun 27.
Published in final edited form as: Magn Reson Med. 2009 May;61(5):1185–1192. doi: 10.1002/mrm.21964

FIG. 2.

FIG. 2.

Bars: standard deviation (STD). a: Graph shows one example of the velocity profile in the phantom (diameter D = 8 mm) acquired using PC-MRI with TR/TE = 61/11 ms, flip angle = 15°, resolution = 0.5 × 0.5 mm2, NEX = 3, slice thickness = 5 mm, Venc = 10/50 cm/s, total scan time ≈25 sec. The MRI-measured average velocity vMRI = 9 cm/s with the repeatability error ≈5%; flow meter measured average velocity vreal = 8.8 cm/s (< the 5% repeatability error of the MRI measurement). b: Phase velocity images for Venc = 10 cm/s, Venc = 50 cm/s, and the three-point method (Venc = 10/50 cm/s) of the phantom in color using the same scan parameters as (a). vMRI = 19 cm/s and vreal = 21.0 cm/s. Phase wrapping is observed in the low Venc image (b1), large noise is observed in high Venc image (b2), and three-point image has lower noise than high-Venc image and no phase wrapping (b3). c: Graph shows one example of the velocity profile in the rat’s PV (diameter D = 2 mm) acquired using PC-MRI with TR/TE = 45/9.7 ms, flip angle = 15°, resolution = 0.25 × 0.25 mm2, NEX = 12, slice thickness = 2.6 mm, Venc = 10/50 cm/s, total scan time ≈5 min. The MRI-measured average velocity v = 6 cm/s with the repeatability error ≈8%.