FLOW IMAGING;
FAST IMAGING;
ANGIOGRAPHY;
MAGNETIC RESONANCE IMAGING;
D O I:
10.1002/mrm.1910330414
中图分类号:
R8 [特种医学];
R445 [影像诊断学];
学科分类号:
1002 ;
100207 ;
1009 ;
摘要:
A velocity k-space formalism facilitates the analysis of flow effects for imaging sequences involving time-varying gradients such as echo-planar and spiral. For each sequence, the velocity k-space trajectory can be represented by k(v)(k(r)); that is, its velocity-frequency (k(v)) position as a function of spatial-frequency (k(r)) position. In an echo-planar sequence, k(v) is discontinuous and asymmetric. However, in a spiral sequence, k(v) is smoothly varying, circularly symmetric, and small near the k(r) origin. To compare the effects of these trajectory differences, simulated images were generated by computing the k-space values for an in-plane vessel with parabolic flow. Whereas the resulting echo-planar images demonstrate distortions and ghosting that depend on the vessel orientation, the spiral images exhibit minimal artifacts.
机构:
Kyushu Univ, Fac Med Sci, Dept Hlth Sci, Fukuoka, Fukuoka 8128582, Japan
Hokkaido Univ Sci, Fac Hlth Sci, Dept Radiol Technol, Sapporo, Hokkaido 0068585, JapanKyushu Univ, Fac Med Sci, Dept Hlth Sci, Fukuoka, Fukuoka 8128582, Japan
Kumazawa, Seiji
Yoshiura, Takashi
论文数: 0引用数: 0
h-index: 0
机构:
Kagoshima Univ, Grad Sch Med & Dent Sci, Dept Radiol, Kagoshima, Kagoshima 8908520, JapanKyushu Univ, Fac Med Sci, Dept Hlth Sci, Fukuoka, Fukuoka 8128582, Japan
Yoshiura, Takashi
Honda, Hiroshi
论文数: 0引用数: 0
h-index: 0
机构:
Kyushu Univ, Grad Sch Med Sci, Dept Clin Radiol, Fukuoka, Fukuoka 8128582, JapanKyushu Univ, Fac Med Sci, Dept Hlth Sci, Fukuoka, Fukuoka 8128582, Japan