Reducing oblique flow effects in interleaved EPI with a centric reordering technique.
Segmented interleaved echo planar imaging offers a fast and efficient approach to magnetic resonance angiography. Unfortunately, this technique is particularly sensitive to oblique flow in the imaging plane. In this work, a mathematical analysis of oblique flow effects for several types of k-space coverage is presented. The conventional linear acquisition scheme, an alternating centric and a nonalternating centric encoding scheme are compared with respect to their flow properties. It is shown both by simulations and imaging experiments that artifacts from oblique in-plane flow are effectively reduced by both centric reordered phase-encoding schemes. The nonalternating centric acquisition scheme is preferred to the alternating centric scheme due to the smoother phase error transition in k-space in the presence of obliquely-angled flow. Magn Reson Med 45:623-629, 2001.
Philips Medical Systems B.V., Best, The Netherlands. gabrielle.beck@philips.com
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G
Beck
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Li
E M
EM
Haacke
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TG
Noll
L R
LR
Schad
D016477:Artifacts; D002339:Carotid Arteries / Q000033:anatomy & histology; D017352:Echo-Planar Imaging / Q000379:methods*; D006801:Humans; D018810:Magnetic Resonance Angiography; D020768:Middle Cerebral Artery / Q000033:anatomy & histology; D019047:Phantoms, Imaging