Numerical equilibration of signal intensity and spatial resolution in time-resolved continuously moving table imaging

• Published in: Magnetic resonance in medicine 2006-03, Vol.55 (3), p.694-699
• Main Authors: Madhuranthakam, Ananth J., Hu, Houchun H., Kruger, David G., Riederer, Stephen J.
• Format: Article
• Language: English
• Subjects: continuously moving table; contrast bolus leading edge; Humans; Magnetic Resonance Angiography - methods; MR angiography; Phantoms, Imaging; signal intensity equilibration; time-resolved imaging
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.20800

Time‐resolved continuously moving table imaging techniques have been previously developed to observe a dynamically changing phenomenon over an extended field‐of‐view. The acquisition involves differential k‐space sampling and view sharing. Since the table is continuously moving during data acquisition, the k‐space for any longitudinal position is sampled only sparsely for the first reconstruction timeframe and is progressively more fully sampled for subsequent frames. Consequently, the signal intensity increases and the lateral spatial resolution improves from frame to frame even for static materials, which can mask true dynamically changing phenomena. This work provides a description of this effect and a means for signal correction in the early reconstruction frames, thus permitting any residual variation in signal intensity to be primarily attributed to true dynamic processes. The method is tested experimentally on a static phantom and in a peripheral vascular study designed to observe the leading edge of the contrast bolus. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.