Browsing by Author "Thedens, DR"

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    3D MR coronary artery segmentation
    (LIPPINCOTT WILLIAMS & WILKINS, 1998) Cline, HE; Thedens, DR; Irarrazaval, P; Meyer, CH; Hu, BS; Nishimura, DG; Ludke, S
    Coronary arteries are segmented from the blood pool using mathematical morphology operations from a 3D magnetic resonance spiral acquisition on a continuously breathing healthy volunteer. The segmented volume is maximal intensity projected at different views to yield coronary angiograms showing the left anterior descending artery (LAD), right coronary artery (RCA), and left circumflex artery (LCX), Magnetic resonance coronary angiography provides a retrospective rotating view of the coronary artery tree that complements oblique reformatted sections.
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    Fast magnetic resonance coronary angiography with a three-dimensional stack of spirals trajectory
    (WILEY, 1999) Thedens, DR; Irarrazaval, P; Sachs, TS; Meyer, CH; Nishimura, DG
    In this work, three-dimensional (3D) spiral imaging has been utilized for magnetic resonance coronary angiography, Spiral-based 3D techniques can dramatically reduce imaging time requirements compared with 3D Fourier Transform imaging. The method developed here utilized a "stack of spirals" trajectory, to traverse 3D k-space rapidly. Both thick-slab volumes encompassing the entire coronary tree with isotropic resolution and thin-slab volumes targeted to a particular vessel of interest were acquired. Respiratory compensation was achieved using the diminishing variance algorithm. TS-prepared contrast was also applied in some cases to improve contrast between vessel and myocardium, while off-resonance blurring was minimized by applying a linear correction to the acquired data. Images from healthy volunteers were displayed using a curved reformatting technique to view long segments of vessel in a single projection. The results demonstrate that this 3D spiral technique is capable of producing high-quality coronary magnetic resonance angiograms, (C) 1999 Wiley-Liss, Inc.