Paper
13 March 2007 Motion compensated reconstructions of calcified coronary plaques in cardiac CT
Author Affiliations +
Abstract
In order to obtain motion-compensated reconstructions of calcified coronary plaques in cardiac CT, the dynamic trajectory of the plaque must be known rather accurately. The purpose of this study is to evaluate whether the dynamic trajectories of a plaque extracted from reconstructions provided by a previously developed tracking algorithm can be used for obtaining motion-compensated reconstructions of this plaque. A single projection dataset of the modified FORBILD phantom containing a calcified plaque undergoing continuous periodic motion was acquired with a gantry rotation time of 0.4 s and a heart rate of 90 bpm. Three sets of phase-correlated 4D ROI images centered on the calcified plaque (labeled G1, G2, and G3) were obtained from this dataset by varying the numbers of data segments used for cardiac gating (N = 1, 2, 3) during the reconstruction steps of the tracking algorithm. Dynamic trajectories from each of these datasets were calculated from edge-based segmentations of these datasets. When compared to the true trajectory (labeled T), root-mean-square (RMS) values of position for trajectories G1, G2, and G3 were 1.473 mm, 1.166 mm, and 0.736 mm, respectively. Trajectories G1, G2, G3, and T then were used to obtain motion-compensated reconstructions MC1, MC2, MC3, and MCT, respectively, at 6.25 ms time intervals over 2 cardiac cycles. The areas (number of pixels) of the plaque then were measured at all time intervals for each set of reconstructions. When compared against areas obtained for MCT, RMS values of areas for reconstructions MC1, MC2, and MC3 were 26.888, 12.384, and 4.837, respectively. On visual inspection, MC3 also exhibited the least motion artifacts at most time intervals.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Martin King, Xiaochuan Pan, Maryellen Giger, and Kenji Suzuki "Motion compensated reconstructions of calcified coronary plaques in cardiac CT", Proc. SPIE 6510, Medical Imaging 2007: Physics of Medical Imaging, 651012 (13 March 2007); https://doi.org/10.1117/12.713798
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KEYWORDS
Reconstruction algorithms

Image segmentation

Algorithm development

Heart

Beam propagation method

Computed tomography

Detection and tracking algorithms

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