title: Edge-enhanced spatiotemporal constrained reconstruction of undersampled dynamic contrast-enhanced radial MRI.
abstract: Dynamic contrast-enhanced magnetic resonance imaging (MRI) is a technique used to study and track contrast kinetics in an area of interest in the body over time. Reconstruction of images with high contrast and sharp edges from undersampled data is a challenge. While good results have been reported using a radial acquisition and a spatiotemporal constrained reconstruction (STCR) method, we propose improvements from using spatially adaptive weighting and an additional edge-based constraint. The new method uses intensity gradients from a sliding window reference image to improve the sharpness of edges in the reconstructed image. The method was tested on eight radial cardiac perfusion data sets with 24 rays and compared to the STCR method. The reconstructions showed that the new method, termed edge-enhanced spatiotemporal constrained reconstruction, was able to reconstruct images with sharper edges, and there were a 36%±13.7% increase in contrast-to-noise ratio and a 24%±11% increase in contrast near the edges when compared to STCR. The novelty of this paper is the combination of spatially adaptive weighting for spatial total variation (TV) constraint along with a gradient matching term to improve the sharpness of edges. The edge map from a reference image allows the reconstruction to trade-off between TV and edge enhancement, depending on the spatially varying weighting provided by the edge map.
authors.affiliation: Electrical and Computer Engineering Department, University of Utah, Salt Lake City, UT, USA.
authors.forename: Srikant
authors.initials: S
authors.lastname: Kamesh Iyer
authors.forename: Tolga
authors.initials: T
authors.lastname: Tasdizen
authors.forename: Edward V R
authors.initials: EV
authors.lastname: Dibella
mesh_terms: D000465:Algorithms; D003324:Coronary Artery Disease / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007451:Iodamide / Q000031:analogs & derivatives; D007458:Iodipamide / Q000031:analogs & derivatives; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008536:Meglumine / Q000031:analogs & derivatives*; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D009942:Organometallic Compounds; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D009942:Organometallic Compounds; C064572:gadobenic acid; D007451:Iodamide; D008536:Meglumine; D007458:Iodipamide; C006753:meglumine iodipamide