title: Assessing cardiac function from total-variation-regularized 4D C-arm CT in the presence of angular undersampling.
abstract: Time-resolved tomographic cardiac imaging using an angiographic C-arm device may support clinicians during minimally invasive therapy by enabling a thorough analysis of the heart function directly in the catheter laboratory. However, clinically feasible acquisition protocols entail a highly challenging reconstruction problem which suffers from sparse angular sampling of the trajectory. Compressed sensing theory promises that useful images can be recovered despite massive undersampling by means of sparsity-based regularization. For a multitude of reasons-most notably the desired reduction of scan time, dose and contrast agent required-it is of great interest to know just how little data is actually sufficient for a certain task. In this work, we apply a convex optimization approach based on primal-dual splitting to 4D cardiac C-arm computed tomography. We examine how the quality of spatially and temporally total-variation-regularized reconstruction degrades when using as few as [Formula: see text] projection views per heart phase. First, feasible regularization weights are determined in a numerical phantom study, demonstrating the individual benefits of both regularizers. Secondly, a task-based evaluation is performed in eight clinical patients. Semi-automatic segmentation-based volume measurements of the left ventricular blood pool performed on strongly undersampled images show a correlation of close to 99% with measurements obtained from less sparsely sampled data.
authors.affiliation: Pattern Recognition Lab, Friedrich-Alexander-University Erlangen-Nuremberg, Germany. Erlangen Graduate School in Advanced Optical Technologies (SAOT), Germany.
authors.forename: O
authors.initials: O
authors.lastname: Taubmann
authors.forename: V
authors.initials: V
authors.lastname: Haase
authors.forename: G
authors.initials: G
authors.lastname: Lauritsch
authors.forename: Y
authors.initials: Y
authors.lastname: Zheng
authors.forename: G
authors.initials: G
authors.lastname: Krings
authors.forename: J
authors.initials: J
authors.lastname: Hornegger
authors.forename: A
authors.initials: A
authors.lastname: Maier
mesh_terms: D000465:Algorithms; D004562:Electrocardiography; D056973:Four-Dimensional Computed Tomography / Q000379:methods*; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D019047:Phantoms, Imaging; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016277:Ventricular Function, Left