title: Compressed sensing for rapid late gadolinium enhanced imaging of the left atrium: A preliminary study.
abstract: Current late gadolinium enhancement (LGE) imaging of left atrial (LA) scar or fibrosis is relatively slow and requires 5-15min to acquire an undersampled (R=1.7) 3D navigated dataset. The GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) based parallel imaging method is the current clinical standard for accelerating 3D LGE imaging of the LA and permits an acceleration factor ~R=1.7. Two compressed sensing (CS) methods have been developed to achieve higher acceleration factors: a patch based collaborative filtering technique tested with acceleration factor R~3, and a technique that uses a 3D radial stack-of-stars acquisition pattern (R~1.8) with a 3D total variation constraint. The long reconstruction time of these CS methods makes them unwieldy to use, especially the patch based collaborative filtering technique. In addition, the effect of CS techniques on the quantification of percentage of scar/fibrosis is not known. We sought to develop a practical compressed sensing method for imaging the LA at high acceleration factors. In order to develop a clinically viable method with short reconstruction time, a Split Bregman (SB) reconstruction method with 3D total variation (TV) constraints was developed and implemented. The method was tested on 8 atrial fibrillation patients (4 pre-ablation and 4 post-ablation datasets). Blur metric, normalized mean squared error and peak signal to noise ratio were used as metrics to analyze the quality of the reconstructed images, Quantification of the extent of LGE was performed on the undersampled images and compared with the fully sampled images. Quantification of scar from post-ablation datasets and quantification of fibrosis from pre-ablation datasets showed that acceleration factors up to R~3.5 gave good 3D LGE images of the LA wall, using a 3D TV constraint and constrained SB methods. This corresponds to reducing the scan time by half, compared to currently used GRAPPA methods. Reconstruction of 3D LGE images using the SB method was over 20 times faster than standard gradient descent methods.
authors.affiliation: Electrical and Computer Engineering, University of Utah, UT, United States; Scientific, Computational and Imaging Institute (SCI), University of Utah, UT, United States; UCAIR, Dept of Radiology, University of Utah, UT, United States.
authors.forename: Srikant
authors.initials: S
authors.lastname: Kamesh Iyer
authors.affiliation: Electrical and Computer Engineering, University of Utah, UT, United States; Scientific, Computational and Imaging Institute (SCI), University of Utah, UT, United States.
authors.forename: Tolga
authors.initials: T
authors.lastname: Tasdizen
authors.affiliation: CARMA, Department of Internal Medicine, University of Utah, UT, United States.
authors.forename: Nathan
authors.initials: N
authors.lastname: Burgon
authors.affiliation: CARMA, Department of Internal Medicine, University of Utah, UT, United States; UCAIR, Dept of Radiology, University of Utah, UT, United States.
authors.forename: Eugene
authors.initials: E
authors.lastname: Kholmovski
authors.affiliation: CARMA, Department of Internal Medicine, University of Utah, UT, United States.
authors.forename: Nassir
authors.initials: N
authors.lastname: Marrouche
authors.affiliation: UCAIR, Dept of Radiology, University of Utah, UT, United States.
authors.forename: Ganesh
authors.initials: G
authors.lastname: Adluru
authors.affiliation: CARMA, Department of Internal Medicine, University of Utah, UT, United States; UCAIR, Dept of Radiology, University of Utah, UT, United States. Electronic address: edward.dibella@hsc.utah.edu.
authors.forename: Edward
authors.initials: E
authors.lastname: DiBella
mesh_terms: D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000601:surgery; D017115:Catheter Ablation; D002921:Cicatrix / Q000000981:diagnostic imaging; D005260:Female; D005355:Fibrosis / Q000000981:diagnostic imaging; D005682:Gadolinium; D006325:Heart Atria / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D015588:Observer Variation; D011877:Radionuclide Imaging; D012680:Sensitivity and Specificity
chemical_list: D005682:Gadolinium
keywords: Atrial fibrillation; Compressed sensing; Fast minimization; LGE imaging of the left atrium; MRI