title: Adaptive anisotropic gaussian filtering to reduce acquisition time in cardiac diffusion tensor imaging.
abstract: Diffusion tensor imaging (DTI) is used to quantify myocardial fiber orientation based on helical angles (HA). Accurate HA measurements require multiple excitations (NEX) and/or several diffusion encoding directions (DED). However, increasing NEX and/or DED increases acquisition time (TA). Therefore, in this study, we propose to reduce TA by implementing a 3D adaptive anisotropic Gaussian filter (AAGF) on the DTI data acquired from ex-vivo healthy and infarcted porcine hearts. DTI was performed on ex-vivo hearts [9-healthy, 3-myocardial infarction (MI)] with several combinations of DED and NEX. AAGF, mean (AVF) and median filters (MF) were applied on the primary eigenvectors of the diffusion tensor prior to HA estimation. The performance of AAGF was compared against AVF and MF. Root mean square error (RMSE), concordance correlation-coefficients and Bland-Altman's technique was used to determine optimal combination of DED and NEX that generated the best HA maps in the least possible TA. Lastly, the effect of implementing AAGF on the infarcted porcine hearts was also investigated. RMSE in HA estimation for AAGF was lower compared to AVF or MF. Post-filtering (AAGF) fewer DED and NEX were required to achieve HA maps with similar integrity as those obtained from higher NEX and/or DED. Pathological alterations caused in HA orientation in the MI model were preserved post-filtering (AAGF). Our results demonstrate that AAGF reduces TA without affecting the integrity of the myocardial microstructure.
authors: Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Laboratories, 2015 Neil Avenue, Columbus, OH, 43210, USA.|Department of Radiology, The Ohio State University, Room 460, 395 West 12th Avenue, 4th Floor, Columbus, OH, 43210, USA.
authors: Ria
authors: R
authors: Mazumder
authors: Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Laboratories, 2015 Neil Avenue, Columbus, OH, 43210, USA.
authors: Bradley D
authors: BD
authors: Clymer
authors: Department of Biomedical Informatics, Center for Biostatistics, Room 320D, Lincoln Tower, 1800 Cannon Drive, Columbus, OH, 43210, USA.
authors: Xiaokui
authors: X
authors: Mo
authors: Department of Radiology, The Ohio State University, Room 460, 395 West 12th Avenue, 4th Floor, Columbus, OH, 43210, USA.|Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, 244 Davis Heart and Lung Research Institute, 473 W. 12th Avenue, Columbus, OH, 43210, USA.
authors: Richard D
authors: RD
authors: White
authors: Department of Radiology, The Ohio State University, Room 460, 395 West 12th Avenue, 4th Floor, Columbus, OH, 43210, USA. Arunark.Kolipaka@osumc.edu.|Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, 244 Davis Heart and Lung Research Institute, 473 W. 12th Avenue, Columbus, OH, 43210, USA. Arunark.Kolipaka@osumc.edu.
authors: Arunark
authors: A
authors: Kolipaka
mesh_terms: D000818:Animals; D016880:Anisotropy; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D004195:Disease Models, Animal; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging* / Q000473:pathology; D009206:Myocardium / Q000473:pathology*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D013552:Swine
keywords: Anisotropic filtering; Diffusion tensor imaging (DTI); Fiber orientation; Helical angle (HA); Myocardial infarction (MI)