title: Atherosclerotic plaque fibrous cap assessment under an oblique scan plane orientation in carotid MRI.
abstract: Carotid magnetic resonance imaging (MRI) is used to noninvasively assess atherosclerotic plaque fibrous cap (FC) status, which is closely related to ischemic stroke. Acquiring anisotropic voxels improves in-plane visualization, however, an oblique scan plane orientation could then obscure a FC (i.e., contrast below the noise level) and thus impair a reliable status assessment. To quantify this, we performed single-slice numerical simulations of a clinical 3.0T, 2D T1-weighted, black-blood, contrast-enhanced pulse sequence with various voxel dimensions: in-plane voxel size of 0.62 mm × 0.62 mm and 0.31 mm × 0.31 mm, slice thickness of 1, 2, and 3 mm. Idealized plaque models (FC thickness of 0.5, 1, and 1.5 mm) were imaged at various scan plane angles (0°-40° in steps of 10°), and the FC contrast was quantified. We found that when imaging thin FCs with anisotropic voxels, the FC contrast decreased when the scan plane orientation angle increased. However, a reduced in-plane voxel size at the cost of an increased slice thickness often led to enhanced FC contrast even in the presence of scan plane orientation angles of up to 40°. It can be concluded that while isotropic-voxel imaging eliminates the issue of scan plane obliqueness, it comes at the cost of reduced FC contrast, thus likely decreasing the reliability of FC status assessment in carotid MRI. If scan plane orientation obliquity at the slice of interest is moderate (<40°) or otherwise diminished through careful scan planning, voxel anisotropy could increase FC contrast and, in effect, increase the reliability of FC status assessment.
authors.affiliation: 1 Department of Biomedical Engineering, 2 Department of Radiology, Erasmus MC, Rotterdam, the Netherlands ; 3 Department of MR Clinical Science, Philips Healthcare, Best, the Netherlands ; 4 Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands ; 5 Department of Imaging Science and Technology, Delft University of Technology, Delft, the Netherlands.
authors.forename: Harm A
authors.initials: HA
authors.lastname: Nieuwstadt
authors.affiliation: 1 Department of Biomedical Engineering, 2 Department of Radiology, Erasmus MC, Rotterdam, the Netherlands ; 3 Department of MR Clinical Science, Philips Healthcare, Best, the Netherlands ; 4 Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands ; 5 Department of Imaging Science and Technology, Delft University of Technology, Delft, the Netherlands.
authors.forename: Aad
authors.initials: A
authors.lastname: van der Lugt
authors.affiliation: 1 Department of Biomedical Engineering, 2 Department of Radiology, Erasmus MC, Rotterdam, the Netherlands ; 3 Department of MR Clinical Science, Philips Healthcare, Best, the Netherlands ; 4 Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands ; 5 Department of Imaging Science and Technology, Delft University of Technology, Delft, the Netherlands.
authors.forename: Zaid A M
authors.initials: ZA
authors.lastname: Kassar
authors.affiliation: 1 Department of Biomedical Engineering, 2 Department of Radiology, Erasmus MC, Rotterdam, the Netherlands ; 3 Department of MR Clinical Science, Philips Healthcare, Best, the Netherlands ; 4 Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands ; 5 Department of Imaging Science and Technology, Delft University of Technology, Delft, the Netherlands.
authors.forename: Marcel
authors.initials: M
authors.lastname: Breeuwer
authors.affiliation: 1 Department of Biomedical Engineering, 2 Department of Radiology, Erasmus MC, Rotterdam, the Netherlands ; 3 Department of MR Clinical Science, Philips Healthcare, Best, the Netherlands ; 4 Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands ; 5 Department of Imaging Science and Technology, Delft University of Technology, Delft, the Netherlands.
authors.forename: Anton F W
authors.initials: AF
authors.lastname: van der Steen
authors.affiliation: 1 Department of Biomedical Engineering, 2 Department of Radiology, Erasmus MC, Rotterdam, the Netherlands ; 3 Department of MR Clinical Science, Philips Healthcare, Best, the Netherlands ; 4 Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands ; 5 Department of Imaging Science and Technology, Delft University of Technology, Delft, the Netherlands.
authors.forename: Frank J H
authors.initials: FJ
authors.lastname: Gijsen
keywords: Magnetic resonance imaging (MRI); atherosclerosis; fibrous cap (FC); simulations; stroke