Cardiovascular morphometry with high-resolution 3D magnetic resonance: First application to left ventricle diastolic dysfunction

Abstract

a b s t r a c tIn this study, an image-based morphometry toolset quantifying geometric descriptors of the left ventricle, aorta and their coupling is applied to investigate whether morphological information can differentiate between subjects affected by diastolic dysfunction (patient group) and their age-matched controls (control group). The ventriculo-aortic region of 20 total participants (10 per group) were segmented from highresolution 3D magnetic resonance images, from the left ventricle to the descending aorta. Each geometry was divided into segments in correspondence of anatomical landmarks. The orientation of each segment was estimated by least-squares fitting of the respective centerline segment to a plane. Curvature and torsion of vessels' centerlines were automatically extracted, and aortic arch was characterized in terms of height and width.Tilt angle between subsequent best-fit planes in the left ventricle and ascending aorta regions, curvature and cross-sectional area in the descending aorta resulted significantly different between patient and control groups ( P -values < 0.05). Aortic volume ( P = 0.04) and aortic arch width ( P = 0.03) resulted significantly different between the two groups. The observed morphometric differences underlie differences in hemodynamics, by virtue of the influence of geometry on blood flow patterns.The present exploratory analysis does not determine if aortic geometric changes precede diastolic dysfunction, or vice versa. However, this study (1) underlines differences between healthy and diastolic dysfunction subjects, and (2) provides geometric parameters that might help to determine early aortic geometric alterations and potentially prevent evolution toward advanced diastolic dysfunction.

The Role of Circle of Willis Anatomy Variations in Cardio-embolic Stroke: A Patient-Specific Simulation Based Study

“…Embolus particles of finite size and inertia interact with these spatio-temporally varying flow features, leading to a nearly chaotic advection from their origin site to their destination [37] (see supplementary animation). This anatomy-flow-embolus synergy can be utilized to devise tools that integrate quantitative vascular geometry analysis [12] with embolus dynamics [36]. This can enable embolism predictions based on medical image-based vascular geometry information, which may have diagnostic utility owing to geometry analysis times being comparable with clinical timings.…”

Comparison of Qualitative and Quantitative Assessments of Iliac Artery Tortuosity and Calcification

“…Lastly, there is some uncertainty in the tortuosity calculations due to the approach used to define the vessel centerlines. Sangalli et al 25 and Gallo et al 26 propose a more robust approach for centerline smoothing using free-knots regression splines, which turn the discrete centerlines from VMTK into continuous ones. While this approach will likely improve the calculation of local variables, such as curvature, which are based on the derivative of the centerline, it is not likely to have a significant impact on the tortuosity which is a global variable and is less sensitive to the smoothness of the centerline.…”

Validation of contralateral premolars as the substrate for endodontic comparison studies

“…The mean absolute torsion (degree of twisting of curve out of the osculating plane for each centreline point; Bulant et al 2017, Gallo et al 2017) of the entire length of the root canal was compared pre-and post-instrumentation to evaluate the influence of the file and instrumentation mechanics (Bergmans et al 2001). Torsion is expressed as a negative or positive value depending on whether the twisting is counter clockwise or clockwise, and this study considered the absolute mean of the point-wise torsion along the entire length of the root canal models.…”