Measurement and Display of Instantaneous Regional Motion of the Myocardium

Quantitative assessment of regional heart motion has significant potential for more accurate diagnosis of heart disease and / or cardiac irregularities. Local heart motion may be studied from medical imaging sequences. Using functional parametric mapping, regional myocardial motion during a cardiac cycle can be color mapped onto a deformable heart model to obtain better understanding of the structure-to-function relationships in the myocardium. In this study, 3D reconstructions were obtained from the Dynamic Spatial Reconstructor 1-3 (DSR) at 15 time points throughout one cardiac cycle. Deformable models were created from the 3-D images for each time point of the cardiac cycle. From these polygonal models, regional excursions and velocities of each vertex representing a unit of myocardium were calculated for successive time intervals. The calculated results were visualized through model animations and / or specially formatted static images. The time point of regional maximum velocity and excursion of myocardium through the cardiac cycle was displayed using color mapping. The absolute value of regional maximum velocity and maximum excursion were displayed in a similar manner. Using animations, the local myocardial velocity changes were visualized as color changes on the cardiac surface during the cardiac cycle. Moreover, the magnitude and direction of motion for individual segments of myocardium could be displayed. These results suggest that the ability to encode quantitative functional information on dynamic cardiac anatomy enhances the diagnostic value of 4D images of the heart. Myocardial mechanics quantified this way adds a new dimension to the analysis of cardiac functional disease, including diastolic filling deficits and / or disturbances in regional electrophysiology and contraction patterns

Quantitative Analysis and Parametric Display of Regional Myocardial Mechanics

Quantitative assessment of regional heart motion has significant potential for more accurate diagnosis of heart disease and / or cardiac irregularities. Local heart motion may be studied from medical imaging sequences. Using functional parametric mapping, regional myocardial motion during a cardiac cycle can be color mapped onto a deformable heart model to obtain better understanding of the structure-to-function relationships in the myocardium, including regional patterns of akinesis or diskinesis associated with ischemia or infarction. In this study, 3D reconstructions were obtained from the Dynamic Spatial Reconstructor 1,2 (DSR) at 15 time points throughout one cardiac cycle of pre-infarct and post-infarct hearts. Deformable models were created from the 3-D images for each time point of the cardiac cycles. From these polygonal models, regional excursions and velocities of each vertex representing a unit of myocardium were calculated for successive time intervals. The calculated results were visualized through model animations and / or specially formatted static images. The time point of regional maximum velocity and excursion of myocardium through the cardiac cycle was displayed using color mapping. The absolute value of regional maximum velocity and maximum excursion were displayed in a similar manner. Using animations, the local myocardial velocity changes were visualized as color changes on the cardiac surface during the cardiac cycle. Moreover, the magnitude and direction of motion for individual segments of myocardium could be displayed. Comparisons of these dynamic parametric displays suggest that the ability to encode quantitative functional information on dynami

Data on the occurrence of corticolous myxomycetes from Denali National Park, Alaska

This data set contains data about corticolous (bark-inhabiting) myxomycetes from a 100×100 m2 plot including ca. 380 trees of Picea glauca (white spruce), of which 260 were large enough that bark could been sampled to prepare moist chamber cultures. At the end of the data set records of myxomycetes from 66 moist chambers prepared with bark of deciduous trees and shrubs, and outermost twiglets of P. glauca are included. These were sampled around the plot for purposes of comparison. A second data set shows measured tree parameters for the 380 trees examined in the plot. Data were used for a statistical analysis to search for environmental factors decisive for the occurrence of corticolous myxomycetes (Schnittler et al., 2016) [1]. Keywords: Amoebozoa, Myxomycete

Contrast enhancement with dual energy CT for the assessment of atherosclerosis

A drawback of the commonly used single source computed tomography systems (CT) is that different materials might show very similar attenuation at any selected radiation energy. However, the assessment of atherosclerosis requires good differentiation between vessel lumen, calcium, adipose, and surrounding tissue. Dual energy CT (DECT) simultaneously measures attenuations at two energies and therefore can improve the differentiation to some extent. A tissue cancelation and enhancement algorithm for dual energy data was already proposed in 1981 and evaluated on experimental settings with a stationary X-ray source. For this study, we adapted this algorithm for DECT and propose its usage as a pre-processing step for the assessment of atherosclerosis. On clinical DECT patient data and with fixed parameters we could show a simultaneous contrast enhancement between 8% and 67% among all targeted tissues

Environment drives spatio-temporal patterns of clonality in white spruce (Picea glauca) in Alaska

Many plant species reproduce by cloning, if environmental conditions are unfavorable for sexual reproduction. To test the alternative hypotheses whether cloning is an â exit strategyâ or caused by selection, clonal growth in white spruce (Picea glauca (Moench) Voss) was investigated in three stands in Alaska, each consisting of a core (closed forest) and an edge (treeline) plot. A total of 2571 trees were mapped and genotyped with 11 SSR markers. The proportion of clonal trees follows a moisture gradient and was lowest in the dry Interior basin (4.5%), followed by the sites at the Alaska Range (9.0%) and Brooks Range (21.7%). At the two latter sites, clonal growth was more frequent in the edge plot. A comparison among 960 aged trees revealed that clonal growth becomes more likely with increasing age and continues over the life span of a tree. Genetic data do not indicate any genetic predisposition for cloning. Most likely, clonal growth in white spruce takes place via layering and depends on environmental conditions. Since performance of the trees, and therefore likely plant reproductive success, is lower in plots with a high proportion of clones, selection for clonal growth seems to be highly unlikely.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author