Segmentation of the fascia lata and reproducible quantification of intermuscular adipose tissue (IMAT) of the thigh

Magnetic Resonance Materials in Physics, Biology and Medicine - To develop a precise semi-automated segmentation of the fascia lata (FL) of the thigh to quantify IMAT volume in T1w MR images and...     

Reproducibility of Planewave Transit Times in three explosives during initiation: Comparison to wedge experiments

Planewave transit times were measured in three explosives: PBX-9404, pressed TNT, and PBX-9502. Four nominally identical disks were used on each shot to measure the reproducibility of the transit time. Standard deviations in transit times were 1%–2% if most of the wave trajectory was in the initiation phase. The standard deviation in transit times is larger than the measurement precision; this indicates a distribution in the response to the input pressure wave. Comparison was made to results of previous wedge initiation experiments. We conclude that most of the scatter in run distances to detonation found in wedge experiments is not inherent in the initiation process or the explosive quality. The scatter may be due to the imprecision of the free-surface velocity measurement coupled with the power-law character of the relation between run distance to detonation and input pressure.     

A new accurate and precise 3-D segmentation method for skeletal structures in volumetric CT data

We developed a highly automated three-dimensionally based method for the segmentation of bone in volumetric computed tomography (CT) datasets. The multistep approach starts with three-dimensional (3-D) region-growing using local adaptive thresholds followed by procedures to correct for remaining boundary discontinuities and a subsequent anatomically oriented boundary adjustment using local values of cortical bone density. We describe the details of our approach and show applications in the proximal femur, the knee, and the skull. The accuracy of the determination of geometrical parameters was analyzed using CT scans of the semi-anthropomorphic European spine phantom. Depending on the settings of the segmentation parameters cortical thickness could be determined with an accuracy corresponding to the side length of 1 to 2.5 voxels. The impact of noise on the segmentation was investigated by artificially adding noise to the CT data. An increase in noise by factors of two and five changed cortical thickness corresponding to the side length of one voxel. Intraoperator and interoperator precision was analyzed by repeated analysis of nine pelvic CT scans. Precision errors were smaller than 1% for trabecular and total volumes and smaller than 2% for cortical thickness. Intraoperator and interoperator precision errors were not significantly different. Our segmentation approach shows: 1) high accuracy and precision and is 2) robust to noise, 3) insensitive to user-defined thresholds, 4) highly automated and fast, and 5) easy to initialize.     

Spatially Resolved Stress Measurements in Materials With Polarisation-Sensitive Optical Coherence Tomography: Image Acquisition and Processing Aspects

Abstract:  We demonstrate that polarisation-sensitive optical coherence tomography (PS-OCT) is suitable for mapping the stress distribution within materials in a contact-free and non-destructive way. In contrast to transmission photoelasticity measurements, the samples do not have to be transparent but can be of scattering nature. Denoising and analysis of fringe patterns in single PS-OCT retardation images are demonstrated to be the bases for a quantitative whole-field evaluation of the internal stress state of samples under investigation.     

X-masking during logic BIST and its impact on defect coverage

We present a technique for making a circuit ready for logic built-in self test by masking unknown values at its outputs. In order to keep the silicon area cost low, some known bits in output responses are also allowed to be masked. These bits are selected based on a stuck-at n-detection based metric, such that the impact of masking on the defect coverage is minimal. An analysis based on a probabilistic model for resistive short defects indicates that the coverage loss for unmodeled defects is negligible for relatively low values of n.     

Indications for dental-CT. Case reports

In an earlier study we demonstrated that Concanavalin-A stimulated bovine T cell supernatants inhibited the growth of Cowdria ruminantium in bovine endothelial cells in vitro. An investigation was conducted to identify the cytokines which were responsible for this growth inhibition. Addition of antiserum against bovine interferon gamma (IFN gamma) reproducibly neutralized the inhibitory effect of the T cell supernatants, whereas addition of antisera against bovine tumor necrosis factor alpha (TNF alpha) had no effect. The inhibitory effect of IFN gamma on C. ruminantium growth was not mediated by the production of nitric oxide as there was no detectable difference in nitric oxide levels in cultures that were supplemented with T cell supernatants compared with those that were not. The IFN gamma mediated anti-C. ruminantium effect highlights the importance of cell mediated immune responses in control of these infections and in particular incriminates the protective role of T cells, or cells that secrete IFN gamma.