Identification of Carotid Artery Microstructure and Plaque Rupture Using C-Arm Cone-Beam CT: A Case Report

C-arm cone-beam computed tomography (CBCT) offers a high imaging resolution with a wide range of contrast to visualize vessels, soft tissue, and bone. We report the usefulness of CBCT in observing neovascularization, microcalcification, and plaque rupture. A 56-year-old man presented with vertigo and complain of an unsteady gait for 5 months. Catheter angiography demonstrated right severe carotid stenosis with irregular filling defect, which on high-resolution MRI showed vessel wall enhancement. The CBCT showed high density structures and linear contrast enhancement from the vascular lumen to the plaque, related to microstructure and plaque rupture. Carotid endarterectomy was performed, and histopathology confirmed that the high-density areas represented neovascularization and microcalcification, with linear enhancement representing plaque rupture. This is the first report showing that microcalcifications and plaque rupture can be identified by CBCT. Thus, CBCT can be used as a promising supplement to current imaging modalities to evaluate plaque components more accurately.

Harumanis Mango Leaves Image Segmentation on RGB and HSV Colour Spaces using Fast k-Means Clustering

Harumanis mango is the signature fruit in Perlis due to its delicious taste and its sweet-smelling. A good quality Harumanis tree requires rich in nutrition (healthy), and the tree will grow lots of fruits compared to the trees which are poor in nutrition (unhealthy). The health condition of a tree can be observed through the leaves in term of shape of leaves. For a healthy Harumanis tree, the leaves grow in scattering shapes. Meanwhile, an unhealthy Harumanis tree grows in gathered shapes. Therefore, this research is focusing on Harumanis mango leaves image segmentation by comparing between RGB and HSV colour spaces in order to obtain the best segmentation performance. 100 of Harumanis mango tree leaves images are used in this research. These images have undergo through image pre-processing such as modified linear contrast stretching and colour components extraction based on RGB and HSV colour spaces. Then, the colour component images have been segmented by using fast k-means clustering in order to obtain the leaves segmented images. Finally, quantitative analyses have been performed to measure the segmentation performance based on sensitivity, specificity and accuracy. Overall, the results show that S component of HSV colour space archives the highest accuracy with 85.81%.

Simulation study towards quantitative X-ray and neutron tensor tomography regarding the validity of linear approximations of dark-field anisotropy

Tensor tomography is fundamentally based on the assumption of a both anisotropic and linear contrast mechanism. While the X-ray or neutron dark-field contrast obtained with Talbot(-Lau) interferometers features the required anisotropy, a preceding detailed study of dark-field signal origination however found its specific orientation dependence to be a non-linear function of the underlying anisotropic mass distribution and its orientation, especially challenging the common assumption that dark-field signals are describable by a function over the unit sphere. Here, two approximative linear tensor models with reduced orientation dependence are investigated in a simulation study with regard to their applicability to grating based X-ray or neutron dark-field tensor tomography. By systematically simulating and reconstructing a large sample of isolated volume elements covering the full range of feasible anisotropies and orientations, direct correspondences are drawn between the respective tensors characterizing the physically based dark-field model used for signal synthesization and the mathematically motivated simplified models used for reconstruction. The anisotropy of freely rotating volume elements is thereby confirmed to be, for practical reconstruction purposes, approximable both as a function of the optical axis’ orientation or as a function of the interferometer’s grating orientation. The eigenvalues of the surrogate models’ tensors are found to exhibit fuzzy, yet almost linear relations to those of the synthesization model. Dominant orientations are found to be recoverable with a margin of error on the order of magnitude of 1$$^{\circ }$$ ∘ . Although the input data must adequately address the full orientation dependence of dark-field anisotropy, the present results clearly support the general feasibility of quantitative X-ray dark-field tensor tomography within an inherent yet acceptable statistical margin of uncertainty.

Benefits of Maternal Thiamine Supplementation for Enhancing Cambodian Infants’ Social Responsiveness at 24 Weeks

Objectives Infants in Cambodia are at risk for thiamine deficiency, with long-term negative consequences for neuro-cognitive development. We investigated the extent to which maternal thiamine supplementation enhances infants’ responsiveness to social engagement. Such responsiveness is both indicative of neuro-cognitive development and beneficial for subsequent neuro-cognitive progress. Methods 335 lactating Cambodian mothers were randomly assigned to receive a capsule containing 0, 1.2, 2.4, or 10 mg of thiamine daily from 2- until 24-weeks postnatal. We assessed infants’ social responsiveness via a new method – the Primary Engagement Task (PET) – when infants were 2-, 12-, and 24-weeks. In the PET, mothers were asked to elicit and sustain a smile from infants as they added and then removed modalities of engagement (eye-contact/facial expression, voice and touch) across six 30-second “epochs.” Subsequent behavioral coding from video-recordings determined changes in infants’ state across the epochs of the PET. Results Preliminary analyses based on 103 of the 335 infants in the PET at 24 weeks revealed that infants displayed significantly increased alertness as mothers introduced new modalities of engagement in the PET, and a partial decline in alertness as modalities were removed (linear contrast F(1,102) = 24.37, P = 0.000; quadratic contrast F(1,102) = 7.27, P = 0.008). Although maternal thiamine dosage did not influence these patterns overall (F's < 1.56, P's > 0.20), higher maternal thiamine dosage was associated with infants displaying enhanced alertness when mothers first offered eye-contact in the PET (beta-weight = 0.026; t = 2.01, P = 0.047). This pattern of alerting to maternal eye-contact was statistically significant only in the 10 mg group (paired t(25) = 3.14, P = 0.004). Conclusions Infants whose mothers received 10 mg daily thiamine supplementation displayed increased alertness to opportunities to interact socially. These preliminary findings (a) showcase the value of the PET for assessing infants’ responsiveness to caregiver's efforts to engage them socially, and (b) hint that maternal thiamine supplementation promotes infants’ social responsiveness, thereby underscoring the importance of infants’ early access to adequate thiamine for neuro-cognitive thriving. Funding Sources Bill & Melinda Gates Foundation & New York Academy of Sciences.

Non-linear Acoustic Characterization of Microbubbles and Nanobubbles

Non-linear contrast-enhanced ultrasound can provide high contrast images by enhancing the non-linear signals from bubble oscillations. In this work, we developed a methodology to detect individual bubble scattering using focused transducers with dilute bubble solutions. Microbubbles and nanobubbles were made with five different lipid shell compositions. Their structure is altered through additional components added to the shell that affect their stability. Dilute samples of bubbles were sonicated at 25 MHz with 30 cycles using a commercial high frequency ultrasound instrument with a pressure range of 75 kPa to 3 MPa. Criteria were developed to ensure signals were only classified if they contained an isolated bubbles’ response. The response of the bubbles of different shell compositions were compared using analysis tools developed. There were no observable differences in the non-linear behaviour between the different shells. However, when comparing microbubbles to nanobubbles differences involving signal count, stability and harmonic amplitudes were observed.

Non-linear Acoustic Characterization of Microbubbles and Nanobubbles

Non-linear contrast-enhanced ultrasound can provide high contrast images by enhancing the non-linear signals from bubble oscillations. In this work, we developed a methodology to detect individual bubble scattering using focused transducers with dilute bubble solutions. Microbubbles and nanobubbles were made with five different lipid shell compositions. Their structure is altered through additional components added to the shell that affect their stability. Dilute samples of bubbles were sonicated at 25 MHz with 30 cycles using a commercial high frequency ultrasound instrument with a pressure range of 75 kPa to 3 MPa. Criteria were developed to ensure signals were only classified if they contained an isolated bubbles’ response. The response of the bubbles of different shell compositions were compared using analysis tools developed. There were no observable differences in the non-linear behaviour between the different shells. However, when comparing microbubbles to nanobubbles differences involving signal count, stability and harmonic amplitudes were observed.

Nephrogenic Systemic Fibrosis as a Complication after Gadolinium-Containing Contrast Agents: A Rapid Review

Introduction: Nephrogenic systemic fibrosis (NFS) is a generalized disorder occurring in people with kidney failure. This new disease entity can lead to significant disability or even death. Gadolinium-associated systemic fibrosis is related to exposure to contrast agents used for magnetic resonance imaging. The aim of this study was to review the literature in available scientific databases on NFS—complication after gadolinium-containing contrast agents. Methods: PubMed and Cochrane Library databases were searched using adequate key words. A literature review of the described cases of NSF occurrence after exposure to gadolinium-containing contrast agents was performed. A review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A review written protocol was not drafted. Results: Originally, 647 studies were searched in scientific databases. After rejecting the duplicate results, 515 results were obtained. Finally, nine studies were included in the review. A total of 173 cases with NSF were included in the analysis. The majority of patients were undergoing dialysis. The contrast agent used for MRI was most often gadodiamide and gadopentetate dimeglumine. The time from exposure to NSF symptoms was from two days to three years. Three authors pointed out other factors in their papers that could potentially influence the occurrence of NSF. These included: metabolic acidosis, ongoing infection, higher doses of erythropoietin and higher serum concentrations of ionized calcium and phosphate. Since 2008, the number of reported cases of NSF has decreased significantly. More recent guidelines and reports indicate that not all contrast agents are associated with the same risk of developing NSF. Conclusions: Most NSF occurs after exposure to linear contrast agents. Therefore, it is recommended to limit their use, especially in dialyzed patients and patients with a GFR < 30 mL/min.

Motion Planning Algorithm for a Mobile Robot with a Smart Machine Vision System

This study is devoted to the challenges of motion planning for mobile robots with smart machine vision systems. Motion planning for mobile robots in the environment with obstacles is a problem to deal with when creating robots suitable for operation in real-world conditions. The solutions found today are predominantly private, and are highly specialized, which prevents judging of how successful they are in solving the problem of effective motion planning. Solutions with a narrow application field already exist and are being already developed for a long time, however, no major breakthrough has been observed yet. Only a systematic improvement in the characteristics of such systems can be noted. The purpose of this study: develop and investigate a motion planning algorithm for a mobile robot with a smart machine vision system. The research subject for this article is a motion planning algorithm for a mobile robot with a smart machine vision system. This study provides a review of domestic and foreign mobile robots that solve the motion planning problem in a known environment with unknown obstacles. The following navigation methods are considered for mobile robots: local, global, individual. In the course of work and research, a mobile robot prototype has been built, capable of recognizing obstacles of regular geometric shapes, as well as plan and correct the movement path. Environment objects are identified and classified as obstacles by means of digital image processing methods and algorithms. Distance to the obstacle and relative angle are calculated by photogrammetry methods, image quality is improved by linear contrast enhancement and optimal linear filtering using the Wiener-Hopf equation. Virtual tools, related to mobile robot motion algorithm testing, have been reviewed, which led us to selecting Webots software package for prototype testing. Testing results allowed us to make the following conclusions. The mobile robot has successfully identified the obstacle, planned a path in accordance with the obstacle avoidance algorithm, and continued moving to the destination. Conclusions have been drawn regarding the concluded research.

Non-invasive focusing and imaging in scattering media with a fluorescence-based transmission matrix

In biological microscopy, light scattering represents the main limitation to image at depth. Recently, a set of wavefront shaping techniques has been developed in order to manipulate coherent light in strongly disordered materials. The Transmission Matrix approach has shown its capability to inverse the effect of scattering and efficiently focus light. In practice, the matrix is usually measured using an invasive detector or low-resolution acoustic guide stars. Here, we introduce a non-invasive and all-optical strategy based on linear fluorescence to reconstruct the transmission matrices, to and from a fluorescent object placed inside a scattering medium. It consists in demixing the incoherent patterns emitted by the object using low-rank factorizations and phase retrieval algorithms. We experimentally demonstrate the efficiency of this method through robust and selective focusing. Additionally, from the same measurements, it is possible to exploit memory effect correlations to image and reconstruct extended objects. This approach opens up a new route towards imaging in scattering media with linear or non-linear contrast mechanisms.

COMPARISON OF IMAGE ENHANCEMENT TECHNIQUES FOR RAPID PROCESSING OF POST FLOOD IMAGES

Satellite images are widely used for assessing the areal extent of flooded areas. However, presence of clouds and shadow limit the utility of these images. Numerous digital algorithms are available for enhancing such images and highlighting areas of interest. These algorithms range from simple to complex, and the time required to process these images also varies considerably. For disaster response, it is important to select an algorithm that can enhance the quality of the images in relatively short time. This study compared the relative performance of five traditional (Histogram Equalization, Local Histogram Equalization, Contrast Limited Adaptive Histogram Equalization, Gamma Correction, and Linear Contrast Stretch) algorithms for enhancing post-flood satellite images. Flood images with different levels of clouds and shadows were enhanced and output generated were evaluated in terms of processing time and quality as measured by Blind/Reference less Image Spatial Quality Evaluator (BRISQUE), a no-reference image quality metric. Findings from this study will provide valuable information to image analysts for selecting a suitable algorithm for rapidly processing post-flood satellite images.