Purpose: The trend towards lower radiation doses and advances in computed tomography (CT) reconstruction may impair the operation of pretrained segmentation models, giving rise to the problem of estimating the dose robustness of existing segmentation models. Previous studies addressing the issue suffer either from a lack of registered low- and full-dose CT images or from simplified simulations.
Approach: We employed raw data from full-dose acquisitions to simulate low-dose CT scans, avoiding the need to rescan a patient.
Objectives: Cardiac motion artifacts hinder the assessment of coronary arteries in coronary computed tomography angiography (CCTA). We investigated the impact of motion compensation reconstruction (MCR) on motion artifacts in CCTA at various heart rates (HR) using a dynamic phantom.
Materials And Methods: An artificial hollow coronary artery (5-mm diameter lumen) filled with iodinated contrast agent (400 HU at 120 kVp), positioned centrally in an anthropomorphic chest phantom, was scanned using a dual-layer spectral detector CT.
It is now recognized that a number of excipients previously considered to be "inert" have the capacity to alter drug oral bioavailability through a range of in vivo effects. The various mechanisms through which an excipient can affect in vivo gastrointestinal physiology and drug absorption characteristics were explored in "A Critical Overview of The Biological Effects of Excipients (Part I): Impact on Gastrointestinal Absorption." The next critical issue that needs to be discussed is how these biological effects are evaluated.
View Article and Find Full Text PDFImplanting stents to re-open stenotic lesions during percutaneous coronary interventions is considered a standard treatment for acute or chronic coronary syndrome. Intravascular ultrasound (IVUS) can be used to guide and assess the technical success of these interventions. Automatically segmenting stent struts in IVUS sequences improves workflow efficiency but is non-trivial due to a challenging image appearance entailing manifold ambiguities with other structures.
View Article and Find Full Text PDFInteractions of ceramic proton conductors with the environment under operating conditions play an essential role on material properties and device performance. It remains unclear how the chemical environment of material, as modulated by the operating condition, affects the proton conductivity. Combining near-ambient pressure X-ray photoelectron spectroscopy and impedance spectroscopy, we investigate the chemical environment changes of oxygen and the conductivity of BaZrYO under operating condition.
View Article and Find Full Text PDFMany active pharmaceutical ingredients (APIs) in the pharmaceutical pipeline require bioavailability enhancing formulations due to very low aqueous solubility. Although spray dried dispersions (SDDs) have demonstrated broad utility in enhancing the bioavailability of such APIs by trapping them in a high-energy amorphous form, many new chemical entities (NCEs) are poorly soluble not just in water, but in preferred organic spray drying solvents, e.g.
View Article and Find Full Text PDFThe recent publication "Association between Urinary Metabolites and the Exposure of Intensive Care Newborns to Plasticizers of Medical Devices Used for Their Care Management" by L. Bernard et al. (2021) [.
View Article and Find Full Text PDFAngiography-derived physiological assessment of coronary lesions has emerged as an alternative to wire-based assessment aiming at less-invasiveness and shorter procedural time as well as cost effectiveness in physiology-guided decision making. However, current available image-derived physiology software have limitations including the requirement of multiple projections and are time consuming. METHODS/DESIGN: The ReVEAL iFR (Radiographic imaging Validation and EvALuation for Angio-iFR) trial is a multicenter, multicontinental, validation study which aims to validate the diagnostic accuracy of the Angio-iFR medical software device (Philips, San Diego, US) in patients undergoing angiography for Chronic Coronary Syndrome (CCS).
View Article and Find Full Text PDFObjective: The aim is to evaluate whether smart worklist prioritization by artificial intelligence (AI) can optimize the radiology workflow and reduce report turnaround times (RTATs) for critical findings in chest radiographs (CXRs). Furthermore, we investigate a method to counteract the effect of false negative predictions by AI-resulting in an extremely and dangerously long RTAT, as CXRs are sorted to the end of the worklist.
Methods: We developed a simulation framework that models the current workflow at a university hospital by incorporating hospital-specific CXR generation rates and reporting rates and pathology distribution.
Recently published studies have proposed that amorphous drug nanoparticles in gastrointestinal fluids may be beneficial for the absorption of poorly soluble compounds. Nanosized drug particles are known to provide rapid dissolution rates and, in some instances, a slight increase in solubility. However, in recent studies, the differences observed in vivo could not be explained solely by these attributes.
View Article and Find Full Text PDFThe increased availability of labeled X-ray image archives (e.g. ChestX-ray14 dataset) has triggered a growing interest in deep learning techniques.
View Article and Find Full Text PDFBackground: Vasodilator stress computed tomography perfusion (sCTP) imaging is complementary to coronary CT angiography (CCTA), used to determine the hemodynamic significance of coronary artery disease. However, it requires a separate image acquisition due to motion artifacts caused by higher heart rates during stress, resulting in increased iodine contrast dose and radiation. We sought to determine whether a novel motion correction algorithm applied to stress images would improve the visualization of the coronary arteries to potentially allow CCTA + sCTP evaluation in a single scan.
View Article and Find Full Text PDFObjective: The goal of this study was to develop and validate a system for automatic segmentation of the spine, pedicle identification, and screw path suggestion for use with an intraoperative 3D surgical navigation system.
Methods: Cone-beam CT (CBCT) images of the spines of 21 cadavers were obtained. An automated model-based approach was used for segmentation.
We report the development of a new spray-drying and nanoparticle assembly process (SNAP) that enables the formation of stable, yet rapidly dissolving, sub-200 nm nanocrystalline particles within a high T glassy matrix. SNAP expands the class of drugs that spray-dried dispersion (SDD) processing can address to encompass highly crystalline, but modestly hydrophobic, drugs that are difficult to process by conventional SDD. The process integrates rapid precipitation and spray-drying within a custom designed nozzle to produce high supersaturations and precipitation of the drug and high T glassy polymer.
View Article and Find Full Text PDFImproving the oral absorption of compounds with low aqueous solubility is a common challenge that often requires an enabling technology. Frequently, oral absorption can be improved by formulating the compound as an amorphous solid dispersion (ASD). Upon dissolution, an ASD can reach a higher concentration of unbound drug than the crystalline form, and often generates a large number of sub-micrometer, rapidly dissolving drug-rich colloids.
View Article and Find Full Text PDFBioavailability-enhancing formulations are often used to overcome challenges of poor gastrointestinal solubility for drug substances developed for oral administration. Conventional in vitro dissolution tests often do not properly compare such formulations due to the many different drug species that may exist in solution. To overcome these limitations, we have designed a practical in vitro membrane flux test, that requires minimal active pharmaceutical ingredient (API) and is capable of rapidly screening many drug product intermediates.
View Article and Find Full Text PDFDespite continuous progress in X-ray angiography systems, X-ray coronary angiography is fundamentally limited by its 2D representation of moving coronary arterial trees, which can negatively impact assessment of coronary artery disease and guidance of percutaneous coronary intervention. To provide clinicians with 3D/3D+time information of coronary arteries, methods computing reconstructions of coronary arteries from X-ray angiography are required. Because of several aspects (e.
View Article and Find Full Text PDFMinim Invasive Ther Allied Technol
January 2017
Purpose: To evaluate the technical feasibility of automatically removing the ribs and spine from C-arm cone-beam computed tomography (CBCT) images acquired during transcatheter arterial chemoembolization (TACE).
Material And Methods: Fifty-eight patients (45.8 ± 5.
Purpose To assess the visibility of radiopaque microspheres during transarterial embolization (TAE) in the VX2 rabbit liver tumor model by using multimodality imaging, including single-snapshot radiography, cone-beam computed tomography (CT), multidetector CT, and micro-CT. Materials and Methods The study was approved by the institutional animal care and use committee. Fifteen VX2-tumor-bearing rabbits were assigned to three groups depending on the type of embolic agent injected: 70-150-μm radiopaque microspheres in saline (radiopaque microsphere group), 70-150-μm radiopaque microspheres in contrast material (radiopaque microsphere plus contrast material group), and 70-150-μm radiolucent microspheres in contrast material (nonradiopaque microsphere plus contrast material group).
View Article and Find Full Text PDFMacromol Rapid Commun
December 2015
The properties of plasticized poly(vinyl chloride) (PVC) , one of the most important polymers today, are strongly dictated by the concentration of plasticizer. Yet, it has been impossible to quantify this concentration at different positions inside a PVC product without its destruction because of a lack of suitable analytical methods. Thus, this paper introduces a simple, fast, and efficient way to determine truly nondestructively the concentration of plasticizer in PVC by single-sided nuclear magnetic resonance (NMR).
View Article and Find Full Text PDFRationale And Objectives: Selecting the optimal phase for coronary artery evaluation can be challenging, especially at higher heart rates, given that the optimal phase may differ for each of the coronary arteries. This study aimed to evaluate a novel vessel-specific algorithm which automatically outputs the minimum motion phase per coronary artery.
Materials And Methods: The study included 44 patients who underwent 256-slice cardiac computed tomography for evaluation of chest pain.
C-arm cone-beam computed tomography (CBCT) is a new imaging technology integrated in modern angiographic systems. Due to its ability to obtain cross-sectional imaging and the possibility to use dedicated planning and navigation software, it provides an informed platform for interventional oncology procedures. In this paper, we highlight the technical aspects and clinical applications of CBCT imaging and navigation in the most common loco-regional oncological treatments.
View Article and Find Full Text PDFJ Xray Sci Technol
January 2015
Background: 4D cardiac computed tomography aims at reconstructing the beating heart from a series of 2D projections and the simultaneously acquired electrocardiogram. Each cardiac phase is reconstructed by exploiting the subset of projections acquired during this particular cardiac phase only. In these conditions, the Feldkamp, Davis and Kress method (FDK) generates large streak artifacts in the reconstructed volumes, hampering the medical interpretation.
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