Detectability of Small Low-Attenuation Lesions With Deep Learning CT Image Reconstruction: A 24-Reader Phantom Study.

Iterative reconstruction (IR) techniques are susceptible to contrast-dependent spatial resolution, limiting overall radiation dose reduction potential. Deep learning image reconstruction (DLIR) may mitigate this limitation. The purpose of our study was to evaluate low-contrast detectability performance and radiation-saving potential of a DLIR algorithm in comparison with filtered back projection (FBP) and IR using a human multireader noninferiority study design and task-based observer modeling.

Quantification and visualization of anterior pelvis bone density to optimize screw fixation: A novel technique.

Plate fixation of anterior pelvic ring fractures is often a vital component when surgically treating unstable pelvis fractures. Certain plate and screw configurations can have premature implant loosening, potentially in part due to insufficient pullout strength in lower density bone. This study sought to define densities about the anterior pelvic ring using a novel computer-based technique.

Assessment of regional sacral bone quality: A step towards patient-specific fracture fixation.

Characterizing changes in sacral bone density could help us to inform instrumentation choices for procedures involving the sacrum. The aim of this study is to provide detailed maps of changes in sacral bone density across a series of patients using opportunistic quantitative computed tomography (QCT). We hypothesized that there would be significant differences in local cortical and trabecular bone density associated with age and sex.

Transcorneal Freezing in Aged Rabbits as a Platform for Evaluating Corneal Endothelial Cell Therapeutics.

Purpose: Transcorneal freezing is a common technique used in rabbits to induce damage to the corneal endothelium. Previous studies have been performed with a range of freezing temperatures, times, and rabbit ages. Here, we aimed to characterize the aged rabbit endothelium after transcorneal freezing to establish an innate corneal endothelial cell regrowth rate and propose it as a mechanism for evaluation of therapeutic efficacy in rabbit models.

A Method for Reducing Variability Across Dual-Energy CT Manufacturers in Quantification of Low Iodine Content Levels.

Clinical use of the dual-energy CT (DECT) iodine quantification technique is hindered by between-platform (i.e., across different manufacturers) variability in iodine concentration (IC) values, particularly at low iodine levels.

Accuracy of Dual-Energy Computed Tomography Techniques for Fat Quantification in Comparison With Magnetic Resonance Proton Density Fat Fraction and Single-Energy Computed Tomography in an Anthropomorphic Phantom Environment.

Objective: To investigate in an anthropomorphic phantom study the accuracy of dual-energy computed tomography (DECT) techniques for fat quantification in comparison with magnetic resonance (MR) proton density fat fraction (PDFF) and single-energy computed tomography (SECT), using known fat content as reference standard.

Methods: Between August 2018 and November 2020, organic material-based cylinders, composed of mixtures of lean and fat tissues mimics, iodine, and iron, were constructed to simulate varying fat content levels (0%, 10%, 15%, 25%, 50%, 75%, and 100%) in a parenchymal organ and were embedded into an anthropomorphic phantom simulating 3 patient sizes (circumference, 91, 126, and 161 cm). The phantom was imaged with multiecho MR, DECT, and SECT.

Assessment of Commercial Off-the-Shelf Tissue Adhesives for Sealing Military-Relevant Corneal Perforation Injuries.

Introduction: Open-globe ocular injuries have increased in frequency in recent combat operations due to increased use of explosive weaponry. Unfortunately, open-globe injuries have one of the worst visual outcomes for the injured warfighter, often resulting in permanent loss of vision. To improve visual recovery, injuries need to be stabilized quickly following trauma, in order to restore intraocular pressure and create a watertight seal.

Estimation of patient skin dose in fluoroscopy: summary of a joint report by AAPM TG357 and EFOMP.

Background: Physicians use fixed C-arm fluoroscopy equipment with many interventional radiological and cardiological procedures. The associated effective dose to a patient is generally considered low risk, as the benefit-risk ratio is almost certainly highly favorable. However, X-ray-induced skin injuries may occur due to high absorbed patient skin doses from complex fluoroscopically guided interventions (FGI).

Characterization of an anterior segment organ culture model for open globe injuries.

Open-globe injuries have poor visual outcomes and have increased in frequency. The current standard of care is inadequate, and a therapeutic is needed to stabilize the injury until an ophthalmic specialist is reached. Unfortunately, current models or test platforms for open-globe injuries are insufficient.

Virtual Unenhanced Dual-Energy CT Images Obtained with a Multimaterial Decomposition Algorithm: Diagnostic Value for Renal Mass and Urinary Stone Evaluation.

Background Virtual unenhanced (VUE) images obtained by using a dual-energy CT (DECT) multimaterial decomposition algorithm hold promise for diagnostic use in the abdomen in lieu of true unenhanced (TUE) images. Purpose To assess VUE images obtained from a DECT multimaterial decomposition algorithm in patients undergoing renal mass and urinary stone evaluation. Materials and Methods In this retrospective Health Insurance Portability and Accountability Act-compliant study, DECT was performed in patients undergoing evaluation for renal mass or urinary stone.

Through-the-Glass Portable Radiography of Patients in Isolation Units: Experience During the COVID-19 Pandemic.

To reduce staff exposure to infection and maintain operational efficiency, we have developed a protocol to image patients using portable chest radiography through the glass of an isolation room. This technique is safe and easy to implement. Images are of comparable quality to standard portable radiographs.

Amniotic membrane allografts maintain key biological properties post SCCO and lyophilization processing.

Amniotic membrane (AM) has been shown to enhance corneal wound healing due to the abundance of growth factors, cytokines, and extracellular matrix (ECM) proteins inherent to the tissue. As such, AM has garnered widespread clinical utility as a biological dressing for a number of ophthalmic and soft tissue applications. The preparation, sterilization, and storage procedures used to manufacture AM grafts are extremely important for the conservation of inherent biological components within the membrane.

The effect of age and sex on pelvic bone density measured opportunistically in clinical CT scans.

Unstable pelvic ring fractures are severe and complex injuries, and surgical fixation is challenging and can be complicated by early failure due in part to difficulties with securely fixing screws in low-density bone. There is limited information in the literature about how the density distribution across the pelvic bones changes with age and sex. In this study, we used 60 sets of calibrated bone density measurements obtained opportunistically from clinical computed tomography scans of the pelvis.

Development and Characterization of a Benchtop Corneal Puncture Injury Model.

During recent military operations, eye-related injuries have risen in frequency due to increased use of explosive weaponry which often result in corneal puncture injuries. These have one of the poorest visual outcomes for wounded soldiers, often resulting in blindness due to the large variations in injury shape, size, and severity. As a result, improved therapeutics are needed which can stabilize the injury site and promote wound healing.

PEGylated Platelet-Free Blood Plasma-Based Hydrogels for Full-Thickness Wound Regeneration.

To develop a cost-effective and clinically usable therapy to treat full-thickness skin injuries. We accomplished this by preparing a viscoelastic hydrogel using polyethylene glycol (PEG)-modified platelet-free plasma (PEGylated PFP) combined with human adipose-derived stem cells (ASCs). PEGylated PFP hydrogels were prepared by polymerizing the liquid mixture of PEG and PFP±ASCs and gelled either by adding calcium chloride (CaCl) or thrombin.

A Mouse Model of Repetitive Blast Traumatic Brain Injury Reveals Post-Trauma Seizures and Increased Neuronal Excitability.

Repetitive blast traumatic brain injury (TBI) affects numerous soldiers on the battlefield. Mild TBI has been shown to have long-lasting effects with repeated injury. We have investigated effects on neuronal excitability after repetitive, mild TBI in a mouse model of blast-induced brain injury.

Current state of practice regarding digital radiography exposure indicators and deviation indices: Report of AAPM Imaging Physics Committee Task Group 232.

Beginning with the advent of digital radiography systems in 1981, manufacturers of these systems provided indicators of detector exposure. These indicators were manufacturer-specific, and users in facilities with equipment from multiple manufacturers found it a challenge to monitor and manage variations in indicated exposure in routine clinical use. In 2008, a common definition of exposure index (EI) was realized in International Electrotechnical Commission (IEC) International Standard 62494-1 Ed.

CT Detectability of Small Low-Contrast Hypoattenuating Focal Lesions: Iterative Reconstructions versus Filtered Back Projection.

Purpose To investigate performance in detectability of small (≤1 cm) low-contrast hypoattenuating focal lesions by using filtered back projection (FBP) and iterative reconstruction (IR) algorithms from two major CT vendors across a range of 11 radiation exposures. Materials and Methods A low-contrast detectability phantom consisting of 21 low-contrast hypoattenuating focal objects (seven sizes between 2.4 and 10.

Treatment of corneal chemical alkali burns with a crosslinked thiolated hyaluronic acid film.

Purpose: The study objective was to test the utilization of a crosslinked, thiolated hyaluronic acid (CMHA-S) film for treating corneal chemical burns.

Methods: Burns 5.5mm in diameter were created on 10 anesthetized, male New Zealand white rabbits by placing a 1N NaOH soaked circular filter paper onto the cornea for 30s.

Targeted CT Dose Reduction Using a Novel Dose Metric and the American College of Radiology Dose Index Registry: Application to Thoracic CT Angiography.

Objective: The purpose of this article is to illustrate the use of the American College of Radiology Dose Index Registry data with a novel measurement of exposure to guide quality improvement efforts.

Materials And Methods: Using information from the Dose Index Registry report covering July through December 2012, we examined our relative ranking compared with the national median CT dose for the 20 most frequently performed examinations at our institution. The total exposure variance, defined as the difference between institutional and median national dose multiplied by the local examination frequency and expressed in units of mGy-persons, was calculated.

Fibrin-based stem cell containing scaffold improves the dynamics of burn wound healing.

For severe burn injuries, successful medical intervention is accomplished by rapidly and safely providing physical barriers that can cover damaged skin tissues, thereby preventing critical danger of extensive bleeding and infection. Despite availability of a large assortment of wound coverage options, the etiology of wound healing is rather complex leading to significant defects in skin repair. The use of cell-mediated treatment approaches in combination with bioengineered wound coverage constructs may provide the missing tool to improve wound healing outcomes.

Magnetic Nanoparticles as a Potential Vehicle for Corneal Endothelium Repair.

The corneal endothelium is paramount to the health and function of the cornea as damage to this cell layer can lead to corneal edema, opacification, and ultimately vision loss. Transplantation of the corneal endothelium is associated with numerous limitations, including graft rejection, thus an alternative therapeutic treatment is needed to restore endothelial layer integrity. We hypothesize that a nanotechnology-based approach using superparamagnetic iron oxide nanoparticles (SPIONPs) can ultimately be used to guide corneal endothelial cells (CECs) to injured areas via an external magnetic force without changing their morphology or viability.

Estimated skin dose look-up tables and their effect on dose awareness in the fluoroscopy-guided imaging suite.

Objective: The displayed air kerma during a fluoroscopy-guided procedure often does not represent the entrance skin dose. The purpose of this work is to develop a system-specific air kerma-to-entrance skin dose look-up table (LUT) for immediate reference and to evaluate its clinical utility.

Materials And Methods: Physicists are often involved in retrospective dosimetry and risk estimates.