An adult and pediatric size-based contrast administration reduction phantom study for single and dual-energy CT through preservation of contrast-to-noise ratio.

Background: Global shortages of iodinated contrast media (ICM) during COVID-19 pandemic forced the imaging community to use ICM more strategically in CT exams.

Purpose: The purpose of this work is to provide a quantitative framework for preserving iodine CNR while reducing ICM dosage by either lowering kV in single-energy CT (SECT) or using lower energy virtual monochromatic images (VMI) from dual-energy CT (DECT) in a phantom study.

Materials And Methods: In SECT study, phantoms with effective diameters of 9.

COVID-19 Case Investigation and Contact Tracing in New York City, June 1, 2020, to October 31, 2021.

Importance: Contact tracing is a core strategy for preventing the spread of many infectious diseases of public health concern. Better understanding of the outcomes of contact tracing for COVID-19 as well as the operational opportunities and challenges in establishing a program for a jurisdiction as large as New York City (NYC) is important for the evaluation of this strategy.

Objective: To describe the establishment, scaling, and maintenance of Trace, NYC's contact tracing program, and share data on outcomes during its first 17 months.

Multi-institution consensus paper for acquisition of portable chest radiographs through glass barriers.

Background: To conserve personal protective equipment (PPE) and reduce exposure to potentially infected COVID-19 patients, several Californian facilities independently implemented a method of acquiring portable chest radiographs through glass barriers that was originally developed by the University of Washington.

Methods: This work quantifies the transmission of radiation through a glass barrier using six radiographic systems at five facilities. Patient entrance air kerma (EAK) and effective dose were estimated both with and without the glass barrier.

Mini EXPLORER II: a prototype high-sensitivity PET/CT scanner for companion animal whole body and human brain scanning.

As part of the EXPLORER total-body positron emission tomography (PET) project, we have designed and built a high-resolution, high-sensitivity PET/CT scanner, which is expected to have excellent performance for companion animal whole body and human brain imaging. The PET component has a ring diameter of 52 cm and an axial field of view of 48.3 cm.

Lead Apron Inspection Using Infrared Light: A Model Validation Study.

Purpose: To evaluate defect detection in radiation protective apparel, typically called lead aprons, using infrared (IR) thermal imaging. The use of IR lighting eliminates the need for access to x-ray-emitting equipment and radiation dose to the inspector.

Materials And Methods: The performance of radiation workers was prospectively assessed using both a tactile inspection and the IR inspection with a lead apron phantom over a 2-month period.

Methods for CT automatic exposure control protocol translation between scanner platforms.

Purpose: An imaging facility with a diverse fleet of CT scanners faces considerable challenges when propagating CT protocols with consistent image quality and patient dose across scanner makes and models. Although some protocol parameters can comfortably remain constant among scanners (eg, tube voltage, gantry rotation time), the automatic exposure control (AEC) parameter, which selects the overall mA level during tube current modulation, is difficult to match among scanners, especially from different CT manufacturers.

Methods: Objective methods for converting tube current modulation protocols among CT scanners were developed.

Real-time dosimeter employed to evaluate the half-value layer in CT.

Half-value layer (HVL) measurements on commercial whole body computer tomography (CT) scanners require serial measurements and, in many institutions, the presence of a service engineer. An assembly of aluminum filters (AAF), designed to be used in conjunction with a real-time dosimeter, was developed to provide estimates of the HVL using clinical protocols. Two real-time dose probes, a solid-state and air ionization chamber, were examined.

Development of a patient-specific two-compartment anthropomorphic breast phantom.

The purpose of this paper is to develop a technique for the construction of a two-compartment anthropomorphic breast phantom specific to an individual patient's pendant breast anatomy. Three-dimensional breast images were acquired on a prototype dedicated breast computed tomography (bCT) scanner as part of an ongoing IRB-approved clinical trial of bCT. The images from the breast of a patient were segmented into adipose and glandular tissue regions and divided into 1.

Kilovoltage rotational external beam radiotherapy on a breast computed tomography platform: a feasibility study.

Purpose: To demonstrate the feasibility of a dedicated breast computed tomography (bCT) platform to deliver rotational kilovoltage (kV) external beam radiotherapy (RT) for partial breast irradiation, whole breast irradiation, and dose painting.

Methods And Materials: Rotational kV-external beam RT using the geometry of a prototype bCT platform was evaluated using a Monte Carlo simulator. A point source emitting 178 keV photons (approximating a 320-kVp spectrum with 4-mm copper filtration) was rotated around a 14-cm voxelized polyethylene disk (0.

The characterization of breast anatomical metrics using dedicated breast CT.

Purpose: Accurate anatomical characterization of the breast is useful in breast phantom development and computer modeling of breast imaging technologies. Capitalizing on the three-dimensional capabilities of dedicated breast CT (bCT), a number of parameters which describe breast shape and fibroglandular distribution are defined.

Methods: Among 219 bCT data sets, the effective diameter and length of the pendant breast as well as the breast volume were measured and characterized for each bra cup size.

Experimental validation of a method characterizing bow tie filters in CT scanners using a real-time dose probe.

Purpose: Beam-shaping or "bow tie" (BT) filters are used to spatially modulate the x-ray beam in a CT scanner, but the conventional method of step-and-shoot measurement to characterize a beam's profile is tedious and time-consuming. The theory for characterization of bow tie relative attenuation (COBRA) method, which relies on a real-time dosimeter to address the issues of conventional measurement techniques, was previously demonstrated using computer simulations. In this study the feasibility of the COBRA theory is further validated experimentally through the employment of a prototype real-time radiation meter and a known BT filter.

Is it a fact? Timed arithmetic performance of children with mathematical learning disabilities (MLD) varies as a function of how MLD is defined.

Poor fact retrieval is a frequently reported characteristic of children with mathematical learning disability (MLD). To better understand the nature and specificity of poor fact retrieval in MLD, in the present study, we examined eighth graders' accuracy on timed addition and multiplication problems of varying levels of difficulty. We compared the performance of 16 children with deficient math achievement (MLD), 19 children with below average (but not deficient) math achievement (LA), and 100 typically achieving (TA) children.