Photon-Counting-Detector CT: Technology Overview and Radiation Dose Reduction.

Photon-counting detector computed tomography (PCD-CT) represents a transformative advancement in CT technology, overcoming limitations of conventional energy-integrating detector (EID) based systems. It uses semiconductor materials such as cadmium telluride, cadmium zinc telluride, and silicon to directly count x-ray photons while resolving their energy levels. This energy-resolving capability ensures equal weighting of low- and high-energy photons, eliminates electronic noise, and enables material-specific imaging.

The Environmental Impact of Iodinated Contrast Media: Strategies for Optimized Use and Recycling.

Iodinated contrast media (ICM) is an integral and ubiquitous component of modern diagnostic imaging. Although most radiology practices are familiar with ICM administration and physiological excretion, they may be less aware of how much ICM is wasted on a per exam basis. Furthermore, radiologists may not recognize the environmental fate of discarded ICM waste.

Photon counting CT clinical adoption, integration, and workflow.

Photon counting CT was recently introduced into clinical practice [Rajendran K, Petersilka M, Henning A, Shanblatt ER, Schmidt B, Flohr TG, Ferrero A, Baffour F, Diehn FE, Yu L, Rajiah P, Fletcher JG, Leng S, McCollough CH. First Clinical Photon-counting Detector CT System: Technical Evaluation. Radiology 2022;303(1):130-138.

Dual-Energy Computed Tomography: Integration Into Clinical Practice and Cost Considerations.

Optimization of dual-energy CT (DECT) workflow is critical for successful integration of DECT into practice. Patient selection strategies differ by scanner type and may be based on patient size, exam indication, or both. All stakeholders involved in patient scheduling and scan acquisition should be involved in patient triage to DECT.

Dual-Energy Computed Tomography Applications in the Genitourinary Tract.

By virtue of material differentiation capabilities afforded through dedicated postprocessing algorithms, dual-energy CT (DECT) has been shown to provide benefit in the evaluation of various diseases. In this article, we review the diagnostic use of DECT in the assessment of genitourinary diseases, with emphasis on its role in renal stone characterization, incidental renal and adrenal lesion characterization, retroperitoneal trauma, reduction of radiation, and contrast dose and cost-effectiveness potential. We also discuss future perspectives of the DECT scanning mode, including the use of novel contrast injection strategies and photon-counting detector computed tomography.

Vascular Applications of Dual-Energy Computed Tomography.

Dual- or multi-energy CT imaging provides several advantages over conventional CT in the context of vascular imaging. Specific advantages include the use of low-energy virtual monoenergetic images (VMIs) to boost iodine attenuation to salvage suboptimal enhanced studies, perform low-contrast material dose studies, and increase conspicuity of small vessels and lesions. Alternatively, high-energy VMIs reduce artifacts caused by some metals, endoprosthesis, calcium blooming, and beam hardening.

Herpes Proctitis in Men Mimicking Rectal Adenocarcinoma: Two Cases of an Easily Overlooked Diagnosis in the Proximal Rectum.

We describe two cases of rectal herpes simplex virus (HSV) infection in men that clinically mimicked rectal adenocarcinoma. Herpes infection in this location more commonly presents as an anal mass with viral inclusions in squamous epithelial cells. We report these cases to increase awareness of the unusual presentation as a proximal rectal mass with viral inclusions in endothelial cell nuclei.

Optimization of Iodinated Contrast Media Inventory Management: Effect of Inventory Diversification on Waste Reduction.

Purpose: Iodinated contrast medium (ICM) is available in single- and multiuse vials of varying sizes, but CT departments often preferentially stock only a single or a limited number of vial sizes. The aims of this study were to assess actual ICM waste at a large safety-net hospital and to compare with estimated waste if single-use vials in a variety of vial sizes or multiuse vials were used.

Methods: ICM administrations were retrospectively reviewed for all CT examinations performed in 2021 in a department that stocked only 100-mL ICM vials.

What the Baby Formula and Medical Contrast Material Shortages Have in Common: Insights and Recommendations for Managing the Iodinated Contrast Media Shortage.

The impact of supply chain and supply chain logistics, including personnel directly and indirectly related to the movement of supplies, has come to light in a variety of industries since the global COVID-19 pandemic. Acutely, the experience with baby formula and iodinated contrast material exposes key vulnerabilities to supply chains. The rather sudden diminished availability of iodinated contrast material has forced health care systems to engage in more judicious use of product through catalyzing the adoption of behaviors that had been recommended and deemed reasonable prior to the shortage.

Differentiating unexpected hyperattenuating intraluminal material from gastrointestinal bleeding on contrast enhanced dual-energy CT.

We present the case of a 24-year-old woman who presented to the emergency department with mid-epigastric pain and nausea. Contrast enhanced dual-energy CT showed high iodine signal in the small bowel lumen concerning for gastrointestinal bleeding since oral contrast was not given. However, overt bleeding symptoms were absent.

Fidelity of Electronic Documentation for Reactions Prompting Premedication to Iodinated Contrast Media.

Purpose: The aims of this study were to assess the fidelity of electronic health record documentation prompting premedication to iodinated contrast media and to determine the appropriateness of administered premedication on the basis of that documentation.

Methods: In this retrospective quality assurance cohort study, medication adverse events recorded in electronic health records between January 1, 2018, and August 31, 2019, to "iodine," "iodine-containing products," and "iodinated contrast media" were identified (N = 4,309); entries missing documentation (n = 1,651) and breakthrough reactions (n = 22) were excluded. Reaction description, severity, and free-text comments were used to categorize each entry as concordant (documentation matches recorded severity per the ACR Manual on Contrast Media version 10.

Clinical Implementation of Dual-Energy CT for Gastrointestinal Imaging.

Dual-energy CT (DECT) overcomes several limitations of conventional single-energy CT (SECT) for the evaluation of gastrointestinal diseases. This article provides an overview of practical aspects of the DECT technology and acquisition protocols, reviews existing clinical applications, discusses current challenges, and describes future directions, with a focus on gastrointestinal imaging. A head-to-head comparison of technical specifications among DECT scanner implementations is provided.

Use of Spectral Detector Computed Tomography to Improve Liver Segmentation and Volumetry.

Introduction: Liver segmentation and volumetry have traditionally been performed using computed tomography (CT) attenuation to discriminate liver from other tissues. In this project, we evaluated if spectral detector CT (SDCT) can improve liver segmentation over conventional CT on 2 segmentation methods.

Materials And Methods: In this Health Insurance Portability and Accountability Act-compliant institutional review board-approved retrospective study, 30 contrast-enhanced SDCT scans with healthy livers were selected.

Radiation doses and image quality of abdominal CT scans at different patient sizes using spectral detector CT scanner: a phantom and clinical study.

Purpose: To compare radiation dose and image quality for abdominal CTs performed on a spectral detector CT (SDCT) and a comparable single-energy conventional CT scanner for patients of different sizes.

Methods: Four semi-anthropomorphic phantoms were scanned on an SDCT (IQon, Philips Healthcare) and a comparable single-energy CT (iCT 256, Philips Healthcare) under matched scan parameters. Image noise and radiation dose were compared.

Prevalence and clinical significance of discordant LI-RADS observations on multiphase contrast-enhanced MRI in patients with cirrhosis.

Purpose: To determine the prevalence and clinical significance of discordant LI-RADS (Liver Imaging Reporting and Data System) liver observations on multiphase contrast-enhanced (MCE) magnetic resonance imaging (MRI) in patients with cirrhosis.

Methods: This cross-sectional study included 93 cirrhosis patients who underwent 1.5 or 3 T MCE MRI for evaluation of hepatocellular carcinoma (HCC).

A Technique to Identify Isoattenuating Gallstones with Dual-Layer Spectral CT: An ex Vivo Phantom Study.

Background Previously reported dual-energy CT methods for detecting noncalcified gallstones have reduced accuracy for gallstones smaller than 9 mm. Purpose To develop a dual-energy CT method for differentiating isoattenuating gallstones from bile and compare it with previously reported dual-energy CT methods by using a prospective ex vivo phantom reader study. Materials and Methods From May 2017 to May 2018, gallstones were collected from 105 patients (34 men; mean age, 51 years; age range, 18-84 years) undergoing cholecystectomy and placed inside 120-mL vials containing ox bile.

Abbreviated-protocol screening MRI vs. complete-protocol diagnostic MRI for detection of hepatocellular carcinoma in patients with cirrhosis: An equivalence study using LI-RADS v2018.

Background: The high operational cost of MRI limits its utility for hepatocellular carcinoma (HCC) screening. Abbreviated-protocol dynamic contrast-enhanced MRI (aMRI) may help lower cost while maintaining the high accuracy of complete-protocol diagnostic MRI (cMRI).

Purpose: To compare aMRI to cMRI for HCC detection in cirrhosis patients.

Separating High-Z Oral Contrast From Intravascular Iodine Contrast in an Animal Model Using Dual-Layer Spectral CT.

Rationale And Objectives: To show that water and iodine two-material decomposition images from dual-layer dual-energy spectral X-ray computed tomography (DECT) can be used to separate intravascular iodine contrast from simultaneously administered oral tantalum, tungsten, or rhenium contrast in an animal model.

Materials And Methods: In this Institutional Animal Care and Use Committee approved study, four female Fischer rats were given simultaneous intravenous and oral X-ray computed tomography contrast. Intravenous iodine contrast was administered via tail vein injection.

Imaging for Screening and Surveillance of Patients with Hereditary Forms of Renal Cell Carcinoma.

Purpose Of Review: To summarize the literature providing the basic genetic and clinical characteristics of renal cell carcinoma (RCC) familial syndromes, as well as to describe associated unique imaging characteristics and appropriate imaging protocols.

Recent Findings: At least 5-8% of RCC cases are associated with hereditary syndromes. These patients are prone to developing multiple renal tumors or associated malignancies and require more intense diagnostic and follow-up imaging studies.