AI-Based Evaluation of Prostate MR Imaging at a Modern Low-field 0.55 T Scanner Compared to 3 T in a Screening Cohort.

Purpose: To evaluate the effect of lower field strength on quantitative apparent-diffusion-coefficient (ADC) values, contrast of the T2-weighted MR images and the performance of an AI-based segmentation.

Materials And Methods: 25 screening clients (61.6 ± 7.

Intra-Individual Reproducibility of Automated Abdominal Organ Segmentation-Performance of TotalSegmentator Compared to Human Readers and an Independent nnU-Net Model.

The purpose of this study is to assess segmentation reproducibility of artificial intelligence-based algorithm, TotalSegmentator, across 34 anatomical structures using multiphasic abdominal CT scans comparing unenhanced, arterial, and portal venous phases in the same patients. A total of 1252 multiphasic abdominal CT scans acquired at our institution between January 1, 2012, and December 31, 2022, were retrospectively included. TotalSegmentator was used to derive volumetric measurements of 34 abdominal organs and structures from the total of 3756 CT series.

Interventional Imaging Systems in Radiology, Cardiology, and Urology: Energy Consumption, Carbon Emissions, and Electricity Costs.

The energy demand of interventional imaging systems has historically been estimated using manufacturer-provided specifications rather than directly measured. The purpose of this study was to investigate the energy consumption of interventional imaging systems and estimate potential savings in the carbon emissions and electricity costs of such systems through hypothetical operational adjustments. An interventional radiology suite, neurointerventional suite, radiology fluoroscopy unit, two cardiology laboratories, and two urology fluoroscopy units were equipped with power sensors.

Opportunistic Prostate Cancer Screening with Biparametric Magnetic Resonance Imaging (VISIONING).

Background: This study investigates the use of biparametric magnetic resonance imaging (bpMRI) as primary opportunistic screening for prostate cancer (PCa) without using a prostate-specific antigen (PSA) cut-off.

Objective: The primary endpoint was to assess the efforts and effectiveness of identifying 20 participants with clinically significant prostate cancer (csPCa) using bpMRI.

Design, Setting, And Participants: Biopsy-naïve men aged over 45 yr were included.

Quantitative computed tomography analysis of body composition changes in paediatric patients with acute lymphoblastic leukaemia.

Children with acute lymphoblastic leukaemia (ALL) are at risk for obesity and cardiometabolic diseases. To gain insight into body composition changes among children with ALL, we assessed quantitative computed tomography (QCT) data for specific body compartments (subcutaneous adipose tissue [SAT], visceral adipose tissue [VAT], total adipose tissue [TAT], lean tissue [LT], LT/TAT and VAT/SAT at lumbar vertebrae L1 and L2) at diagnosis and at off-therapy for 189 children with ALL and evaluated associations between body mass index (BMI) Z-score and clinical characteristics. BMI Z-score correlated positively with SAT, VAT and TAT and negatively with LT/TAT and VAT/SAT.

The Impact of Modern Imaging Techniques on Carbon Footprints: Relevance and Outlook.

It is estimated that the health care sector accounts for 4.0-8.5% of total global CO emissions, with medical imaging representing an energy-intensive contributor.

Assessment of hepatic function employing hepatocyte specific contrast agent concentrations to multifactorially evaluate fibrotic remodeling.

Background: Diffuse parenchymal liver diseases are contributing substantially to global morbidity and represent major causes of deaths worldwide. The aim of our study is to assess whether established hepatic fat and iron quantitation and relaxometry-based quantification of hepatocyte-specific contrast material as surrogate for liver function estimation allows to evaluate liver fibrosis.

Methods: Retrospective consecutive study.

More Space, Less Noise-New-generation Low-Field Magnetic Resonance Imaging Systems Can Improve Patient Comfort: A Prospective 0.55T-1.5T-Scanner Comparison.

Objectives: The objectives of this study were to assess patient comfort when imaged on a newly introduced 0.55T low-field magnetic resonance (MR) scanner system with a wider bore opening compared to a conventional 1.5T MR scanner system.

Before/after Bayes: A comparison of frequentist and Bayesian mixed-effects models in applied psychological research.

Bayesian methods are becoming increasingly used in applied psychological research. Previous researchers have thoroughly written about much of the details already, including the philosophy underlying Bayesian methods, computational issues associated with Bayesian model estimation, Bayesian model development and summary, and the role of Bayesian methods in the so-called replication crisis. In this paper, we seek to provide case studies comparing the use of frequentist methods to the use of Bayesian methods in applied psychological research.

Score-based measurement invariance checks for Bayesian maximum-a-posteriori estimates in item response theory.

A family of score-based tests has been proposed in recent years for assessing the invariance of model parameters in several models of item response theory (IRT). These tests were originally developed in a maximum likelihood framework. This study discusses analogous tests for Bayesian maximum-a-posteriori estimates and multiple-group IRT models.

[Economic aspects of low-field magnetic resonance imaging : Acquisition, installation, and maintenance costs of 0.55 T systems].

Background: Low-field magnetic resonance imaging (MRI) scanners offer an opportunity for cost reduction in the healthcare system. This is due to lower manufacturing costs and reduced construction requirements for installation and operation.

Objectives: To discuss potential cost reductions in acquisition, installation, and maintenance by using new low-field MRI systems.

[New clinical applications for low-field magnetic resonance imaging : Technical and physical aspects].

Background: Low-field magnetic resonance imaging (MRI) is experiencing a renaissance due to technical innovations. The new-generation devices offer new applications for imaging and a possible solution to increasing cost pressures in the healthcare system.

Objectives: Effects of field strength on technique, physics, image acquisition, and diagnostic quality of examinations are presented.

Computation and application of generalized linear mixed model derivatives using lme4.

Maximum likelihood estimation of generalized linear mixed models (GLMMs) is difficult due to marginalization of the random effects. Derivative computations of a fitted GLMM's likelihood are also difficult, especially because the derivatives are not by-products of popular estimation algorithms. In this paper, we first describe theoretical results related to GLMM derivatives along with a quadrature method to efficiently compute the derivatives, focusing on fitted lme4 models with a single clustering variable.

Seeing the impossible: Visualizing latent variable models with flexplavaan.

Latent variable models (LVMs) are incredibly flexible tools that allow users to address research questions they might otherwise never be able to answer (McDonald, 2013). However, one major limitation of LVMs is evaluating model fit. There is no universal consensus about how to evaluate model fit, either globally or locally.

A note on identification constraints and information criteria in Bayesian latent variable models.

It is well known that, in traditional SEM applications, a scale must be set for each latent variable: typically, either the latent variance or a factor loading is fixed to one. While this has no impact on the fit metrics in ML estimation, it can potentially lead to varying Bayesian model comparison metrics due to the use of different prior distributions under each parameterization. This is a problem, because a researcher could artificially improve one's preferred model simply by changing the identification constraint.

Respiratory anomalies associated with gadoxetate disodium and gadoterate meglumine: compressed sensing MRI revealing physiologic phenomena during the entire injection cycle.

Objectives: The goal of this study was to investigate the precise timeline of respiratory events occurring after the administration of two gadolinium-based contrast agents, gadoxetate disodium and gadoterate meglumine.

Materials And Methods: This retrospective study examined 497 patients subject to hepatobiliary imaging using the GRASP MRI technique (TR/TE = 4/2 ms; ST = 2.5 mm; 384 × 384 mm).

Investigating difficult to detect pancreatic lesions: Characterization of benign pancreatic islet cell tumors using multiparametric pancreatic 3-T MRI.

Introduction: Pancreatic islet-cell tumors (PICT) often present with atypical signal-characteristics and are often missed on preoperative imaging. The aim of this study is to provide a multiparametric PICT characterization and investigate factors impeding PICT detection.

Material And Methods: This is a detailed MRI analysis of a prospective, monocenter study, including 49 consecutive patients (37 female, 12 male; median age 50) with symptoms due to endogenous hyperinsulinemic hypoglycemia (EHH) and mostly negative prior-imaging.

Detecting Heterogeneity of Intervention Effects in Comparative Judgments.

Comparative measures such as paired comparisons and rankings are frequently used to evaluate health states and quality of life. The present article introduces log-linear Bradley-Terry (LLBT) models to evaluate intervention effectiveness when outcomes are measured as paired comparisons or rankings and presents a combination of the LLBT model and model-based recursive partitioning (MOB) to detect treatment effect heterogeneity. The MOB LLBT approach enables researchers to identify subgroups that differ in the preference order and in the effect an intervention has on choice behavior.

Quantifying Radiology Resident Fatigue: Analysis of Preliminary Reports.

Background Workloads in radiology departments have constantly increased over the past decades. The resulting radiologist fatigue is considered a rising problem that affects diagnostic accuracy. Purpose To investigate whether data mining of quantitative parameters from the report proofreading process can reveal daytime and shift-dependent trends in report similarity as a surrogate marker for resident fatigue.

The Effect of Pediatric Early Warning Score Use on Emergency Response Calls After Admission From the Pediatric Emergency Department.

Objectives: Pediatric Early Warning Scores (PEWS) are an easy-to-use diagnostic tool for patient evaluation. The goal of this study was to determine if using PEWS in our pediatric emergency department (PED) at the time of admission to the hospital was associated with a decrease in the number of emergency response calls within 6 hours of admission.

Methods: A retrospective chart review of 6 months before (May 2013-October 2013) and after (December 2013-May 2014) initiation of PEWS upon inpatient admission from our urban, tertiary care PED was conducted to determine the number of patients who had emergency response calls within 6 hours of admission.

Event-Level Predictors of Alcohol-Impaired Driving Intentions.

Objective: Alcohol-impaired driving is a significant public safety concern and is highly prevalent among young adults. Considerable research has examined between-person predictors of alcohol-impaired driving, but there has been little research on factors that predict alcohol-impaired driving at the event level. This pilot/feasibility study was designed to identify within-person, event-level predictors of alcohol-impaired driving intentions in the natural environment using an ecological momentary assessment (EMA) design.

Revealing the most common reporting errors through data mining of the report proofreading process.

Objectives: To investigate the most common errors in residents' preliminary reports, if structured reporting impacts error types and frequencies, and to identify possible implications for resident education and patient safety.

Material And Methods: Changes in report content were tracked by a report comparison tool on a word level and extracted for 78,625 radiology reports dictated from September 2017 to December 2018 in our department. Following data aggregation according to word stems and stratification by subspecialty (e.

Score-based tests for detecting heterogeneity in linear mixed models.

Cross-level interactions among fixed effects in linear mixed models (also known as multilevel models) can be complicated by heterogeneity stemming from random effects and residuals. When heterogeneity is present, tests of fixed effects (including cross-level interaction terms) are subject to inflated type I or type II error. While the impact of variance change/heterogeneity has been noticed in the literature, few methods have been proposed to detect this heterogeneity in a simple, systematic way.