A multi-institutional assessment of low-dose protocols in chest computed tomography: Dose and image quality.

Background: Low-dose CT (LDCT) chest protocols have widespread clinical applications for many indications; as a result, there is a need for protocol assessment prior to standardization. Dalhousie University and Oslo Metropolitan University have a formally established cooperative relationship. Purpose: The purpose is to assess radiation dose and image quality for LDCT chest protocols in seven different hospital locations in Norway and Canada. Material and methods: Retrospective dosimetry data, volumetric CT dose index (CTDIvol), and dose length product (DLP) from 240 average-sized patients as well as CT protocol parameters were included in the survey. Effective dose (ED) and size-specific dose estimate (SSDE) were calculated for each examination. For a quantitative image quality analysis, noise, CT number, and signal-to-noise ratio (SNR) were determined for three regions in the chest. The contrast-to-noise ratio (CNR) was calculated for lung parenchyma in comparison to the subcutaneous fat. Differences in dose and image quality were evaluated by a single-factor ANOVA test. A two-sample t-test was performed to determine differences in means between individual scanners. Results: The ANOVA test revealed significant differences (p < .05) in dose values for all scanners, including identical scanner models. Statistically significant differences (p < .05) were determined in mean values of the SNR distributions between the scanners in all three measured regions in the chest, as well as the CNR values. Conclusion: The observed variations in dose and image quality measurements, even within the same hospitals and between identical scanner models, indicate a potential for protocol optimization in the involved hospitals in both countries.

Strategies for calculating contrast media dose for chest CT.

BACKGROUND: Total body weight (TBW) is a frequently used contrast media (CM) strategy for dose calculation in enhanced CT, yet it is suboptimal as it lacks consideration of patient characteristics, such as body fat percentage (BFP) and muscle mass. Alternative CM dosage strategies are suggested by the literature. Our objectives were to analyze the CM dose impact when adjusting to body composition using methods of obtaining lean body mass (LBM) and body surface area (BSA) along with its correlation with demographic factors in contrast enhanced chest CT examinations. METHODS: Eighty-nine adult patients referred for CM thoracic CT were retrospectively included, categorized as either normal, muscular, or overweight. Patient body composition data was used to calculate the CM dose according to LBM or BSA. LBM was calculated with the James method, Boer method, and bioelectric impedance (BIA). BSA was calculated using the Mostellar formula. We then correlated the corresponding CM doses with demographic factors. RESULTS: BIA demonstrated the highest and lowest calculated CM dose in muscular and overweight groups respectively, compared to other strategies. For the normal group, the lowest calculated CM dose was achieved using TBW. The calculated CM dose was more closely correlated with BFP using the BIA method. CONCLUSIONS: The BIA method is more adaptive to variations in patient body habitus especially in muscular and overweight patients and is most closely correlated to patient demographics. This study could support utilizing the BIA method for calculating LBM for a body-tailored CM dose protocol for enhanced chest CT examinations. RELEVANCE STATEMENT: The BIA-based method is adaptive to variations in body habitus especially in muscular and overweight patients and is closely correlated to patient demographics for contrast-enhanced chest CT. KEY POINTS: • Calculations based on BIA showed the largest variation in CM dose. • Lean body weight using BIA demonstrated the strongest correlation to patient demographics. • Lean body weight BIA protocol may be considered for CM dosing in chest CT.

A survey of local diagnostic reference levels for the head, thorax, abdomen and pelvis computed tomography in Norway and Canada.

Background: Computed tomography (CT) contributes to 60% of the collective dose in medical imaging. Literature has demonstrated that patient dose varies across regions and countries. Establishing diagnostic reference levels (DRLs) contributes to the optimization of clinical practices and radiation protection. Purpose: To survey the dose indices (CTDIvol and dose-length product) for frequently performed CT examinations from the chosen hospitals in Norway and Canada and to determine local DRLs (LDRLs) based on the collected data. Material and Methods: The survey included eight scanners from two Norwegian hospitals and four scanners from four Canadian hospitals. Dosimetry data were collected for the following routine CT examinations: head, contrast-enhanced thorax, and abdomen and pelvis. Overall 480 adult average-sized patients from Norway and 360 from Canada were included in the survey. The LDRLs were determined as the 75th percentile of distributions of median values of dose indicators from different CT scanners. The differences in dose between scanners were determined using single-factor ANOVA. Results: The LDRLs determined in Norway were higher overall than in Canada. The obtained values were compared to the national DRLs. The dose from several scanners in Norway exceeded national Norwegian DRLs, while Canadian LDRLs were below the Canadian reference levels. The differences between the means of the dose distributions from each scanner were statistically significant (p < 0.05) for all examinations with exception of identical scanners located in the same hospital and using the same protocols. Conclusion: Observed dose variations even in the same hospital, or from the same scanner model confirmed the need for CT protocol optimization.

Translating interprofessional collaboration competencies to an international research team.

INTRODUCTION: While there has been strong emphasis on enhancing interprofessional education and interprofessional care in the published literature, there is relatively little literature focused on advancing interprofessional research. In extrapolating from the current frameworks of interprofessional collaboration (IPC), it becomes clear that the core competencies of IPC are transferable to research teams. The aim of this paper is to present our experience of an international research team framed within core competencies for IPC. METHODS: A simplified narrative inquiry approach was used to share the experience of an international research team framed within six core competencies of IPC. RESULTS AND DISCUSSION: By way of our international research collaboration, we demonstrate the translation of key core competencies for IPC. We share key learnings and mitigation strategies for the successful outcomes of the research team. CONCLUSION: To embark on a successful international research collaboration requires integrating IPC core competencies across the entire research continuum. In addition to the core competencies of collaboration, enablers to success also include digital collaborative forums, existing professional relationships and research projects that offer global meaning and value.

International Student Mobility in Radiography: Agency and Experience.

PURPOSE: The purpose of the study was to evaluate student exchange experiences to gain insight into what students perceived as benefits, challenges, and overall areas for improvement that might inform and enhance future exchange projects. METHODS: A general program evaluation survey, adapted to address the project objectives, was conducted. Eight students from Norway, Canada, and South Africa participating in an international exchange project completed an online survey. The responses were coded and organized in themes such as pre-exchange preparation, home/host country support, challenges, and new learning. RESULTS & CONCLUSIONS: Despite the challenges the students experienced, students indicated advantages such as new learning, personal development, and expanded professional knowledge. Students gained an international perspective and deeper understanding of their profession and insight into the similarities and differences in clinical practice emphasizing the importance of creating global citizens through internationalization in radiography education. These student experiences confirmed their agency in disposition, motivation, self-efficacy, and position.

Are Antimony-Bismuth Aprons as Efficient as Lead Rubber Aprons in Providing Shielding against Scattered Radiation?

AIM: The aim of this study is to compare the absorption ability of two lead-free aprons with a lead apron. METHOD: The absorption ability of three aprons was measured and compared; Opaque Fusion 0.35 mm (OpaqFu) bilayer apron containing bismuth and antimony, No Lead 0.35 mm (NoLead) one-layer apron containing antimony, and a lead apron. The measurements were repeated with and without each of the aprons present in both primary and scattered beams. The selected tube voltages were between 60 and 113 kVp with constant mAs, a fixed field size, and fixed source-to-object distance. RESULTS: No significant difference in absorption ability of the two lead-free aprons compared with that of the lead apron was observed when the dose was measured in the primary beam. When measurements were performed in the scatter radiation field, the absorption ability of the OpaqFu apron was 1.3 times higher than that of NoLead apron and nearly equal to the absorption ability of the lead apron. An increase in the difference between the OpaqFu and NoLead aprons was observed for the tube energies higher than 100 kVp in favour of OpaqFu apron. CONCLUSION: It is safe to use the lead-free aprons that were tested in this study in a clinical environment for the tube energy range of 60 kVp-113 kVp.