Cost-effectiveness of point-of-care creatinine testing to assess kidney function prior to contrast-enhanced computed tomography imaging.

BACKGROUND: Patients undergoing contrast-enhanced computed tomography (CECT) imaging in a non-emergency outpatient setting often lack a recent estimated Glomerular Filtration Rate measurement. This may lead to inefficiencies in the CECT pathway. The use of point-of-care (POC) creatinine tests to evaluate kidney function in these patients may provide a safe and cost-effective alternative to current practice, as these can provide results within the same CECT appointment. METHODS: A decision tree model was developed to characterise the diagnostic pathway and patient management (e.g., intravenous hydration) and link these to adverse renal events associated with intravenous contrast media. Twelve diagnostic strategies including three POC devices (i-STAT, ABL800 Flex and StatSensor), risk factor screening and laboratory testing were compared with current practice. The diagnostic accuracy of POC devices was derived from a systematic review and meta-analysis; relevant literature sources and databases informed other parameters. The cost-effective strategy from a health care perspective was identified based on highest net health benefit (NHB) which were expressed in quality-adjusted life years (QALYs) at £20,000/QALY. RESULTS: The cost-effective strategy, with a NHB of 9.98 QALYs and a probability of being cost-effective of 79.3%, was identified in our analysis to be a testing sequence involving screening all individuals for risk factors, POC testing (with i-STAT) on those screening positive, and performing a confirmatory laboratory test for individuals with a positive POC result. The incremental NHB of this strategy compared to current practice, confirmatory laboratory test, is 0.004 QALYs. Results were generally robust to scenario analysis. CONCLUSIONS: A testing sequence combining a risk factor questionnaire, POC test and confirmatory laboratory testing appears to be cost-effective compared to current practice. The cost-effectiveness of POC testing appears to be driven by reduced delays within the CECT pathway. The contribution of intravenous contrast media to acute kidney injury, and the benefits and harms of intravenous hydration remain uncertain.

Computed tomography during the COVID-19 pandemic: A survey of changes to service delivery, working practices and decision-making role of radiographers.

INTRODUCTION: During the COVID-19 pandemic, Computed Tomography (CT) departments have established additional acute capacity whilst maintaining essential services. The purpose of this study was to investigate the changes in service delivery, working practices and decision-making role of diagnostic radiographers during the pandemic. METHODS: We conducted an electronic cross-sectional survey of diagnostic radiographers working in CT during the COVID-19 pandemic. The survey was open for 6-weeks, with radiographers from all geographical regions encouraged to respond. The questionnaire explored social distancing, patient scheduling and departmental organisation; PPE usage; recognition and escalation of COVID-19 changes, patient management pathways and any training. Additionally, we sought the personal perspectives of radiographers through free text comments. RESULTS: Following exclusions, 180 responses were analysed. Service delivery changes included social distancing (59.4%; n= 107), restriction of referrals to those considered time-critical (63.3%; n=114) and dedicated COVID-19 scanners (66.1%; n=119). Working practices were impacted by a need to implement PPE, although variation in PPE worn for different scenarios was seen. Half of the radiographers were routinely reviewing asymptomatic outpatient images for common COVID-19 signs, despite 63.5% of respondents not receiving formal training. Ad hoc patient pathways were in place in 90.5% of cases with 35% indicating that this was radiographer-led. CT staff had experienced anxiety, fatigue, and low morale, but praised teamwork. CONCLUSIONS: Radiographers were able to reduce the risk of transmission through social distancing, designated scanners, and PPE. This study has demonstrated that despite variance in practice, radiographers play a key role in identifying and triaging high-risk patients.

Point of care creatinine testing in diagnostic imaging: A feasibility study within the outpatient computed tomography setting.

INTRODUCTION: Although the risks associated with iodinated contrast administration are acknowledged to be very low, screening of kidney function prior to administration is still standard practice in many hospitals. This study has evaluated the feasibility of implementing a screening form in conjunction with point of care (PoC) creatinine testing as a method to manage the risks of post contrast acute kidney injury (PC-AKI) within the CT imaging pathway. METHOD: Over an eight-week period 300 adult outpatients attending a UK CT department for contrast-enhanced scans were approached. Participants completed a screening questionnaire for co-morbidities linked to kidney dysfunction and consented to have a PoC and laboratory creatinine tests. Comparison was made against with previous baseline blood tests obtained within the preceding 3 months, as required by the study site. Participants were also invited to attend for follow up PoC and laboratory bloods tests at 48-72 h. RESULTS: 14 patients (4.7%) had a scan-day eGFR below 45mL/min/1.73m2, all identified through screening. The majority of patients (n=281/300; 93.7%) fell in the same risk category based on previous and scan-day blood results. Six PoC test failures were recorded on the scan day. The constant error between the Abbott i-STAT PoC scan-day measurements and the laboratory scan-day measurements was -3.71 (95% CI: -6.41 to -0.50). Five patients had an elevated creatinine (≥25% from baseline) post contrast administration, but no instances of PC-AKI (≥50% from baseline) were identified. CONCLUSION: PoC creatinine testing is a practical method of ensuring renal function and is feasible in the radiology environment.

A UK survey exploring the assistant practitioner role across diagnostic imaging: current practice, relationships and challenges to progression.

OBJECTIVE:: Skill mix has been established as one method of maintaining imaging service delivery, with vertical and horizontal substitution of roles and tasks. Assistant practitioners (APs) have been undertaking limited imaging practice for almost two decades, but there remains a paucity of evidence related to the impact of their roles. METHODS:: This article reports on an electronic survey of individual APs within the NHS in the UK to explore utilisation, role scope and aspirations. RESULTS:: Responses were analysed from APs (n = 193) employed in 97 different organisations across the UK. The majority work in general radiography or mammography, with very few responses from other imaging modalities. Training routes varied across modalities, with most achieving Band 4 under Agenda for Change on completion of education. Limitations on practice vary between organisations and modalities, with many reporting blurring of the radiographer-AP boundary. Many aspire to continue their training to achieve registrant radiographer status, although there were clear frustrations from respondents over the lack of overt career prospects. CONCLUSION:: Integration of the role into imaging department practice does not appear to be universal or consistent and further research is required to examine the optimal skill mix composition. ADVANCES IN KNOWLEDGE:: Skill mix implementation is inconsistent across modalities and geography in the UK. Opportunities for further workforce utilisation and expansion are evident.

Point-of-care creatinine testing for kidney function measurement prior to contrast-enhanced diagnostic imaging: evaluation of the performance of three systems for clinical utility.

BACKGROUND: Acute kidney injury (AKI) can occur rarely in patients exposed to iodinated contrast and result in contrast-induced AKI (CI-AKI). A key risk factor is the presence of preexisting chronic kidney disease (CKD); therefore, it is important to assess patient risk and obtain kidney function measurement prior to administration. Point-of-care (PoC) testing provides an alternative strategy but there remains uncertainty, with respect to diagnostic accuracy and clinical utility. METHODS: A device study compared three PoC analysers (Nova StatSensor, Abbott i-STAT and Radiometer ABL800 FLEX) with a reference laboratory standard (Roche Cobas 8000 series, enzymatic creatinine). Three hundred adult patients attending a UK hospital phlebotomy department were recruited to have additional blood samples for analysis on the PoC devices. RESULTS: The ABL800 FLEX had the strongest concordance with laboratory measured serum creatinine (mean bias=-0.86, 95% limits of agreement=-9.6 to 7.9) followed by the i-STAT (average bias=3.88, 95% limits of agreement=-8.8 to 16.6) and StatSensor (average bias=3.56, 95% limits of agreement=-27.7 to 34.8). In risk classification, the ABL800 FLEX and i-STAT identified all patients with an eGFR≤30, whereas the StatSensor resulted in a small number of missed high-risk cases (n=4/13) and also operated outside of the established performance goals. CONCLUSIONS: The screening of patients at risk of CI-AKI may be feasible with PoC technology. However, in this study, it was identified that the analyser concordance with the laboratory reference varies. It is proposed that further research exploring PoC implementation in imaging department pathways is needed.

Doctoral profile of the medical radiation sciences: a baseline for Australia and New Zealand.

INTRODUCTION: Research is critical to evidence-based practice, and the rapid developments in technology provide opportunities to innovate and improve practice. Little is known about the research profile of the medical radiation science (MRS) profession in Australia and New Zealand (NZ). This study provides a baseline of their doctoral activity. METHODS: A cross-sectional survey of MRS professionals in Australia and NZ holding a doctorate or undertaking doctoral studies, was performed using an online tool (Bristol Online Survey® , Bristol, UK). A chain-referral sampling technique was adopted for data collection. An email invitation with a link to the survey was generated and distributed through email and social media. The survey contained questions related to participant demographics, doctoral status, qualification route, funding and employment. RESULTS: There were 63 responses to the survey comprising 50.8% diagnostic radiographers (DRs; n = 32), 23.8% radiation therapists (RTs; n = 15), with the remaining 25.4% (n = 16) equally split between sonographers and nuclear medicine technologists (NMTs). A total of 40 (63.5%) of respondents had completed their doctoral qualification. In NZ, only DRs held a doctoral award constituting 0.3% of DRs and 0.2% of the total registered MRS population. In Australia, there was a greater proportion of doctoral NMTs (n = 8/1098; 0.7%) than RTs (n = 15/2394; 0.6%) and DRs (n = 27/12,001; 0.2%). CONCLUSION: Similar to other countries, findings show a very small percentage of doctoral MRS professionals in Australia and NZ. Strategies to engage and support individuals in research, up to and beyond doctoral study, need to be embedded in practice.

The Acceptability of Iterative Reconstruction Algorithms in Head CT: An Assessment of Sinogram Affirmed Iterative Reconstruction (SAFIRE) vs. Filtered Back Projection (FBP) Using Phantoms.

BACKGROUND: Computed tomography (CT) is the primary imaging investigation for many neurologic conditions with a proportion of patients incurring cumulative doses. Iterative reconstruction (IR) allows dose optimization, but head CT presents unique image quality complexities and may lead to strong reader preferences. OBJECTIVES: This study evaluates the relationships between image quality metrics, image texture, and applied radiation dose within the context of IR head CT protocol optimization in the simulated patient setting. A secondary objective was to determine the influence of optimized protocols on diagnostic confidence using a custom phantom. METHODS AND SETTING: A three-phase phantom study was performed to characterize reconstruction methods at the local reference standard and a range of exposures. CT numbers and pixel noise were quantified supplemented by noise uniformity, noise power spectrum, contrast-to-noise ratio (CNR), high- and low-contrast resolution. Reviewers scored optimized protocol images based on established reporting criteria. RESULTS: Increasing strengths of IR resulted in lower pixel noise, lower noise variance, and increased CNR. At the reference standard, the image noise was reduced by 1.5 standard deviation and CNR increased by 2.0. Image quality was maintained at ≤24% relative dose reduction. With the exception of image sharpness, there were no significant differences between grading for IR and filtered back projection reconstructions. CONCLUSIONS: IR has the potential to influence pixel noise, CNR, and noise variance (image texture); however, systematically optimized IR protocols can maintain the image quality of filtered back projection. This work has guided local application and acceptance of lower dose head CT protocols.