Diagnostic reference levels in spinal CT: Jordanian assessments and global benchmarks

BACKGROUND

To reduce radiation dose and subsequent risks, several legislative documents in different countries describe the need for Diagnostic Reference Levels (DRLs). Spinal radiography is a common and high-dose examination. Therefore, the aim of this work was to establish the DRL for Computed Tomography (CT) examinations of the spine in healthcare institutions across Jordan.

METHODS

Data was retrieved from the picture archiving and communications system (PACS), which included the CT Dose Index (CTDI (vol) ) and Dose Length Product (DLP). The median radiation dose values of the dosimetric indices were calculated for each site. DRL values were defined as the 75th percentile distribution of the median CTDI (vol)  and DLP values.

RESULTS

Data was collected from 659 CT examinations (316 cervical spine and 343 lumbar-sacral spine). Of the participants, 68% were males, and the patients' mean weight was 69.7 kg (minimum = 60; maximum = 80, SD = 8.9). The 75th percentile for the DLP of cervical and LS-spine CT scans in Jordan were 565.2 and 967.7 mGy.cm, respectively.

CONCLUSIONS

This research demonstrates a wide range of variability in CTDI (vol)  and DLP values for spinal CT examinations; these variations were associated with the acquisition protocol and highlight the need to optimize radiation dose in spinal CT examinations.

Efficacy of Artificial Intelligence in the Categorisation of Paediatric Pneumonia on Chest Radiographs: A Systematic Review

This study aimed to systematically review the literature to synthesise and summarise the evidence surrounding the efficacy of artificial intelligence (AI) in classifying paediatric pneumonia on chest radiographs (CXRs). Following the initial search of studies that matched the pre-set criteria, their data were extracted using a data extraction tool, and the included studies were assessed via critical appraisal tools and risk of bias. Results were accumulated, and outcome measures analysed included sensitivity, specificity, accuracy, and area under the curve (AUC). Five studies met the inclusion criteria. The highest sensitivity was by an ensemble AI algorithm (96.3%). DenseNet201 obtained the highest level of specificity and accuracy (94%, 95%). The most outstanding AUC value was achieved by the VGG16 algorithm (96.2%). Some of the AI models achieved close to 100% diagnostic accuracy. To assess the efficacy of AI in a clinical setting, these AI models should be compared to that of radiologists. The included and evaluated AI algorithms showed promising results. These algorithms can potentially ease and speed up diagnosis once the studies are replicated and their performances are assessed in clinical settings, potentially saving millions of lives.

Prevalence of low back pain among Irish radiographers

BACKGROUND

According to the literature, low back pain (LBP) is one of the top ten diseases and injuries contributing to disability-adjusted life years worldwide. To the best of the authors' knowledge there are no studies investigating the prevalence of LBP among radiographers working in Ireland or have compared prevalence rates with the national population or other cohorts of radiographers or healthcare professionals. This study aimed to determine the prevalence of LBP among radiographers working or who have previously worked in Ireland and to identify any causative factors.

METHODS

A cross-sectional study in the form of an online questionnaire was developed. Participation was advertised online via social media platforms. Inclusion criteria included qualified radiographers working in Ireland or who had recently worked in Ireland. Section A of the questionnaire focussed on acquiring demographic data. Section B comprised eight questions relating to LBP, including current and previous experiences, causative factors and consequences. Further details on any episodes of LBP in the previous year, whether work and leisure activities had been affected, whether any extracurricular activities caused LBP, and whether a participant sought professional advice. Section C (six questions) used a 5-point ordinal scale to collect information on the frequency of specific tasks performed by radiographers in their daily roles. Section D involved exploratory questions, including whether LBP has forced a career change if they knew anyone who has changed their career as a result of LBP, reaction to the amount of manual handling required for radiographers, whether they thought manual handling training was sufficient, thoughts on the availability of assistive transfer devices, reasons for not following correct patient transfer guidelines, and finally whether they were concerned about LBP affecting their future.

RESULTS

151 radiographers participated in this study, and the point prevalence rate of LBP was 50%, with 12 months prevalence rate of 75%. Regarding activity levels, 25% (n=37) reported reduced work activity, and a further 43%(n=65) reduced leisure activities due to LBP. 37% (n=56) have sought medical advice from a doctor, physiotherapist, or other HCP concerning their LBP in the last year. 68% (n=104) of respondents who have LBP confirmed it was not a result of any extracurricular activities.

CONCLUSION

The prevalence of LBP among radiographers in Ireland was high and 4.7 times higher than the period prevalence rate recorded in the general population. LBP rates were similar to radiographers working in other jurisdictions. Data from this study may help manage LBP and monitor any interventions' effectiveness.

Research ethics systems, processes, and awareness across Europe: Radiography research ethics standards for Europe (RRESFE)

INTRODUCTION

The Radiography Research Ethics Standards for Europe (RRESFE) project aims to provide a cross-sectional snapshot of current research ethics systems, processes, and awareness of such, across Europe together with identifying the associated challenges, education, and training needs.

METHODS

A cross-sectional online survey targeting radiography researchers in Europe was conducted. Data collection took place between April 26 and July 12, 2021, using a snowball sampling approach. Descriptive and analytical statistics were used to identify trends in research ethics frameworks across Europe.

RESULTS

285 responses were received across 33 European and 23 non-European countries. Most (n = 221; 95%) European respondents stated ethics approval is required before commencing research in their country. Requirements around research ethics approval and awareness of such requirements varied by European region (X² (2, n = 129) = 7.234, p = 0.013) and were found to differ depending on the type of research participant and study design. Additionally, European respondents reported ethics approval is a national requirement more often than their non-European counterparts (X² (1, n = 282) = 4.316, p = 0.049). Requirements for ethics approval were also associated with the undergraduate programme duration (2-year vs. 3-year vs. 3.5 year vs. 4-year vs. multiple programme durations; X² (4, n = 231) = 10.075, p = 0.016) and availability of postgraduate training (postgraduate training available vs. postgraduate training not available; X² (1, n = 231) = 15.448, p = <0.001) within respondents' country.

CONCLUSION

Respondents from countries with longer programme durations/availability of multiple programme lengths, availability of postgraduate training, and establishment of European Qualifications Framework Level 6 were generally associated with less uncertainty and more comprehensive research ethics requirements.

IMPLICATIONS FOR PRACTICE

Results are informative of the current status of research ethics within evidence-based radiography.

Research ethics training, challenges, and suggested improvements across Europe: Radiography research ethics standards for Europe (RRESFE)

INTRODUCTION

The Radiography Research Ethics Standards for Europe (RRESFE) project aimed to provide a cross-sectional view of the current state of radiography research ethics across Europe. This included investigating education and training in research ethics, and identifying the key challenges and potential improvements associated with using existing research ethics frameworks.

METHODS

This cross-sectional online survey targeting radiography researchers in Europe was conducted between April 26 and July 12, 2021. Descriptive and analytical statistics were used to identify research ethics education and training trends. Content analysis of qualitative responses was employed to identify significant challenges and proposed improvements in research ethics frameworks of practice.

RESULTS

There were 232 responses received across 33 European countries. Most (n = 132; 57%) respondents had received some research ethics training; however, fewer participants had received training on safeguarding vulnerable patients (n = 72; 38%), diversity and inclusivity (n = 62; 33%), or research with healthy volunteers (n = 60; 32%). Training was associated with a greater perceived importance of the need for research ethics review (p = 0.031) and with the establishment of EQF Level 6 training (p = 0.038). The proportion of formally trained researchers also varied by region (p = <0.001). Time-to-ethics-approval was noted as the biggest challenge for professionals making research ethics applications.

CONCLUSION

Early and universal integration of research-oriented teaching within the radiography education framework which emphasises research ethics is recommended. Additionally, study findings suggest research ethics committee application and approval processes could be further simplified and streamlined.

IMPLICATIONS FOR PRACTICE

The survey contributes to a growing body of knowledge surrounding the importance of education and training in research ethics for assuring a high standard of research outputs in Radiography and has identified hurdles to obtaining research ethics approval for further investigation and address.

An evaluation of information online on artificial intelligence in medical imaging

Background

Opinions seem somewhat divided when considering the effect of artificial intelligence (AI) on medical imaging. The aim of this study was to characterise viewpoints presented online relating to the impact of AI on the field of radiology and to assess who is engaging in this discourse.

Methods

Two search methods were used to identify online information relating to AI and radiology. Firstly, 34 terms were searched using Google and the first two pages of results for each term were evaluated. Secondly, a Rich Search Site (RSS) feed evaluated incidental information over 3 weeks. Webpages were evaluated and categorized as having a positive, negative, balanced, or neutral viewpoint based on study criteria.

Results

Of the 680 webpages identified using the Google search engine, 248 were deemed relevant and accessible. 43.2% had a positive viewpoint, 38.3% a balanced viewpoint, 15.3% a neutral viewpoint, and 3.2% a negative viewpoint. Peer-reviewed journals represented the most common webpage source (48%), followed by media (29%), commercial sources (12%), and educational sources (8%). Commercial webpages had the highest proportion of positive viewpoints (66%). Radiologists were identified as the most common author group (38.9%). The RSS feed identified 177 posts of which were relevant and accessible. 86% of posts were of media origin expressing positive viewpoints (64%).

Conclusion

The overall opinion of the impact of AI on radiology presented online is a positive one. Consistency across a range of sources and author groups exists. Radiologists were significant contributors to this online discussion and the results may impact future recruitment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-022-01209-4.

Breast cancer detection across dense and non-dense breasts: Markers of diagnostic confidence and efficacy

Background

The impact of radiologists’ characteristics has become a major focus of recent research. However, the markers of diagnostic efficacy and confidence in dense and non-dense breasts are poorly understood.

Purpose

This study aims to assess the relationship between radiologists’ characteristics and diagnostic performance across dense and non-dense breasts.

Materials and methods

Radiologists specialising in breast imaging (n = 128) who had 0.5–40 (13±10.6) years of experience reading mammograms were recruited. Participants independently interpreted a test set containing 60 digital mammograms (40 normal and 20 abnormal) with similarly distributed breast densities. Diagnostic performance measures were analysed via Jamovi software (version 1.6.22).

Results

In dense breasts, breast-imaging fellowship completion significantly improved specificity (p = 0.004), location sensitivity (p = 0.01) and the area under the curve (AUC) of the receiver operating characteristic (p = 0.03). Only participation in BreastScreen reading significantly improved all performance metrics: specificity (p = 0.04), sensitivity (p = 0.005), location sensitivity (p < 0.001) and AUC (p < 0.001). Reading > 100 mammograms weekly significantly improved sensitivity (p = 0.03), location sensitivity (p = 0.001), and AUC (p = 0.03).In non-dense breasts, breast fellowship completion significantly improved sensitivity (p = 0.02), location sensitivity (p = 0.04) and AUC (p = 0.002). Participation in BreastScreen reading and reading > 100 mammograms weekly significantly improved only sensitivity (p = 0.002 and p = 0.003, respectively) and location sensitivity (p < 0.001 and p < 0.001, respectively).

Conclusion

Participating in screening programs, breast fellowships and reading > 100 mammograms weekly are important indicators of the diagnostic performance of radiologists across dense and non-dense breasts. In dense breasts, optimal performance resulted from participation in a breast screening program.

Endovascular management of pelvic trauma

Traumatic pelvic injuries are an important group of acquired pathologies given their frequent association with significant vascular compromise. Potentially fatal as a consequence of rapid hemorrhage, achievement of early hemostasis is a priority; endovascular management of traumatic pelvic arterial injuries is an important potential option for treatment. Precipitated by any number of mechanisms of trauma, pelvic vascular injury necessitates timely patient assessment. Variable patterns of arterial injury may result from blunt, penetrating or iatrogenic trauma. Selection of the most appropriate imaging modality is a priority, ensuring streamlined access to treatment. In the case of CT, this is complemented by acquisition of the most appropriate phase of imaging; review of both arterial and delayed phase imaging improves the accuracy of detection of low-flow hemorrhage. In cases where surgical intervention is not deemed appropriate, endovascular treatment provides an alternative means for cessation of hemorrhage associated with pelvic injuries. This may be achieved in a selective or nonselective manner depending on the patient's clinical status and time constraints. Consequently, a detailed understanding of vascular anatomy is essential, including an appreciation of the normal variant anatomy between males and females. Additional consideration must be given to variant anatomy which may co-exist in both sexes. This review article aims to provide a synopsis of endovascular management of pelvic vascular injury. Through case examples, available treatment options will be discussed, including thrombin injection and transcatheter arterial embolization. Furthermore, potential adverse complications of pelvic arterial embolization will be highlighted. Finally, in view of the potential severity of these injuries, a brief overview of initial management of the hemodynamically unstable patient is provided.

Breast cancer detection: Comparison of digital mammography and digital breast tomosynthesis across non-dense and dense breasts

INTRODUCTION

Breast density is associated with an increase in breast cancer risk and limits early detection of the disease. This study assesses the diagnostic performance of mammogram readers in digital mammography (DM) and digital breast tomosynthesis (DBT).

METHODS

Eleven breast readers with 1-39 years of experience reading mammograms and 0-4 years of experience reading DBT participated in the study. All readers independently interpreted 60 DM cases (40 normal/20 abnormal) and 35 DBT cases (20 normal/15 abnormal). Sensitivity, specificity, ROC AUC, and diagnostic confidence were calculated and compared between DM and DBT.

RESULTS

DBT significantly improved diagnostic confidence in both dense breasts (p = 0.03) and non-dense breasts (p = 0.003) but not in other diagnostic performance metrics. Specificity was higher in DM for readers with >7 years' experience (p = 0.03) in reading mammography, non-radiologists (p = 0.04), readers who had completed a 3-6 months training fellowship in breast imaging (p = 0.04), and those with ≤2 years' experience in reading DBT (p = 0.02), particularly in non-dense breasts.

CONCLUSION

Diagnostic confidence was higher in DBT when compared to DM. In contrast, other performance metrics appeared to be similar or better with DM and may be influenced by the lack of experience of the reader cohort in reading DBT.

IMPLICATIONS FOR PRACTICE

The benefits of DBT may not be entirely accrued until radiologists attain expertise in DBT interpretation. Specificity of DBT varied according to reader characteristics, and these characteristics may be useful for optimising pairing strategies in independent double reading of DBT as practiced in Australia to reduce false positive diagnostic errors.

Diagnostic Performance of Adjunctive Imaging Modalities Compared to Mammography Alone in Women with Non-Dense and Dense Breasts: A Systematic Review and Meta-Analysis

PURPOSE

To compare the diagnostic performance of mammography (MG) alone versus MG combined with adjunctive imaging modalities, including handheld ultrasound (HHUS), automated breast ultrasound (ABUS), digital breast tomosynthesis (DBT), contrast-enhanced mammography (CEM), and magnetic resonance imaging (MRI) in women with non-dense and dense breasts.

PATIENTS AND METHODS

Medline, Embase, PubMed, CINAHL, Scopus, and the Web of Science databases were searched up to October 2019. Quality assessment was performed using QUADAS-2. RevMan 5.3 was used to conduct a meta-analysis of the studies.

RESULTS

In dense breasts, adding adjunctive modalities significantly increased cancer detection rates (CDRs): HHUS (relative risk [RR] = 1.49; 95% confidence interval [CI], 1.19-1.86; P = .0005); ABUS (RR = 1.44; 95% CI, 1.16-1.78; P = .0008); DBT (RR = 1.38; 95% CI, 1.14-1.67; P = .001); CEM (RR = 1.37; 95% CI, 1.12-1.69; P = .003); and MRI (RR = 2.16; 95% CI, 1.81-2.58; P < .00001). The recall rate was significantly increased by HHUS (RR = 2.03; 95% CI, 1.89-2.17; P < .00001), ABUS (RR = 1.90; 95% CI, 1.81-1.99; P < .00001), and MRI (RR = 2.71; 95% CI, 1.73-4.25; P < .0001), but not by DBT (RR = 1.14; 95% CI, 0.95-1.36; P = .15). In non-dense breasts, HHUS and MRI showed significant increases in CDRs but not DBT: HHUS (RR = 1.14; 95% CI, 1.01-1.29; P = .04); MRI (RR = 1.78; 95% CI, 1.14-2.77; P = .01); and DBT (RR = 1.09; 95% CI, 1.13-1.75; P = .08). The recall rate was also significantly increased by HHUS (RR = 1.43; 95% CI, 1.28-1.59; P < .00001) and MRI (RR = 3.01; 95% CI, 1.68-5.39; P = .0002), whereas DBT showed a non-significant reduction (RR = 0.83; 95% CI, 0.65-1.05; P = .12).

CONCLUSION

Adding adjunctive modalities to MG increases CDRs in women with dense and non-dense breasts. Ultrasound and MRI increase recall rates across all breast densities; however, MRI results in higher values for both CDRs and recall rates.

Bridging the divide between medical school and clinical practice: identification of six key learning outcomes for an undergraduate preparatory course in radiology

BACKGROUND

There exists a significant divide between what is learnt in medical school and subsequently what is required to practice medicine effectively. Despite multiple strategies to remedy this discordance, the problem persists. Here, we describe the identification of a comprehensive set of learning outcomes for a preparation for practice course in radiology.

METHODS

Assessment of interns' readiness to interact with the radiology department was conducted using a national survey of both interns and radiologists. In parallel, group concept mapping (GCM) which involves a combination of qualitative and quantitative techniques was used to identify the shared understanding of participants from a diverse range of medical specialties regarding what topics should be included in an intern preparatory course for interacting with the radiology department.

RESULTS

The survey demonstrated that most interns and radiologists felt that undergraduate medical training did not prepare interns to interact with the radiology department. GCM identified six learning outcomes that should be targeted when designing a preparatory module: requesting investigations; clinical decision support; radiology department IT and communication; adverse reactions and risks; interpretation of radiology results and urgent imaging. The thematic clusters from the group concept mapping corroborated the deficiencies identified in the national survey.

CONCLUSION

We have identified six key learning outcomes that should be included in a preparation for practice module in radiology. Future courses targeting these thematic clusters may facilitate a smoother transition from theory to practice for newly graduated doctors.

The impact of COVID-19 upon student radiographers and clinical training

Introduction

To investigate student clinical placement concerns and opinions, during the initial COVID-19 pandemic outbreak and to inform educational institution support planning.

Methods

Between mid-June to mid-July 2020, educational institutions from 12 countries were invited to participate in an online survey designed to gain student radiographer opinion from a wide geographical spread and countries with varying levels of COVID-19 cases.

Results

1277 respondents participated, of these 592 had completed clinical placements during January to June 2020. Accommodation and cohabiting risks were identified as challenging, as was isolation from family, travel to clinical placements, and to a lesser extent childcare. Students stated they had been affected by the feeling of isolation and concerns about the virus whilst on placement. Overall 35.4% of all respondents were ‘Not at all worried’ about being a radiographer, however, 64.6% expressed varying levels of concern and individual domestic or health situations significantly impacted responses (p ≤ 0.05). Year 4 students and recent graduates were significantly more likely to be ‘Not worried at all’ compared to Year 2 and 3 students (p ≤ 0.05). The need for improved communication regarding clinical placements scheduling was identified as almost 50% of students on clinical placements between January to June 2020 identified the completion of assessments as challenging. Furthermore, only 66% of respondents with COVID-19 imaging experience stated being confident with personal protective equipment (PPE) use.

Conclusion

Student radiographers identified key challenges which require consideration to ensure appropriate measures are in place to support their ongoing needs. Importantly PPE training is required before placement regardless of prior COVID-19 imaging experience.

Implications for practice

As the next academic year commences, the study findings identify important matters to be considered by education institutions with responsibility for Radiography training and as students commence clinical placements during the on-going global COVID-19 pandemic.

The associated factors for radiation dose variation in cardiac CT angiography

OBJECTIVE:

This study aimed to examine the associated factors for dose variation and influence cardiac CT angiography (CCTA) dose benchmarks in current CT imaging centres.

METHODS:

A questionnaire was distributed to CT centres across Australia and Saudi Arabia. All participating centres collected data for adults who underwent a CCTA procedure. The questionnaire gathered information about the examination protocol, scanning parameters, patient parameters, and volume CT dose index (CTDI vol) and dose-length product (DLP). A stepwise regression analysis was performed to assess the contribution of tube voltage (kV), padding time technique, cross-sectional area (CSA) of chest and weight to DLP.

RESULTS:

A total of 17 CT centres provided data for 423 CCTA examinations. The median CTDI_vol, DLP and effective dose were 18 mGy, 256 mGy.cm and 5.2 mSv respectively. There was a statistically significant difference in DLP between retrospective and prospective ECG-gating modes (p = 0.001). Median DLP from CCTA using padding technique was 61% higher than CCTA without padding (p = 0.001). The stepwise regression showed that kV was the most significant predictor of DLP followed by padding technique then CSA while patient weight did not statistically significantly predict DLP. Correlation analysis showed a strong positive correlation between weight and CSA (r = 0.78), and there was a moderate positive correlation between weight and DLP (r = 0.42), as well as CSA and DLP (r = 0.48).

CONCLUSION:

Findings show radiation dose variations for CCTA. The associated factors for dose variation found in this study are scanning mode, kV, padding time technique and CSA of the chest. This results support the need to include CSA measurements in future dose survey and for setting DRLs.

ADVANCES IN KNOWLEDGE:

The study provides baseline information that helps to understand the associated factors for dose variations and high doses within and between centres performing CCTA.

Inter-rater reliability of a reflective rubric to assess pharmacy students' reflective thinking

INTRODUCTION

Many health education programs aspire to foster reflective practices to enhance the reflective thinking of students during their study years and throughout their professional careers. Given the increasing attention paid to incorporating reflective practice activities into health education and evidence attributed to rater variability, it is important for educators to carefully consider the assessment criteria and reliability of assessment tools. A reflective rubric was developed to assess pharmacy students' levels of reflection from a reflective writing task. This study investigates the inter-rater reliability (IRR) of a rubric as a tool to assess the levels of reflective thinking apparent in students' written statements.

METHODS

The research involved four raters from different disciplines utilizing a rubric to assess a random sample of the same forty-three reflective statements from a cohort of two hundred and sixty-four students. The IRR was measured using the intra-class correlation coefficient (ICC), using a two-way random effects model (ANOVA) with absolute agreement, to determine reliability of the assessment tool among the raters.

RESULTS

Results showed measures between the raters for (i) overall reflective statement scores, and (ii) average scores for stages of reflection with an "almost perfect" agreement, ICC = 0.81 (95% CI 0.61-0.90), (F(42, 126) = 7.83, p < 0.01); and ICC = 0.89 (95% CI 0.83-0.93), (F(42, 840) = 12.49, p < 0.01) respectively.

DISCUSSION AND CONCLUSIONS

The proposed rubric utilized by four raters showed high agreement with each other's scores, and is a tool for academic assessment of pharmacy students' reflective thinking processes.

Effective Dose and Effective Risk from Post-Single Photon Emission Computed Tomography Imaging of the Lumbar Spine

PURPOSE

Planar bone scans play an important role in the staging and monitoring of malignancy and metastases. Metastases in the lumbar spine are associated with significant morbidity; therefore, accurate diagnosis is essential. Supplementary imaging after planar bone scans is often required to characterize lesions; however, this is associated with additional radiation dose. This article provides information on the comparative effective dose and effective risk from supplementary lumbar spine radiographs, low-dose computed tomography (LDCT), and diagnostic CT (DCT).

METHOD

Organ dose was measured in a phantom using thermoluminescent dosimeters. Effective dose and effective risk were calculated for radiographs, LDCT, and DCT imaging of the lumbar spine.

RESULTS

Radiation dose was 0.56 mSv for the anteroposterior and lateral lumbar spine radiographs, 0.80 mSv for LDCT, and 3.78 mSv for DCT. Additional imaging resulted in an increase in effective dose of 12.28%, 17.54%, and 82.89% for radiographs, LDCT, and DCT, respectively. Risk of cancer induction decreased as age increased. The difference in risk between the modalities also decreased. Males had a statistically significant higher risk than female patients (P = .023), attributed to the sensitive organs being closer to the exposed area.

CONCLUSIONS

Effective dose for LDCT is comparable with radiographs of the lumbar spine. With the known benefits of image fusion, it is recommended that LDCT replace radiograph imaging for characterization of lumbar spine lesions identified on planar bone scans. DCT is associated with significantly higher effective dose than LDCT. Effective risk is also higher, and the difference is more marked in younger female patients.

Increasing Prevalence Expectation in Thoracic Radiology Leads to Overcall

RATIONALE AND OBJECTIVES

The aim of this study was to measure the effect of prevalence expectation as determined by clinical history on the diagnostic performance of radiologists during pulmonary nodule detection on adult chest radiographs.

MATERIALS AND METHODS

A multi-observer, counter-balanced study (having half the readers in each group read a different condition initially) was performed to assess the effect of abnormality expectation on experienced radiologists' performance. A total of 33 board-certified radiologists were divided into three groups and searched for evidence of malignancy on a single set of 47 postero-anterior (PA) chest radiographs, 10 of which contained a single pulmonary nodule. The radiologists were unaware of disease prevalence. Before each viewing of the same dataset, the radiologists were allocated to two of three conditions based on the differing clinical information (previous cancer, no history, visa applicant). Location sensitivity, specificity, and jack-knife free-response receiver operator characteristics figure of merit were used to compare radiologist performance between conditions.

RESULTS

A significant reduction in specificity was shown for the cancer compared to that for the visa condition (W = -41 P = 0.02). No other significant findings were demonstrated for this or the other condition comparisons. No significant difference in the performance of radiologists was noted when viewing images under the same conditions.

CONCLUSIONS

This study suggested that there is a reduction in specificity with high compared to low prevalence expectation following specific radiological contexts. A reduction in specificity can have important clinical consequences leading to unnecessary interventions. The results and their implications emphasize the caution that should be placed on providing accurate referral criteria.

Detection of an explosive simulant via electrical impedance spectroscopy utilizing the UiO-66-NH2 metal–organic framework

Electrical impedance spectroscopy, in conjunction with the metal–organic framework (MOF) UiO-66-NH₂, is used to detect trace levels of the explosive simulant 2,6-dinitrotoluene.

Precision imaging-its impact on image quality and diagnostic confidence in breast ultrasound examinations

OBJECTIVE

To determine the effect of noise-reducing innovation-precision imaging (PI)-on image quality and diagnostic efficacy in breast ultrasound.

METHODS

The study, which assessed four levels of PI from zero to three, consisted of two parts: image quality assessment and diagnostic efficacy evaluation. For the first part, 247 sets of ultrasound images displayed at each PI level were evaluated by 6 experienced breast imaging observers, by rating image quality using visual grading analysis on a 1-4 scale. For the diagnostic efficacy part 51 breast lesions were displayed at each PI level and scored 1-6 to generate a receiver operating characteristic (ROC) curve. These images were evaluated by radiologists and sonographers. Analyses were performed using non-parametric Friedman and Wilcoxon signed rank tests and a multireader multicase methodology.

RESULTS

Statistically, higher scores of image quality were observed with increased levels of PI than with the zero setting (p < 0.001). The ROC analysis did not demonstrate any significant change in diagnostic efficacy, with mean scores for all observers being 0.79, 0.80, 0.81 and 0.81 for settings zero, one, two and three, respectively.

CONCLUSION

This study suggested a perceived improvement in image quality with increasing levels of PI; however, no changes in diagnostic efficacy were noted. The importance of looking at the impact of new imaging technologies in a multifaceted way is emphasized.

ADVANCES IN KNOWLEDGE

To our knowledge, this is the first article investigating the impact of the PI algorithm on ultrasound image quality and breast lesion characterization.

Radiologists remember mountains better than radiographs, or do they?

Expertise with encoding material has been shown to aid long-term memory for that material. It is not clear how relevant this expertise is for image memorability (e.g., radiologists' memory for radiographs), and how robust over time. In two studies, we tested scene memory using a standard long-term memory paradigm. One compared the performance of radiologists to naïve observers on two image sets, chest radiographs and everyday scenes, and the other radiologists' memory with immediate as opposed to delayed recognition tests using musculoskeletal radiographs and forest scenes. Radiologists' memory was better than novices for images of expertise but no different for everyday scenes. With the heterogeneity of image sets equated, radiologists' expertise with radiographs afforded them better memory for the musculoskeletal radiographs than forest scenes. Enhanced memory for images of expertise disappeared over time, resulting in chance level performance for both image sets after weeks of delay. Expertise with the material is important for visual memorability but not to the same extent as idiosyncratic detail and variability of the image set. Similar memory decline with time for images of expertise as for everyday scenes further suggests that extended familiarity with an image is not a robust factor for visual memorability.

Patient-based radiographic exposure factor selection: a systematic review

Introduction

Digital technology has wider exposure latitude and post-processing algorithms which can mask the evidence of underexposure and overexposure. Underexposure produces noisy, grainy images which can impede diagnosis and overexposure results in a greater radiation dose to the patient. These exposure errors can result from inaccurate adjustment of exposure factors in response to changes in patient thickness. This study aims to identify all published radiographic exposure adaptation systems which have been, or are being, used in general radiography and discuss their applicability to digital systems.

Methods

Studies in EMBASE, MEDLINE, CINAHL and SCOPUS were systematically reviewed. Some of the search terms used were exposure adaptation, exposure selection, exposure technique, 25% rule, 15% rule, DuPont™ Bit System and radiography. A manual journal-specific search was also conducted in The Radiographer and Radiologic Technology. Studies were included if they demonstrated a system of altering exposure factors to compensate for variations in patients for general radiography. Studies were excluded if they focused on finding optimal exposures for an ‘average’ patient or focused on the relationship between exposure factors and dose.

Results

The database search uncovered 11 articles and the journal-specific search uncovered 13 articles discussing systems of exposure adaptation. They can be categorised as simple one-step guidelines, comprehensive charts and computer programs.

Conclusion

Only two papers assessed the efficacy of exposure adjustment systems. No literature compares the efficacy of exposure adaptations system for film/screen radiography with digital radiography technology nor is there literature on a digital specific exposure adaptation system.

Phase II study of oral docetaxel and cyclosporine in canine epithelial cancer

The goal of the current study was to determine the efficacy of oral docetaxel in combination with cyclosporine in the treatment of canine epithelial cancer. Requirements for eligibility were histological confirmation of epithelial neoplasia, measurable disease, no chemotherapy treatment within 2 weeks, and a life expectancy of ≥ 3 months. Fifty-one dogs were enrolled. All dogs received 1.625 mg kg(-1) of docetaxel with 5 mg kg(-1) of cyclosporine (DT/CSA) by gavage. Ten dogs had progressive disease at 2 weeks, one dog died, and one dog was withdrawn from the study. Thirty-nine dogs were given a second dose of DT/CSA, three each receiving a third or fourth dose. Eight dogs had a dose reduction (1.5 mg kg(-1)) and six dogs had treatment delays primarily for gastrointestinal toxicity. The overall response rate was 16.7% (8/48 had a partial response there were no complete responses). The highest response rate was seen in dogs with oral squamous cell carcinoma (50%; 6/12).

Maltese CT doses for commonly performed examinations demonstrate alignment with published DRLs across Europe

This work recommends dose reference levels (DRLs) for abdomen, chest and head computerised tomography (CT) examinations in Malta as the first step towards national CT dose optimisation. Third quartiles volume CT dose index  values for abdomen: 12.1 mGy, chest: 13.1 mGy and head: 41 mGy and third quartile dose-length product values for abdomen: 539.4, chest: 492 and head: 736 mGy cm(-1) are recommended as Maltese DRLs derived from this first Maltese CT dose survey. These values compare well with DRLs of other European countries indicating that CT scanning in Malta is consistent with standards of good practice. Further work to minimise dose without affecting image quality and extending the establishment of DRLs for other CT examinations is recommended.

Rheumatoid arthritis: a novel radiographic projection for hand assessment

Rheumatoid arthritis (RA) is the most common form of inflammatory disease, affecting 1-2% of the population. Posteroanterior (PA) and Brewerton projections are well established in radiographic practice for scoring and monitoring RA, but there is little evidence to demonstrate the diagnostic efficacy of these techniques. This work, by varying the positioning of a cadaveric hand, investigates whether an alternative radiographic projection could yield greater diagnostic information than the traditional techniques. Phase I of the study evaluated moving the hand 15 degrees from the anteroposterior position and then in 5 degrees increments in four directions: medial rotation, lateral rotation, flexion of the wrist and extension of the wrist. Phase II of the study took the optimum projections from Phase I and further manipulated these positions in a direction at right angles to the original position. Images were scored based on joint space visualisation in 29 joints. Results demonstrated that significantly higher diagnostic efficacy was evident with 15 degrees lateral rotation of the hand or 15 degrees flexion at the wrist compared to the Brewerton projection. Either projection is recommended, but on the basis of patient comfort, the latter of these novel positions, now known as the UCD projection, was chosen as the optimum procedure to replace the Brewerton projection. The value of using cadavers for the establishment of optimum radiographic procedures is highlighted.

The impact of acoustic noise found within clinical departments on radiology performance

RATIONALE AND OBJECTIVES

In recent years, there has been increasing interest in the impact of environmental factors such as ambient light on radiologist performance. One commonly encountered distractor found within all clinical departments that has received little or no attention is acoustic noise.

MATERIALS AND METHODS

The present work records the level of noises encountered within environments where radiologic images are viewed and establishes the impact of a clinically relevant level of noise on the ability of radiologists to perform a typical diagnostic task. Noise levels were recorded 10 times within each of 14 environments, 11 of which were locations where radiologic images are judged. Thirty chest images were then presented to 26 senior radiologists, who were asked to detect up to three nodular lesions within 30 posteroanterior chest x-ray images in the absence and presence of noise at an amplitude demonstrated in the clinical environment. Jackknife free-response receiver-operating characteristic analyses was performed on the free-response data.

RESULTS

The results demonstrated that noise amplitudes rarely exceeded that encountered with normal conversation with the maximum mean value for an image-viewing environment being 56.1 dB. This level of noise had no impact on the ability of radiologists to identify chest lesions with figure of merits of 0.68, 0.69, and 0.68 with noise and 0.65, 0.68, and 0.67 without noise for chest radiologists, nonchest radiologists, and all radiologists, respectively. Equally, no differences were seen for false-positive and false-negative scores or on the time required to judge the images.

CONCLUSION

These findings suggest that noise at levels encountered within areas where radiologic images are viewed is not a major distractor within the reporting environment, but the need for further work has been identified.

Optimization of region of interest luminances may enhance radiologists' light adaptation

RATIONALE AND OBJECTIVES

Radiologic image details are best discriminated at luminance levels to which the eye is adapted. Recommendations that ambient light conditions are matched to overall monitor luminance to encourage appropriate adaptation are based on an assumption that clinically significant regions within the image match average monitor luminance. The current work examines this assumption.

MATERIALS AND METHODS

Three image types were considered: posteroanterior (PA) chest; PA wrist; and computed tomography (CT) head. Luminance at clinically significant regions was measured at hilar region and peripheral lung (chest), distal radius (wrist), and supraventricular white matter (head). Average monitor luminances were calculated from measurements at 16 regions of the display face plate. Three ambient light levels-30, 100 and 400 lux-were employed. Thirty samples of each image type were used.

RESULTS

Statistically significant differences were noted between average monitor luminances and clinically important regions of interest of up to a factor of 3.8, 2, and 6.3 for chest, wrist, and CT head images respectively (P < .0001). Values for the hilum of the chest and distal radius were higher than average monitor levels, whereas the reverse was observed for the peripheral lung and CT brain. Increasing ambient light had no impact on results.

CONCLUSIONS

Clinically important radiologic information for common radiologic examinations is not being presented to observers in a way that facilitates optimized adaptation. This may have a significant impact on the ability of the observer to identify details with low contrast discriminability. The importance of image-processing algorithms focussing on clinically significant abnormalities rather than anatomic regions is highlighted.

Ambient Lighting: Effect of Illumination on Soft-Copy Viewing of Radiographs of the Wrist

OBJECTIVE

The aim of the work was to establish optimum ambient light conditions for viewing radiologic images of the wrist on liquid crystal display monitors.

MATERIALS AND METHODS

Five ambient light levels were investigated: 480, 100, 40, 25, and 7 lux. Seventy-nine experienced radiologists were asked to examine 30 posteroanterior wrist images and decide whether a fracture was present. All images were displayed on liquid crystal display monitors. Receiver operating characteristic analysis was performed, and the numbers of false-positive and false-negative findings were recorded.

RESULTS

For all the radiologists, greater area under the receiver operating characteristic curve and lower numbers of false-positive and false-negative findings were recorded at 40 and 25 lux compared with 480 and 100 lux. At 7 lux, the results were generally similar to those at 480 and 100 lux. The experience and knowledge of radiologists specializing in imaging of musculoskeletal trauma appeared to compensate in part for inappropriate lighting levels.

CONCLUSION

Typical office lighting and current recommendations on ambient lighting can reduce diagnostic efficacy compared with lower levels of ambient lighting. If, however, no light other than that of the monitor is used, results are similar to those with excessive levels of lighting. Careful control of ambient lighting is therefore required to ensure that diagnostic accuracy is maximized, particularly for clinicians not expert in interpreting posteroanterior wrist images.

Intrathecal enzyme replacement therapy reduces lysosomal storage in the brain and meninges of the canine model of MPS I

Enzyme replacement therapy (ERT) has been developed for several lysosomal storage disorders, including mucopolysaccharidosis I (MPS I), and is effective at reducing lysosomal storage in many tissues and in ameliorating clinical disease. However, intravenous ERT does not adequately treat storage disease in the central nervous system (CNS), presumably due to effects of the blood-brain barrier on enzyme distribution. To circumvent this barrier, we studied whether intrathecal (IT) recombinant human alpha-L-iduronidase (rhIDU) could penetrate and treat the brain and meninges. An initial dose-response study showed that doses of 0.46-4.14 mg of IT rhIDU successfully penetrated the brain of normal dogs and reached tissue levels 5.6 to 18.9-fold normal overall and 2.7 to 5.9-fold normal in deep brain sections lacking CSF contact. To assess the efficacy and safety in treating lysosomal storage disease, four weekly doses of approximately 1 mg of IT rhIDU were administered to MPS I-affected dogs resulting in a mean 23- and 300-fold normal levels of iduronidase in total brain and meninges, respectively. Quantitative glycosaminoglycan (GAG) analysis showed that the IT treatment reduced mean total brain GAG to normal levels and achieved a 57% reduction in meningeal GAG levels accompanied by histologic improvement in lysosomal storage in all cell types. The dogs did develop a dose-dependent immune response against the recombinant human protein and a meningeal lymphocytic/plasmacytic infiltrate. The IT route of ERT administration may be an effective way to treat the CNS disease in MPS I and could be applicable to other lysosomal storage disorders.

Dose-reducing strategies in combination offers substantial potential benefits to females requiring X-ray examination

This work, using an adult anthropomorphic phantom, aimed to establish an optimised technique for ladies of child-bearing age undergoing antero-posterior (AP) pelvis and AP and lateral lumbar spine examinations. Phase one of the work involved introducing the following dose-reducing measures individually: increased kVp, increased focus-film distances, a carbon fibre cassette, a faster film/screen combination. The second phase established an optimised technique based on a combination of the parameters listed above. Radiation dose was measured using thermoluminescent dosimeters and image quality was evaluated using anatomical criteria. All dose-reducing methods were compared with a standard technique, currently being used in a Dublin hospital. The results demonstrated that the optimised procedure reduced effective dose by 77, 62 and 66% for AP pelvis and AP and lateral lumbar spine respectively (p < 0.05) compared with the standard technique, with no significant changes in image quality. Dose-reducing measures used in combination offer substantial potential for optimisation of radiological procedures.

Distinction of basaloid carcinoma of the prostate from benign basal cell lesions by using immunohistochemistry for bcl-2 and Ki-67

The distinction of rare basaloid carcinomas (BC) of the prostate from more common basal cell hyperplasia may be difficult, because basal cell hyperplasia (BCH) may have prominent nucleoli and may appear infiltrative. Using immunohistochemistry, we studied bcl-2 and p53 expression and Ki-67 proliferation index in eight cases of typical BCH, eight cases of BCH with nucleoli, and six cases of BC. Bcl-2 expression (P < .0001) and Ki-67 index (P=.005) were elevated in BC compared with typical BCH or BCH with nucleoli, whereas there was no significant difference between typical BCH and BCH with nucleoli. P53 was not discriminative in separating benign from malignant basal cell lesions of the prostate. Bcl-2 may play a role in the pathogenesis of basal cell lesions of the prostate. Elevated expression of bcl-2 and higher Ki-67 index may aid in the diagnosis of basal cell proliferative lesions of the prostate.

Characterization of HIV-1 vpr nuclear import: analysis of signals and pathways

While the Vpr protein of HIV-1 has been implicated in import of the viral preintegration complex across the nuclear pore complex (NPC) of nondividing cellular hosts, the mechanism by which Vpr enters the nucleus remains unknown. We now demonstrate that Vpr contains two discrete nuclear targeting signals that use two different import pathways, both of which are distinct from the classical nuclear localization signal (NLS)- and the M9-dependent pathways. Vpr import does not appear to require Ran-mediated GTP hydrolysis and persists under conditions of low energy. Competition experiments further suggest that Vpr directly engages the NPC at two discrete sites. These sites appear to form distal components of a common import pathway used by NLS- and M9-containing proteins. Together, our data suggest that Vpr bypasses many of the soluble receptors involved in import of cellular cargoes. Rather, this viral protein appears to directly access the NPC, a property that may help to ensure the capacity of HIV to replicate in nondividing cellular hosts.

Isolated right ventricular cardiomyopathy in a dog

Right-sided heart failure was diagnosed in a young dog with clinical and pathologic features of isolated right ventricular cardiomyopathy. This disorder, also referred to as right ventricular dysplasia, is an infrequent cause of heart failure and sudden death in people. Echocardiography of this dog revealed right ventricular and right atrial dilatation and severe right ventricular systolic dysfunction. Left ventricular size and function were normal. Electrocardiography revealed ventricular bigeminy. The configuration of the ectopic beats was similar to that seen with left bundle branch block. The dog died suddenly, and histologic examination of the heart revealed fibroadipose replacement of right atrial and right ventricular myocardium.

Lentivirus induced arthritis in animals

Retroviral arthritis in sheep and goats depends on persistent infection in the animals. Virus is latent in macrophage precursor cells and viral replication is initiated when these cells are induced to differentiate. Antiviral antibodies and cytokines modulate the efficiency of viral gene product expression. Specific cytokines induced during replication of the lentivirus in mononuclear cells are also responsible for directing infected cells from peripheral blood through the vascular endothelium to particular tissues. Cytokines induced by other infectious agents such as bacteria, mycoplasma or protozoa, may also contribute to this chemotactic process. Once in the tissue, macrophages interact with lymphocytes to induce an inflammatory cascade with further production of cytokines which enhances expression of class II major histocompatibility complex antigens and proliferation of B and CD8 lymphocytes. In addition, immune complexes between viral glycoproteins and immunoglobulins are produced locally and probably lead to further enhancement of pathological changes in the tissues.

Compliance to nicotine gum recommendations in a multicomponent group smoking cessation program: an exploratory study

This is an exploratory study of compliance to nicotine chewing gum in a multicomponent group smoking cessation program where usage was optional. Two-thirds (24 out of 36) of the participants across three group sessions complied with the recommendation to use nicotine chewing gum. All subjects received standard instructions. Demographic characteristics (age, sex, site of employment) and smoking variables (number of years smoked, pretreatment number of cigarettes smoked per day, and nicotine dependence) failed to predict compliance, but complaint participants reported significantly greater confidence at their ability to not smoke in various challenging situations as measured by the Smoking Self Efficacy Questionnaire. Those who did comply mostly failed to chew the gum in the way instructed. Reduced craving was cited as the most positive feature of gum use.

Nasal cavity and frontal sinuses

The anatomy, diagnostic principles, and surgical techniques relating to the nasal cavity and frontal sinuses are reviewed. Disorders are considered under headings of infectious, neoplastic, and miscellaneous conditions. For each disease condition, an attempt is made to emphasize particular problems and discuss new developments on treatment. Specific recommendations have been made where possible, along with the expected outcome.