Exploring Attitudes Toward Pre-Exposure Prophylaxis for HIV Prevention Prior to Implementation Among Female Sex Workers in Malaysia: Results from a Qualitative Study

Introduction

Pre-exposure prophylaxis (PrEP) is an effective method for prevention of HIV transmission. Female sex workers (FSW) in Malaysia are at substantially increased risk of acquiring HIV compared to the general female population, yet little is known about this population's current HIV prevention practices or acceptance of PrEP. This study aims to inform the culturally relevant implementation of PrEP through the qualitative exploration of (1) the potential need for PrEP in this population and (2) the factors that determine FSW willingness to use oral PrEP.

Methods

In-depth, semi-structured interviews (n = 30) were conducted with FSW in English, Malay, or Tamil. Transcribed and translated interviews were analyzed using a grounded theory approach.

Results

FSW express positive interest in PrEP but prefer it as a supplement to condoms, not a replacement. Perceived challenges to PrEP use include cost, adherence, and side effects.

Conclusion

The findings suggest that in combination with condom use, PrEP may be an acceptable method of HIV prevention. Effective PrEP rollout may also include condom promotion using a peer-driven model, cost subsidies, and sex work harm reduction and empowerment components.

Engaging health plans to prioritize HPV vaccination and initiate at age 9

Health plans can influence pediatric and primary care providers and patients to understand HPV vaccination coverage and increase HPV vaccination uptake. By initiating vaccination at age nine, health plans can lay the groundwork for on-time HPV cancer prevention by age 13. In 2022, the American Cancer Society engaged 28 health plans in a 12-month HPV vaccination learning collaborative in which plans set their own quality improvement targets, implemented multi-pronged interventions, and joined quarterly best-practice sharing calls. Twenty-five of the 28 plans reported including a focus on ages 9 to 10. Preliminary pre-intervention data illustrate that vaccination rates from participating plans follow national trends and reaffirm existing gaps for HPV vaccination. Health plan interventions to address HPV vaccination are consistent with best practices but could be maximized to target initiation at ages 9-10 by using provider and patient reminders, targeted provider education, and dose-specific provider pay for performance and patient incentive programs. Health plans should explore future capacity to analyze non-HEDIS required data, including HPV initiation and HPV vaccination data for adolescents below age 13.

Age nine is possible: Improving age 9 HPV initiation through a national quality improvement initiative during the COVID-19 pandemic

The American Cancer Society collaborated with a range of healthcare partners in 2020-2022 to implement quality improvement clinical interventions with the goal of improving HPV vaccination rates among adolescents' ages 9-13. 2020 was the first cohort for which partners had been asked to submit HPV rate data for patients' ages 9-12. At least 80% of the partners across all reported project years were able and willing to report HPV rates for these ages. Partners submitted HPV initiation rates at the beginning and end of the 12-month project year along with project activities, including evidence-based interventions (EBIs) implemented. Mean initiation rates for ages 9-10 significantly increased 4.1% during 2020 compared to non-significant rate increases of 2.6% and 2.0% for ages 11-12 and age 13, respectively. In 2021, ages 9-10 initiation saw a non-significant increase of 2.2%, whereas ages 11-12 and age 13 decreased non-significantly by 0.3% and 0.1%, respectively. The 2022 cohort saw significant initiation rate increases of at least 4% across all ages, potentially a promising result of the myriad back on track HPV vaccination campaigns designed to reverse the damage of the COVID-19 pandemic on adolescent immunizations. These findings demonstrate an effective adaptation of quality improvement in increasing HPV vaccination coverage among younger ages even during a national pandemic.

Investigating CT head diagnostic reference levels based on indication-based protocols - a single site study

INTRODUCTION

This study aimed to provide clinically-relevant insights into establishing CT DRLs based on indication-based protocols in Ireland, focusing on CT head examinations performed at a neurology centre of excellence hospital.

METHODS

Dose data were collected retrospectively. Typical values for six CT head indication-based protocols were established using a sample size of 50 patients for each protocol. Typical values for each protocol were set as the median of the distribution curve. Dose distributions for each protocol were calculated and compared using non-parametric median test (k-samples) to ascertain significant dose differences between the typical values.

RESULTS

Most typical values pairings showed significant differences (p < 0.001) except between stroke/non-vascular brain, stroke/acute brain, and acute brain/non-vascular brain pairings. This was expected due to similar scan parameters. The typical value for stroke (3-phases angiogram) was 52% lower than the typical value for stroke. Dose levels of the male populations recorded were higher than female populations for all protocols. Statistical comparison showed significant differences for dose quantities and/or scan length between both genders in five protocols.

CONCLUSION

Proposed values for DLP were up to 63% and 69% lower than the EU and Irish national DRLs respectively. Establishment of CT stroke DRLs should be based on the scan performed instead of number of scan acquisitions. Lastly, gender-based CT DRLs for specific protocols within the head region require further investigation.

IMPLICATIONS FOR PRACTICE

With increasing CT examinations worldwide, radiation dose optimisation is key. The value of indication based DRLs is to enhance the required patient protection so image quality can be maintained, however with relevant DRLs for varying protocols. Establishment of CT typical values and site specific DRLs for procedures beyond the national DRLs can drive dose optimisation locally.

Predictors of self-harm and suicide in LGBT youth: The role of gender, socio-economic status, bullying and school experience

BACKGROUND

Lesbian, gay and bisexual (LGB) young people's increased risk of self-harm, suicidal attempts and suicide compared with heterosexual youth is well established. The current study sought to examine whether these findings also apply to the trans (T) population and which factors act as additional risk or protective factors.

METHODS

In a national cross-sectional survey, 3713 LGBT adolescents, aged 11-19 years, reported on their own history of self-harm, suicidal ideation and suicide attempts, as well as their experiences of school and homophobic, biphobic and transphobic bullying. Logistic regressions tested the association between risk and protective factors on self-harm, suicidal ideation and suicide attempts.

RESULTS

A high proportion of the sample reported self-harm (65.3%), suicidal ideation (73.8%) and suicide attempts (25.7%). Demographic risk factors included identifying as female, non-binary or trans and being from a low-income background. Bullying and online bullying were associated with an increased risk for each outcome, and positive school experience was associated with a reduced risk for each outcome.

CONCLUSIONS

Consistent with minority stress theory, the study found high rates of mental health problems within LGBT youth. Interventions focused on improving young people's experiences in schools appear useful targets to help improve mental health outcomes.

Low-cost 3D-printed anthropomorphic cardiac phantom, for computed tomography automatic left ventricle segmentation and volumetry - A pilot study

INTRODUCTION

Accurate cardiac left ventricle (LV) delineation is essential to CT-derived left ventricular ejection fraction (LVEF). To evaluate dose-reduction potential, an anatomically accurate heart phantom, with realistic X-ray attenuation is required. We demonstrated and tested a custom-made phantom using 3D-printing, and examined the influence of image noise on automatically measured LV volumes METHODS: A single coronary CT angiography (CCTA) dataset was segmented and converted to Standard Tessellation Language (STL) mesh, using open-source software. A 3D-printed model, with hollow left heart chambers, was printed and cavities filled with gelatinized contrast media. This was CT-scanned in an anthropomorphic chest phantom, at different exposure conditions. LV and "myocardium" noise and attenuation was measured. LV volume was automatically measured using two different methods. We calculated Spearmans' correlation of LV volume with noise and contrast-noise ratio respectively om 486 scans of the phantom. Source images were compared to one phantom series with similar parameters. This was done using Dice coefficient on LV short-axis segmentations.

RESULTS

Phantom "Myocardium" and LV attenuation was comparable to measurements on source images. Automatic volume measurement succeeded, with mean volume deviation to patient images less than 2 ml. There was a moderate correlation of volume with CNR, and strong correlation of volume with image noise. With papillary muscles included in LV volume, the correlation was positive, but negative when excluded. Variation of volumes was lowest at 90-100 kVp for both methods in the 486 repeat scans. The Dice coefficient was 0.87, indicating high overlap between the single phantom series and source scan. Cost of 3D-printer and materials was 400 and 30 Euro respectively.

CONCLUSION

Both anatomically and radiologically the phantom mimicked the source scans closely. LV volumetry was reliably performed with automatic algorithms.

IMPLICATIONS FOR PRACTICE

Patient-specific cardiac phantoms may be produced at minimal cost and can potentially be used for other anatomies and pathologies. This enables radiographic phantom studies without need for dedicated 3D-labs or expensive commercial phantoms.

Awareness, perceptions, and choices of physicians pertaining to human papillomavirus (HPV) vaccination in India: A formative research study

Introduction

India accounts for one-fifth of the global burden of cervical cancer cases and mortality. A safe and effective vaccine to prevent human papillomavirus (HPV) infections, the primary cause of cervical malignancies, is available in India but multiple barriers lead to its low uptake in the country. Physicians are a key stakeholder and communicator in the Indian health system and have the potential to increase HPV vaccine uptake.

Objective

We undertook formative research to understand awareness, perceptions and choices of physicians when recommending the HPV vaccine to parents of adolescent girls.

Methods

We conducted in-depth interviews with 32 physicians in two districts of West Bengal. Data collection was carried out between July and August 2019. The data was transcribed, coded, and analyzed using NVivo software using the thematic analysis technique.

Results

Our findings suggest that while physicians are generally aware about the burden of cervical cancer and its prevention by HPV vaccination, they face several barriers to recommending the HPV vaccine routinely and strongly. These include the lack of national-level guidance on the age eligibility and dosage, lack of practice-level opportunities such as well or non-sick visits and other routine adolescent vaccines, practice-level barriers like out-of-pocket cost and vaccine availability, and perceived parental hesitancy arising from reluctance to discuss cervical cancer, its prevention, and HPV vaccination.

Conclusions

Physicians in our study exhibited hesitancy when recommending the HPV vaccine. They also faced logistical barriers. It is important that the barriers pertaining to when and how physicians recommend the vaccine be tackled through further education, policy change, and development and implementation of interventions that are evidenced-based.

THE EFFECTS OF CONE-BEAM COMPUTED TOMOGRAPHY IMAGING GUIDANCE ON PATIENT RADIATION EXPOSURES IN TRANS-ARTERIAL CHEMOEMBOLISATION FOR HEPATOCELLULAR CARCINOMA

This study investigated the effects of cone-beam computed tomography (CBCT) guidance in trans-arterial chemoembolisation (TACE) procedures on the number of digital subtraction angiography (DSA) runs acquired and total patient radiation exposure in patients with hepatocellular carcinoma (HCC). A retrospective, analytical cross-sectional, single institution, study was conducted. Dose data were compared across the control (DSA guidance alone) and study (DSA and CBCT guidance) groups. A total of 122 procedures were included within the study. There was a significant reduction in the number of DSA runs (3 vs 5, p < 0.001) and DSA air kerma-area product (PKA) (3077.3 vs 4276.6 μGym2, p = 0.042) for the study group when compared to the control group. Total procedural PKA and total procedural reference air kerma (Ka,r) were shown to be 50 and 73% higher, respectively, for the study group when compared to the control group. CBCT imaging guidance does reduce the number of DSA runs and DSA PKA required to complete the TACE procedure for patients diagnosed with HCC; however, a substantial increase in total procedural PKA is to be expected and it is thus important that this increased dose is carefully considered and justified.

European consensus on patient contact shielding

Patient contact shielding has been in use for many years in radiology departments in order to reduce the effects and risks of ionising radiation on certain organs. New technologies in projection imaging and CT scanning such as digital receptors and automatic exposure control (AEC) systems have reduced doses and improved image consistency. These changes and a greater understanding of both the benefits and the risks from the use of shielding have led to a review of shielding use in radiology. A number of professional bodies have already issued guidance in this regard. This paper represents the current consensus view of the main bodies involved in radiation safety and imaging in Europe: European Federation of Organisations for Medical Physics, European Federation of Radiographer Societies, European Society of Radiology, European Society of Paediatric Radiology, EuroSafe Imaging, European Radiation Dosimetry Group (EURADOS), and European Academy of DentoMaxilloFacial Radiology (EADMFR). It is based on the expert recommendations of the Gonad and Patient Shielding (GAPS) Group formed with the purpose of developing consensus in this area. The recommendations are intended to be clear and easy to use. They are intended as guidance, and they are developed using a multidisciplinary team approach. It is recognised that regulations, custom and practice vary widely on the use of patient shielding in Europe and it is hoped that these recommendations will inform a change management program that will benefit patients and staff.

67 A BLENDED MODEL OF CARE USED IN THE ROLLOUT OF AN EARLY SUPPORTED DISCHARGE FOR STROKE SERVICE DURING COVID-19

Background

The Health and Social Care Professionals budget was augmented to develop rehabilitation services that facilitated hospital discharges. Early Supported discharge (ESD) for stroke is a proven model of best care for stroke patients with mild to moderate disability (Langhorne et al., 2005). A pilot was implemented with the team consisting of an Occupational Therapist, Speech and Language Therapist, Physiotherapist and Medical Social Worker.

Methods

The service facilitated an early discharge from the hospital with the delivery of specialist stroke rehabilitation in the home. Therapy is provided with the same intensity and expertise that would be received in hospital and is available for up to 8 weeks, it was provided using a blended model of domiciliary care and the introduction of telehealth in response to COVID 19.

Data was recorded for 100 service users using an excel spreadsheet. Data was recorded to measure number of new referrals, length of stay, bed days released back into the hospital system, mode of service delivery and functional outcomes. A cost analysis was completed. Service user experience was captured using questionnaires.

Results

From September 2020 to July 2021, 100 patients accessed ESD with a reduction of 7.2 days in hospital stay per patient. Improvements in pre- and post- rehabilitation scores on the FIM/FAM were evident. Very positive feedback regarding the rehabilitation experience was captured within the patient satisfaction questionnaire. Therapy delivery was 60% face to face, 37% via telehealth and 3% outpatient appointments. Telehealth received good compliance but with varying reports of experience in comparison to face to face.

Conclusion

ESD provided in the home environment facilitated earlier discharge from hospital with positive outcomes for the hospital and service users. Telehealth ensured that rehabilitation was maintained throughout the pandemic. Telehealth increased access for patients residing outside of the catchment area. However service user preference remains face to face.

Design of a 3D printed coronary artery model for CT optimization

INTRODUCTION

To design a custom phantom of the coronary arteries to optimize CT coronary angiography (CCTA) protocols.

METHODS

Characteristics of the left and right coronary arteries (mean Hounsfield Unit (HU) values and diameters) were collected from consecutive CCTA examinations (n = 43). Four different materials (two mixtures of glycerine, gelatine and water, pig hearts, Ecoflex™ silicone) were scanned inside a Lungman phantom using the CCTA protocol to find the closest model to in vivo data. A 3D printed model of the coronary artery tree was created using CCTA data by exporting a CT volume rendering into Autodesk Meshmixer™ software. The model was placed in an acid bath for 5 h, then covered in Ecoflex™, which was removed after drying. Both the Ecoflex™ and pig heart were later filled with a mixture of contrast (Visipaque 320 mg I/ml), NaCl and gelatin and scanned with different levels of tube current and iterative reconstruction (ASiR-V). Objective (HU, noise and size (vessel diameter) and subjective analysis were performed on all scans.

RESULTS

The gelatine mixtures had HU values of 130 and 129, Ecoflex™ 65 and the pig heart 56. At the different mA/ASiR-V levels the contrast filled Ecoflex™ had a mean HU 318 ± 4, noise 47±7HU and diameter of 4.4 mm. The pig heart had a mean HU of 209 ± 5, noise 38±4HU and a diameter of 4.4 mm. With increasing iterative reconstruction level the visualisation of the pig heart arteries decreased so no measurements could be performed.

CONCLUSION

The use of a 3D printed model of the arteries and casting with the Ecoflex™ silicone is the most suitable solution for a custom-designed phantom.

IMPLICATIONS FOR PRACTICE

Custom designed phantoms using 3D printing technology enable cost effective optimisation of CT protocols.

Impact of a Multilevel Quality Improvement Intervention Using National Partnerships on Human Papillomavirus Vaccination Rates

OBJECTIVE

To evaluate the effectiveness of a multilevel intervention using national partnerships on human papillomavirus (HPV) vaccination rates.

METHODS

The American Cancer Society's Vaccinate Adolescents against Cancer program is a multilevel intervention focusing on systems and providers. The 2017 cohort introduced national partnerships to deliver intervention elements and Maintenance of Certification and continuing medical education credits for physicians. Eleven federally qualified health center (FQHC) systems completed interventions in 2017. Interventions included provider training and ≥1 other evidence-based systems improvement. We compared adolescent vaccination rates in the preintervention period (2016) and intervention period (2017) among adolescents who turned 13 during the calendar year. Intervention effectiveness was assessed using repeated measures paired t tests and Cohen's d effect size for vaccination rate change.

RESULTS

All FQHC systems implemented provider training plus an average of 2.3 additional systems improvements. Series initiation increased by an average of 23.6 percentage points (47.2%-70.8%). HPV completion rates increased by an average of 22.7 percentage points (24.6%-46.3%). Meningococcal and Tdap vaccination rates increased by 23.3 and 25.9 percentage points respectively (47.9%-71.2% and 48.8%-74.7%). All changes were statistically significant (all P < .05) and indicated large effect sizes (Cohen's d³ 1.15). Among clinicians completing postintervention surveys, 90% reported making changes to their health care system or direct patient care based on what they had learned.

CONCLUSIONS

Multilevel interventions focusing on provider training and systems changes can substantially improve on-time adolescent vaccination coverage and can be successfully performed using national partnerships and a train-the-trainer model.

Large differences in education and training of radiographers in Europe and Central Asia: Results from an IAEA coordinated study

INTRODUCTION

Education and training of radiographers is known to be diverse between countries and regions. Under an IAEA project, this work collected data on radiographer education for the Europe and Central Asia region with a particular focus on radiation protection gaps and potential actions.

METHODS

Following piloting, an electronic questionnaire was distributed to all national counterparts for the IAEA Technial Coopearation (TC) Europe region (n = 33 countries) and nominated national representatives. Contacts were additionally invited to a virtual workshop to discuss and rank common problems in education and training of radiographers and to propose potential solutions.

RESULTS

Responses were received from 31 countries, including 14 from the European Union. Just over half of countries reported radiographer education being in higher education with 71% having program durations more than 3 years (range: 1 month-4 years). Programs included a spectrum of both clinical training and radiation protection hours with ten-fold variations noted across the region. Inclusion of core radiation protection topics within curricula varied similarly, as did radiographers' clinical involvement in both justification and optimisation between countries. Workshop participants identified five common training problems, namely education availability, lack of standardisation, radiation protection course quality, teamwork problems and lack of equipment.

CONCLUSION

Radiographer education in the IAEA Europe region is heterogeneous with substantial differences in duration and quality of training programs between countries, which likely impact on quality of patient care delivered. Common problems have been identified and potential solutions proposed to focus quality improvement initiatives.

IMPLICATIONS FOR PRACTICE

Radiographer education and training is diverse throughout the IAEA TC Europe region, with likely impacts on radiation protection practices applied. Clinical involvement of radiographers in justification and optimisation differs, potentially limiting adherence to radiation protection principles.

Correlation of STOP-bang obstructive sleep apnoea screening tool to apnoea-hypopnea index in a general cardiology population

Funding Acknowledgements

Type of funding sources: None.

Introduction

The link between obstructive sleep apnoea (OSA) and cardiovascular disease is well known. Prevalence can be very high in this population, sharing many pathophysiological drivers in addition to being a risk factor. More concerning however is the increasing number of patients with undiagnosed OSA, who are at higher risk of long-term complications such as coronary artery disease, hypertension, atrial fibrillation, heart failure or stroke. There are several OSA screening tools available to clinicians, with variable sensitivities and specificities depending on patient demographics.

Predictive efficacy of the STOP-Bang screening tool in a general cardiology population with mixed cardiovascular disease has not been established.

Proposal

To identify the correlation between the STOP-Bang assessment score (1-8) and real-world Apnoea-Hypopnoea Index (AHI) in a general cardiology clinic population.

Methods

250 successive patients in a general cardiology clinic were asked to complete a STOP-Bang assessment. Of those, 50 patients with a variety of STOP-Bang scores were randomly selected to undergo sleep studies. A STOP-Bang value of ≥ 5 was taken as high-risk for moderate-severe OSA. Statistical linear regression analysis was performed in IBM SPSS version 26.

Results

Of n = 50 patients, mean STOP-Bang score =3.7 (SD +/-2.17) with mean AHI =15.8, (SD +/- 14.3). See Table 1 for categories 1-8. N = 44 (88%) had AHI ≥ 5 (At least mild OSA). N = 18 (36%) had an AHI ≥ 15 (Moderate-severe OSA). N = 29 (58%) had symptoms such as sleepiness, loud snoring or witnessed apnoea. Correlation between STOP-Bang score and AHI was high, with an  R value of 0.704, R2 = 0.496 (p &lt; 0.01). A STOP-Bang score increase of 1 corresponded with a mean AHI rise of 4.648. When taking a STOP-Bang value of ≥ 5 as "positive", we demonstrated a sensitivity of 83.33% (95% C.I. 58.58-96.42) and specificity of 93.94% (95% C.I. 79.77-99.26%) for moderate-severe OSA (AHI ≥ 15). 

Conclusion

We discovered a very high number of patients with undiagnosed OSA of at least mild severity. We found a strong correlation between STOP-Bang score and real-world AHI in a general cardiology population with mixed cardiovascular disease with 5 as an acceptable screening score for moderate-severe OSA.

Table 1 STOP-Bang Value 1 2 3 4 5 6 7 8 Patients (N=) 12 5 7 9 5 5 5 2 AHI (Mean) 6.67 6.62 9.97 11.95 24.44 22.20 39.54 35.25 Standard Deviation (±) 3.29 2.74 3.45 4.63 12.87 5.69 27.2 6.72 Summary of mean apnoea-hypopnoea index and standard deviation for each STOP-Bang patient category.

Abstract Figure 1

Organ-based tube current modulation in chest CT. A comparison of three vendors

INTRODUCTION

Organ-based tube current modulation (OBTCM) is designed for anterior dose reduction in Computed Tomography (CT). The purpose was to assess dose reduction capability in chest CT using three organ dose modulation systems at different kVp settings. Furthermore, noise, diagnostic image quality and tumour detection was assessed.

METHODS

A Lungman phantom was scanned with and without OBTCM at 80-135/140 kVp using three CT scanners; Canon Aquillion Prime, GE Revolution CT and Siemens Somatom Flash. Thermo-luminescent dosimeters were attached to the phantom surface and all scans were repeated five times. Image noise was measured in three ROIs at the level of the carina. Three observers visually scored the images using a fivestep scale. A Wilcoxon Signed-Rank test was used for statistical analysis of differences.

RESULTS

Using the GE revolution CT scanner, dose reductions between 1.10 mSv (12%) and 1.56 mSv (24%) (p < 0.01) were found in the anterior segment and no differences posteriorly and laterally. Total dose reductions between 0.64 (8%) and 0.91 mSv (13%) were found across kVp levels (p < 0.00001). Maximum noise increase with OBTCM was 0.8 HU. With the Canon system, anterior dose reductions of 6-10% and total dose reduction of 0.74-0.76 mSv across kVp levels (p < 0.001) were found with a maximum noise increase of 1.1 HU. For the Siemens system, dose increased by 22-51% anteriorly; except at 100 kVp where no dose difference was found. Noise decreased by 1 to 1.5 HU.

CONCLUSION

Organ based tube current modulation is capable of anterior and total dose reduction with minimal loss of image quality in vendors that do not increase posterior dose.

IMPLICATIONS FOR PRACTICE

This research highlights the importance of being familiar with dose reduction technologies.

Synthesis, evaluation and molecular modelling of piceatannol analogues as arginase inhibitors

Arginase is involved in a wide range of pathologies including cardiovascular diseases and infectious diseases whilst it is also a promising target to improve cancer immunotherapy. To date, only a limited number of inhibitors of arginase have been reported. Natural polyphenols, among them piceatannol, are moderate inhibitors of arginase. Herein, we report our efforts to investigate catechol binding by quantum chemistry and generate analogues of piceatannol. In this work, we synthesized a novel series of amino-polyphenols which were then evaluated as arginase inhibitors. Their structure-activity relationships were elucidated by deep quantum chemistry modelling. 4-((3,4-Dihydroxybenzyl)amino)benzene-1,2-diol 3t displays a mixed inhibition activity on bovine and human arginase I with IC50 (K i) values of 76 (82) μM and 89 μM, respectively.

Optimal abdominal CT protocol for obese patients

INTRODUCTION

This study investigated the impact of different protocols on radiation dose and image quality for obese patients undergoing abdominal CT examinations.

METHODS

Five abdominal/pelvis CT protocols employed across three scanners from a single manufacturer in a single centre used a variety of parameters (kV: 100/120, reference mAs: 150/190/218/250/300, image reconstruction: filtered back projection (FBP)/iterative (IR)). The routine protocol employed 300 reference mAs and 120 kV. Data sets resulting from obese patient examinations (n = 42) were assessed for image quality using visual grading analysis by three experienced radiologists. Objective assessment (noise, signal/contrast-noise ratios) and radiation dose was compared to determine optimal protocols for prospective testing on a further sample of patients (n = 47) for scanners using FBP and IR techniques.

RESULTS

Compared to the routine protocol, mean radiation dose was reduced by 60% when using 100 kV and SAFIRE technique strength 3 (p = 0.001). Reduction of up to 30% in radiation dose was noted for the FBP protocol: 120 kV and 190 reference mAs (p = 0.008). Subjective and objective image quality for both protocols were comparable to that of the routine protocol (p > 0.05). An overall improvement in image quality with increasing strength of SAFIRE was noted. Upon clinical implementation of the optimal dose protocols, local radiology consensus deemed image quality to be acceptable for the participating obese patient cohort.

CONCLUSION

Radiation dose for obese patients can be optimised whilst maintaining image quality. Where iterative reconstruction is available relatively low kV and quality reference mAs are also viable for imaging obese patients at 30-60% lower radiation doses.

CACNA1C risk variant is associated with increased amygdala volume

Genome-wide association studies suggest that genetic variation within L-type calcium channel subunits confer risk to psychosis. The single nucleotide polymorphism at rs1006737 in CACNA1C has been associated with both schizophrenia and bipolar disorder and with several intermediate phenotypes that may serve as neurobiological antecedents, linking psychosis to genetic aetiology. Amongst others, it has been implicated in alterations in amygdala structure and function. In the present study, we show that the risk allele (A) is associated with increased amygdala volume in healthy individuals (n = 258). This observation reinforces a hypothesis that genetic variation may confer risk to psychosis via alterations in limbic structures. Further study of CACNA1C using intermediate phenotypes for psychosis will determine the mechanisms by which variation in this gene confers risk.

Association between genetic risk scoring for schizophrenia and bipolar disorder with regional subcortical volumes

Previous research has shown coincident abnormal regional brain volume in patients with schizophrenia (SCZ) and bipolar disorder (BD) compared with controls. Whether these abnormalities are genetically driven or explained by secondary effects of the disorder or environmental factors is unknown. We aimed to investigate the association between genetic risk scoring (GRS) for SCZ and BD with volume of brain areas previously shown to be different between these clinical groups and healthy controls. We obtained subcortical brain volume measures and GRS for SCZ and BD from a sample of 274 healthy volunteers (71.4% females, mean age 24.7 (s.d. 6.9)). Volume of the globus pallidus was associated with the shared GRS between SCZ and BD, and also with the independent GRS for each of these disorders. Volume of the amygdala was associated with the non-shared GRS between SCZ and BD, and with the independent GRS for BD. Our results for volume of the globus pallidus support the idea of SCZ and BD sharing a common underlying neurobiological abnormality associated with a common genetic risk for both these disorders. Results for volume of the amygdala, though, would suggest the existence of a distinct mechanism only associated with genetic risk for BD. Finally, the lack of association between genetic risk and volume of most subcortical structures suggests that the volumetric differences reported in patient-control comparisons may not be genetically driven, but a consequence of the disorder or co-occurring environmental factors.

A review of cross-sectional imaging, ultrasound and nuclear medicine utilization patterns in paediatric patients in Ireland, 2003-12

OBJECTIVE

Recent trends in paediatric imaging have been examined in Australia and the USA. Such literature in Europe is sparse, incomprehensive and outdated. This research investigated (1) population-based trends in the use of advanced medical imaging in children in Ireland from 2003 to 2012; (2) its use across age and gender; and (3) the most commonly performed examinations within each modality.

METHODS

A retrospective cohort analysis study was carried out within Irish paediatric hospitals. All CT, MRI, ultrasound and nuclear medicine (NM) annual examination data from 2003 to 2012 was obtained from radiology information systems.

RESULTS

224,173 imaging procedures were carried out on 84,511 patients, 68% of which were ultrasound, 15% were MRI, 11% were CT and 6% were NM. Between 2003 and 2012, MRI (+280%) and CT (+80%) saw the largest increases in use, followed by ultrasound (+67%) and NM (+10%). Almost half of the study population were less than 3 years old. CT imaging was more frequent than MR in 2005. By 2012, MR rates were twice that of CT. CT imaging rates were the lowest in the youngest age categories.

CONCLUSION

Advanced imaging use, particularly MRI, has risen substantially over the past 10 years. The utilization of non-ionizing modalities increased between 2003 and 2012, especially in brain, spinal and abdominal imaging. MR is now used at twice the frequency of CT.

ADVANCES IN KNOWLEDGE

Longitudinal advanced imaging utilization trends, including CT trends, have been established in the Irish paediatric population.

A review of Human Immunodeficiency Virus (HIV) rapid testing

BACKGROUND

In Canada, it is estimated that 71,300 persons were living with HIV at the end of 2011. Approximately 25% (14,500 to 21,500) of prevalent cases were unaware of their HIV infection. Expanded use of HIV rapid tests may increase the detection of undiagnosed infections, enable earlier treatment and support services and prevent the onward transmission of HIV.

OBJECTIVE

To examine patient acceptability, impact (defined as receipt of test results and linkage to care) and cost-effectiveness of HIV rapid tests.

METHODS

A search was conducted for systematic reviews on HIV rapid testing, with studies from both developed and developing countries, published in English and between 2000 and 2013. The Assessment of Multiple Systematic Review (AMSTAR) tool was used to assess the included systematic reviews for methodological quality. Results were summarized narratively for each of the outcomes.

RESULTS

Eight systematic reviews were included. Acceptability of HIV rapid tests was generally high in medical settings (69% to 98%) especially among pregnant women and youth attending emergency rooms but was lower in non-medical settings (14% to 46%). The percentage of people who obtained their test results was variable. It was high (83% to 93%) in emergency rooms but was low in a rapid care setting with regular business hours (27%). Impact on linkage to care was limited. Only one systematic review examined cost-effectiveness of rapid testing and concluded that HIV rapid tests were cost-effective in comparison to traditional methods; however, results were all based on static models.

CONCLUSION

Overall, HIV rapid tests demonstrated generally high acceptability, variability in receiving test results and limited impact on linkage to care. While these findings suggest that HIV rapid tests may be useful, further research is needed to confirm in whom, when and where they are best used and how to ensure better linkage to care.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Isolation and characterization of soilborne virulent bacteriophages infecting the pathogen Rhodococcus equi

AIMS

To isolate and characterize a diversity of bacteriophages (phages) that infect the soilborne pathogen Rhodococcus equi.

METHODS AND RESULTS

Twenty-seven phages were isolated from soil samples from geographically distinct locations using a range of R. equi bacterial strains, including clinical isolates. On the basis of host range, genomic DNA restriction profiles and virion protein profiles, the diversity of these phages was extensive, with phages being divided into 16 groupings.

CONCLUSIONS

Based on a range of criteria, these phages could be divided into 16 distinct groupings. The majority of the phages recovered from soil were Siphoviridae, adding to the limited number of Siphoviridae described to date for R. equi. One grouping consisted of phages belonging to the Myoviridae.

SIGNIFICANCE AND IMPACT OF THE STUDY

This represents the first study looking at the diversity of phages infecting the pathogen R. equi, including the first Myoviridae to be isolated and characterized for the genus Rhodococcus and for the nonmycobacterial actinomycetes. Given their diverse host range, including clinical isolates, this collection of phages offers the potential for the development of phage cocktails for use as a therapeutic or alternatively in the biocontrol of this pathogen in reservoirs of infection relating to animal husbandry.