A case series of paediatric patients with spinal muscular atrophy type I undergoing scoliosis correction surgery

Spinal muscular atrophy is a neuromuscular disorder with degeneration of spinal motor neurons. Type I is a severe variant that was recently shown to be amenable to treatment with the antisense oligonucleotide nusinersen. As a result of increased life expectancy with this treatment, more children with spinal muscular atrophy type I are presenting for spinal correction surgery. In this case series, we present four such patients who underwent spinal surgery at our institution over the course of one year. Pre-operative assessment showed evidence of reduced respiratory function requiring nocturnal non-invasive ventilation in all four patients. A difficult airway was encountered in two of the four patients. Postoperative complications were ubiquitous and included CSF leak, poor wound healing, metal frame exposure, frame instability and wound infection. There were no postoperative respiratory complications and all four children returned to their respiratory baseline postoperatively. All patients underwent successful lumbar puncture and intrathecal nusinersen injection following their spinal surgeries. Given the risk of complications and prolonged recovery following spinal surgery, a detailed family discussion is advisable.

Proton pump inhibitor use and the risk of peritoneal dialysis associated peritonitis

BACKGROUND

The use of proton-pump inhibitors (PPI) has been associated with an increased risk of developing spontaneous bacterial peritonitis in patients with cirrhosis. Whether PPI use confers a similar risk in developing peritonitis in peritoneal dialysis (PD) patients remains unclear.

METHODS

Patients on PD were retrospectively identified. Data such as PPI use during PD, underlying diagnoses, comorbidities, and baseline serum tests were collected. Univariable and multivariable analysis was conducted using logistic regression to assess whether PPI use and other factors were associated with PD peritonitis.

RESULTS

57 patients were identified with a median(interquartile range(IQR)) age of 65.0(51.5-74.0) years. The median(IQR) time on PD was 29.0(17.5-45.0) months. 28 patients were on a PPI during PD. 57% of the PPI group went on to develop peritonitis, compared to 31% of patients without PPI exposure (OR=2.96, 95% CI:[1.00, 8.78], p=0.050). Months on PD (OR=1.03, 95% CI:[1.00, 1.06], p=0.026), serum urea (OR=0.88, 95% CI:[0.80, 0.97], p=0.017), congestive cardiac failure (OR=5.44, 95% CI:[1.29, 23.00], p=0.021) and renovascular disease (OR=14.59, 95% CI:[1.68, 126.67], p=0.015) were identified as possible risk factors for peritonitis on univariable analysis. Following adjustment for covariates, serum urea, but not PPI use, was associated with PD peritonitis (OR=0.87, 95% CI:[0.78,0.98], p=0.020).

CONCLUSION

PPI use during PD was not associated with peritonitis. Due to the small number of patients and the limited number of studies investigating the effect of PPI use on PD peritonitis, further research is needed. This article is protected by copyright. All rights reserved.

THU0134 COGNITIVE IMPAIRMENT IN RHEUMATOID ARTHRITIS

Background:

Increasing evidence suggests that systemic inflammation may be associated with an increased risk of developing cognitive dysfunction and Alzheimer’s disease (AD). Some studies have found an association between rheumatoid arthritis (RA) and neurodegeneration with several finding increased incidence of mild cognitive impairment (MCI) in those with RA compared to healthy controls.

Objectives:

This study aims to use preliminary data from theRheumatoid arthritis, medication and memorystudy (RESIST) to investigate the prevalence of MCI in a population of patients with RA and explore the relationship between MCI and specific demographic and clinical characteristics.

Methods:

The Montreal Cognitive Assessment (MoCA) was used as a cognitive screening tool and was administered to subjects ≥55 years of age who had been diagnosed with RA according to the ACR/EULAR criteria. Demographic and clinical data was recorded at screening in face-to-face interviews and included age, gender, date of RA diagnosis and RA medication. RA disease activity score from 28 joints (DAS28), rheumatoid factor (RF) level, anti-cyclic citrullinated peptide (anti-CCP) level, erythrocyte sedimentation rate (ESR) were recorded. 260 participants completed both screening and baseline visits as part of the RESIST longitudinal study, MoCA scores from baseline were analysed for these participants. Statistical analysis was used to provide descriptive statistics and explore possible predictors of cognitive impairment.

Results:

A total of 636 participants (mean age 68.1 yrs, female 67.5%) were screened between May 2018 and December 2019. The mean MoCA for screened participants was 25.4; 45.3% scored <26 in the MoCA and were considered to have mild cognitive impairment. Age was negatively correlated with MoCA score and was the only significant predictor of cognitive impairment. For each year of increase in age the MoCA score reduced by a mean of 0.08 points (p<0.05). There was little evidence of a difference in mean MoCA score by gender, RA medication, duration of disease, DAS28 score, ESR, anti-CCP or RF levels. The mean MoCA scores increased by 0.4 points between screening and baseline (P<0.001).

Conclusion:

A large proportion of participants scored below the proposed cut-off for normal cognition in the MoCA suggesting a high prevalence of MCI in adults >55 years with moderately active RA. This provides further support for the role of chronic inflammation in cognitive dysfunction and AD. Screening for MCI in rheumatology clinics might be clinically useful.

DemographicsOutcomeAge mean years (+/-SD) (n=633)68.1 (8.01)Gender (n=636)Female n (%)429 (67.5)RA Medication (n=636)csDMARD n (%)TNFi n (%)368 (57.9)268 (42.1)Duration of RA mean years (+/-SD) (n=484)14.4 (13.9)DAS28 mean (+/-SD) (n=306)3.5 (2.04)ESR mean (+/-SD) (n=501)23.4 (22.0)Anti-CCP (n=387)Positive n (%)236 (61)Rheumatoid Factor (n=377)Positive n (%)277 (73.5)MoCA Score points (n=636)≥26, n (%)<26 n (%)348 (54.7)288 (45.3)Subjective memory concerns (n=430)Yes n (%)No n (%)95 (22.1)335 (77.9)

Disclosure of Interests:

Christopher Edwards Grant/research support from: Abbvie, Biogen, Roche, Consultant of: Abbvie, Samsung, Speakers bureau: Abbvie, BMS, Biogen, Celgene, Fresenius, Gilead, Janssen, Lilly, Mundipharma, Pfizer, MSD, Novartis, Roche, Samsung, Sanofi, UCB

, Bethany McDowell: None declared, Chris Holroyd: None declared, Chris Cardwell: None declared, Michelle McHenry Speakers bureau: Novartis, Pfizer, AbbVie, Celgene, Lilly, Gary Meenagh: None declared, Clive Holmes: None declared, Bernadette McGuiness: None declared

General and Specific Considerations as to why Osteoporosis-Related Care Is Often Suboptimal

PURPOSE OF REVIEW

The assessment of fracture risk and use of antiosteoporosis medications have increased greatly over the last 20-30 years. However, despite this, osteoporosis care remains suboptimal worldwide. Even in patients who have sustained a fragility fracture, fewer than 20% actually receive appropriate antiosteoporosis therapy in the year following the fracture. There is also evidence that treatment rates have declined substantially in the last 5-10 years, in many countries. The goal of this article is to consider the causes for this decline and consider how this situation could be remedied.

RECENT FINDINGS

A number of possible reasons, including the lack of prioritisation of osteoporosis therapy in ageing populations with multimorbidity, disproportionate concerns regarding the rare side effects of anti-resorptives and adverse changes in reimbursement in the USA, have been identified as contributing factors in poor osteoporosis care. Improved secondary prevention strategies; screening measures (primary prevention) and appropriate, cost-effective guideline and treatment threshold development could support the optimisation of osteoporosis care and prevention of future fractures.

Key Performance Indicators in Paediatric Anaesthesia

Aims Currently no national guidelines on performance measurement exist for paediatric anaesthesia in Ireland1. The purpose of this study was to ascertain if we are achieving Key Performance Indicators (KPIs) in areas of post-operative nausea and vomiting (PONV) and post-operative pain when compared to international standards. Methods The study was carried out from January 2018 to February 2018 at Temple Street Children’s University Hospital. In total 743 patients were included. Results 743 patients were included in the study. 86 (12%) were recorded as having a post-operative pain score of >4/10. 15 (1.2%) of patients were recorded as experiencing PONV. Orthopaedic surgery had the highest frequency of post-operative pain accounting for 33% of all cases. General surgery was associated with highest risk of PONV. Discussion The results from the study indicate we are achieving results similar to data from international centres. There is a paucity of published data from Irish centres and as national guidelines are developed for a model of care for paediatric anaesthesia we hope this data can be used when comparing other paediatric centres within Ireland.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

The Influence of Different Melt Temperatures on the Mechanical Properties of Injection Molded PA-12 and the Post Process Detection by Thermal Analysis

Polyamide 12 (PA-12) test plates were injection molded using different melt temperatures and the influence on mechanical properties was investigated using quasi-static tensile and instrumented impact behavior in two conditioned states: dried, and following accelerated moisture intake. Energy absorption in tension is strongly dependent on process temperature (variations up to 99%) and additional variation (around 18%) was evident when testing at different conditioning states. Under high-velocity loading, the total impact energy varied by up to 8.70% and 9.05%, when systematic changes were made to process melt temperature and at moisture content, respectively, with all samples failing ductile. Differential Scanning Calorimetry (DSC) was used to characterise the unique endothermic melting behavior of molded PA-12 samples, by linking different process histories to the respective mechanical properties. With focus on the first heating curve progression, significant changes within the endothermic melting region were pointed out and quantified by using MatLab (software), proving DSC as a reliable testing tool for post-production analysis with increased practical implications regarding quality control as well as failure analysis. Findings for the initial heating curve progression were explained by studying the re-crystallisation peak values during cooling phase and obtained data for the second heating.

Growing intimate privatepublics: Everyday utopia in the naturecultures of a young lesbian and bisexual women’s allotment

The Young Women’s Group in Manchester is a ‘young women’s peer health project, run by and for young lesbian and bisexual women’, which runs an allotment as one of its activities. At a time when interest in allotments and gardening appears to be on the increase, the existence of yet another community allotment may seem unremarkable. Yet we suggest that this queer allotment poses challenges for conventional theorisations of allotments, as well as for understandings of public and private. In this article we explore how the allotment project might be understood to be intensely engaged in ‘growing intimate publics’, or what we term ‘privatepublics’. These are paradoxical intimacies, privatepublic spaces which are not necessarily made possible in the usual private sphere of domestic homes. Here we focus on the work involved in materialising the allotment, which we understand as a queer privatepublic ‘natureculture’ ( Haraway, 2008 ) which appears as an ‘everyday utopia’ ( Cooper, 2014 ).

Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease

Eleven susceptibility loci for late-onset Alzheimer's disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer's disease cases and 37,154 controls. In stage 2, 11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10(-8)) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer's disease.

Terahertz bandwidth photonic Hilbert transformers based on synthesized planar Bragg grating fabrication

Terahertz bandwidth photonic Hilbert transformers are proposed and experimentally demonstrated. The integrated device is fabricated via a direct UV grating writing technique in a silica-on-silicon platform. The photonic Hilbert transformer operates at bandwidths of up to 2 THz (~16 nm) in the telecom band, a 10-fold greater bandwidth than any previously reported experimental approaches. Achieving this performance requires detailed knowledge of the system transfer function of the direct UV grating writing technique; this allows improved linearity and yields terahertz bandwidth Bragg gratings with improved spectral quality. By incorporating a flat-top reflector and Hilbert grating with a waveguide coupler, an ultrawideband all-optical single-sideband filter is demonstrated.

Study of the use of antidepressants for depression in dementia: the HTA-SADD trial--a multicentre, randomised, double-blind, placebo-controlled trial of the clinical effectiveness and cost-effectiveness of sertraline and mirtazapine

OBJECTIVE

Depression is common in dementia, causing considerable distress and other negative impacts. Treating it is a clinical priority, but the evidence base is sparse and equivocal. This trial aimed to determine clinical effectiveness of sertraline and mirtazapine in reducing depression 13 weeks post randomisation compared with placebo.

DESIGN

Multicentre, parallel-group, double-blind placebo-controlled randomised controlled trial of the clinical effectiveness of sertraline and mirtazapine with 13- and 39-week follow-up.

SETTING

Nine English old-age psychiatry services.

PARTICIPANTS

A pragmatic trial. Eligibility: probable or possible Alzheimer's disease (AD), depression (4+ weeks) and Cornell Scale for Depression in Dementia (CSDD) score of 8+.

EXCLUSIONS

clinically too critical (e.g. suicide risk); contraindication to medication; taking antidepressants; in another trial; and having no carer.

INTERVENTIONS

(1) Sertraline; (2) mirtazapine; and (3) placebo, all with normal care. Target doses: 150 mg of sertraline or 45 mg of mirtazapine daily.

MAIN OUTCOME MEASURES

OUTCOME

CSDD score. Randomisation: Allocated 1 : 1 : 1 through Trials Unit, independently of trial team. Stratified block randomisation by centre, with randomly varying block sizes; computer-generated randomisation. Blinding: Double blind: medication and placebo identical for each antidepressant. Referring clinicians, research workers, participants and pharmacies were blind. Statisticians blind until analyses completed.

RESULTS

Numbers randomised: 326 participants randomised (111 placebo, 107 sertraline and 108 mirtazapine).

OUTCOME

Differences in CSDD at 13 weeks from an adjusted linear-mixed model: mean difference (95% CI) placebo-sertraline 1.17 (-0.23 to 2.78; p = 0.102); placebo-mirtazapine 0.01 (-1.37 to 1.38; p = 0.991); and mirtazapine-sertraline 1.16 (-0.27 to 2.60; p = 0.112).

HARMS

Placebo group had fewer adverse reactions (29/111, 26%) than sertraline (46/107, 43%) or mirtazapine (44/108, 41%; p = 0.017); 39-week mortality equal, five deaths in each group.

CONCLUSIONS

This is a trial with negative findings but important clinical implications. The data suggest that the antidepressants tested, given with normal care, are not clinically effective (compared with placebo) for clinically significant depression in AD. This implies a need to change current practice of antidepressants being the first-line treatment of depression in AD. From the data generated we formulated the following recommendations for future work. (1) The secondary analyses presented here suggest that there would be value in carrying out a placebo-controlled trial of the clinical effectiveness and cost-effectiveness of mirtazapine in the management of Behavioural and Psychological Symptoms of Dementia. (2) A conclusion from this study is that it remains both ethical and essential for trials of new medication for depression in dementia to have a placebo arm. (3) Further research is required to evaluate the impact that treatments for depression in people with dementia can have on their carers not only in terms of any impacts on their quality of life, but also the time they spend care-giving. (4) There is a need for research into alternative biological and psychological therapies for depression in dementia. These could include evaluations of new classes of antidepressants (such as venlafaxine) or antidementia medication (e.g. cholinesterase inhibitors). (5) Research is needed to investigate the natural history of depression in dementia in the community when patients are not referred to secondary care services. (6) Further work is needed to investigate the cost modelling results in this rich data set, investigating carer burden and possible moderators to the treatment effects. (7) There is scope for reanalysis of the primary outcome in terms of carer and participant CSDD results.

Ultra-wide detuning planar Bragg grating fabrication technique based on direct UV grating writing with electro-optic phase modulation

A direct UV grating writing technique based on phase-controlled interferometry is proposed and demonstrated in a silica-on-silicon platform, with a wider wavelength detuning range than any previously reported UV writing technology. Electro-optic phase modulation of one beam in the interferometer is used to manipulate the fringe pattern and thus control the parameters of the Bragg gratings and waveguides. Various grating structures with refractive index apodization, phase shifts and index contrasts of up to 0.8 × 10(-3) have been demonstrated. The method offers significant time/energy efficiency as well as simplified optical layout and fabrication process. We have shown Bragg gratings can be made from 1200 nm to 1900 nm exclusively under software control and the maximum peak grating reflectivity only decreases by 3 dBover a 250 nm (~32 THz) bandwidth.

Phase controlled integrated interferometric single-sideband filter based on planar Bragg gratings implementing photonic Hilbert transform

The monolithically integrated all-optical single-sideband (SSB) filter based on photonic Hilbert transform and planar Bragg gratings is proposed and experimentally demonstrated. An SSB suppression of 12 dB at 6 GHz and sideband switching are achieved via thermal tuning. An X-coupler, photonic Hilbert transformer, flat top reflector, and a micro heater are incorporated in a single silicon-on-silica substrate. The device can be thermally tuned by the micro heater on top of the channel waveguide. The device is fabricated using a combination of direct UV grating writing technology and photolithography.

Hippocampal tissue of patients with refractory temporal lobe epilepsy is associated with astrocyte activation, inflammation, and altered expression of channels and receptors

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy. Previous research has demonstrated several trends in human tissue that, undoubtedly, contribute to the development and progression of TLE. In this study we examined resected human hippocampus tissue for a variety of changes including gliosis that might contribute to the development and presentation of TLE. The study subjects consisted of six TLE patients and three sudden-death controls. Clinicopathological characteristics were evaluated by H&E staining. Immunohistological staining and Western blotting methods were used to analyze the samples. Neuronal hypertrophy was observed in resected epileptic tissue. Immunohistological staining demonstrated that activation of astrocytes was significantly increased in epileptic tissue as compared to corresponding regions of the control group. The Western blot data also showed increased CX43 and AQP4 in the hippocampus and downregulation of Kir4.1, α-syntrophin, and dystrophin, the key constituents of AQP4 multi-molecular complex. These tissues also demonstrated changes in inflammatory factors (COX-2, TGF-β, NF-κB) suggesting that these molecules may play an important role in TLE pathogenesis. In addition we detected increases in metabotropic glutamate receptor (mGluR) 2/3, mGluR5 and kainic acid receptor subunits KA1 (Grik4) and KA2 (Grik5) in patients' hippocampi. We noted increased expression of the α1c subunit comprising class C L-type Ca(2+) channels and calpain expression in these tissues, suggesting that these subunits might have an integral role in TLE pathogenesis. These changes found in the resected tissue suggest that they may contribute to TLE and that the kainic acid receptor (KAR) and deregulation of GluR2 receptor may play an important role in TLE development and disease course. This study identifies alterations in number of commonly studied molecular targets associated with astrogliosis, cellular hypertrophy, water homeostasis, inflammation, and modulation of excitatory neurotransmission in hippocampal tissues from TLE patients.

A human metapneumovirus outbreak at a community hospital in England, July to September 2010

We describe an outbreak of human metapneumovirus (hMPV) which occurred in July-September 2010 at a community hospital in the East of England. Based on the medical and nursing records, cases were retrospectively defined as suspected if they had had an influenza-like illness (ILI), and probable if they had had an ILI and an epidemiological link to a laboratory-confirmed case. Of a total of 17 symptomatic inpatients, five were classified as probable cases, five were laboratory confirmed and seven were suspected. The attack rate was 29.4% for confirmed and probable cases combined. The median age of symptomatic inpatients was 85 years-old (range 68-96) and the majority (16/17) of symptomatic inpatients had an underlying medical condition. Control measures introduced appeared to restrict further exposure of susceptible patients to infection although modelling suggested that up to four of 10 confirmed and probable cases (40%) could have been prevented through more timely diagnosis and recognition of an outbreak. These findings suggest that there should be increased awareness of hMPV infection within healthcare settings, particularly when the population at risk has a high prevalence of underlying co-morbidities.

A human metapneumovirus outbreak at a community hospital in England, July to September 2010

Binary file ES_Abstracts_Final_ECDC.txt matches

Microglial alterations in human Alzheimer's disease following Aβ42 immunization

AIMS

In Alzheimer's disease (AD), microglial activation prompted by the presence of amyloid has been proposed as an important contributor to the neurodegenerative process. Conversely following Aβ immunization, phagocytic microglia have been implicated in plaque removal, potentially a beneficial effect. We have investigated the effects of Aβ42 immunization on microglial activation and the relationship with Aβ42 load in human AD.

METHODS

Immunostaining against Aβ42 and microglia (CD68 and HLA-DR) was performed in nine immunized AD cases (iAD - AN1792, Elan Pharmaceuticals) and eight unimmunized AD (cAD) cases.

RESULTS

Although the Aβ42 load (% area stained of total area examined) was lower in the iAD than the cAD cases (P=0.036), the CD68 load was higher (P=0.046). In addition, in the iAD group, the CD68 level correlated with the Aβ42 load, consistent with the immunization upregulating microglial phagocytosis when plaques are present. However, in two long-surviving iAD patients in whom plaques had been extensively cleared, the CD68 load was less than in controls. HLA-DR quantification did not show significant difference implying that the microglial activation may have related specifically to their phagocytic function. CD68 and HLA-DR loads in the pons were similar in both groups, suggesting that the differences in microglial activation in the cortex were due to the presence of AD pathology.

CONCLUSION

Our findings suggest that Aβ42 immunization modifies the function of microglia by increasing their phagocytic activity and when plaques have been cleared, the level of phagocytosis is decreased below that seen in unimmunized AD.

Proinflammatory cytokines, sickness behavior, and Alzheimer disease

BACKGROUND

In Alzheimer disease (AD), systemic inflammation is known to give rise to a delirium. However, systemic inflammation also gives rise to other centrally mediated symptoms in the absence of a delirium, a concept known as sickness behavior. Systemic inflammation is characterized by the systemic production of the proinflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin-6 (IL-6) that mediate immune to brain communication and the development of sickness behavior.

OBJECTIVE

To determine if raised serum TNFα or IL-6 are associated with the presence of sickness behavior symptoms, independent of the development of delirium, in a prospective cohort study of subjects with AD.

METHODS

A total of 300 subjects with mild to severe AD were cognitively assessed at baseline and a blood sample taken for inflammatory markers. Cognitive assessments, including assessments to detect the development of a delirium, and blood samples were repeated at 2, 4, and 6 months. The development of neuropsychiatric symptoms in the subject with AD over the 6-month follow-up period was assessed independently by carer interview at 2, 4, and 6 months.

RESULTS

Raised serum TNFα and IL-6, but not CRP, were associated with an approximately 2-fold increased frequency of neuropsychiatric symptoms characteristic of sickness behavior. These relationships are independent of the development of delirium.

CONCLUSIONS

Increased serum proinflammatory cytokines are associated with the presence of symptoms characteristic of sickness behavior, which are common neuropsychiatric features found in AD. This association was independent of the presence of delirium.

Initial experience with optical-CT scanning of RadBall Dosimeters

The RadBall dosimeter is a novel device for providing 3-D information on the magnitude and distribution of contaminant sources of unknown radiation in a given hot cell, glovebox, or contaminated room. The device is presently under evaluation by the National Nuclear Lab (NNL, UK) and the Savannah River National Laboratory (SRNL, US), for application as a diagnostic device for such unknown contaminants in the nuclear industry. A critical component of the technique is imaging the dose distribution recorded in the RadBall using optical-CT scanning. Here we present our initial investigations using the Duke Mid-sized Optical-CT Scanner (DMOS) to image dose distributions deposited in RadBalls exposed to a variety of radiation treatments.