Establishment of CT diagnostic reference levels (DRLs) for a Singapore healthcare cluster.

INTRODUCTION: The use of computed tomography (CT) in healthcare institutions has increased rapidly in recent years. The Singapore Health Services (SingHealth) cluster of healthcare institutions has taken the first step in establishing a local cluster-wide CT Diagnostic Reference Levels (DRL) in Singapore. CT dose data from each institution were collected through two primary dosimetry metrics: volume CT dose index (CTDIvol measured in mGy) and dose-length product (DLP measured in mGy.cm). METHODS: Data from 19 CT scanners in seven institutions under one of Singapore healthcare cluster were retrospectively collected and analysed. The five common adult CT examinations analysed were CT Brain (non-contrast enhanced), CT Chest (IV contrast enhanced), CT Kidney-Ureter-Bladder (CT KUB, non-contrast enhanced), CT Pulmonary Angiogram (CT PA, IV contrast enhanced) and CT Abdomen-Pelvis (CT AP, IV contrast enhanced, single phase). Median CTDIvol and DLP values for the five CT examinations from each institution were derived, with the cluster DRLs determined as the 75th percentile of the distribution of the institution median dose values. RESULTS: A total of 2413 dose data points were collected over a six-month period from June to November 2020. The cluster CT DRLs for the five CT examinations were determined to be 47 mGy and 820 mGy.cm for CT Brain, 5.4 mGy and 225 mGy.cm for CT Chest, 6.7 mGy and 248 mGy.cm for CT PA, 4.6 mGy and 190 mGy.cm for CT KUB and 6.9 mGy and 349 mGy.cm for CT AP. CONCLUSION: The establishment of the cluster CT DRLs provided individual institutions with a better understanding if their CT doses are unusually high or low, while emphasising that these DRLs are not meant as hard dose limits or constraints to follow strictly.

24 hour movement behaviours and the health and development of pre-school children from Zimbabwean settings: the SUNRISE pilot study.

Background: In 2019, the World Health Organization (WHO) released global guidelines for physical activity, sedentary behaviour and sleep for the early years. The International Study of Movement Behaviours in the Early Years, SUNRISE, aimed to assess the extent to which children aged three and four years meet the WHO global guidelines and its association with health and development. Objectives: To assess movement behaviours in pre-school children from low-income settings in Zimbabwe and to establish associations between these movement behaviours and adiposity, motor skills and executive function. Methods: Pre-school children/caregivers were recruited from two urban and two rural public schools respectively in Zimbabwe. The caregivers answered questions on the children's physical activity, screen time, sedentary behaviour and sleep patterns. Children's movement behaviours were objectively measured using accelerometers. Gross and fine motor skills and executive function were assessed using the Ages and Stages Questionnaire-3 and Early Years Toolbox, respectively. Focus group discussions were carried out with caregivers and teachers on the acceptability and feasibility of the study. Results: Eighty-one children participated in the study. The proportions of children meeting the guidelines were physical activity 92%, sedentary behaviour 70%, and sleep 86%, and all guidelines combined 24%. Boys and girls were similar (p>0.05 for all variables) for all executive function variables, but rural children had significantly lower inhibition scores (p=0.026) than urban children. Conclusion: The study adds to the growing literature on movement behaviours and associated risk factors in low-resourced settings. Further investigations of movement behaviours in this age group in Zimbabwe are recommended.

A clinical appraisal of patients with psoriasis treated in Seremban General Hospital, Malaysia.

A prospective clinical study of 181 patients with psoriasis seen in Seremban General Hospital showed the incidence of psoriasis among dermatology outpatients was 2.15%. A significantly higher proportion of male patients were affected, with a male to female ratio of 1.7:1. Within the racial groups; 63 were Malays, 37 Chinese, and 81 Indians. There was a significantly higher proportion of Indians affected as compared with the races. The mean age of patients in this study was 43.7 years old but the mean age of onset of psoriasis in these patients was 33.1 years old. Thirty-one (17.1%) patients gave a positive family history of psoriasis and the mean age of onset of psoriasis was lower (29.3 years old) for patients with a positive family history. Plaque psoriasis was the commonest type of clinical presentation with the scalp being the commonest site affected. Psoriatic arthropathy was seen in 35 (19.3%) patients. Ninety-five (52.5%) patients gave a positive history of factors exacerbating their pre-existing disease and stress was singled out as the most common exacerbating factor.

Pelvic fractures and mortality.

A retrospective study of all patients (N = 343) with pelvic fractures admitted to our trauma service was conducted to evaluate the impact of pelvic fractures on mortality. All patients sustained additional injuries with an average Injury Severity Score (ISS) of twenty. Thirty-six patients died. This group had more severe pelvic fractures as graded by the Tile classification as well as a greater number and severity of associated injuries. Six patients died as a direct result of pelvic hemorrhage. In six other patients, pelvic fractures contributed to their demise. The other twenty-four patients died from brain injury, thoracic hemorrhage, or other non-pelvic causes. Overall mortality for patients with pelvic fractures was 10.5 percent This was a 1.4 fold increase in mortality compared to other trauma patients during the same time period without pelvic fractures. Mortality was dramatically increased in patients over sixty years of age (37 percent mortality compared to 8 percent). This greater than four-fold increase in deaths in the elderly appears to be an age related effect because the elderly patients generally had a lower ISS and less severe pelvic trauma than younger patients. We conclude that sustaining a pelvic fracture places the patient at an increased risk of death. Pelvic fractures contributed directly to death in one-third of the mortalities, one-third died from complications associated with pelvic fractures, and one-third died from other causes.

Metal biosorption equilibria in a ternary system.

Equilibrium metal uptake performance of a biosorbent prepared from Ascophyllum nodosum seaweed biomass was studied using aqueous solutions containing copper, cadmium, and zinc ions in binary and ternary mixtures. Triangular equilibrium diagrams can graphically represent all the ternary equilibrium sorption data. Application of the multicomponent Langmuir model to describe the three-metal system revealed its nonideal characteristics, whereby the value of apparent dissociation constants for the respective metals differed for each system. This restricted the prediction of the ternary equilibria from the binary systems. However, some predictions of the ternary system behavior from the model were consistent with experimental data and with conclusions postulated from the three possible binary subsystems. (c) 1996 John Wiley & Sons, Inc.

Description of two-metal biosorption equilibria by Langmuir-type models.

A biosorbent prepared from Ascophyllum nodosum seaweed biomass, FCAN2, was examined for its sorption capacity. Equilibrium batch sorption studies were performed using two-matal systems containing either (Cu + Zn), (Cu + Cd), or (Zn + Cd). In the evaluation of the two-metal sorption system performance, simple isotherm curves had to be replaced by three-dimensional sorption isotherm surfaces. In order to describe the isotherm surfaces mathematically, three Langmuir-type models were evaluated. The apparent one-parameter Langmuir constant (b) was used to quantify FCAN2 "affinity" for one metal in the presence of another one. The uptake of Zn decreased drastically when Cu or Cd were present. The uptake of Cd wasmuch more sensitive to the presence of Cu than to that of Zn. The presence of Cd and Zn alter the "affinity" of FCAN2 for Cu the least at high Cu equilibrium concentrations. The mathematical model of the two-metal sorption system enabled quantitative estimation of one-metal (bio)sorption inhibition due to the influence of a second metal. (c) 1995 John Wiley & Sons Inc.