ORCID Profile
0000-0002-3866-8562
Current Organisations
Prince of Wales Hospital
,
ACPSEM
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Publisher: Elsevier BV
Date: 06-2019
Publisher: AOSIS
Date: 30-09-2022
Abstract: Background: Occupational exposure to ionising radiation may have detrimental health effects. Longer and more complex fluoroscopic procedures have placed interventionalists at increased occupational health risks especially for developing cataracts in the radiosensitive lenses of the eyes.Objectives: This study aimed to determine the prevalence of occupational related cataracts and describe the risk factors for cataracts in occupationally exposed interventionalists compared with unexposed doctors.Method: A cross-sectional study using multiple methods. A survey was conducted. The radiation workload was determined based on a self-administered questionnaire and dose area product values determined in previous studies. Both groups had slit l examinations. The data were analysed analytically using R software version 9.3.Results: The study included 98 interventionalists. The combined prevalence of posterior sub-capsular (PSC) and cortical cataracts was 18.8% in the exposed and 13.9% in the unexposed group. The prevalence of PSC cataracts in the exposed group was 5.9% and 2.8% in the unexposed group, with an odds ratio (OR) of 2.2 (95% confidence interval [CI]: 0.58 8.61). Posterior sub-capsular cataracts were more common in the left eye. The increase in cataracts was not statistically significant in the exposed group but is of clinical significance.Conclusion: The findings are important as they highlight the need for greater vigilance for protecting the radiation healthcare workforce in a developing country setting.Contribution: The research is the first of its kind in South Africa and Africa and contributes to determining the prevalence in this highly skilled and occupationally vulnerable group.
Publisher: AOSIS
Date: 07-11-2019
Abstract: Background: Ionising radiation (IR) is an occupational hazard for interventionalists. Dry eye syndrome may develop. There may be damage to the corneal epithelium, causing irritation and ulceration. Radiation-induced cataracts commonly develop in the posterior sub-capsular (PSC) region of the lens and are more common in the left eye.Aim: The aim of this study was to describe the ophthalmological findings in South African interventionalists occupationally exposed to IR.Setting: This study was conducted in South Africa.Methods: A prospective cross-sectional study was conducted. Interventional radiologists (25), adult cardiologists (42) and paediatric cardiologists (31) were recruited at conferences and included in the study. Convenience s ling was used. Participants completed a survey that collected data on their demographics, their cataract risk factors and co-morbid diseases, their occupational history, their radiation safety practices and their training in occupational history. Participants’ eyes were examined using a slit l after dilation of the eyes. Ethics clearance was obtained and each participant gave informed consent. A descriptive analysis was done.Results: The median age of the 98 interventionalists screened was 43.5 years. They worked with radiation for a median of 7.5 years. Cataracts occurred in the left eye of 17 (17.3%) participants and in the right eye of nine (9.2%). There were five (5.1%) PSC cataracts in the left eye and one (1%) in the right eye. The vitreous was abnormal in 19.4% of participants. The tear break-up time was abnormal in 48% of participants.Conclusion: Ionising radiation is an occupational hazard posing a risk to interventionalists’ eyes. They are at increased risk of cataracts and dry eye syndrome, which can affect their occupational performance and quality of life. Education can positively influence the radiation safety practices of interventionalists that could reduce the detrimental effects of IR on their eyes.
Publisher: Elsevier BV
Date: 11-2202
Publisher: Wiley
Date: 08-05-2023
DOI: 10.1002/JMRS.686
Abstract: Recently developed Long (≥100 cm) axial field of view (AFOV) PET/CT scanners are capable of producing images with higher signal‐to‐noise ratio, or performing faster whole‐body acquisitions, or scanning with lower radiation dose to the patient, compared with conventional PET/CT scanners. These benefits, which arise due to their substantially higher, by more than an order of magnitude, geometric efficiency, have been well described in the recent literature. The introduction of Long AFOV PET/CT technology into the clinic also has important implications for the design and workflow of PET/CT facilities and their effects on radiation exposure to staff and patients. Maximising the considerable benefits of this technology requires a thorough understanding of the relationships between these factors to optimise workflows while appropriately managing radiation exposure. This article reviews current knowledge on PET/CT facility design, workflows and their effects on radiation exposure, identifies gaps in the literature and discusses the challenges that need to be considered with the introduction of Long AFOV PET/CT into the clinic.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Springer Science and Business Media LLC
Date: 20-07-2023
DOI: 10.1007/S11547-023-01681-Y
Abstract: Accurate segmentation (separating diseased portions of the lung from normal appearing lung) is a challenge in radiomic studies of non-neoplastic diseases, such as pulmonary tuberculosis (PTB). In this study, we developed a segmentation method, applicable to chest X-rays (CXR), that can eliminate the need for precise disease delineation, and that is effective for constructing radiomic models for automatic PTB cavity classification. This retrospective study used a dataset of 266 posteroanterior CXR of patients diagnosed with laboratory confirmed PTB. The lungs were segmented using a U-net-based in-house automatic segmentation model. A secondary segmentation was developed using a sliding window, superimposed on the primary lung segmentation. Pyradiomics was used for feature extraction from every window which increased the dimensionality of the data, but this allowed us to accurately capture the spread of the features across the lung. Two separate measures (standard-deviation and variance) were used to consolidate the features. Pearson’s correlation analysis (with a 0.8 cut-off value) was then applied for dimensionality reduction followed by the construction of Random Forest radiomic models. Two almost identical radiomic signatures consisting of 10 texture features each (9 were the same plus 1 other feature) were identified using the two separate consolidation measures. Two well performing random forest models were constructed from these signatures. The standard-deviation model (AUC = 0.9444 (95% CI, 0.8762 0.9814)) performed marginally better than the variance model (AUC = 0.9288 (95% CI, 0.9046 0.9843)). The introduction of the secondary sliding window segmentation on CXR could eliminate the need for disease delineation in pulmonary radiomic studies, and it could improve the accuracy of CXR reporting currently regaining prominence as a high-volume screening tool as the developed radiomic models correctly classify cavities from normal CXR.
Location: South Africa
No related grants have been discovered for William Rae.