Browsing by Author "Griffith-Richards, Stephanie"

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    The accuracy of after-hour registrar Computed Tomography (CT) reporting in a tertiary South African teaching hospital
    (AOSIS Publishing, 2014-05-16) De Witt, Juruan F.; Griffith-Richards, Stephanie; Pitcher, Richard D.
    Background: The Division of Radiodiagnosis at Tygerberg Academic Hospital, a 1384-bed tertiary training institution in Cape Town, South Africa provides a comprehensive 24-hour clinical radiology service, and has a duty registrar on-site at all times. The demand for computed tomography (CT) imaging is increasing and plays a pivotal role in patient management. Objectives: The purpose of this study was to determine the accuracy of after-hour registrar CT reporting, to identify possible factors that may affect the error rate, and to assess whether or not errors had any clinical impact. Method: A set of senior registrar reports (provisional reports) issued during a 28-day period was compared with the corresponding consultant reports (final reports). Discrepancies were identified and quantified, based on their impact on patient management. Results: The overall discrepancy rate was 8% (18 out of 225) and the overall accuracy rate was 92% (207 out of 225). The major error rate was 4% (9 out of 225) and the minor error rate was also 4% (9 out of 225). Conclusion: We observed that the accuracy of after-hour CT reporting by senior registrars at the Division of Radiodiagnosis at Tygerberg Hospital was on par with international standards. We investigated three factors which may have affected discrepancy rates, and only found one factor, namely the time of day, to be significant. Steps can be taken to create awareness of this fact amongst registrars, which hopefully would result in improved patient care and management.
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    Mammography reporting at Tygerberg Hospital, Cape Town, South Africa
    (Health & Medical Publishing Group, 2014-07) Pitcher, Richard; Lotz, Jan; Ackermann, Christelle; Bagadia, Asif; Davis, Razaan; Du Plessis, Anne-Marie; Griffith-Richards, Stephanie; Hattingh, Retha; Wagener, Georg; Apffelstaedt, Justus; Dalmayer, Lisa; Baatjes, Karin
    In their recent article, Apffelstaedt et al.[1] analysed 16 105 mammograms performed at Tygerberg Hospital (TBH), Cape Town, South Africa (SA), between 2003 and 2012. The summary reported that ‘mammograms were read by experienced breast surgeons’, while the discussion stated: ‘A further noteworthy fact is that this TBH series was based exclusively on mammography interpretation by surgeons with a special interest in breast health.’ The suggestion that mammograms were exclusively interpreted by breast surgeons does not reflect the mammography workflow at our institution.
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    Ovarian germ cell tumour and bleomycin-induced lung injury
    (Medpharm Publications, 2018) Barnardt, Pieter; Griffith-Richards, Stephanie
    Bleomycin, an antibiotic agent with antitumour activity, is an important drug in the management of many oncological malignancies such as lymphoma and germ cell tumours. These tumours are potentially curable and mostly affect young people. The potential side effects and long-term toxicities should be considered. The major limitation of bleomycin therapy is pulmonary toxicity and may be life threatening in about 10% of cases. This article reports a case of an ovarian mixed germ cell tumour, which presented with bleomycin-associated pulmonary toxicity.
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    PROVE—Pre-Eclampsia Obstetric Adverse Events: Establishment of a Biobank and Database for Pre-Eclampsia
    (MDPI, 2021-04) Bergman, Lina; Bergman, Karl; Langenegger, Eduard; Moodley, Ashley; Griffith-Richards, Stephanie; Wikström, Johan; Hall, David; Joubert, Lloyd; Herbst, Philip; Schell, Sonja; Van Veen, Teelkien; Belfort, Michael; Tong, Stephen Y. C.; Walker, Susan; Hastie, Roxanne; Cluver, Catherine
    Pre-eclampsia is a leading cause of maternal and perinatal morbidity and mortality. The burden of disease lies mainly in low-middle income countries. The aim of this project is to establish a pre-eclampsia biobank in South Africa to facilitate research in the field of pre-eclampsia with a focus on phenotyping severe disease.The approach of our biobank is to collect biological specimens, detailed clinical data, tests, and biophysical examinations, including magnetic resonance imaging (MRI) of the brain, MRI of the heart, transcranial Doppler, echocardiography, and cognitive function tests.Women diagnosed with pre-eclampsia and normotensive controls are enrolled in the biobank at admission to Tygerberg University Hospital (Cape Town, South Africa). Biological samples and clinical data are collected at inclusion/delivery and during the hospital stay. Special investigations as per above are performed in a subset of women. After two months, women are followed up by telephonic interviews. This project aims to establish a biobank and database for severe organ complications of pre-eclampsia in a low-middle income country where the incidence of pre-eclampsia with organ complications is high. The study integrates different methods to investigate pre-eclampsia, focusing on improved understanding of pathophysiology, prediction of organ complications, and potentially future drug evaluation and discovery.
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    Reliability and diagnostic performance of CT imaging criteria in the diagnosis of Tuberculous Meningitis
    (PLOS One, 2012-06) Botha, Hugo; Ackerman, Christelle; Candy, Sally; Carr, Jonathan; Griffith-Richards, Stephanie; Bateman, Kathleen J.
    Introduction: Abnormalities on CT imaging may contribute to the diagnosis of tuberculous meningitis (TBM). Recently, an expert consensus case definition (CCD) and set of imaging criteria for diagnosing basal meningeal enhancement (BME) have been proposed. This study aimed to evaluate the sensitivity, specificity and reliability of these in a prospective cohort of adult meningitis patients. Methods: Initial diagnoses were based on the CCD, classifying patients into: ‘Definite TBM’ (microbiological confirmation), ‘Probable TBM’ (diagnostic score $10), ‘Possible TBM’ (diagnostic score 6–9), ‘Not TBM’ (confirmation of an alternative diagnosis) or ‘Uncertain’ (diagnostic score of ,6). CT images were evaluated independently on two occasions by four experienced reviewers. Intra-rater and inter-rater agreement were calculated using the kappa statistic. Sensitivities and specificities were calculated using both ‘Definite TBM’ and either ‘Definite TBM’ or ‘Probable TBM’ as gold standards. Results: CT scan criteria for BME had good intra-rater agreement (k range 0.35–0.78) and fair to moderate inter-rater agreement (k range 0.20–0.52). Intra- and inter-rater agreement on the CCD components were good to fair (k = ranges 0.47–0.81 and 0.21–0.63). Using ‘Definite TBM’ as a gold standard, the criteria for BME were very specific (61.5%–100%), but insensitive (5.9%–29.4%). Similarly, the imaging components of the CCD were highly specific (69.2–100%) but lacked sensitivity (0–56.7%). Similar values were found when using ‘Definite TBM’ or ‘Probable TBM’ as a gold standard. Discussion: The fair to moderate inter-rater agreement and poor sensitivities of the criteria for BME suggest that little reliance should be placed in these features in isolation. While the presence of the CCD criteria of acute infarction or tuberculoma(s) appears useful as rule-in criteria, their absence is of little help in excluding TBM. The CCD and criteria for BME, as well as any new criteria, need to be standardized and validated in prospective cohort studies.
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    A semi-automatic technique to quantify complex tuberculous lung lesions on 18F-fluorodeoxyglucose positron emission tomography/computerised tomography images
    (Springer Open, 2018-06-25) Malherbe, Stephanus T.; Dupont, Patrick; Kant, Ilse; Ahlers, Petri; Kriel, Magdalena; Loxton, Andre G.; Chen, Ray Y.; Via, Laura E.; Thienemann, Friedrich; Wilkinson, Robert J; Barry, Clifton E.; Griffith-Richards, Stephanie; Ellman, Annare; Ronacher, Katharina; Winter, Jill; Walzl, Gerhard; Warwick, James M.
    Background: There is a growing interest in the use of 18F-FDG PET-CT to monitor tuberculosis (TB) treatment response. However, TB causes complex and widespread pathology, which is challenging to segment and quantify in a reproducible manner. To address this, we developed a technique to standardise uptake (Z-score), segment and quantify tuberculous lung lesions on PET and CT concurrently, in order to track changes over time. We used open source tools and created a MATLAB script. The technique was optimised on a training set of five pulmonary tuberculosis (PTB) cases after standard TB therapy and 15 control patients with lesion-free lungs. Results: We compared the proposed method to a fixed threshold (SUV > 1) and manual segmentation by two readers and piloted the technique successfully on scans of five control patients and five PTB cases (four cured and one failed treatment case), at diagnosis and after 1 and 6 months of treatment. There was a better correlation between the Z-score-based segmentation and manual segmentation than SUV > 1 and manual segmentation in terms of overall spatial overlap (measured in Dice similarity coefficient) and specificity (1 minus false positive volume fraction). However, SUV > 1 segmentation appeared more sensitive. Both the Z-score and SUV > 1 showed very low variability when measuring change over time. In addition, total glycolytic activity, calculated using segmentation by Z-score and lesion-to-background ratio, correlated well with traditional total glycolytic activity calculations. The technique quantified various PET and CT parameters, including the total glycolytic activity index, metabolic lesion volume, lesion volumes at different CT densities and combined PET and CT parameters. The quantified metrics showed a marked decrease in the cured cases, with changes already apparent at month one, but remained largely unchanged in the failed treatment case. Conclusions: Our technique is promising to segment and quantify the lung scans of pulmonary tuberculosis patients in a semi-automatic manner, appropriate for measuring treatment response. Further validation is required in larger cohorts.