A study of the chest imaging findings of adult patients with COVID-19 on admission to a tertiary hospital in Johannesburg, South Africa.

Background: South Africa has experienced multiple waves of the coronavirus disease 2019 (COVID-19) with little research documenting chest imaging features in an human immunodeficiency virus (HIV) and tuberculosis (TB) endemic region. Objectives: Describe the chest imaging features, demographics and clinical characteristics of COVID-19 in an urban population. Method: Retrospective, cross-sectional, review of chest radiographs and computed tomographies (CTs) of adults admitted to a tertiary hospital with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, between 01 May 2020 and 30 June 2020. Imaging was reviewed by three radiologists. Clinical parameters and laboratory data were analysed. Results: A total of 113 adult patients with a mean age of 46 years and 10 months were included. A total of 113 chest radiographs and six CTs were read. Nineteen patients were HIV-positive (16.8%), 40 were hypertensive and diabetic (35.4%), respectively, and one had TB (0.9%). Common symptoms included cough (n = 69; 61.6%), dyspnoea (n = 60; 53.1%) and fever (n = 46; 40.7%). Lower zone predominant ground glass opacities (58.4%) and consolidation (29.2%) were most frequent on chest radiographs. The right lower lobe was most involved (46.9% ground glass opacities and 17.7% consolidation), with relative sparing of the left upper lobe. Bilateral ground glass opacities (66.7%) were most common on CT. Among the HIV-positive, ground glass opacities and consolidation were less common than in HIV-negative or unknown patients (p = 0.037 and p = 0.05, respectively). Conclusion: COVID-19 in South Africa has similar chest imaging findings to those documented globally, with some differences between HIV-positive and HIV-negative or unknown patients. The authors corroborate relative sparing of the left upper lobe; however, further research is required to validate this currently unique local finding.

An audit of the adequacy of contrast enhancement in CT pulmonary angiograms in a South African tertiary academic hospital setting.

Background: Undiagnosed pulmonary embolism carries high mortality and morbidity. Computed tomography pulmonary angiogram (CTPA) is the diagnostic method of choice for accurate diagnosis. Inadequate contrast opacification is the second most common cause of indeterminate CTPAs. Objectives: Audit the adequacy of CTPA contrast enhancement and determine whether inadequate enhancement is affected by the size and site of the intravenous cannula, flow rate, contrast volume, contrast leakage and day shift versus after hours services. Method: Retrospective and prospective audits of the adequacy of contrast enhancement of CTPAs at the Charlotte Maxeke Johannesburg Academic Hospital were conducted using the Royal College of Radiologists guidelines (≤ 11% of studies with < 210 HU). Protocol variables were collected prospectively from questionnaires completed by radiographers performing the CTPAs. Adequate versus inadequate groups were analysed. Results: A total of 63 (retrospective) and 130 (prospective) patients were included with inadequate contrast enhancement rates of 19% (12/63) and 20.8% (27/130), respectively. The majority of CTPAs were performed during the day 56.2% (73/130) with a 20G cannula 66.2% (86/130) in the forearm 33.8% (44/130) injecting 100 mL - 120 mL contrast 43.1% (56/130) at 3 mL/s 63.1% (82/130). The median flow rate (3 mL/s) and contrast volume (80 mL) were identical in both adequate and inadequate groups, while the remaining variables showed no statistical difference. Conclusion: The rate of inadequately enhanced CTPAs in this study was high. The protocol variables did not have a significant influence on the rate of inadequate enhancement. Further research, particularly using flow rates > 4 mL/s, is required for protocol optimisation.

Fatal non-accidental injury in South Africa: A Gauteng hospital's perspective on the incidence and fracture types in post-mortem skeletal surveys.

Background: In its severest form, non-accidental injury (NAI) in children is fatal. South Africa has been reported to have double the global average of child homicides. Autopsy is the main investigation in fatal NAI with post-mortem skeletal surveys (PMSS) playing an adjunctive role. Whilst fracture patterns associated with NAI in living patients have been established, this has not been investigated in PMSS in South Africa. Objectives: To determine the incidence and characteristics of fractures in suspected fatal NAI cases. To calculate the incidence of fractures according to high-, moderate- and low-specificity fracture locations for NAI. Methods: A retrospective review of all PMSS performed between 01 January 2012 and 03 December 2018 was conducted at the Charlotte Maxeke Johannesburg Academic Hospital. Results: Of the 73 PMSS, 33 (45.2%) demonstrated fractures. No statistical significance in sex was found: 38 (52.1%) were male and 35 (47.9%) were female (p > 0.05). The mean age of those who sustained fractures was 28 months (standard deviation [s.d.]: 21 months). A total of 115 fractures were sustained, of that the top five bones fractured were the ribs 37 (32.2%), parietal bone 13 (11.3%), ulna 13 (11.3%), femur 13 (11.3%), and radius 11 (9.6%). High-specificity fracture locations accounted for 40/133 (30.1%). Conclusion: The fracture types in PMSS were similar to those in live skeletal surveys. Our study's fracture rate was higher in comparison to international studies. The PMSS is a valuable adjunct to autopsy in detecting occult fractures of the limbs. We recommend that PMSS be performed in suspected fatal NAI cases at least in children up to 24 months of age.

Computer-aided diagnosis for World Health Organization-defined chest radiograph primary-endpoint pneumonia in children.

BACKGROUND: The chest radiograph is the most common imaging modality to assess childhood pneumonia. It has been used in epidemiological and vaccine efficacy/effectiveness studies on childhood pneumonia. OBJECTIVE: To develop computer-aided diagnosis (CAD4Kids) for chest radiography in children and to evaluate its accuracy in identifying World Health Organization (WHO)-defined chest radiograph primary-endpoint pneumonia compared to a consensus interpretation. MATERIALS AND METHODS: Chest radiographs were independently evaluated by three radiologists based on WHO criteria. Automatic lung field segmentation was followed by manual inspection and correction, training, feature extraction and classification. Radiographs were filtered with Gaussian derivatives on multiple scales, extracting texture features to classify each pixel in the lung region. To obtain an image score, the 95th percentile score of the pixels was used. Training and testing were done in 10-fold cross validation. RESULTS: The radiologist majority consensus reading of 858 interpretable chest radiographs included 333 (39%) categorised as primary-endpoint pneumonia, 208 (24%) as other infiltrate only and 317 (37%) as no primary-endpoint pneumonia or other infiltrate. Compared to the reference radiologist consensus reading, CAD4Kids had an area under the receiver operator characteristic (ROC) curve of 0.850 (95% confidence interval [CI] 0.823-0.876), with a sensitivity of 76% and specificity of 80% for identifying primary-endpoint pneumonia on chest radiograph. Furthermore, the ROC curve was 0.810 (95% CI 0.772-0.846) for CAD4Kids identifying primary-endpoint pneumonia compared to other infiltrate only. CONCLUSION: Further development of the CAD4Kids software and validation in multicentre studies are important for future research on computer-aided diagnosis and artificial intelligence in paediatric radiology.

Chest ultrasound compared to chest X-ray for pediatric pulmonary tuberculosis.

INTRODUCTION: Chest ultrasound is increasingly used to radiologically diagnose childhood pneumonia, but there are limited data on its use for pulmonary tuberculosis (PTB). AIM: Compare chest ultrasound with a chest X-ray (CXR) findings. METHODS: Children (up to 13 years) with suspected PTB were enrolled. Bedside chest ultrasound findings were compared to CXR. The analysis was stratified by PTB category: confirmed PTB (microbiologically confirmed), unconfirmed PTB (clinical diagnosis with negative microbiological tests), or unlikely PTB (other respiratory diseases with improvement without tuberculosis treatment). RESULTS: One hundred fifty-nine children were enrolled (57% boys, median age 26.6 months [interquartile range 15.1-59.3]). Ultrasound detected abnormalities in 72% (n = 114), CXR in 56% (n = 89), P < .001. Pleural effusion was detected on ultrasound in 15% (n = 24) compared 9% (n = 14) on CXR, P = .004, more in confirmed PTB (33%, n = 12 vs 8%, n = 4 unlikely PTB, P = .013). Ultrasound detected enlarged mediastinal lymph nodes more commonly (22%, n = 25) than CXR (6%, n = 10, P = .001); the size of lymph nodes in the unlikely category (1.0 cm) was smaller than the other two PTB categories (1.4 and 1.5 cm, P = .001). Inter-reader agreement (kappa Cohen) was higher for ultrasound than CXR for several findings (consolidation 0.67 vs 0.47, pleural effusion 0.86 vs 0.56, enlarged lymph nodes 0.56 vs 0.27). CONCLUSION: Ultrasound detected abnormalities more frequently than CXR with the higher inter-reader agreement; ultrasound abnormalities were most common in children with confirmed PTB. Ultrasound is a promising modality for detecting abnormalities in PTB. Further studies should evaluate the diagnostic accuracy of ultrasound against a gold standard.

A systemic review of tuberculosis with HIV coinfection in children.

The epidemiology of tuberculosis is adversely impacted by the human immunodeficiency virus (HIV) coinfection. HIV-infected patients are more prone to opportunistic infections, most commonly tuberculosis, and the risk of death in coinfected patients is higher than in those without HIV. Due to the impaired cellular immunity and reduced immunological response in HIV-infected patients, the classic imaging features of tuberculosis usually seen in patients without HIV may present differently. The aim of this review article is to highlight the imaging features that may assist in the diagnosis of tuberculosis in patients with HIV coinfection.