TYPICAL VALUES OF DOSIMETRIC DATA FOR CARDIAC FLUOROSCOPY-GUIDED PROCEDURES IN A SOUTH AFRICAN TEACHING HOSPITAL.

Currently there are limited diagnostic reference level (DRL) data for South African (SA) public sector cardiac fluoroscopy-guided procedures (FGPs). A 4-y retrospective study of dosimetric data on 6265 patients determined typical values (50th percentile) of dosimetric data for the seven most frequent cardiac FGPs at a SA teaching hospital. Kerma-area-product (KAP), reference point air Kerma (Ka,r) and fluoroscopy time (FT) were, respectively, calculated for coronary angiography (CA) (n = 1935; 61Gy.cm2, 624 mGy, 5 min); CA with left ventriculography (n = 1687; 85Gy.cm2, 840 mGy, 3.9 min), valve screening (n = 129; 6Gy.cm2, 164 mGy, 2.3 min), percutaneous coronary intervention (n = 1922; 145Gy.cm2, 1569 mGy, 11.9 min), pacemaker implantation (n = 432; 9Gy.cm2, 100 mGy, 6.5 min), pericardial tap (n = 115; 1.9Gy.cm2, 18 mGy, 1.5 min) and transcatheter aortic valve implantation (n = 45; 65Gy.cm2, 658 mGy, 14.1 min). This work presents the largest SA public sector cardiac FGP dosimetric data to date and provides a key resource for future work in this domain.

An audit of published South African diagnostic reference level data.

Diagnostic reference levels (DRLs) are accepted as a dose optimisation tool for patients undergoing x-ray imaging and are required by South African (SA) legislation for 26 fluoroscopically guided procedures (FGPs). The aim of this paper is to collate all published SA data on DRLs in preparation for a project to establish national DRLs. Systematic searches were conducted of various applicable databases. All research that proposed DRLs for any imaging procedure in South Africa was included. Twenty-one works met inclusion criteria, the earliest from 2001. Two-thirds of all work reported on FGPs and five studies documented computed tomography DRLs. Three publications focussed exclusively on paediatric imaging DRLs. No studies on mammography or dental radiography were found. For clinical procedures with more than one proposed DRL, the range of proposed DRL varied by up to a factor of five. The highest proposed DRL is 373.1 Gy cm2for endovascular aneurysm/aortic repair procedures. Data were collected in six public hospitals and two private hospital groups. Thirty-six authors contributed to the manuscripts, but only six studies had an inter-disciplinary authorship. This is the first paper to provide a comprehensive review of SA DRL data and thereby advances international radiation protection initiatives. The data suggests there is room for more interdisciplinary work and that there must be rigorous standardization of reported parameters and data collection. This audit also highlights the need for standardized terminology, particularly for FGPs.

RSNA International Trends: A Global Perspective on the COVID-19 Pandemic and Radiology in Late 2020.

The coronavirus disease 2019 pandemic has challenged and changed health care systems around the world. There has been a heterogeneity of disease burden, health care resources, and nonimaging testing availability, both geographically and over time. In parallel, there has been a continued increase in understanding how the disease affects patients, effectiveness of therapeutic options, and factors that modulate transmission risk. In this report, radiology experts in representative countries from around the world share insights gained from local experience. These insights provide a guidepost to help address management challenges as cases continue to rise in many parts of the world and suggest modifications in workflow that are likely to continue after this pandemic subsides.

An audit of the polytrauma fracture detection rate of clinicians evaluating lodox statscan bodygrams in two South African public sector trauma units.

BACKGROUND: Increasing global demand for specialized radiological investigations has resulted in delayed or non-reporting of plain trauma radiographs by radiologists. This is particularly true in resource-limited environments, where referring clinicians rely largely on their own radiographic interpretation. A wide accuracy range has been documented for non-radiologist reporting of conventional trauma radiographs. The Lodox Statscan whole-body digital X-ray machine is a relatively new technology that poses unique interpretive challenges. The fracture detection rate of trauma clinicians utilizing this modality has not been determined. OBJECTIVE: An audit of the polytrauma fracture detection rate of clinicians evaluating Lodox Statscan bodygrams in two South African public-sector Trauma Units. METHODS: A retrospective descriptive study of imaging data of Cape Town Level 1-equivalent public-sector Trauma Units during March-April 2015. Statscan bodygrams acquired for adult polytrauma triage were reviewed and correlated with follow-up imaging and patient records. Missed fractures were stratified by body part, mechanism of injury and ventilatory support. The fracture detection rate was determined with 95% confidence. The Generalised Fischer Exact Test assessed any association between the fracture site and failure of detection. Specialist orthopaedic review assessed the potential need for surgical management of missed fractures. RESULTS: 227 patients (male = 193, 85%; mean age: 33 years) were included; 195 fractures were demonstrated on the whole-body triage projections. Lower limb fractures predominated (n = 66, 34%). The fracture detection rate was 89% (95% CI = 86-93%), with the site of fracture associated with failure of detection (p = 0.01). Twelve of 21 undetected fractures (57%) involved the elbow or shoulder girdle. All elbow fractures (n = 3, 100%), more than half the shoulder girdle fractures (9/13,69%) and 12% (15/123) of extremity fractures were undetected. One missed fracture (1/21,4.7%) unequivocally required surgical management, while a further 7 (7/21, 33.3%) could potentially have benefitted from surgery, depending on follow-up imaging findings. CONCLUSION: This is the first analysis of the accuracy of bodygram polytrauma fracture detection by clinicians. Particular review of the shoulder girdle, elbow and extremities for subtle fractures, in addition to standardized limb positioning, are recommended for improved diagnostic accuracy in this setting. These findings can inform clinician training courses in this domain.

Advanced radiological investigations and findings amongst community assault victims admitted to a tertiary South African hospital.

BACKGROUND: Community assault (CA) has been increasing in certain Cape Town suburbs over the past decade. There are limited CA-related imaging data. The aim of this study was to review CA-related advanced radiological investigations and findings at a Level 1 South African Trauma Centre. METHOD: A retrospective study at Tygerberg Hospital, Cape Town, from 1 January through 30 June 2013. All advanced radiological investigations performed on CA victims at the time of admission were retrieved and analysed by patient demographics, imaging investigations and radiological findings. RESULTS: Sixty-two patients (n=62) with a median age of 25 years were included; CT brain was acquired in 90% (n=56) and was abnormal in 68% (n=42). Craniofacial fractures were demonstrated in 60% (n=37), with involvement of the paranasal sinuses in 32% (n=20) and the base of skull in 19% (n=12). Almost half (n=28/62; 45%) had intracranial haemorrhage, which was intra-axial in 36% (n=22/62), extra-axial in 34% (n=21/62) and both intra- and extra-axial in 23% (n=14/62). Cerebral oedema was present in 29% (n=18/62), with herniation in 10% (n=6/62). Non-cranial CT was acquired in 52% (n=32/62), of whom 19 (n=19/32; 59%) also underwent CT brain. CT abdomen was acquired in approximately a quarter of the cohort (n=16/62, 26%), demonstrating abnormalities in 15 (24%). Fifteen cervical spine CTs were performed (n=15/62; 24%) demonstrating no acute bony injury. CONCLUSION: We recommend a high index of suspicion for severe intracranial injury in CA victims and urgent tertiary referral of those with a depressed level of consciousness. Prospective work is required to determine the long-term outlook for survivors.

The impact of an electronic clinical decision support for pulmonary embolism imaging on the efficiency of computed tomography pulmonary angiography utilisation in a resource-limited setting.

BACKGROUND: Pulmonary embolism (PE) is associated with high morbidity and mortality. Effective intervention requires prompt diagnosis. Computed tomography pulmonary angiography (CTPA) is sensitive and specific for PE and is the investigation of choice. Inappropriate CTPA utilisation results in unnecessary high radiation exposure and is costly. State-of-the-art electronic radiology workflow can provide clinical decision support (CDS) for specialised imaging requests, but there has been limited work on the clinical impact of CDS in PE, particularly in resource-constrained environments. OBJECTIVE: To determine the impact of an electronic CDS for PE on the efficiency of CTPA utilisation in a resource-limited setting. METHODS: In preparation, a PE diagnostic algorithm was distributed to hospital clinicians, explaining the combined role of the validated modified Wells score and the quantitative D-dimer test in defining the pre-test probability of PE. Thereafter, an automated, electronic CDS was introduced for all CTPA requests. Total CTPA referrals and the proportion positive for PE were assessed for three study phases: (i) pre- diagnostic algorithm; (ii) post-algorithm, pre-CDS; and (iii) post-CDS. RESULTS: The proportion of CTPAs positive for PE after CDS implementation was almost double that prior to introduction of the diagnostic algorithm (phase 1 v. 3, 17.4% v. 30.7%; p=0.036), with a correspondingly significant decrease in the proportion of non-positive CTPAs (phases 1 v. 3, 82.6% v. 69.3%; p=0.015) During phases 2 and 3, no CTPAs were requested for patients with a modified Wells score of ≤4 and a documented negative D-dimer, indicating adherence to the algorithm. CONCLUSION: Implementing an electronic CDS for PE significantly increased the efficiency of CTPA utilisation and significantly decreased the proportion of inappropriate scans.

Chest radiographic features of lymphocytic interstitial pneumonitis in HIV-infected children.

AIM: To review the radiological features of biopsy-proven lymphocytic interstitial pneumonitis (LIP) in human immunodeficiency virus (HIV)-infected children and establish whether these are based on systematic radiological analysis, and to investigate whether more specific radiological diagnostic criteria can be developed. MATERIALS AND METHODS: A Medline search of English-language articles on the radiological features of biopsy-proven LIP in HIV-infected children was conducted for the period 1982 to 2007 inclusive. Radiological findings were compared with the Centers for Disease Control and Prevention (CDC) criteria for a presumptive diagnosis of LIP. RESULTS: Pulmonary pathology was recorded as "diffuse" and "bilateral" in 125 (97.6%) of 128 reported cases of LIP. Twenty-five different terms were used to describe the pulmonary parenchyma. In 96 (75%), the terminology was consistent with CDC diagnostic criteria. Radiological evolution was documented in 43 (33.5%). Persistent focal opacification superimposed on diffuse pulmonary nodularity was demonstrated in 10 (7.8%). The method of radiological evaluation was described in six (4.6%). In no instance was the terminology defined. CONCLUSION: The radiological features of LIP have not been systematically analysed. However, CDC criteria remain reliable, allowing diagnosis of at least 75% of cases. The sensitivity of these criteria may be increased by including cases with persistent focal pulmonary opacification superimposed on diffuse nodularity. Longitudinal studies utilizing standardized radiographic analysis are needed to elucidate the natural history of LIP.

Digital radiographic measurement of the main bronchi: a pilot study.

BACKGROUND: Conventional chest radiographs do not afford consistently good visualisation of the main bronchi and sub-carinal angle. Improved visualisation would facilitate accurate measurement of the airways, definition of normal radiographic anatomy and, possibly, earlier identification of extrinsic compression or displacement. AIM: The main objective of this study was to establish whether the paediatric main bronchi and sub-carinal angle could be measured consistently on AP supine chest images obtained using a specific digital radiographic system (DRS). SUBJECTS AND METHODS: The proximal bronchial diameters were measured on supine DRS chest images of 102 children between the ages of 6 months and 13 years. RESULTS: The left and right main bronchi could be seen clearly and measured in over 90% of cases, with intraclass correlation co-efficients of reliability indicating high intra- and inter-observer agreement. The sub-carinal angle had lower intra- and inter-observer agreement. CONCLUSION: Supine chest images acquired using DRS facilitate accurate measurement of the main bronchi and sub-carinal angle in children. Further work is required to establish population-specific age-related norms for bronchial dimensions. These could serve as reference standards for early detection of deviations from normal.

Radiographic features of paediatric pneumocystis pneumonia -- a historical perspective.

AIM: To determine differences between the plain radiographic features of paediatric pneumocystis pneumonia (PCP) recorded before the emergence of human immunodeficiency virus (HIV) in 1982 and those documented in the HIV era. To establish differences in the radiographic features of PCP documented in HIV-infected children in developed and developing countries. METHOD: A Medline search of articles was conducted from 1950 to 2006, using the terms "pneumocystis pneumonia in children" and "chest radiographic features" or "bilateral opacification" or "lobar consolidation" or "asymmetrical opacification" or "pneumatocoeles" or "cavities" or "pneumothorax" or "pneumomediastinum" or "pleural effusion" or "mediastinal adenopathy" or "nodules" or "normal chest radiography". Appropriate articles were retrieved, radiological data extracted, reference lists examined and hand searches of referenced articles conducted. RESULTS: Diffuse bilateral "ground-glass" or alveolar pulmonary opacification, which may show some asymmetry, has been consistently documented as the commonest radiographic finding in childhood PCP throughout the period under review. The less common radiological features of PCP in children are similar to those in adults. In developed countries, PCP-related pulmonary air cysts have been reported at an earlier age in HIV-infected children, compared with uninfected children. PCP-related air cysts, pneumothorax, and pneumomediastinum have been reported in children in developed but not in developing countries. CONCLUSION: The radiological features of paediatric PCP documented before the HIV epidemic are similar to those recorded in the HIV era. Further study of the determinants of the uncommon radiographic features in children is warranted.