Variation, sexual dimorphism, and enlargement of the frontal sinus with age in adult South Africans.

OBJECTIVES: To document frontal sinus volume (FSV) in a sample of sub-Saharan Africans with a view to evaluating claims that such populations exhibit comparatively small sinuses. This study also addresses questions related to sexual dimorphism, incidence of sinus aplasia, and the possibility that FSV continues to increase through adulthood. MATERIALS AND METHODS: FSV was measured from CT scans of adult crania from the Dart Collection. Sex and age were known for each individual. Linear cranial dimensions were used to compute a geometric mean from which a scaled FSV was computed for each cranium. RESULTS: FSV does not differ significantly between sexes, but females exhibit a higher incidence of aplasia. There is considerable variation in FSV in this sample, with the average ranking among the higher means reported for other population samples. The incidence of FS aplasia falls within the range of values recorded for other population samples. Although our study is cross-sectional rather than longitudinal, there is strong evidence that FSV continues to increase with age throughout adulthood. DISCUSSION: The FSV mean of our sample contradicts the notion that sub-Saharan Africans possess small sinuses. In a global context, geography (climate and altitude) does not appear to be related to FSV. The absence of sexual dimorphism in our sample is unexpected, as significant dimorphism has been reported for most other population samples. Our results support other indications that the frontal sinus continues to expand throughout adulthood, especially in females, and that it is likely due to bone resorption.

Association of brain arterial diameters with demographic and anatomical factors in a multi-national pooled analysis of cohort studies.

BACKGROUND AND PURPOSE: Brain arterial diameters are markers of cerebrovascular disease. Demographic and anatomical factors may influence arterial diameters. We hypothesize that age, sex, height, total cranial volume (TCV), and persistent fetal posterior cerebral artery (fPCA) correlate with brain arterial diameters across populations. METHODS: Participants had a time-of-flight MRA from nine international cohorts. Arterial diameters of the cavernous internal carotid arteries (ICA), middle cerebral arteries (MCA), and basilar artery (BA) were measured using LAVA software. Regression models assessed the association between exposures and brain arterial diameters. RESULTS: We included 6,518 participants (mean age: 70 ± 9 years; 41% men). Unilateral fPCA was present in 13.2% and bilateral in 3.2%. Larger ICA, MCA, and BA diameters correlated with older age (Weighted average [WA] per 10 years: 0.18 mm, 0.11 mm, and 0.12 mm), male sex (WA: 0.24 mm, 0.13 mm, and 0.21 mm), and TCV (WA: for one TCV standard deviation: 0.24 mm, 0.29 mm, and 0.18 mm). Unilateral and bilateral fPCAs showed a positive correlation with ICA diameters (WA: 0.39 mm and 0.73 mm) and negative correlation with BA diameters (WA: -0.88 mm and -1.73 mm). Regression models including age, sex, TCV, and fPCA explained on average 15%, 13%, and 25% of the ICA, MCA, and BA diameter interindividual variation, respectively. Using height instead of TCV as a surrogate of head size decreased the R-squared by 3% on average. CONCLUSION: Brain arterial diameters correlated with age, sex, TCV, and fPCA. These factors should be considered when defining abnormal diameter cutoffs across populations.

Metopism in adult South Africans and its relationship to frontal sinus size.

This study documents the incidences of complete and partial metopism and their possible relationship to frontal sinus volume (FSV) in a sample of modern adult black South Africans with a view to evaluating the hypothesis that metopism affects frontal sinus hypoplasia. FSV was measured from CT scans and the incidence of metopism was recorded from direct observations of dried cadaveric crania. The sex of each individual was known. Four linear cranial dimensions were used to compute a geometric mean by which to scale FSV. The incidence of partial metopism (38%) is comparable to that reported for other population samples, although there is considerable variation among these global sample frequencies. It is significantly more common in male than female South Africans. FSV in individuals with complete metopism is smaller than average but not inordinately so. On the other hand, FSV is significantly larger in individuals with partial metopism than in those that do not present with this sutural remnant. The data on FSV in individuals with and without partial metopism contradict the hypothesis that there is a relationship between partial metopism and frontal sinus hypoplasia. As such, the metopic remnant evinced by the Late Pleistocene cranium from Hofmeyr, South Africa is unlikely to be related to its very small FSV.

Endovascular management of intracranial aneurysms at Chris Hani Baragwanath Academic Hospital.

Background: Worldwide, intracranial aneurysms are associated with a high mortality rate. While endovascular management has proven to be the choice of treatment in selected patients, patient demographics and aneurysm characteristics differ between study populations. Objectives: This study aimed to investigate the profile of patients with intracranial aneurysms who underwent endovascular management in the Interventional Neuroradiology Unit at Chris Hani Baragwanath Academic Hospital. Patient demographics, risk factors, indications, aneurysm characteristics and intra-operative complications were studied. Method: This was a 3-year retrospective study of all adult patients between 01 January 2018 and 31 January 2021. The Chi-square test was used to compare categorical variables. Results: A total of 77 patients were included in this study. The mean age of the patients was 47 ± 11.6 with a male-to-female ratio of 1:1.8. Hypertension was the most reported risk factor in 27% of patients. There was no statistical correlation between the gender groups according to presentation, multiplicity, aneurysmal size dimensions and locations. According to the presentation, there was statistical significance in ruptured intracranial aneurysms (p = 0.020), neck size dimensions less than 4 mm (p = 0.010), and aneurysms located in the internal cerebral artery (ICA) circulation (p = 0.001). Conclusion: The study findings support known parameters including females and anterior circulation aneurysm preponderance, and the low complication risk of endovascular management. Interestingly, intracranial aneurysms presented with rupture at smaller size dimensions. Contribution: This study provides valuable insights into intracranial aneurysm characteristics and endovascular management efficacy in a resource-limited setting.

Accuracy of CT angiography for detecting ruptured intracranial aneurysms.

Background: Digital subtraction angiography (DSA) is invasive, costly and unavailable in many South African hospitals; however, it remains the gold standard for imaging intracranial aneurysms. CT angiography (CTA) is a non-invasive and readily available screening tool prior to DSA. Objectives: This study aimed to evaluate the diagnostic performance of CTA in detecting ruptured intracranial aneurysms using DSA as the reference standard and to determine the effect of aneurysm size and location on CTA sensitivity. Method: A retrospective analysis of CTA and DSA data from reports of patients suspected to have aneurysmal subarachnoid haemorrhage (SAH) at Chris Hani Baragwanath Academic Hospital between January 2017 and June 2020. Results: Conventional DSA detected aneurysms in 94 out of 115 patients; while of these, CTA detected 75 and missed 19. The CTA sensitivity, specificity and accuracy was 80%, 43% and 73%, respectively. The CTA sensitivity for aneurysms < 3 mm and 3 mm - 5 mm in size was 30% and 81.5%, respectively (p = 0.024). Sensitivity of CTA for posterior communicating artery (PComm) aneurysms was 56% and lower than other major anterior circulation locations (83% - 91%) (p = 0.045). Conclusion: The CTA diagnostic efficiency was lower than previously reported, with even lower sensitivity for aneurysms < 3 mm and for those arising from the PComm. Thus, CTA should remain a screening tool prior to DSA in all local patients suspected to have aneurysmal SAH. Contribution: Larger, prospective studies are required to accurately define the role of CTA in diagnosing intracranial aneurysms in a developing country with limited resources.

Synchronous solid pseudopapillary neoplasm of the pancreas with intrahepatic cholangiocarcinoma in a young male patient: An unusual deadly occurrence.

INTRODUCTION AND IMPORTANCE: Solid pseudopapillary neoplasm of the pancreas (SPN) is a tumour with low malignant potential, albeit with good prognosis. Intrahepatic cholangiocarcinoma (iCCA) is a malignant and aggressive tumour with poor prognosis. CLINICAL PRESENTATION: We report a case of a 38 years old African male patient with abdominal pain for 5 years that worsened in the preceding 5 months. Radiology showed pancreatic and liver lesions which were thought to be malignant and benign, respectively. However, intra-operative and histopathological assessment confirmed SPN and iCCA which were contrary to radiological findings. Whilst surgery was uneventful, the patient died after 15 days. CLINICAL DISCUSSION: Whilst SPN is commonly seen in young females, it is rare in males and has been associated with aggressive behaviour. The prognosis is good, albeit the presence of metastasis. iCCA is rare in younger population notwithstanding the presence of risk factor. Combination of iCCA and SPT has not been described. Both these tumours do not share risk factors, pathogenesis or molecular alterations. CONCLUSION: The concomitant occurrence of these two pathologies in young male patient is unusual and preoperative diagnosis may be very difficult.

Secular trends in cranial size and shape among black South Africans over the late 19th and 20th centuries.

BACKGROUND: Previous studies of secular change in cranial size among black South Africans have produced conflicting results. AIM: We re-examined cranial size change in this population during the 19th and 20th century by evaluating its relationship with individual year-of-birth, and the significance of trends among eight decennial cohorts. SUBJECTS AND METHODS: This study is based on 102 male and 89 female adults born between 1865 and 1959. Linear regressions were employed to evaluate possible relationships between year-of-birth and cranial dimensions; ANOVAs were used to evaluate the significance of long-term trends among decennial cohorts. RESULTS: No analysis revealed a secular change in cranial length in either sex; however, the ANOVA for cranial length in the combined sex sample was significant. There is no secular trend in female cranial breadth, but males display a negative trend in this dimension. This results in a secular trend for increased male dolichocephaly. CONCLUSIONS: The factors that underlie the negative secular trend in male cranial breadth and the absence of a secular trend in overall cranial size in this population are unclear. Nevertheless, these observations accord with findings related to stature and long bone strength in this population and are consistent with observations for other sub-Saharan African populations.

Secular decline in limb bone strength among South African Africans during the 19th and 20th centuries.

OBJECTIVES: South African Africans have been reported to have experienced negative or null secular trends in stature and other measures of skeletal structure across the 19th and 20th centuries, presumably due to poor living conditions during a time of intensifying racial discrimination. Here, we investigate whether any secular trend is apparent in limb bone strength during the same period. MATERIALS AND METHODS: Cadaver-derived skeletons (n = 221) were analyzed from female and male South African Africans who were born between 1839 and 1970, lived in and around Johannesburg, and died between 1925 and 1991 when they were 17-90 years of age. For each skeleton, a humerus and femur were scanned using computed tomography, and mid-diaphyseal cross-sectional geometric properties were calculated and scaled according to body size. RESULTS: In general linear mixed models accounting for sex, age at death, and skeletal element, year of birth was a significant (p < .05) negative predictor of size-standardized mid-diaphyseal cortical area (a proxy for resistance to axial loading) and polar moment of area (a proxy for resistance to bending and torsion), indicating a temporal trend toward diminishing limb bone strength. No significant interactions were detected between year of birth and age at death, suggesting that the decline in limb bone strength was mainly due to changes in skeletal maturation rather than severity of age-related bone loss. DISCUSSION: Limb bone strength is thus potentially another feature of the skeletal biology of South African Africans that was compromised by poor living conditions during the 19th and 20th centuries.

Influence of Internal Organ Pathology on Vascular Permeability of Related Skin Zones: An Attempt to Visualize Organ Projection Areas.

Objective: Pathology of an internal organ/body part changes electrical features of the corresponding skin areas-organ projection areas (OPAs)-which are often identified with traditional acupuncture points/zones. Once the resistance "breakthrough effect" has been induced in these specific skin areas, rectification of applied electrical currents (a diode phenomenon) occurs. In addition, increased impedance can be observed. It is presumed that these skin bioelectrical phenomena are the result of increased local capillary permeability with extravasation of blood-plasma albumins. Contrast-enhanced magnetic resonance imaging (MRI) of the microvasculature, using labeled albumins as markers, allows visualization of skin areas with higher albumin concentrations. The goal of this research was experimental verification of the abovementioned physiologic hypothesis by visualization of the OPAs. Materials and Methods: Preselected, comparative, contrast-enhanced magnetic resonance imaging (MRI) studies of the auricular microvasculature were performed in the Division of Diagnostic Radiology of Charlotte Maxeke Academic Hospital in Johannesburg, South Africa, in a group of 42 volunteers with proven clinical conditions of 49 (in total) chosen internal organs/body parts. Previously, 28 auricular OPAs related to internal organs/body parts with proven pathologies showed the abovementioned bioelectrical phenomena and 21 auricular OPAs in a control group did not show those phenomena to a significant extent. Contrast-enhanced MRI assessment of the study participants' ear auricle vascular permeability was performed after 1, 2, 3, 4, and 5 minutes after a standard contrast, which binds to albumins transiently, was injected intravenously. Contrast-enhanced magnetic resonance images of the diseased body part-related OPAs versus images of the same but healthy body part-related OPAs (control group) were subjected to a final statistical comparison. Results: It was presumed that 24 OPAs related to internal organs/body parts with serious pathologies were visualized by means of labeled albumins and 25 OPAs corresponding to healthy body parts or minor pathologies were not seen. OPA visibility depended on the extent of pathology within the related internal organ/body part, but not on the kind of organ/body part nor etiology or kind of disease. Conclusions: Pathology of internal organ/body parts appears to cause higher concentrations of albumins within related OPAs and, in this way, creates specific electrical phenomena observed at the OPAs. Contrast-enhanced MRI of the microvasculature, using labeled albumins, can be useful for visualizing OPAs.

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BACKGROUND: Despite ranking third as a cause of hospital-acquired acute kidney injury (AKI), iatrogenic contrast-induced nephropathy (CIN) impacts significantly on morbidity and mortality and is associated with high hospital costs. In sub-Saharan Africa, the rates and risk factors for CIN and patient outcomes remain unexplored. METHODS: We conducted a prospective observational study at the Charlotte Maxeke Johannesburg Academic Hospital, South Africa, from 1 July 2014 to 30 July 2015. Hospitalised patients undergoing computed tomography scan contrast media administration and angiography were consecutively recruited to the study and followed up for development of AKI. CIN was defined as an increase in serum creatinine >25% or an absolute increase of >44 µmol/L from baseline at 48 - 72 hours post exposure to contrast media. Outcome variables were the occurrence of CIN, length of hospitalisation and in-hospital mortality. RESULTS: We recruited 371 hospitalised patients with a mean (standard deviation) age of 49.3 (15.9). The rates of CIN, assessed using an absolute or relative increase in serum creatinine from baseline, were 4.6% and 16.4%, respectively. Anaemia was an independent predictor for the development of CIN (risk ratio (RR) 1.71, 95% confidence interval (CI) 1.01 - 2.87; p=0.04). The median serum albumin was 34 g/L (interquartile range (IQR) 29 - 39.5) and 38 g/L (IQR 31 - 42) in the CIN and control groups, respectively (p=0.01), and showed a significant trend for CIN development (RR 1.68, 95% CI 0.96 - 2.92; p=0.06). Mortality was significantly increased in the CIN group (22.4% v. 6.8%; p<0.001), and CIN together with anaemia increased mortality twofold (RR 2.39, 95% CI 1.20 - 4.75; p=0.01) and threefold (RR 3.32, 95% CI 1.48 - 7.43; p=0.003), respectively. CONCLUSIONS: CIN has a relatively high incidence in sub-Saharan Africa and predicts poorer clinical outcomes. The presence of CIN and anaemia positively predicted mortality. Caution should be exercised in patients with hypoalbuminaemia and anaemia undergoing contrast media administration.

The incidence of tuberculosis among hiv-positive individuals with high CD4 counts: implications for policy.

BACKGROUND: Intensified case finding (ICF) and earlier antiretroviral therapy (ART) initiation are strategies to reduce burden of HIV-associated tuberculosis (TB). We describe incidence of and associated factors for TB among HIV-positive individuals with CD4 counts > 350 cells/µl in South Africa. METHODS: Prospective cohort study of individuals recruited for a TB vaccine trial. Eligible individuals without prevalent TB were followed up at 6 and 12 months after enrolment. Cox proportional hazards regression was used to determine factors associated with risk of incident TB. RESULTS: Six hundred thirty-four individuals were included in the analysis [80.9 % female, 57.9 % on ART, median CD4 count 562 cells/µl (IQR 466-694 cells/µl)]. TB incidence was 2.7 per 100 person-years (pyrs) (95 % CI 1.6-4.4 per 100 pyrs) and did not differ significantly between those on ART and those not on ART [HR 0.65 (95 % CI 0.24-1.81)]. Low body mass index (BMI <18.5 kg/m(2)) was associated with incident TB [HR 3.87 (95 % CI 1.09-13.73)]. Half of the cases occurred in the first 6 months of follow up and may have been prevalent or incubating cases at enrolment. CONCLUSIONS: TB incidence was high and associated with low BMI. Intensified case finding for TB should be strengthened for all HIV positive individuals regardless of their CD4 count or ART status.

Advances in stroke treatment are within reach.

Five recent trials have shown that mechanical removal of clot from cerebral arteries after a stroke can achieve a functional independent outcome in up to 60% of patients. This was an absolute benefit of between 13.5% and 31% for patients who had clot removal initiated within 6 hours of symptoms over those who had best medical treatment. Coupled with this, there is a strong drive to develop stroke units internationally and in South Africa. As a starting point, more primary stroke care centres that can administer intravenous thrombolysis are needed. Comprehensive stroke centres that can offer mechanical thrombectomy are available, but more will be required as referral of patients increases. Collaboration of all roleplayers will ensure that we can deliver training and care at the best level for stroke patients.

Undiagnosed tuberculosis among HIV clinic attendees: association with antiretroviral therapy and implications for intensified case finding, isoniazid preventive therapy, and infection control.

OBJECTIVES: Initiation of antiretroviral therapy (ART) and the 3I's are strategies to prevent HIV-associated tuberculosis (TB). We describe factors associated with undiagnosed TB among HIV-infected patients attending an HIV clinic in South Africa and discuss implications for the 3 Is. DESIGN: Convenience sample of HIV clinic attendees. METHODS: HIV-infected participants were assessed for TB using a symptom screen, sputum-smear microscopy, sputum and blood mycobacterial culture, fine needle aspiration of enlarged lymph nodes, and chest radiography. RESULTS: Four hundred twenty-two participants were enrolled. The median age and CD4+ T-cell count were 37 years [interquartile range (IQR): 31-44 years] and 215 cells per microliter (IQR: 107-347 cells/µL). Forty-seven percent had been on ART for a median duration of 8 months (IQR: 3.3-22.8 months). Three hundred sixty-one participants (85.6%) reported TB symptoms. Twenty-seven participants (6.4%) met criteria for bacteriologically confirmed TB and 50 (11.6%) for any form of TB. Bacteriologically confirmed TB was associated with CD4+ T-cell counts ≤100 cells per microliter (odds ratio: 5.05, 95% confidence interval: 1.69 to 15.12) when compared with CD4+ T-cell counts >200 cells per microliter and hemoglobin {hemoglobin < 10 g/dL [odds ratio 3.12 (95% confidence interval: 1.26 to 7.72)]}. CONCLUSIONS: Undiagnosed TB among HIV-infected ambulatory patients was associated with low CD4+ T-cell counts regardless of ART status. TB screening algorithms which include CD4+ T-cell count and hemoglobin testing may be an effective way to identify HIV-infected clinic attendees at highest risk of undiagnosed TB. Isoniazid preventive therapy and TB infection control are essential for reducing occurrence of HIV-associated TB even after ART initiation.

Diagnostic accuracy of a urine lipoarabinomannan enzyme-linked immunosorbent assay for screening ambulatory HIV-infected persons for tuberculosis.

OBJECTIVE: To assess the diagnostic accuracy of the urine lipoarabinomannan (LAM) test among ambulatory HIV-infected persons. DESIGN: Cross-sectional. METHODS: HIV-infected persons consecutively presenting to the HIV Clinic at Tembisa Main Clinic in Ekhuruleni, South Africa, were screened for symptoms of tuberculosis (TB) and asked to provide sputum and blood samples for smears for acid-fast bacilli and mycobacterial culture and a urine specimen for a LAM enzyme-linked immunosorbent assay. Fine needle aspirates were obtained from participants with enlarged lymph nodes and sent for histopathology. Nonpregnant participants underwent chest x-ray. RESULTS: : Four hundred twenty-two HIV-infected participants were enrolled with median age 37 years (interquartile range: 31-44 years), median CD4+ T-cell count 215 cells per microliter (interquartile range: 107-347 cells/µL), and 212 (50%) receiving antiretroviral therapy. Thirty (7%) had active TB: 18 with only pulmonary TB, 5 with only extrapulmonary TB, and 7 with both pulmonary TB and extrapulmonary TB. Twenty-seven percent [95% confidence interval (CI): 12% to 48%] of TB cases were sputum acid-fast bacilli positive. The sensitivity and specificity of the urine LAM compared with the gold standard of positive bacteriology or histopathology were 32% (95% CI: 16% to 52%) and 98% (95% CI: 96% to 99%), respectively. Urine LAM had higher sensitivity in TB cases with higher bacillary burdens, though these differences were not statistically significant. CONCLUSIONS: The sensitivity of urine LAM testing is inadequate to replace mycobacterial culture. In contrast to prior research on the urine LAM, this study was conducted among less sick, ambulatory HIV-infected patients presenting for routine care.

Paediatric radiology seen from Africa. Part I: providing diagnostic imaging to a young population.

Paediatric radiology requires dedicated equipment, specific precautions related to ionising radiation, and specialist knowledge. Developing countries face difficulties in providing adequate imaging services for children. In many African countries, children represent an increasing proportion of the population, and additional challenges follow from extreme living conditions, poverty, lack of parental care, and exposure to tuberculosis, HIV, pneumonia, diarrhoea and violent trauma. Imaging plays a critical role in the treatment of these children, but is expensive and difficult to provide. The World Health Organisation initiatives, of which the World Health Imaging System for Radiography (WHIS-RAD) unit is one result, needs to expand into other areas such as the provision of maintenance servicing. New initiatives by groups such as Rotary and the World Health Imaging Alliance to install WHIS-RAD units in developing countries and provide digital solutions, need support. Paediatric radiologists are needed to offer their services for reporting, consultation and quality assurance for free by way of teleradiology. Societies for paediatric radiology are needed to focus on providing a volunteer teleradiology reporting group, information on child safety for basic imaging, guidelines for investigations specific to the disease spectrum, and solutions for optimising imaging in children.

Paediatric radiology seen from Africa. Part II: recognising research advantages in a developing country.

Radiologists in developing countries cite numerous reasons for poor research output including heavier workloads, poor remuneration (resulting in "brain drain"), poor infrastructure, language barriers, lack of modern imaging equipment, and a disease spectrum that may be of little interest to journals and readers in the developed world. On the other hand, large populations of patients suffering from distinctive diseases, cost-effective healthcare systems, and a set-up with highly centralised tertiary referral hospitals, may be seen as advantages to those willing to tap into this as a data source for research. The lack of resources may even stimulate cost-effective innovations relevant to the needs of poor communities. This paper challenges preconceived ideas and identifies advantages for radiologists in developing countries to producing good research and publications. It also cautions against "annexation of sites" by stakeholders from developed countries, and suggests simple solutions to maximise research output without a significant financial cost.

Musculoskeletal tuberculosis - imaging using low-end and advanced modalities for developing and developed countries.

Musculoskeletal involvement by TB is rare in comparison to other forms of the disease. It most commonly involves the spine but can also involve large weight-bearing joints, long bones, the skull and the soft tissues. Characteristic appearances of musculoskeletal TB are described for numerous imaging modalities in this paper but it is also highlighted that when based on imaging appearances alone, there is always a differential diagnosis, including other infections and malignancies. Awareness of of TB as a possible cause of vertebral body lesions, arthritis and synovitis, long bone lesions and soft tissue collections will allow clinicians to consider TB based on imaging and will sometimes be characteristic enough to allow for a trial of therapy, thereby avoiding biopsy. This paper specifically describes the imaging appearances on both basic modalities such as plain radiographs and ultrasound for those working in resource-restricted areas, as well as on high-end modalities such as CT and MRI for those with access to these. Tuberculosis is no longer a disease limited to the developing world and radiologists in the developed world must be able to make this diagnosis in both immigrants and the native population.