MRI scarcity in low- and middle-income countries.

Since the introduction of MRI as a sustainable diagnostic modality, global accessibility to its services has revealed a wide discrepancy between populations-leaving most of the population in LMICs without access to this important imaging modality. Several factors lead to the scarcity of MRI in LMICs; for example, inadequate infrastructure and the absence of a dedicated workforce are key factors in the scarcity observed. RAD-AID has contributed to the advancement of radiology globally by collaborating with our partners to make radiology more accessible for medically underserved communities. However, progress is slow and further investment is needed to ensure improved global access to MRI.

Artificial Intelligence in Low- and Middle-Income Countries: Innovating Global Health Radiology.

Scarce or absent radiology resources impede adoption of artificial intelligence (AI) for medical imaging by resource-poor health institutions. They face limitations in local equipment, personnel expertise, infrastructure, data-rights frameworks, and public policies. The trustworthiness of AI for medical decision making in global health and low-resource settings is hampered by insufficient data diversity, nontransparent AI algorithms, and resource-poor health institutions' limited participation in AI production and validation. RAD-AID's three-pronged integrated strategy for AI adoption in resource-poor health institutions is presented, which includes clinical radiology education, infrastructure implementation, and phased AI introduction. This strategy derives from RAD-AID's more-than-a-decade experience as a nonprofit organization developing radiology in resource-poor health institutions, both in the United States and in low- and middle-income countries. The three components synergistically provide the foundation to address health care disparities. Local radiology personnel expertise is augmented through comprehensive education. Software, hardware, and radiologic and networking infrastructure enables radiology workflows incorporating AI. These educational and infrastructure developments occur while RAD-AID delivers phased introduction, testing, and scaling of AI via global health collaborations.

Building Radiology Equity: Themes from the 2023 RAD-AID Conference on International Radiology and Global Health.

Low- and middle-income countries are significantly impacted by the global scarcity of medical imaging services. Medical imaging is an essential component for diagnosis and guided treatment, which is needed to meet the current challenges of increasing chronic diseases and preparedness for acute-care response. We present some key themes essential for improving global health equity, which were discussed at the 2023 RAD-AID Conference on International Radiology and Global Health. They include (1) capacity building, (2) artificial intelligence, (3) community-based patient navigation, (4) organizational design for multidisciplinary global health strategy, (5) implementation science, and (6) innovation. Although not exhaustive, these themes should be considered influential as we guide and expand global health radiology programs in low- and middle-income countries in the coming years.

Outcomes by Race in Breast Cancer Screening With Digital Breast Tomosynthesis Versus Digital Mammography.

PURPOSE: Digital breast tomosynthesis (DBT) in conjunction with digital mammography (DM) is becoming the preferred imaging modality for breast cancer screening compared with DM alone, on the basis of improved recall rates (RR) and cancer detection rates (CDRs). The aim of this study was to investigate racial differences in the utilization and performance of screening modality. METHODS: Retrospective data from 63 US breast imaging facilities from 2015 to 2019 were reviewed. Screening outcomes were linked to cancer registries. RR, CDR per 1,000 examinations, and positive predictive value for recall (cancers/recalled patients) were compared. RESULTS: A total of 385,503 women contributed 542,945 DBT and 261,359 DM screens. A lower proportion of screenings for Black women were performed using DBT plus DM (referred to as DBT) (44% for Black, 48% for other, 63% for Asian, and 61% for White). Non-White women were less likely to undergo more than one mammographic examination. RRs were lower for DBT among all women (8.74 versus 10.06, P < .05) and lower across all races and within age categories. RRs were significantly higher for women with only one mammogram. CDRs were similar or higher in women undergoing DBT compared with DM, overall (4.73 versus 4.60, adjusted P = .0005) and by age and race. Positive predictive value for recall was greater for DBT overall (5.29 versus 4.45, adjusted P < .0001) and by age, race, and screening frequency. CONCLUSIONS: All racial groups had improved outcomes with DBT screening, but disparities were observed in DBT utilization. These data suggest that reducing inequities in DBT utilization may improve the effectiveness of breast cancer screening.

A Global Perspective on Screening.

Breast cancer is emerging as a major global public health problem. Incidence and mortality continues to rise in low- and middle-income countries (LMICs). A significant and growing disparity exists between high-income countries and LMICs in the availability of screening services and associated preventable mortality. However, population imaging-based screening programs are not appropriate for all settings. Planners should perform a thorough assessment of the target setting prior to implementing any breast cancer detection program, as appropriate guidelines vary according to the resources available. Financial, social, and cultural barriers to breast cancer care need to be addressed to sustainably improve the morbidity and mortality of the populations and make efficient use of available services. Creative approaches, such as mobile and portable imaging and bundling of services, can facilitate the installation of early breast cancer detection programs in LMICs. While image-based screening programs are not initially resource-appropriate in many LMICs, planners can work towards this goal as part of their comprehensive breast cancer detection strategy.

Ultrasound for Breast Cancer Detection Globally: A Systematic Review and Meta-Analysis.

PURPOSE: Mammography is not always available or feasible. The purpose of this systematic review and meta-analysis is to assess the diagnostic performance of ultrasound as a primary tool for early detection of breast cancer. MATERIALS AND METHODS: For this systematic review and meta-analysis, we comprehensively searched PubMed and SCOPUS to identify articles from January 2000 to December 2018 that included data on the performance of ultrasound for detection of breast cancer. Studies evaluating portable, handheld ultrasound as an independent detection modality for breast cancer were included. Quality assessment and bias analysis were performed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Sensitivity analyses and meta-regression were used to explore heterogeneity. The study protocol has been registered with the international prospective register of systematic reviews (PROSPERO identifier: CRD42019127752). RESULTS: Of the 526 identified studies, 26 were eligible for inclusion. Ultrasound had an overall pooled sensitivity and specificity of 80.1% (95% CI, 72.2% to 86.3%) and 88.4% (95% CI, 79.8% to 93.6%), respectively. When only low- and middle-income country data were considered, ultrasound maintained a diagnostic sensitivity of 89.2% and specificity of 99.1%. Meta-analysis of the included studies revealed heterogeneity. The high sensitivity of ultrasound for the detection of breast cancer was not statistically significantly different in subgroup analyses on the basis of mean age, risk, symptoms, study design, bias level, and study setting. CONCLUSION: Given the increasing burden of breast cancer and infeasibility of mammography in certain settings, we believe these results support the potential use of ultrasound as an effective primary detection tool for breast cancer, which may be beneficial in low-resource settings where mammography is unavailable.

Differentiating intracranial aspergillosis from a high grade glioma using MRI and MR spectroscopic imaging.

We compare the MRI (magnetic resonance imaging) and MRSI (MR spectroscopic imaging) findings in a patient with intracerebral aspergillosis to those typically seen in an infiltrating high-grade glioma (HGG). We demonstrate paramagnetic areas of T2-hypointensity due to the pathologic deposition of iron and other paramagnetic elements seen in intracerebral aspergillosis. We also demonstrate the diffusion-weighted imaging (DWI) findings and discuss how MR spectroscopy can be useful in differentiating an aspergilloma from a high-grade glioma.

"Typical" but not "atypical" antipsychotic effects on startle gating deficits in prepubertal rats.

RATIONALE: Dopamine (DA) agonists and NMDA antagonists disrupt sensorimotor gating in rats, as measured by a loss of prepulse inhibition of the startle reflex. These effects are used in predictive models for antipsychotic efficacy: clinically "typical" and "atypical" antipsychotics restore PPI in adult rats treated with DA agonists such as apomorphine (APO), while clinically "atypical" antipsychotics restore PPI in rats treated with NMDA antagonists such as phencyclidine (PCP). We previously reported that the PPI disruptive effects of both APO and PCP are evident in 16- to 18-day-old rat pups, suggesting that the brain substrates for these effects are functional very early in development. OBJECTIVE: In the present study we assessed the developmental patterns of antipsychotic effects in these measures. METHODS: The PPI-disruptive effects of APO and PCP, and their antagonism by the typical antipsychotic haloperidol, and the atypical antipsychotic quetiapine, were assessed across development in Sprague-Dawley rats. RESULTS: Similar to the pattern seen in adults, both haloperidol and quetiapine opposed APO-induced PPI deficits in 16- to 19-day-old rat pups. However, the "atypical" antipsychotic quetiapine did not oppose PCP-induced PPI deficits in pups or prepubertal (45 day) adolescents, but did oppose these PCP effects in postpubertal rats. CONCLUSIONS: While brain substrates mediating the PPI-disruptive effects of DA agonists and NMDA antagonists are functional early in development, some physiological event associated with puberty is a necessary condition for the "atypical antipsychotic profile" in this predictive model.

Novel device to conduct flash-heat treatment in efforts to reduce mother-to-child HIV transmission in low-resource areas.

The objective of this design project was to create a device to prevent mother-to-child transmission (MTCT) of HIV through breast milk in preterm infants. Our team created a robust and intuitive device which utilizes Flash Heat Treatment (FHT), an established method to inactivate HIV. The FHT method heats jarred breast milk in boiling water for a short amount of time, enough to denature HIV reverse transcriptase while preserving the nutritional value of breast milk. Thorough observation of users and available resources in Cape Town, South Africa enabled establishment of a design that can be used in urban/peri-urban areas. User research conveyed that low cost and effortless household adaptability were the most important elements of the design. As a result, a modified electric kettle was designed to function as a breast milk pasteurization device. Published data illustrating temperature curves during FHT with corresponding virology tests on the pasteurized milk were used to verify whether the device is likely to function effectively. Experimental results indicate that the device matches the required temperature profile. After virology experimentation is complete, the new device may be incorporated into hospitals as well as households in the Cape Town area, and may be expanded to other low resource periurban/urban areas as well.

Comparison of region-of-interest analysis with three different histogram analysis methods in the determination of perfusion metrics in patients with brain gliomas.

PURPOSE: To compare routine ROI analysis and three different histogram analyses in the grading of glial neoplasms. The hypothesis is that histogram methods can provide a robust and objective technique for quantifying perfusion data in brain gliomas. Current region-of-interest (ROI)-based methods for the analysis of dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC MRI) data are operator-dependent. MATERIALS AND METHODS: A total of 92 patients underwent conventional and DSC MRI. Multiple histogram metrics were obtained for cerebral blood flow (CBF), cerebral blood volume (CBV), and relative CBV (rCBV) maps using tumoral (T), peritumoral (P), and total tumoral (TT) analysis. Results were compared to histopathologic grades. Statistical analysis included Mann-Whitney (MW) tests, Spearman rank correlation coefficients, logistic regression, and McNemar tests. RESULTS: The maximum value of rCBV (rCBV(max)) showed highly significant correlation with glioma grade (r = 0.734, P < 0.001). The strongest histogram correlations (P < 0.0001) occurred with rCBV(T) SD (r = 0.718), rCBV(P) SD(25) (r = 0.724) and rCBV(TT) SD(50) (r = 0.685). Multiple rCBV(T), rCBV(P), and rCBV(TT) histogram metrics showed significant correlations. CBF and CBV histogram metrics were less strongly correlated with glioma grade than rCBV histogram metrics. CONCLUSION: Histogram analysis of perfusion MR provides prediction of glioma grade, with peritumoral metrics outperforming tumoral and total tumoral metrics. Further refinement may lead to automated methods for perfusion data analysis.