RESUMO
Clinicians frequently study arterial Doppler velocimetric waveforms depicted by Doppler sonography of the kidneys, the heart, the brain, and the feto-maternal circulation to assess the well-being of the aforementioned vital organs. The waveform interpretation of the Doppler indices can be studied using a mathematical model. The developed models serve as teaching tools and for easy comprehension of the regulatory mechanism of the organs. It will also obtain accurate wall shear stress (WSS) and likely atherosclerotic sites can be predicted early. The aim of this review is to reveal the imperatives of mathematical models in the study of the physical interpretation of Doppler velocimetry. The models will explore sonographic Doppler velocimetry and computational fluid dynamics (CFD) in determining the segments of the arteries that are prone to the development of atheromatous plaque. It will be achieved by comparing and computing the measurement differences of the WSS. A thorough literature review was carried out between 1971 and 2021 on the mathematical modeling of blood dynamics and Doppler velocimetry of different blood vessels, across various electronic databases including NC AHEC Digital Library, PUBMED, ERIC, MEDLINE, Free Medical Journals, and EMBASE. The results of the literature search were presented using the PRISMA flow chat. The narrative review of the mathematical models of arterial blood dynamics is based on incompressible Navier-Stokes equations, the Windkessel model, and CFD. It was deduced that the blood flow velocity decreased with time across the varying frequency from 0.2Hz to 0.50Hz in the interlobar arterial channels. The review also revealed that adult humans' Doppler indices of the renal-interlobar artery agree with developed models of renal interlobar arterial blood dynamics. The mathematical model measurements of the great vessels matched the sonographic Doppler velocimetry with <15% variation. In our fast-paced world of epidemiological transition, the imperatives of mathematical modeling of arterial flow dynamics based on the Navier-Stokes equations to represent various physiologic and pathologic situations cannot be overstated. The practical consequences include the possibility of mathematical models to acquire precise WSS distribution and early detection of potential atherosclerotic sites during cardiovascular Doppler sonography.
RESUMO
Sonography has proven to be valuable diagnostic imaging equipment in the work-up of patients infected with acquired immune deficiency syndrome (AIDS) and tuberculosis (TB) coinfection. An extensive literature search was conducted between 1994 and 2021 for original peer-reviewed articles in the English language on ultrasound application in the diagnosis of extrapulmonary TB (EPTB), ultrasound application in infectious diseases in resource-constrained settings, point-of-care ultrasound in resource-scarce settings among others, across various electronic databases including MEDLINE, PubMed, POPLINE, Scopus and Google Scholar, among others and some gray literature were also retrieved. Emerging themes were identified by their recurrence in literature. Ultrasound imaging is a rapid diagnostic tool and can accurately identify and characterize pathologic findings in patients infected with HIV/AIDS and TB co-infection, such as enlarged lymph nodes, pericarditis, and pleural effusion, among others for prompt patient management. Ultrasonography is cheaper and portable; interfacing software has become more users friendly and image quality significantly improved, making it possible for the provision of imaging services in an increasing number of clinical settings in resource-limited settings where access to diagnostic imaging is scarce. The use of focused assessment with sonography for HIV (FASH) for prompt diagnosis of EPTB in regions with a high incidence of HIV/AIDS and TB co-infection will aid in prompt diagnosis and treatment of patients with undifferentiated TB, thus impacting on morbidity and mortality. The training and deployment of sonographers in endemic regions with a high prevalence of HIV/AIDS and TB co-infection, to diagnose EPTB using FASH protocol is a viable option that is in line with the global drive for intensified case finding and treatment algorithm, with a view to meeting the sustainable development goals target of ending HIV and TB epidemics and achieving universal health coverage.
