A comprehensive scoping review of existing carotid duplex ultrasound scanning and reporting protocols: identifying gaps and opportunities for standardization of practice in low-income countries.

Background: Duplex carotid ultrasound is a non-invasive imaging test that is essential for assessing carotid artery disease, particularly in determining the presence and severity of atherosclerosis and the risk of cerebrovascular events. However, the interpretation of ultrasound results can differ widely due to variations in diagnostic criteria, lack of standardization in scanning methods, and differing approaches to evaluating carotid intimal medial thickness (CIMT), plaques, and stenosis. These inconsistencies create challenges in clinical practice and the reproducibility of results. While various protocols for CIMT, plaque measurement, and stenosis grading are available in the literature, a standardized global protocol is still lacking. This article presents a scoping review of current carotid duplex ultrasound scanning and reporting protocols. It aims to identify existing protocols and guidelines for carotid ultrasound scanning and reporting, highlight variations, and propose a standardized approach to enhance diagnostic accuracy and clinical outcomes in carotid atherosclerosis.

Methods: Using predefined search protocols developed in collaboration with the specialized librarian from the University of Pretoria, we searched different databases and gray literature to identify existing protocols on carotid ultrasound including scanning technique, carotid intimal medial thickness, carotid plaques, and carotid stenosis grading. Due to limitations in the length of the review, and the existence of a large number of protocols, this review focused on the protocols developed and published by institutions and professional societies rather than individual articles.

Results: Among 2496 articles identified from databases and 22 from other sources, 17 articles met the criteria for this review. The most common criteria that was found following this review are those established by the Society of Radiologists in Ultrasound (SRU) in 2003. The researchers further noted that these criteria were, however, been criticized for relying heavily on peak systolic velocities, a measurement that, when used alone, can be misleading. Literature further demonstrated that other researchers and professional societies have called for consensus on unified criteria for the diagnosis of carotid atherosclerosis.

Conclusion: While carotid ultrasound is an important, non-invasive, and widely available method for evaluating carotid atherosclerosis, the variations in scanning techniques, measurements, and cut-off values underscore the need for standardized diagnostic criteria. Standardization is essential to provide consistent patient care and ensure accurate examination in various clinical settings. This will lead to the reduction of stroke and cardiovascular incidence which are the leading causes of death worldwide and more prevalent in low-income countries.