Ultrasound IMT measurement on a multi-ethnic and multi-institutional database: Our review and experience using four fully automated and one semi-automated methods

Abstract

Automated and high performance carotid intima-media thickness (IMT) measurement is gaining increasing importance in clinical practice to assess the cardiovascular risk of patients. In this paper, we compare four fully automated IMT measurement techniques (CALEX, CAMES, CARES and CAUDLES) and one semi-automated technique (FOAM). We present our experience using these algorithms, whose lumen-intima and media-adventitia border estimation use different methods that can be: (a) edge-based; (b) training-based; (c) feature-based; or (d) directional Edge-Flow based. Our database (DB) consisted of 665 images that represented a multi-ethnic group and was acquired using four OEM scanners. The performance evaluation protocol adopted error measures, reproducibility measures, and Figure of Merit (FoM). FOAM showed the best performance, with an IMT bias equal to 0.025±0.225mm, and a FoM equal to 96.6%. Among the four automated methods, CARES showed the best results with a bias of 0.032±0.279mm, and a FoM to 95.6%, which was statistically comparable to that of FOAM performance in terms of accuracy and reproducibility. This is the first time that completely automated and user-driven techniques have been compared on a multi-ethnic dataset, acquired using multiple original equipment manufacturer (OEM) machines with different gain settings, representing normal and pathologic cases.

The role of vascular biomarkers for primary and secondary prevention. A position paper from the European Society of Cardiology Working Group on peripheral circulation

“…The optimal reproducibility obtained by scanning the common carotid artery is due to the ease of acquiring good quality images at an insonification angle of 90 ; this, however, comes at the cost of missing disease that more often develops at the carotid bulb/ internal carotid artery [16]. Reading should be done with semiautomated reading software (better than automated) [17] over a 1-cm segment because of the ease of use, potential to improve ultrasound quality, and probably lower variability compared to manual measurements [15,18,19]. An alternative method with better spatial and temporal resolution is the measurement of cIMT using echo-tracking [20], however, a possible advantage of B-mode based analysis is that it can be easily used with standard highresolution ultrasound equipment.…”

Accurate cloud-based smart IMT measurement, its validation and stroke risk stratification in carotid ultrasound: A web-based point-of-care tool for multicenter clinical trial

“…Even though there are automated desktop-based intelligent cIMT systems by Suri (PI of this project) and his team, 9,11,13,14,30,48,49 this study is the first of its kind in which cIMT is measured in carotid ultrasound scans through intelligent cloud-computing, with automated analysis occurring in the cloud-based settings. The workflow is shown in Figure. 3.…”

“…Several studies [17][18][19][20] emphasized the need for an automated system for cIMT computation. This is mainly because current manual 19 or semi-automated systems 30 used by sonographers are subjective and associated with operator or observer bias. Current systems are not fully automated 30 and lack advanced image-based features for risk assessment.…”

“…This is mainly because current manual 19 or semi-automated systems 30 used by sonographers are subjective and associated with operator or observer bias. Current systems are not fully automated 30 and lack advanced image-based features for risk assessment. 31,32 Often, these systems lack reliability, accuracy, reproducibility, and provide no comparative reference marker needed for monitoring.…”

Two Automated Techniques for Carotid Lumen Diameter Measurement: Regional versus Boundary Approaches

“…The proximal and distal lumen morphologic borders are then delineated which constitute the borders of the lumen. Finally, the LD is estimated using the Polyline distance metric [36,37].…”