Validity and Reliability of Point-of-Care Ultrasound for Detecting Moderate- or High-Grade Carotid Atherosclerosis in an Outpatient Department

Figures

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  Figure 1. Two types of carotid plaque scores obtained using B-mode ultrasound. (A) sCPSs were calculated by counting the number of areas of the bilateral carotid arteries (the CCA, carotid bifurcation, and proximal ICA) with 1 or more plaques (arrows; presence = 1; absence = 0), with total scores ranging from 0 to 6. (B) hCPSs were computed by summing the maximal plaque thickness (in millimeters) in segments (a) S1 (region of ICA < 15 mm distal to bifurcation), (b) S2 (region of ICA and CCA < 15 mm proximal to bifurcation), (c) S3 (region of CCA 15–30 mm proximal to bifurcation), and (d) S4 (region of CCA > 30 mm proximal to bifurcation) on both sides. BIF, bifurcation; CCA, common carotid artery; ECA, external carotid artery; hCPS, Handa’s carotid plaque score; ICA, internal carotid artery; sCPS, simplified carotid plaque score.

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  Figure 2. Flowchart of patient enrollment. OPD, outpatient department; POCUS, point-of-care ultrasound. ICA, internal carotid artery.

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  Figure 3. Carotid ultrasound of a 91−year−old woman. Her outpatient sCPS, laboratory sCPS, and laboratory hCPS were 6, 6, and 19.5, respectively. (A) Segmental heteroechogenic plaques (arrows) were detected in the right carotid bifurcation (BIF) and internal carotid artery (ICA) through transverse (upper left) and longitudinal (upper right) POCUS performed in the outpatient department. Laboratory sonography revealed the same segmental plaques more clearly with various plaque thickness (lower left). Color duplex sonography indicated an elevated peak systolic velocity in the ICA (lower right). (B) Segmental plaques (arrows) were detected in the left carotid BIF and ICA through transverse (upper left) and longitudinal (upper right) approach POCUS. Laboratory sonography indicated more segmental plaques extending to the common carotid artery (lower right). BIF, right carotid bifurcation; hCPS, Handa’s carotid plaque score; ICA, internal carotid artery; POCUS, point-of-care ultrasound; sCPS, simplified carotid plaque score.

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  Figure 4. Distributions of the participants’ hCPS based on initial carotid risk scores. The patients with a carotid risk score of >12 had a higher hCPS than did those with a carotid risk score of ≤12.

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  Figure 5. Discrepancy in implified carotid plaque score (sCPS) between the outpatient and laboratory measurements.

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  Figure 6. Participants’ outpatient and laboratory simplified carotid plaque scores. (A) Bland−Altman plots indicate that the mean differences in the participants’ outpatient and laboratory-derived sCPSs were within ±2 standard deviations of their laboratory sCPSs. The blue continuous line labeled as “mean” indicates the bias, the red dashed lines labeled as “1.96 SD” indicate the level of agreement, and the green bars indicate the 95% confidence interval. (B) Spearman’s rank correlation coefficient plots revealed a strong linear correlation between the outpatient and laboratory-derived sCPSs. (C) Intraclass correlation coefficient analysis revealed excellent reliability between the outpatient and laboratory sCPSs. sCPS, simplified carotid plaque score.