Simplified ultrasound protocol for the exclusion of clinically significant carotid artery stenosis

Figures & data

Figure 1. Carotid artery with stenosis on greyscale.

Figure 2. Carotid artery with stenosis and mosaic pattern on colour Doppler.

Table 1. Standard criteria for grading carotid stenosis in Sweden (16–18).

Systolic maximal velocity		Degree of stenosis
Angle <45°	Angle 55–60°	ECST	NASCET
<1.1 m/s	<1.3 m/s	<50%	<20%
1.1–1.6 m/s	1.3–2.2 m/s	50%–69%	20%–49%
1.7–2.0 m/s	2.3–3.1 m/s	70%–79%	50%–69%
≥2.1 m/s	≥3.2 m/s	80%–99%	70%–99%
No signal	No signal	Occlusion	Occlusion

ECST: The European Carotid Surgery Trial.

Table 2. Contingency table of ultrasound outcome.

	ICA stenosis defined by PSV measurement (NASCET)
	Normal	20%–49%	50%–69%	70%–99%	100%	Total
ICA stenosis by greyscale/mosaic measurement
Yes	238	71	16	23	4	352
No	9116	11	0	0	14	9141
Total	9354	82	16	23	18	9493