Inter-rater Reliability of 4-Item Arterial Doppler Waveform Classification System for Description of Arterial Doppler Waveforms.

Background: Non-invasive Doppler waveform (DW) analysis is a widely adopted method for detecting and evaluating lower extremity peripheral artery disease (PAD). Previous investigations have reported that broad heterogeneity in the description of Doppler waveforms is reduced by using a classification method. The reliability of arterial Doppler classification, however, is unknown. Purpose: The purpose of this study is to assess the reliability of a 4-category arterial DW classification method among Chinese sonographers. Methods: During a national ultrasound conference in China attendees were invited to classify thirty arterial Doppler waveforms. After viewing a 4-category (triphasic, biphasic, monophasic, and other) arterial Doppler waveform descriptor presentation, attendees were asked to classify 15 continuous wave (CW) and 15 pulsed wave (PW) Doppler waveforms. Their responses were recorded via mobile phone and the reliability of this 4-category classification was estimated by Fleiss' Kappa inter-rater statistical analysis. Results: One hundred and seventy-eight attendees participated in the analysis. The Kappa coefficient of Fleiss (κ) for all attendees was 0.522 (p < 0.005) with 95% confidence interval (CI): 0.520-0.523. The reliability of the waveform descriptor triphasic was the highest (κ = 0.621, p < 0.005), and other was the lowest (κ = 0.341, p < 0.005). Conclusion: The inter-rater reliability of a 4-category arterial Doppler waveform classification by Chinese sonographers is considered weak (κ = 0.522, CI95%: 0.520-0.523, p < 0.005). This study reinforces the importance of assessing DW classification reliability and the development of DW descriptors that are more accurately predictive of clinical hemodynamic events.

Interpretation of peripheral arterial and venous Doppler waveforms: A consensus statement from the Society for Vascular Medicine and Society for Vascular Ultrasound.

This expert consensus statement on the interpretation of peripheral arterial and venous spectral Doppler waveforms was jointly commissioned by the Society for Vascular Medicine (SVM) and the Society for Vascular Ultrasound (SVU). The consensus statement proposes a standardized nomenclature for arterial and venous spectral Doppler waveforms using a framework of key major descriptors and additional modifier terms. These key major descriptors and additional modifier terms are presented alongside representative Doppler waveforms, and nomenclature tables provide context by listing previous alternate terms to be replaced by the new major descriptors and modifiers. Finally, the document reviews Doppler waveform alterations with physiologic changes and disease states, provides optimization techniques for waveform acquisition and display, and provides practical guidance for incorporating the proposed nomenclature into the final interpretation report.

Heterogeneity of Doppler waveform description is decreased with the use of a dedicated classification.

BACKGROUND: The analysis of Doppler ultrasound waveforms (DW) provides a method for detecting and evaluating arterial stenosis in the lower limb arteries but no recommendation exists on how to describe the DWs. Aims of this study were to assess the heterogeneity of the description of DWs among vascular residents and the impact of the use of a 4-item classification. METHODS: Thirty different DWs were presented to residents using Microsoft PowerPoint® slides. They were invited to describe the 30 DWs before and after the presentation of a 4-item classification (triphasic, biphasic, monophasic, and others). The heterogeneity was assessed by the number of different answers used by the residents. Nineteen residents with six to eighteen months of vascular medicine training and ultrasound experience were included. RESULTS: The average of different answers was 9 ± 4 for the whole analysis of the 30 DWs without the use of a specific classification, whereas the average was 2 ± 1 using the 4-item classification (p < 0.005). There was a significant difference in correct answers, i. e. in combined continuous waveforms and pulsed waveforms between experienced residents and younger residents (p < 0.05). CONCLUSIONS: Using a 4-item classification for DWs reduced the heterogeneity of the DW description. There is an urgent need to standardize the DW description in order to improve the patients care with peripheral artery disease.

Noninvasive measurement of shear rate in autologous and prosthetic bypass grafts.

There is a major difference in thrombogenicity between lower extremity prosthetic and autologous vein bypass grafts, and arterial blood flow shear rate is known to influence thrombus formation. Despite this association, there has been little direct clinical observation of shear rates in bypass grafts. The authors developed a new noninvasive method to quantitate human arterial shear rate and used it in a pilot study to characterize differences in lower extremity bypasses. Shear rates were measured in 10 prosthetic and 14 autologous vein femoropopliteal bypass grafts. With CVI-M-mode color flow ultrasonography in resting supine patients, a velocity profile was recorded from a midgraft longitudinal section in the ultrasound beam direction. Shear rates were calculated by using a mathematical-graphic computer program at the anteromedial (near) and posterolateral (far) graft walls by averaging values immediately before and after peak systolic velocity (PSV). Comparison between prosthetic and autologous graft groups respectively revealed that differences in age (67 +/- 12 [SD] vs 71 +/- 10 yr), male gender (60% vs 43%), prevalence of hypertension (50% vs 71%), diabetes (40% vs 64%), smoking (50% vs 50%), hypercholesterolemia (30% vs 29%), coronary artery disease (60% vs 50%), and critical ischemia (60% vs 86%) did not reach statistical significance (p>0.19). Median PSVs were significantly less in prosthetic than in autologous vein bypasses (37 +/- 13 vs 57 +/- 22 cm/s, p=0.018). Prosthetic and autologous graft diameters were not statistically significantly different (6.3 +/- 1.1 vs 5.6 +/- 1.3 mm, p = 0.18). Shear rates were significantly less in prosthetic than in autologous vein bypasses both at the near wall (382 +/- 146 vs 698 +/- 271 s(-1), p=0.003) and at the far wall (551+/-235 vs 827+/-339 s(-1), p-0.037). This mathematical model can be used to calculate shear rate from observed ultrasound flow patterns. Prosthetic bypass grafts had lower shear rates than autologous vein grafts.