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Doppler waveform analysis is a fundamental part of evaluating peripheral arterial disease. Waveform characteristics are traditionally defined as multiphasic (triphasic, biphasic) and monophasic. The purpose of this investigation is to evaluate whether sonography professionals correctly classify waveforms into these three categories. Thirty Doppler waveforms (15 continuous-wave [CW] and 15 pulsed-wave [PW] Doppler) were obtained from patients with previous noninvasive peripheral arterial evaluations. Participating readers were asked to interpret waveforms as triphasic, biphasic, or monophasic using standard definitions. 'Other' was used to classify waveforms whose morphology could not be determined or accurately classified as triphasic, biphasic, or monophasic. Because multiphasic waveforms with pandiastolic flow have been associated with biphasic and monophasic waveform terminology, answer key responses were based on waveform descriptors used by interpreters of the originating noninvasive evaluation. There were a total of 97 participants, and of all Doppler waveforms, 73% were correctly identified (75% CW and 71% PW). Participants training or specializing in medical sonography misidentified an average of 27% triphasic, biphasic, or monophasic CW and PW Doppler waveforms and correctly interpreted more CW than PW waveforms. Because there is considerable variability among sonography professionals and educators in defining and classifying peripheral arterial waveforms, this issue deserves higher priority. [ABSTRACT FROM AUTHOR]

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., (Copyright © 2020 Zhao, Lanéelle, Gao, Fu, Tong, Scissons, Wen and Mahé.)

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.

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.

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.

Previous research has suggested that arterial aneurysm might result from a systemic tendency to dilatation. This systemic effect would involve both arterial and venous dilatation. The authors investigated whether venous grafts implanted to bypass popliteal artery aneurysms (PAA) had larger diameters than those implanted to treat peripheral arterial occlusive disease (PAOD). They compared representative diameters of 20 vein grafts implanted for PAA with matched bypass grafts implanted for PAOD. Graft diameters were obtained by means of CVI-Q M-mode ultrasound imaging. Each PAA patient/graft was matched to an equivalent PAOD patient/graft based on the patient's gender and age and the vein graft type and distal anastomosis. Secondarily, graft proximal anastomosis was matched in 60% (12/20) of the cases. Age was matched if the difference was < or = 4 years. Average age at the time of surgery was 68 +/-12 years for PAA and 68 +/-13 for PAOD groups. There were 11 reversed greater saphenous vein (GSV), 2 nonreversed GSV, and 7 in situ GSV in each group. Distal anastomoses were at the popliteal (15), peroneal (3), posterior (1), and anterior tibial (1) arteries in each group. Matching was not possible for lesser saphenous and cephalic vein grafts or bypasses to the tibial-peroneal trunk. Graft diameters were significantly larger for the PAA group, 6.24 +/-0.66 mm (standard deviation), than for the PAOD group, 5.73 +/-0.69 mm (p < 0.02, Mann-Whitney U test). Of 10 bypasses with diameter >6.5 mm, 8 were implanted for PAA. If these 10 largest bypasses were eliminated from the calculations, the mean graft diameters were 5.82 +/-0.51 mm and 5.57 +/-0.52 mm for the PAA and PAOD groups, respectively (p = 0.28). Bypass grafts implanted in PAA patients had significantly greater diameters than grafts implanted in PAOD patients. This finding, however, was due to a subgroup of grafts with diameters >6.5 mm. Perhaps systemic abnormalities associated with PAA should be first studied in patients with large vein grafts or large original veins.

Purpose: Management decisions regarding carotid artery disease are critically dependent on stenosis but have been made difficult because of conflicting methods used to determine such stenosis. The increasing use of duplex ultrasound scanning has conventionally depended on Doppler velocity measurement, an indirect method for calculating carotid stenosis. Recent technical advances have improved the quality of B-mode/color-flow ultrasound scan imaging (USI). We tested prospectively whether USI was clinically effective as the primary criterion for estimating carotid stenosis., Methods: Transverse and longitudinal USI, Doppler velocity, and arteriography data were obtained sequentially and independently for 713 carotid bifurcations. The internal carotid artery (ICA) residual lumen, the local outer diameter at the stenotic site, and the diameter distal to the bulb were measured in a representative USI longitudinal section. The peak systolic velocity and the end diastolic velocity (EDV) were measured at the stenosis. Local stenosis as determined with USI was compared with the x-ray arteriographic clinical radiology interpretation (XRI). As the primary method, radiologists compared the residual lumen with the distal ICA diameter, as recommended by the North American Symptomatic Carotid Endarterectomy Trial and the Asymptomatic Carotid Atherosclerosis Study. Analysis was by means of the USI positive predictive value (PPV) and negative predictive value (NPV) of the XRI findings, with the assumption that 80%, 70%, and 60% local stenosis with USI related to 70%, 60%, and 50% stenosis with XRI, respectively., Results: All 56 ICA occlusions as determined with USI were confirmed with XRI. When the USI showed 80% to 99% stenosis, the PPV of the XRI showing 70% to 99% stenosis was 94% (116/123). Two ICAs that were shown to be severely diseased with USI appeared to be occluded with XRI. For <50% stenosis shown with USI, the prediction of <50% stenosis shown with XRI was 94% (253/269). For borderline stenosis in the 50% to 79% range with USI, the addition of velocity criteria to USI data improved both the PPV and the NPV. In the range of 70% to 79% stenosis with USI, the PPV improved from 82% (76/93) to 91% (53/58) for the subgroup with an EDV of more than 80 cm/s. For the range of 60% to 69% stenosis with USI, the PPV improved from 75% (71/95) to 95% (21/22) for the subgroup with an EDV of more than 80 cm/s. In the range of 50% to 59% stenosis with USI, the NPV improved from 69% (53/77) to 93% (14/15) for the subset with a peak systolic velocity of less than 100 cm/s., Conclusion: On the basis of the USI data alone, a prediction of arteriographic findings was possible at the 95% level for occlusion and severe stenosis and for ruling out hemodynamically significant stenosis. The addition of velocity data improved prediction in borderline degrees of stenosis. USI was effective for quantifying clinically significant degrees of stenosis.

Purpose: Physiologic observations with blood flow waveform analysis and pressure measurements can document the severity of lower extremity arterial disease. Segmental blood pressures (SEGPs) taken at the thigh, calf, and ankle are commonly used, but their utility has seldom been studied. We quantified improvements in accuracy compared with arteriography when ankle pressures alone (ABI) or SEGP data were added to velocity waveforms obtained by Doppler ultrasound., Methods: Continuous-wave Doppler velocity waveforms were recorded at common femoral (CFA), popliteal (POP), and dorsal pedal and posterior tibial (TIB) arterial levels. Systolic SEGP data were obtained with appropriately sized upper thigh, upper calf, and ankle cuffs. Waveforms, waveforms plus ABI, and waveforms plus SEGP data from 81 patients were randomly interpreted by 14 technologists or physicians from four institutions blinded to clinical and arteriographic data. Arteriograms were assigned negative or significant, severe (>75% diameter stenosis) values for four segments: iliofemoral (CFA), superficial femoral (SFA), popliteal (POP), and infrapopliteal (TIB) arteries. A total of 9072 segmental interpretations were analyzed., Results: Compared with arteriography, the accuracy of waveform analysis was 83% for severe disease at and proximal to the CFA, 79% for SFA disease, 64% for POP disease, and 73% for TIB disease. Adding ABI improved the accuracy significantly (p < 0.01) to 88% (CFA), 86% (SFA), 70% (POP), and 85% (TIB). Accuracy was inferior when SEGP data replaced ABI: 86% (CFA), 85% (SFA), 70% (POP), and 80% (TIB)., Conclusions: ABIs significantly improved Doppler waveform accuracy at all levels. Compared with ABI, the addition of segmental pressure to waveform data failed to improve accuracy. Pressure measurements above the ankle may lack cost effectiveness and clinical utility.

Purpose: We observed that ultrasound examinations for deep venous thrombosis (DVT) were more frequently requested for women than for men in our vascular laboratory serving a general outpatient population and referral 774-bed hospital. Because existing literature presents conflicting information about sex differences in occurrence of DVT, we investigated correlation in our population with positive ultrasound study results and risk factors for DVT., Methods: In 13 months, 2055 ultrasound examinations for DVT were requested. Of these, 300 patients (15%) were categorized in four subgroups: 75 ultrasonography-negative men, 75 ultrasonography-negative women, 75 ultrasonography (DVT)-positive men, and 75 ultrasonography (DVT)-positive women for risk factor analysis., Results: Women comprised 64% (1311 of 2055) and men 36% (744 of 2055) of ultrasound examinations requested, but men had significantly higher incidence of DVT-positive ultrasonography results (101 of 744 [14%]) compared with women (118 of 1311 [9%]) (p = 0.002 by chi-square testing). There were no significant sex differences in conventional DVT risk factors and no difference in aggregate number of risk factors. The anatomic distribution of DVT was the same in men as in women. Among those having negative ultrasonography results, significantly more outpatient examinations were performed in women (p = 0.018 by t testing)., Conclusions: Gender bias exists in use of ultrasonography for diagnosis of DVT. The greater incidence of women undergoing venous ultrasonography is not explained by higher prevalence of DVT risk factors or of higher occurrence of positive ultrasound examination results. Further investigation is needed to determine whether these differences indicate underuse of ultrasonography in men or overuse in women.