Fig 1.
Example of quantitative angiography analysis.
Red lines represent the reconstructed reference contours (positioned along the vessel segment), while the yellow area represents the plaque. In this particular angiographic case, the obstruction diameter was 1.17 mm, and the reference diameter at the narrowing was 3.46 mm, yielding a percentage diameter stenosis of 66%.
Fig 2.
Example of triphasic waveforms measured in the normal distal tibial artery and schematic representation of the principle acceleration algorithm.
A) Waveforms captured within 15 seconds in pulsed-wave mode. The blue line demonstrates the digital contour produced by the modified geometric method. B) Digitalized contoured curves are presented. The blue cross shows the maximal slope of the systolic phase. C) The ensemble of the velocity-curve is shown as a green line, where each point is based on the arithmetic average of the velocity values. The black cross shows the maximal slope of the systolic phase on the ensemble curve.
Table 1.
Baseline characteristics of study participants, stratified by presence/absence of diabetes.
Fig 3.
Comparison of hemodynamic values between different waveform subgroups from all patients.
A) Comparison of ACCmax values between different waveform subgroups. B) Comparison of RPSI values between different waveform subgroups. C) Comparison of ABI values between different waveform subgroups. I: physiological; II: fine monophasic; III: weak monophasic; IV: weak monophasic with diastolic forward flow. ***p < 0.001.
Fig 4.
Comparison of ABI, ACCmax and RPSI values between the no-PAD and PAD group in all patients as well as those with and without diabetes.
ABI: ankle-brachial index; ACCmax: systolic maximal acceleration, RPSI: relative pulse slope index. Data presented as medians with IQR, minimum and maximum values. Values stated are medians and IQRs. Medians were significantly different between PAD and no-PAD subgroups for all comparisons (p < 0.05).
Fig 5.
Correlation between novel parameters (ACCmax and RPSI) and ABI/percentage stenosis in patients with and without diabetes (quantitative evaluation).
ABI, ankle-brachial index; ACCmax: systolic maximal acceleration, RPSI: relative pulse slope index; PAD, peripheral artery disease. Patients with PAD and MAC can be observed as blue points in the area of ABI ≤ 0.90, presenting with lower positive ACCmax and RPSI values. Patients without PAD but with MAC can be observed as red points in the area of ABI ≥ 1.30, presenting with extraordinarily high ACCmax values. *** p < 0.001.
Fig 6.
ROC curves for ACCmax, ABI and RPSI.
AUC, area under the curve; ABI, ankle-brachial index; ACCmax: systolic maximal acceleration, RPSI: relative pulse slope index; RS, risk score. *p < 0.05; **p < 0.01; ***p < 0.001.
Table 2.
ROC analysis for RPSI, ACCmax, and ABI.
Fig 7.
Comparison of the diagnostic sensitivity, specificity, and accuracy of the parallel test and ABI methods in patients with diabetes (limbs = 160) and in those without diabetes (limbs = 150).
ABI, ankle-brachial index.