Data from: Reliability of a New Semi-automatic Image Analysis Method for Evaluating the Doppler Signal and Intratendinous Vascular Resistance in Patellar Tendinopathy

The aim of this study was to study the intra e inter-rater reliability of a new semi-automatic image analysis method for the quantification of the shape of the Doppler signal and the intratendinous vascular resistance in patellar tendinopathy.Thirty athletes (27.4 years; SD: 8.57 years) with patellar intratendinous vascularity were included in a cross-sectional study (42 tendons analysed). The intratendinous blood flow was assessed by Power Doppler and the quantification ImageJ software (v.1.50b) over manual selected ROI. Two blinded observers perform the analysis of the Doppler signal (vascular index vascular resistance) and shape descriptors (number of signals, pixel intensity, area, perimeter, major diameter, minor diameter, circularity and solidity). The intraclass correlation coefficient (ICC) was calculated also the Bland-Altman’s mean of differences (MoD) and limits of agreement (LOA) were determined. Also, small real differences (SRD) and standard error of measurement (SEM) was calculated. The intra-rater reliability was maximum for area (ICC=0.999; 95%CI=0.998-0.999) and minimum for solidity (ICC=0.782; 95%CI: 0.682 - 0.853). The MoD and the LoA were very low and the relatively SRD and SEM were below 5.3% and 2% respectively. The inter-rater reliability was maximum ICC was for area (ICC= 0.993; 95%CI=0.989-0.996) and the minimum for circularity (ICC= 0.73; 95%CI=0.611-0.817). The MoD and the LoA were low, with SRD and SEM below of 6% and 2.2%. The reliability of the proposed quantitative method to study the intratendinous Doppler signal in patellar tendon is reliability and reproducibility.