Validity and Reliability of New Intravascular Ultrasound Analysis Software for Morphological Measurement of Coronary Artery Disease

Background: Intravascular ultrasound (IVUS) analysis software enables precise planimetry measurement and tissue characterization of coronary plaque. Recently, a new IVUS analysis software compatible with integrated backscatter-IVUS, VISIATLASTM, was developed. The validity and reliability of VISIATLASTM were evaluated. Methods and Results: Forty patients who underwent IVUS-guided percutaneous coronary intervention were enrolled, and planimetry measurements were performed by 2 observers using VISIATLASTM and echoPlaqueTM. IVUS analysis was performed in non-stent segments in 10 patients (non-target vessel, n=5; target vessel before stent implantation, n=5) at every 2.5mm for 20 slices in each patient. Stent segments were analyzed in the remaining 30 patients. With VISIATLASTM, the intraobserver and interobserver intraclass correlation coefficients (ICC) for the area of external elastic membrane (EEM), lumen, and plaque plus media (P+M) were 0.999 and 0.999, 0.996 and 0.993, and 0.993 and 0.991, respectively. The intersoftware ICC for EEM, lumen, and P+M area were 0.997, 0.993, and 0.985, respectively. The ICC of stent volume for intraobserver, interobserver and intersoftware comparisons were 0.997, 0.993, and 0.998, respectively. Bland-Altman plots showed small differences and narrow limits of agreement for all of the above parameters. Conclusions: VISIATLASTM has high repeatability and reproducibility of measurement. This new IVUS analysis software is suitable for accurate measurement of coronary artery and stent structure in future IVUS studies.  (Circ J 2013; 77: 424–431)