QUANTIFICATION OF INTRAMURAL CALCIFICATION IN CORONARY INTRAVASCULAR ULTRASOUND IMAGES WITH AUTOMATED IMAGE-ANALYSIS

Background Recent studies have documented the utility of intravascular ultrasonography in quantifying coronary morphologic characteristics a nd determining an appropriate intervention. Unfortunately, its potenti al for quantifying lesion calcification is limited by subjective evalu ation and manual tracing. The aim of this study was to develop an obje ctive automated method for quantifying calcification in intracoronary images with digital image analysis. Methods images of human coronary a rteries acquired with a 30 MHz intracoronary ultrasound catheter were evaluated with digital image analysis and compared with manual tracing s. Calcifications were automatically identified as highly echogenic re gions detected by global thresholding within sectors of acoustic shado wing defined as regions devoid of texture. Results The mean percentage agreement, sensitivity and specificity of detecting calcification in 1-degree sectors of calcified vessels were 82%, 73%, and 87%, respecti vely. Similar results were obtained in noncalcified images. Conclusion The accuracy of this automated technique was comparable to interopera tor and intraoperator variability in manually tracing calcification.