Digital quantification eliminates intraobserver and interobserver variability in the evaluation of coronary artery stenosis

• Published in: The American journal of cardiology Vol. 56; no. 12; pp. 718 - 723
• Main Authors: Vas, Ran, Eigler, Neal, Miyazono, Calvin, Martin Pfaff, J., Resser, Kenneth J., Weiss, Mason, Nivatpumin, Thasana, Whiting, James, Forrester, James
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-11-1985; Elsevier
• Subjects: Angiography - methods; Biological and medical sciences; Cardiology. Vascular system; Computers; Coronary Disease - diagnostic imaging; Coronary heart disease; Heart; Humans; Medical sciences; Human; Intravenous administration; Radiodiagnosis; Variability; Coronary artery; Stenosis; Cardiovascular disease; Digital processing; Coronary arteriography; Coronary heart disease; Intraindividual comparison; Interindividual comparison; Computerized processing; Observation; Electronic subtraction
• ISSN: 0002-9149; 1879-1913
• DOI: 10.1016/0002-9149(85)91122-1

A leading problem with subjective interpretation of coronary angiography is high intraobserver and interobserver variability. Four experienced angiographers independently determined percent diameter narrowing of 36 stenoses using 3 methods: by subjective analysis of single-frame cine film images (film), by subjective analysis of digitized nonenhanced single-frame images (digital), and by using a semiautomated digital caliper quantification system (Corona). The reproducibility of interpretations was assessed by comparison of estimated intraclass correlation coefficients. Digital and Corona readings correlated well with subjective interpretation of film (r > 0.85 for both). In contrast to Corona, the angiographers systematically overestimated the magnitude of stenoses in the intermediate (50 to 75%) range. Corona markedly improved intraobserver (p < 0.005) and interobserver (p < 0.001) reproducibility. Corona less frequently misclassified individual observations than did film when categories of less than 50%, 50 to 75% and more than 75% diameter stenosis were used (3.7% vs 31.5%, p < 0.001). Our results suggest that digitization of a coronary angiogram in a 512 × 512 matrix has no significant adverse effects on the perception and quantification of stenosis by angiographers. Additionally, automatic measurement of coronary stenosis has 2 major advantages: It is accurate compared with a group of experienced angiographers and for the practical purpose of clinical decision-making, it eliminates intraobserver and interobserver variability.