Expertise with MSCT-CA takes time

Multislice CT coronary angiography is becoming a practical alternative to conventional angiography. Physicians experienced with technique are able to diagnose coronary stenoses of 50% or greater with very high sensitivity and specificity, but acquiring the expertise is time-consuming.

A study to evaluate the effects of experience with multislice coronary CTA on the ability to detect stenoses involved three radiologists and one cardiologist inexperienced with the technique. They attended an MSCT unit for a one-year fellowship where they interpreted 12 to 15 coronary CTA scans per week. The same cases were also interpreted by two experts.

To assess progression in diagnostic performance, the fellows were asked to interpret 50 test cases as beginners, after two months, after six months, and at the end of the year-long fellowship. After six months, their sensitivity ranged from 59% to 79%, specificity from 73% to 83%, and the diagnostic odds ratio from 6 to 12. After one year, sensitivity ranged from 66% to 75%, specificity from 87% to 92%, and the diagnostic odds ratio from 15 to 26. The sensitivity of expert readers was 95%, specificity was 93%, and their diagnostic odds ratio was 256.

"It might take more than one year for a beginner to evaluate images as an expert," said lead author Dr. Francesca Pugliese of the radiology department at Erasmus MC University Medical Center Rotterdam in the Netherlands.