@article {Borst1978, author = {J. Borst and H.A. Marquering and M. Kappelhof and T. Zadi and A.C. van Dijk and P.J. Nederkoorn and R. van den Berg and A. van der Lugt and C.B.L.M. Majoie}, title = {Diagnostic Accuracy of 4 Commercially Available Semiautomatic Packages for Carotid Artery Stenosis Measurement on CTA}, volume = {36}, number = {10}, pages = {1978--1987}, year = {2015}, doi = {10.3174/ajnr.A4400}, publisher = {American Journal of Neuroradiology}, abstract = {BACKGROUND AND PURPOSE: Semiautomatic measurement of ICA stenosis potentially increases observer reproducibility. In this study, we assessed the diagnostic accuracy and interobserver reproducibility of a commercially available semiautomatic ICA stenosis measurement on CTA and estimated the agreement among different software packages.MATERIALS AND METHODS: We analyzed 141 arteries from 90 patients with TIA or ischemic stroke. Manual stenosis measurements were performed by 2 neuroradiologists. Semiautomatic measurements by using 4 methods (3mensio and comparable software from Philips, TeraRecon, and Siemens) were performed by 2 observers. Diagnostic accuracy was estimated by comparing semiautomatic with manual measurements. Interobserver reproducibility and agreement between different packages was assessed by calculation of the intraclass correlation coefficient and Bland-Altman 95\% limits of agreement. False-negative classifications were retrospectively inspected by a neuroradiologist.RESULTS: There was no significant difference in the diagnostic performance of the 4 semiautomatic methods. The sensitivity for detecting >=50\% and >=70\% degree of stenosis was between 76\% and 82\% and 46\% and 62\%, respectively. Specificity and overall diagnostic accuracy were between 92\% and 97\% and 85\% and 90\%, respectively. The interobserver intraclass correlation coefficient was between 0.83 and 0.96 for semiautomatic measurements and 0.81 for manual measurement. The limits of agreement between each pair of semiautomatic packages ranged from -18\%{\textendash}24\% to -33\%{\textendash}31\%. False-negative classifications were caused by ulcerative plaques and observer variation in stenosis and reference measurements.CONCLUSIONS: Semiautomatic methods have a low-to-good sensitivity and a good specificity and overall diagnostic accuracy. The high interobserver reproducibility makes semiautomatic stenosis measurement valuable for clinical practice, but semiautomatic measurements should be checked by an experienced radiologist.ICCintraclass correlation coefficient}, issn = {0195-6108}, URL = {https://www.ajnr.org/content/36/10/1978}, eprint = {https://www.ajnr.org/content/36/10/1978.full.pdf}, journal = {American Journal of Neuroradiology} }