Diagnostic accuracy and reading time to detect intracranial aneurysms on MR angiography using a computer-aided diagnosis system

OBJECTIVE. The objective of our study was to determine whether the use of a computer-aided diagnosis (CAD) system can shorten the reading time while maintaining the diagnostic performance of MR angiography for the detection of intracranial aneurysms. MATERIALS AND METHODS. Fifty maximum-intensity- projection MR angiograms in 50 patients (16 intracranial aneurysms and 34 negative cases) were used for this observer performance study. Sixteen radiologists - eight neuroradiologists and eight less experienced radiologists - participated in the observer studies and interpreted the MR angiograms without and with CAD output images using an independent test method. The reading times without and with CAD were compared separately for the aneurysm and negative cases. The observers' performances were evaluated using receiver operating characteristic (ROC) analysis. We analyzed separately the data obtained from neuroradiologists and from less experienced radiologists. RESULTS. For all observers, the mean area under the ROC curve (A_z) with CAD was improved compared with that without CAD (0.903 vs 0.851, respectively; p = 0.109), and the mean reading time per case was reduced significantly by 18.1 seconds (28.5%) (from 63.4 to 45.3 seconds, p < 0.05). When CAD output images were available, the mean A_z for the less experienced radiologists was significantly improved (0.911 vs 0.787, p < 0.05), but not for the neuroradiologists. The mean reading time of the less experienced radiologists with CAD was significantly shorter than that of the neuroradiologists without CAD (39.8 vs 54.5 seconds, p < 0.05). CONCLUSION. The use of a CAD system for the detection of intracranial aneurysms on MR angiography can shorten the reading time while improving diagnostic performance for less experienced radiologists.