Figure 4.

Changes to the true positive rate (y-axis, TPR) and false positive rate (x-axis, FPR) for each individual reader for KL > 0, KL > 1, JSN > 0, sclerosis OARSI grade >0, sclerosis OARSI grade >1, and osteophyte OARSI grade >0. Red line denotes the ROC curve of KOALA of the dataset. Arrows point from the unaided to the aided modality. Arrows pointing upward and left are absolute improvements in detection ability. Note that even though some arrows point downward and left, the improvement in FPR is greater than the loss in TPR, representing a net increase in accuracy. KL, Kellgren-Lawrence; JSN, joint space narrowing; OARSI, Osteoarthritis Research Society International; ROC, receiver operating characteristic; AUC, area under the ROC curve.