Non-echo planar imaging diffusion-weighted imaging (nEPID) is a useful tool for diagnosing middle ear cholesteatoma. The cut-off value of nEPID has not yet been determined, however, as fused thin-slice nEPID and computed tomography (nEPID-CT) color imaging cannot correctly distinguish cholesteatoma from other soft tissue. We examined the detectability of cholesteatoma with nEPID using nEPID-CT color images obtained as preoperative studies. The appropriate cut-off value of the signal intensity ratio on nEPID is 0.925 on the receiver operating characteristic (ROC) curve with Youden’s index. Here, we evaluate the efficacy of nEPID-CT color images based on this nEPID cut-off value.