Among the 50 patients studied, CT and MRI yielded concordant findings in 30 cases, with both modalities demonstrating a similar number and distribution of peritoneal lesions. However, in 15 patients, MRI identified additional lesions or revealed differences in lesion location that were not evident on CT, leading to a reclassification of disease stage. In five patients, lesions were exclusively detected by MRI, having been completely missed on CT. Notably, the combined use of DWI and T1 out-of-phase sequences was crucial not only for detecting subtle lesions—particularly in fat-containing regions or in lesions with low cellularity—but also for identifying invasion of adjacent structures, such as the bowel wall.