Figure 5b. Tubo-ovarian actinomycosis in a 52-year-old woman. The TOA has a predominantly solid appearance. (a) Contrast-enhanced CT scan shows a solid mass in the left adnexal region (solid arrows). Multiple air bubbles (arrowheads) and rim-enhancing lesions (open arrow) are seen in the mass. (b) Axial T2-weighted MR image shows that the mass (arrows) has low signal intensity with some regions of high signal intensity. (c) Axial contrast-enhanced fat-suppressed T1-weighted MR image shows good enhancement of the mass. The small cystic lesions with enhancing rims (black arrows) are clearly visible inside the mass. The cystic lesion in the right adnexal region (white arrows) is an incidentally found hemorrhagic cyst of the right ovary.