The mycetoma lesions, its capsule and the accompanying inflammatory granuloma have characteristic ultrasonic appearances. Ultrasound imaging can differentiate between eumycetoma and actinomycetoma and between mycetoma and other non-mycetoma lesions. In eumycetoma lesions, the grains produce numerous sharp bright hyperreflective echoes, which are consistent with the black grains. The grain cement substance is most probably the origin of these sharp echoes. In addition, there are multiple thick walled cavities with absent acoustic enhancement. In actinomycetoma lesion, the findings are similar but the grains are less distinct. This may be due to their smaller size and consistency, individual embedding of the grains or the absence of the cement substances in few of them.
The ultrasonic diagnosis of mycetoma is more precise and accurate in lesions with no sinuses. The extent of the lesion can be accurately determined ultrasonically and this is useful in planning surgical incisions and procedures.