Ultrasonographic imaging of mycetoma.

Abstract

The ultrasonographic appearance of mycetoma is described in this prospective study. One hundred patients with foot swellings had sonographic evaluation of the swelling and surgical excision within 2 weeks of ultrasonography. The histopathological findings were compared with the preoperative images. Some of the excised swellings and grains were also imaged and compared with the in vivo findings. The mycetoma grains, their capsules and the accompanying inflammatory granulomas have characteristic ultrasonographic appearances. In eumycetoma lesions, the grains produce numerous, sharp hyper-reflective echoes and there are single or multiple thick-walled cavities with no acoustic enhancement. In actinomycetoma, the findings are similar but the hyper-reflective echoes are fine, closely aggregated and commonly settle at the bottom of the cavities. None of the non-mycetoma foot swellings (which included lipoma, ganglion, foreign body granuloma and others) studied had these features. Ultrasonography is simple, non-invasive, quick, reproducible and acceptable to patients. Mycetoma has characteristic ultrasonographic features. Furthermore, ultrasonography delineates the extent of mycetoma more accurately than clinical examination alone.