RESUMEN
BACKGROUND: Actinomycetoma is a chronic infection caused by several aerobic actinomycetes; it is a relatively frequent condition in tropical countries like Mexico. It is important to be aware of the extension and depth of the disease (bone and visceral) to make the prognosis and select treatment. OBJECTIVES: Our objective was to evaluate actinomycetomas using helical computed tomography (HCT) as well as its three-dimensional (3D) reconstruction. MATERIAL AND METHODS: Prospective study of clinically and microbiologically proven cases of actinomycetomas, all of them recently diagnosed and untreated or unresponsive to various treatments. All patients underwent simple and contrast HCT with various helical slices of the involved zones. Then three-dimensional reconstructions on the sagittal and coronal planes were made. RESULTS: Twenty-one patients with actinomycetomas were included, 19 males and two females, with a mean age of 35.5 years and mean duration of disease of 4.1 years. The disease was located in the lower limbs in 81%, and in the upper limbs and trunk in 19%. Twenty of the 21 cases were caused by Nocardia brasiliensis and one by Actinomadura madurae. In all patients the disease was localized to the skin and subcutaneous tissue; 76.2% had muscular involvement; 23.8% visceral involvement; 9.5% had bone involvement and 9.5% vascular involvement. The affected area was determined in each case. CONCLUSIONS: HCT provides precise information about the grade of invasion at diverse levels such as visceral, muscular and vascular systems, and the calculation of the affected area.