Nowadays the multilayer computed tomography shots with contrast dye used for detection of small pathological growth are widespread in medical clinics. Although, tomography study with contrast dye use has contraindications and is much more expensive for patients than study without use of dye. This article proposes data processing method based on segmentation of multilayer computed tomography shots without use of dye. The method allows to automatically identify pathological growths and to detect studying object areas. The software, developed according to this method, evaluates parameters of small objects and sinuses, which occupy only small part of initial computed tomography layers, with high accuracy.