Digital-image analysis of the rhomboid fossa surface

Forty brainstems were investigated in order to evaluate morphological and morphometrical variability of the 4th ventricle floor. Visibility evaluation of the following rhomboid fossa structures: striae medullares, facial colliculus, superior fovea, vestibular area, sulcus limitans, incisure, medial eminence, median sulcus, vagal triangle, hypoglossal triangle and obex was performed. Obex, median sulcus, vestibular area, vagal and hypoglossal triangles were found to be sufficiently visible in all specimens. Facial colliculus was poorly visible in 37% of the examined brainstems. Striae medullares were invisible in 30% of the analysed material and exhibited individual variability of a high degree in relation to their number and arrangement. Morphometrical study showed measured distances to be individually variable with a relatively low coefficient of variation of approximately 10%.