The parameters of the bone passage of foramen rotundum in normal adults on MSCT images

Objective To investigate the parameter ranges of the bone passage of foramen rotundum on MSCT images. Methods Clinical records of 152 non-traumatic patients (80 males aged 16-89 years and 72 females aged 17-79 years), who underwent MSCT of skulls, paranasal sinuses and eyepits from January 1, 2014 to August 20, 2014, were reviewed retrospectively. On the coronal, cross-sectional and sagittal plane images of 304 sides of the foramen rotundum, the following parameters were measured: longitudinal diameter of foramen rotundum (D), angle between the central axes of foramen rotundum and pterygopalatine fossa (B), angle between the connection of the midpoints of both sides of foramen rotundum and its central axis (A1), angle between the central axes of foramen rotundum and pterygopalatine fossa on the same side (A2), angle between the central axis of the pterygopalatine fossa and the connection of internal and external port of foramen rotundum on the same side (A3). Cross-side comparisons were made for the same gender and cross-gender comparisons were made on the same side. The coefficient of variation (CV) and the within subject CV were calculated. Reliability of the parameters measured were analyzed using correlation coefficient (ICC). Results The shape, size and direction of the foramen rotundum could be clearly seen on MSCT with images of good quality. D was (4.76±1.61) mm, and B, A1, A2, A3 were 93.13°±8.68°, 87.78°±8.64°, 134.49°±8.63°, and 160.16°±8.22°. Cross-side comparisons were made for the same gender: A1 on the right side was greater than on the left with statistically significant differences (all P values 0.05). cross-gender comparisons were made on the same side: D, A1, A2, A3 and B had no significant difference between males and females (all P values>0.05). The CV ranges of D, B, A1, A2, A3 were 31.58%-37.14%, 8.15%-9.78%, 8.35%-9.94%, 5.50%-6.74%, 4.43%-5.59%, and the within subject CV were 20.63%-21.54%, 9.13%-9.16%, 2.54%-3.77%, 2.00%-2.59%, 1.58%-2.69%, respectively. B had moderate reliability while D, A1, A2, and A3 had good reliability. Conclusions Measuring parameters of the bone passage of foramen rotundum on MSCT images has table and reliable results, which can provide references for clinical applications. Key words: Foramen rotundum; Pterygopalatine fossa; Tomography, spinal computed; Anatomy, cross-sectional