Sella Turcica Dimension and Shape in Trisomy 21: A CT Examination.

Objective: The aim of the study was to compare the morphologic features of the sella turcica (ST) in patients with trisomy 21 (T21) with a control group.

Methods: This retrospective study contained computed tomography images of 45 T21s and 53 controls. Of 45 T21s patients aged 10.31±3.92 years, 21 were females and 24 were males. Of 53 controls aged 12.11±3.91 years, 26 were females and 27 were males. ST shape and size were noted.

Results: T21 subjects had statistically greater ST length (P<0.001), anterior height (P=0.004), middle height (P=0.001) and width (P<0.001) than controls, but similar diameter (P=0.098) and posterior height (P=0.097). Six types related to Axelsson classification were noted in T21s with the following frequencies: normal ST (42.2%)>oblique anterior wall (28.9%)>pyramidal shape of the dorsum sellae (15.6%)>double contour of the floor (6.7%)>irregularity (4.4%)>ST bridge (2.2%). Four types regarding this classification were noted in controls with the following frequencies: normal ST (41.5%)>pyramidal shape of the dorsum sellae (34%)>oblique anterior wall (22.6%)>double contour of the floor (1.9%). Three types related to Camp classification were noted in T21s with the following frequencies: round (44.4%)>oval (33.4%)>flattened (22.2%). Three types regarding this classification were noted in controls with the following frequencies: round (49.1%)>oval (37.7%)>flattened (13.2%).

Conclusion: Our CT study displays that ST size is affected by T21. However, the ST shape does not correlate with T21.