Determination of the width of the presacral space on magnetic resonance imaging among adults in south-western Nigeria.

BACKGROUND: The presacral space is a clinically relevant potential space and contents may give rise to a variety of benign and malignant conditions, hence the need for detailed knowledge of its dimensions. PURPOSE: To determine the width of the presacral space and existing variations among adults in south-western Nigeria using a magnetic resonance imaging (MRI) technique. MATERIAL AND METHODS: A total of 369 consenting adults were included in the study. Measurements of the presacral space were then made electronically by consensus of two radiologists. Values derived were recorded and subjected to analyses of variance. RESULTS: The mean normal widths of the presacral space in men and women were 11.7 mm and 11.1 mm at the S1 level, 11.7 mm and 10.35 mm at the S2 level, and 12.3 mm and 9.7 mm at the S3 level, respectively. Measurements of the presacral space width were significantly larger in the male population. Variations in the dimensions due to age greater than 40 years, male sex, and increasing body mass index (BMI) were also noted. CONCLUSION: This study provides baseline dimensions under more physiological conditions and gives more accurate information about the true width of the space in Nigerian adults. Variations due to age, sex, and BMI may also be considered while interpreting abnormal values.