Morphometric evaluation of sacrum volume in healthy women

Introduction: The aim of this study was to calculate volume of the sacrum, sacral canal, caudal part of the epidural space, and dural sac volumes using stereological methods on magnetic resonance images (MRIs). Material and Methods: We used MRI series of 50 healthy women (the mean age; 44.0) in the study, retrospectively. Point counting and planimetry methods were used to calculate the volumetric parameters on MRIs. Volume calculation was performed by placing the dotted field ruler on MRI sections for point counting method, whereas ImageJ software was used for planimetry method. Results: Sacrum volume was measured as 135.38 ± 24.12 cm3 using point counting method, whereas it was 136.87 ± 24.76 cm3 in planimetry method. The mean volume of sacral canal was determined as 10.11 ± 2.64 cm3 and 10.30 ± 2.73 cm3 using point counting and planimetry methods, respectively. The mean volume of the caudal portion of the epidural space was 6.54 ± 2.04 cm3 in point counting method, whereas it was 6.53 ± 1.89 cm3 in planimetry method. Discussion and Conclusion: Knowing the volume of sacrum would contribute to minimization of complications during surgical approaches and anesthesia procedures in that region. Our results showed that sacrum volume can be calculated accurately using stereological methods such as point counting and planimetry.