Sex determination from measurements of the sternum and fourth rib using multislice computed tomography of the chest

Abstract

Introduction: One of the most important data that can be obtained from bones is sex determination for which the recommended method is taking metric measurements. Metric measurements can be performed directly on dried bones obtained from the cadaver or indirectly from their radiographs.

Aim: We assessed the accuracy of sex determination and the applicability of previously defined rules using the sternum and 4th rib measurement data from chest multislice computed tomography (MSCT) imaging of 340 patients and developed a model/formula that would provide the best way to determine sex.

Methods: We analyzed the chest MSCT of 340 patients (143 females, 197 males; mean age: 57.6+/-15.2 years) and created a coronal image parallel to the sternal long axis and a coronal image at the level of sternal ending of the 4th rib. The 5 sternal measurements [length of the manubrium and sternal body, combined length of the manubrium and sternal body (CL), manubrium width and corpus sterni width] and 4th rib width (FRW) described in the literature were obtained. Sternal index (SI) and sternal area (SA) were calculated from these measurements.

Results: The left FRW values were used for sex determination as the left FRW was found to be more significant than the right FRW. An accuracy of over 80% was achieved for sex determination when the "142 rule" was used for CL only, a cut-off value of 5600 mm(2) for SA only and a cut-off value of 16 mm for FRW only. We found that Hyrtl's law and SI did not provide adequate accuracy for sex determination in our patients. The model with the highest accuracy (88.2%) for sex determination used SA and FRW together. We also believe that the best predictors for sex determination using the sternum and 4th rib are SA and FRW, similar to the Torwalt and Hoppa report.

Conclusion: Radiological methods such as MSCT are useful in making reliable measurements to be used in various anthropological and forensic investigations and determining their accuracy.