The average electron density value within the marrow cavity at the fracture site in the unilateral rib fracture group was 106.1% EDW, higher than the corresponding contralateral healthy segment at 102.1% EDW (P<0.001). There was no statistically significant difference in electron density values between corresponding anatomical segments of the left and right ribs in the normal control group (P>0.05). The average difference in electron density values between the affected and contralateral sides in the fracture group was 4.07% EDW, higher than the difference of 1.33% EDW between the left and right sides in the control group (P<0.001). The area under the ROC curve (AUC) for the difference in electron density values between the affected and contralateral sides was 0.863 (P<0.001), with an optimal cutoff value of 1.7% EDW and a Youden index of 0.6759.