To evaluate the clinical value of multi-slice spiral CT (MSCT) imaging features and high-frequency ultrasound in differentiating indirect and direct inguinal hernias in adults.

Clinical data of 125 patients presenting with an inguinal mass and admitted to Yulin Hospital of Traditional Chinese Medicine between January 2020 and December 2024 were retrospectively analyzed. All patients underwent laparoscopic hernia repair. Intraoperative findings during laparoscopic exploration were used as the reference standard. All patients received MSCT and high-frequency ultrasonography. The diagnostic performance of MSCT and high-frequency ultrasonography for inguinal hernia was evaluated, as well as their performance in diagnosing indirect and direct inguinal hernias. MSCT location characteristics and imaging signs, high-frequency ultrasonographic findings, and the detection of hernia contents were compared between indirect and direct inguinal hernias.

The sensitivity and specificity of MSCT in diagnosing inguinal hernias were 97.79% and 80.00%, respectively, with a kappa value of 0.652. The sensitivity and specificity of high-frequency ultrasound in diagnosing inguinal hernias were 96.32% and 80.00%, respectively, with a kappa value of 0.551. For the diagnosis of indirect hernias, MSCT had a sensitivity of 97.00% and a specificity of 94.44%, with a kappa value of 0.906; for the diagnosis of direct hernias, MSCT had a sensitivity of 94.44% and a specificity of 97.00%, with a kappa value of 0.906. High-frequency ultrasound had a sensitivity of 92.00% and a specificity of 88.89% for diagnosing indirect hernias, with a kappa value of 0.781, and a sensitivity of 88.89% and a specificity of 92.00% for diagnosing direct hernias, with a kappa value of 0.781. Indirect inguinal hernias presented with mixed density or were cystic-solid, all distributed on the anterior side of the inguinal ligament and lateral to the inferior epigastric artery, without a crescent sign or filling of the femoral triangle. Direct hernias were all distributed on the anterior side of the inguinal ligament and medial to the inferior epigastric artery, without filling of the femoral triangle, and often with a lateral crescent sign. The indirect hernia sac was located lateral to the origin of the inferior epigastric artery, and the diameter and shape of the hernia ring varied greatly. The direct hernia sac was located medial to the inferior epigastric artery, with no significant changes in the local abdominal wall, clear intestinal wall layers, no obvious hernia sac neck, and a small amount of fluid dark area could be detected in the hernia sac cavity of some patients. The hernia ring was located medial to the inferior epigastric vessels, and there was a small amount of color blood flow signal in the intestinal wall. The proportions of contents in indirect hernias were, in descending order: intestinal canal, greater omentum, ovary, effusion, intra-abdominal fat, and bladder. The proportions of contents in direct hernias were, in descending order: intestinal canal, intra-abdominal fat, greater omentum, effusion, ovary, fat, and bladder. After Bonferroni correction (corrected significance level of P<0.0083), there were no statistically significant differences in the detection rates of all contents between the two groups (all P>0.0083).

Both MSCT imaging features and high-frequency ultrasound have important clinical value in differentiating indirect and direct inguinal hernias in adults. MSCT can provide a basis for the classification of inguinal hernias by confirming the presence of specific imaging signs and combining the relationship between the hernia sac neck and the inferior epigastric artery. High-frequency ultrasound can dynamically assess the reducibility of hernia contents in real time, which is of great guiding significance for clinical classification.