To analyze the value of the multi-planar reconstruction (MPR) technique of multi-slice spiral computed tomography (MSCT) in the identification of inguinal hernia and prediction of incarcerated hernia.

Retrospectively analyze the preoperative MSCT images of 110 cases of surgically confirmed inguinal hernia at the Affiliated Suzhou Hospital of Nanjing Medical University from January 2017 to December 2022, including 49 cases of indirect inguinal hernia, 36 cases of direct inguinal hernia, and 25 cases of femoral hernia. To observe the following targets in coronal and oblique coronal MPR images: inguinal ligament, inferior epigastric artery, Hesselbach's triangle, femoral triangle, hernia contents, the ratio of the hernia sac to the neck and special CT signs.

In coronal MPR and oblique coronal MPR images, the inguinal ligament was completely displayed in 24 (20.7%) and 63 (54.3%) cases respectively, partially displayed in 43 (37.1%) and 33 (28.4%) cases respectively, and not displayed in 49 (42.2%) and 20 (17.2%) cases respectively. The complete display rate of the inguinal ligament in oblique coronal MPR was better than that in coronal MPR, and the difference was statistically significant (P<0.05). The contents of three types of inguinal hernia included small intestine, fluid, mesentery, fat, etc. The incidence of fluid accumulation in the femoral hernia sac was higher than that in indirect inguinal hernias and direct inguinal hernias (P<0.05). The incidence of fat in the indirect inguinal hernia sac was lower than that in direct inguinal hernias and femoral hernias (P<0.05). The lateral crescent sign and Hesselbach's triangle filling sign only appeared in direct inguinal hernias (P<0.05). The femoral triangle filling sign only appeared in femoral hernia (P<0.05). Seven (7/51, 13.7%) indirect inguinal hernia sacs were incarcerated, 6 (6/39, 15.4%) direct inguinal hernia sacs incarcerated, and 19 (19/26, 73.1%) femoral hernia sacs were incarcerated. The incidence of incarceration in femoral hernia was higher than that in indirect inguinal hernias and direct inguinal hernias (P<0.05). The incidence of fluid accumulation in the hernia sac of incarcerated indirect hernia and direct hernia was higher than that in non-incarcerated hernia (P<0.05). The median of the ratio of the hernia sac to the neck in incarcerated and non-incarcerated indirect inguinal hernias was 3.1 and 1.3, respectively. The differences between the two groups were statistically significant (P<0.05). When the critical value was 2.3, the area under the receiver operating characteristic curve (AUC) was 0.97. The median of the ratio of the hernia sac to the neck in incarcerated and non-incarcerated direct inguinal hernias was 4.5 and 2.8, respectively. The differences between the two groups were statistically significant (P=0.03). When the critical value was 3.9, AUC was 0.98. The median of the ratio of the hernia sac to the neck in incarcerated and non-incarcerated femoral hernias was 3.8 and 2.3, respectively. The differences between the two groups were statistically significant (P<0.05). When the critical value was 3.2, the AUC was 0.84.

MSCT MPR technology is advantageous in displaying the anatomical structure of the inguinal area and determining the type of inguinal hernia. The presence of fluid accumulation in the hernia sac and an increase in the ratio of the hernia sac to the neck can provide clues for incarcerated hernia.