Prone 'computed tomography hernia study' for the diagnosis of inguinal hernia

To improve diagnostic accuracy in cases of a suspected inguinal hernia, we perform a “CT hernia study,” with the patient lying prone to allow decompression of the structures in the inguinal region. We reviewed the records of 914 patients with a suspected inguinal hernia who underwent prone non-contrast lower abdominal CT with two rolled-up towels, 20 cm in diameter, placed transversely beneath them, at the umbilicus and hips, respectively. The CT hernia study yielded a diagnosis of inguinal hernia in 861 (94.2%) patients and a condition other than inguinal hernia in 43 (4.7%) patients. Hernia was not detected preoperatively but found intraoperatively in 10 patients (1.1%). Surgery was performed for a collective total of 1029 hernias in 873 patients, and the CT hernia study-based hernia detection rate was 98.3%. We compared the preoperative diagnoses of various types of hernia (Japanese Hernia Society Types I–V) against the intraoperative diagnoses and found that the CT hernia study yielded 95.8% accuracy. The CT hernia study appears to provide a high detection rate and makes differentiating the various types of inguinal hernia possible. We believe our CT hernia study adds a level of objectivity that is diagnostically beneficial.