Radiologic Anatomy of the Inguinofemoral Region: Insights from MDCT

Abstract

We set out to reexamine the radiologic anatomy of the inguinofemoral region using volume data sets obtained with an MDCT scanner. We conducted a systematic prospective review of CT scans of 20 consecutively enrolled patients, 10 men and 10 women chosen retrospectively from our CT database. An experienced radiologist and a senior trainee surgeon conducted an image review to maximize recognition of relevant anatomic detail. The inferior epigastric artery and femoral canal were identified in all planes in all patients. On axial views a spur on the pubic bone was visible in 17 (85%) of the patients, but the inguinal ligament was not reliably identified in any. The round ligament or spermatic cord was visible in only 15 (75%) of 20 patients. In contrast, on coronal and sagittal views, the inguinal ligament, which is vital to reliable identification and accurate classification of groin hernias, was visible in 19 (95%) of the 20 patients. Scans in the sagittal plane best depicted the gutter-like aspect of the ligament, the canal and contents being clearly visible in 95% of the patients. On sagittal views, the internal ring was identifiable in 90% and the round ligament or spermatic cord in 95% of the patients. On coronal images, the internal ring was identified in all and the conjoint tendon in 95% of the patients. The round ligament or spermatic cord was not seen in 10% of the patients. MDCT produces images of the inguinal region in detail not possible with previous generations of scanners. In our small series, 100% identification of key anatomic structures was achieved when information from all three views was combined. We found subtle differences between imaging findings and standard anatomic teaching.