CT herniography in the diagnosis of occult groin hernias

An Evaluation of the Diagnostic Potential of CT Scans and Herniography for Inguinal Hernias

We evaluated and compared the diagnostic potential of computed tomography (CT) and herniography in the identification of inguinal hernias. Herniography is typically utilized in the diagnosis of inguinal hernias in our institute. We utilized transabdominal preperitoneal repair in the treatment of inguinal hernias since October 2010 and performed a laparoscopic diagnosis followed by single-incision laparoscopic surgery for totally extraperitoneal repair since November 2013. We herein evaluated and compared the diagnostic potential of CT and herniography. From February 2012 to March 2016, 46 patients (male/female: 43/3; median age: 70 years) with 63 inguinal hernias were investigated using CT and herniography. We classified each inguinal hernia according to the Japan Hernia Society classification using CT (prone position) and herniography, and evaluated the accuracy of each of the diagnostic methods. A total of 29 patients had unilateral hernias and 17 had bilateral hernias; 62% (39/63) and 84% (53/63) of the inguinal hernias were correctly diagnosed and classified by CT and herniography, respectively. A total of 87% (55/63) and 98% (62/63) of the inguinal hernias were detected by CT and herniography, respectively. Thus, herniography was found to be more sensitive than CT and the difference in the detectability of inguinal hernias by the 2 methods was statistically significant. Herniography appears to be superior to CT, for both the classification and detection of inguinal hernias.

Meta-analysis of sonography in the diagnosis of inguinal hernias

Groin hernias are common conditions, and there is a need for accurate imaging when the clinical diagnosis is not clear. A meta-analysis was undertaken to investigate the diagnostic accuracy of sonography in the diagnosis of inguinal hernias. After review of literature searches, 9 original articles were included. Data were pooled and statistically analyzed. In the studies included, sensitivity ranged from 92.7% to 100%; specificity ranged from 22.2% to 100%; the positive predictive value ranged from 83.3 to 100%; and the negative predictive value ranged from 40 to 100%. Sonography has overall sensitivity of 96.6 %, specificity of 84.8%, and a positive predictive value of 92.6%. In cases of diagnostic uncertainty, sonography offers value as an initial imaging modality. It has advantages over other radiologic methods, as it is inexpensive and has minimal complications. When the clinical diagnosis of an inguinal hernia is uncertain, sonographic findings should be interpreted in conjunction with clinical judgment, as its diagnostic accuracy is reduced in the absence of any clinically palpable hernia.

Diagnosis of inguinal region hernias with axial CT: the lateral crescent sign and other key findings

Differentiation of direct inguinal hernias, indirect inguinal hernias, and femoral hernias is often difficult at clinical examination and presents challenges even at diagnostic imaging. With the advent of higher-resolution multidetector computed tomography (CT), the minute anatomic detail of the inguinal region can be better delineated. The authors examine the appearance of these hernias at axial CT, as the axial plane remains the diagnostic mainstay of evaluation of acute abdomen. They review and label key anatomic structures, present cases of direct and indirect inguinal hernias and femoral hernias, and demonstrate their anatomic differences on axial images. Direct inguinal hernias protrude anteromedial and inferior to the course of the inferior epigastric vessels, whereas indirect inguinal hernias protrude posterolateral and superior to the course of those vessels. The proposed lateral crescent sign may be useful in diagnosis of early direct inguinal hernias, as it represents lateral compression and stretching of the inguinal canal fat and contents by the hernia sac. Femoral hernias protrude inferior to the course of the inferior epigastric vessels and medial to the common femoral vein, often have a narrow funnel-shaped neck, and may compress the femoral vein, causing engorgement of distal collateral veins. Familiarity with these anatomic differences at axial CT, along with the lateral crescent sign of direct inguinal hernias, may help the radiologist better assist the clinician in accurate diagnosis of the major types of hernias of the inguinal region. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.312105129/-/DC1.

Herniography: analysis of its role and limitations

INTRODUCTION

Herniography is a radiographic procedure shown to be valuable in the examination of groin symptoms. It is useful in clinical situations, including the detection of occult hernia, the investigation of groin hernia when physical findings are equivocal, and the assessment of pain after inguinal hernia repair.

OBJECTIVE

To systematically review the current literature on the use of herniography and to evaluate its reliability, risk, and limitations.

METHOD

The Medline database was searched for publications on herniography.

RESULTS

Herniography has a low false-positive rate, ranging from 0 to 18.75%. The sensitivity rate ranges from 81 to 100%, and the specificity rate ranges from 92 to 98.4%.

CONCLUSION

Herniography is a safe and effective diagnostic procedure for assessing obscure groin symptoms. It has the potential of reducing the incidence of unnecessary operations. It should be considered in the evaluation of patients where the etiology of inguinal pain is unclear.

Radiologic Anatomy of the Inguinofemoral Region: Insights from MDCT

OBJECTIVE

We set out to reexamine the radiologic anatomy of the inguinofemoral region using volume data sets obtained with an MDCT scanner.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

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.