Abdominal hernias: Radiological features

Abstract

Abdominal wall hernias are common diseases of the abdomen with a global incidence approximately 4%-5%. They are distinguished in external, diaphragmatic and internal hernias on the basis of their localisation. Groin hernias are the most common with a prevalence of 75%, followed by femoral (15%) and umbilical (8%). There is a higher prevalence in males (M:F, 8:1). Diagnosis is usually made on physical examination. However, clinical diagnosis may be difficult, especially in patients with obesity, pain or abdominal wall scarring. In these cases, abdominal imaging may be the first clue to the correct diagnosis and to confirm suspected complications. Different imaging modalities are used: conventional radiographs or barium studies, ultrasonography and Computed Tomography. Imaging modalities can aid in the differential diagnosis of palpable abdominal wall masses and can help to define hernial contents such as fatty tissue, bowel, other organs or fluid. This work focuses on the main radiological findings of abdominal herniations.

Keywords: Abdominal Radiology; Abdominal Wall; Computed tomography; Diagnostic Radiology; External Hernia; Hernia; Hiatal Hernia; Internal Hernia; Intestinal Obstruction; Ultrasonography.

Figures

Figure 1

Ultrasonography of Strangulated midline hernia. Hyperechoic haemorrhagic loops surrounded by a transonic (black) thin film of fluid.

Figure 2

Computed tomography. A: Coronal reconstruction of a right indirect inguinal hernia. Bowel loops are visible in the hernial sac and the vascular axis passing trough the inguinal canal; B: Pilot scan. Bladder underlined by the contrast media in a right direct inguinal hernia; C: Axial scan. Bilateral direct inguinal hernia. On the right contains the bladder, on the left intestinal loops. Note the epigastric vessels lateral to the hernia (arrow); D: Obturator hernias. A thickened bowel loop is located between the external obturator and pectineal muscles (arrow); E: Very large hiatal hernia containing also mesenteric fat and bowel loops; F: Sagittal reconstruction of bockdaleck hernia. The spleen, part of the left kidney and small bowel pass in the thorax through a posterior diaphragmatic defect; G: Thick slab MIP coronal reconstruction of left paraduodenal hernia. Both, the inferior mesenteric vein (white arrow) and the ascending left colic artery (black arrow) can be seen above the herniated loop along the anterior aspect.

Figure 3

Ultrasonography of transmesenteric hernia in an infant (calipers).