From the Guidelines
CT features used to diagnose a hiatal hernia include diaphragmatic discontinuity, segmental non-recognition of the diaphragm, and intrathoracic herniation of abdominal contents.
Key CT Features
- Diaphragmatic discontinuity
- Segmental non-recognition of the diaphragm
- “Dangling diaphragm” sign
- “Dependent viscera” sign
- Intrathoracic herniation of abdominal contents
- “Collar sign”
- Contiguous injuries of both sides of the diaphragm
- Elevated abdominal organs
- Thickened diaphragm
- Thoracic fluid
- Abutting intra-abdominal viscera
- Hypo-attenuated hemidiaphragm
- Associated fractured ribs 1
CT Scan Findings of Ischemia
- Forward displacement of the gastric bubble
- Missing of the gastric folds
- Absence of gastric walls contrast enhancement
- Intestinal wall thickening with target enhancement
- Spontaneous hyper-density of the intestinal wall
- Lack of enhancement after injection of iodinated contrast agent
- Parietal pneumatosis with portal and mesenteric venous gas 1 The CT scan is the gold standard for diagnosing diaphragmatic hernia, with a sensitivity and specificity of 14–82% and 87%, respectively 1.
From the Research
CT Features of Hiatal Hernia
The following CT features are used to diagnose a hiatal hernia:
- Identification of the hiatal hernia by computed tomography (CT) scanning, particularly with axial imaging from a coronary artery calcium score exam 2
- Direct visualization and objective evaluation of anatomic structures, such as diaphragmatic crus and esophageal foramen 3
- Presence of a sliding hiatal hernia, which can be graded as small, moderate, or large 4
- CT findings can be used to diagnose unsuspected hernias and to distinguish hernias from masses of the abdominal wall 5
- High-resolution 3-dimensional tomography can be used to understand the anatomy of hiatal hernias and for surgical planning 6
Diagnostic Criteria
The diagnostic criteria for hiatal hernia on CT include:
- Distance from the esophagogastric junction (EGJ) to the hiatus 6
- Total gastric volume and herniated gastric volume, percentage of herniated volume in relation to the total gastric volume 6
- Diameters and area of the esophageal hiatus 6
- Presence of a sliding hiatal hernia, which can be graded as small, moderate, or large 4
Comparison with Other Diagnostic Tests
CT findings can be compared with other diagnostic tests, such as: