From the Guidelines
The normal thickness of the esophageal wall on a CT scan is typically less than 5 mm, as distal esophageal wall thickening (≥5 mm) has been reported to have a moderate association with reflux esophagitis. This measurement is crucial for diagnosing various esophageal conditions, including reflux esophagitis, which has a moderate association with distal esophageal wall thickening (≥5 mm) on CT, with test performance characteristics including an area under the receiver operating characteristic curve of 0.78, sensitivity of 56%, and specificity of 88% 1. The esophageal wall thickness can vary depending on several factors, including the level of the esophagus being examined and whether the esophagus is adequately distended.
Key Considerations
- The esophageal wall thickness should be measured perpendicular to the lumen at a well-distended portion of the esophagus for the most accurate assessment.
- A collapsed esophagus may falsely appear thickened, highlighting the importance of adequate distension.
- Patient positioning, degree of inspiration, and the use of oral contrast can affect the appearance and measurability of the esophageal wall.
Diagnostic Implications
- Wall thickness exceeding 5 mm is generally considered abnormal and may indicate pathological conditions such as esophagitis, malignancy, or other inflammatory processes.
- The presence of air in the esophagus, especially the middle and lower parts, can suggest a diagnosis of GERD 1.
- CT findings suggestive of gastritis or peptic ulcer disease (PUD) include gastric or duodenal wall thickening, mucosal hyperenhancement, fat stranding, fluid along the gastroduodenal region, and focal outpouching or interruption of mucosal enhancement due to ulcerations 1.
From the Research
Esophageal Wall Thickness on CT Scan
The normal thickness of the esophageal wall on a Computed Tomography (CT) scan can vary.
- According to a study published in the AJR. American journal of roentgenology 2, the mean esophageal wall thickness in controls was 2.9 mm (standard deviation [SD], 0.8 mm; 95% confidence interval [CI], 1.3-4.5 mm).
- Another study published in the European journal of radiology 3 found that the largest wall thickness when the esophagus was in contraction and dilatation was 4.70 (95%CI: 4.44-4.95)mm and 2.11 (95%CI: 2.00-2.23)mm, respectively.
- The study also found that when the esophagus was contracting, the intraabdominal esophagus was thicker than the cervical, thoracic, and retrocardiac parts, with an average thickness of 5.68 (95%CI: 5.28-6.09)mm, 4.67 (95%CI: 4.36-4.86)mm, 4.56 (95%CI: 4.31-4.87)mm, and 4.05 (95%CI: 3.71-4.21)mm, respectively.
- A threshold of 5 mm is often used to define a thickened esophageal wall on CT scans, as seen in a study published in the AJR. American journal of roentgenology 2.
Factors Affecting Esophageal Wall Thickness
Several factors can affect the thickness of the esophageal wall, including:
- Sex: a study published in the European journal of radiology 3 found that the thickness of the esophageal wall was larger in males than in females (5.26 mm vs. 4.34 mm, p<0.001).
- Age and subcutaneous fat thickness: the same study found that age and the thickness of subcutaneous fat had no significant impact on the thickness of the esophageal wall (p-value was 0.056 and 0.173, respectively) 3.
- Esophageal diseases: various studies have found that esophageal wall thickening can be associated with esophageal diseases such as esophagitis 2, corrosive esophageal strictures 4, and diffuse esophageal spasm 5.