Lesson plan
String sign
String sign, or gastrointestinal string sign (also called string sign of Kantour), is a medical term for a radiographic finding on an upper GI series, in which the patient is given a radio-opaque material, such as barium, to drink. X-rays are then taken of the patient's stomach and intestines. The gastrointestinal string sign represents a severe narrowing of loop of bowel, in which a thin stripe of contrast within the lumen looks like a string. It may be seen in Crohn's disease, hypertrophic pyloric stenosis, carcinoid tumor and colon cancer. In people with Crohn's Disease, the string sign is caused by incomplete filling of the intestinal lumen, which results from irritability and spasm associated with severe ulceration. In such cases, the string sign is most frequently seen at the terminal ileum. In infants with hypertrophic pyloric stenosis, the pylorus is narrowed and the radio-opaque material will take on the appearance of a thin string as it passes through this narrowed channel. Often, there are several of these strings seen (called the "railroad track sign"). The use of the upper GI series for the diagnosis of HPS, which was the primary diagnostic tool for this condition in the 1980s and 1990s, has been largely replaced by the use of ultrasound, which is less invasive and can visualize the thickened pylorus, giving actual measurements of this thickening.
Article summary
String sign, or gastrointestinal string sign (also called string sign of Kantour), is a medical term for a radiographic finding on an upper GI series, in which the patient is given a radio-opaque material, such as barium, to drink. X-rays are then taken of the patient's stomach and intestines. The gastrointestinal string sign represents a severe narrowing of loop of bowel, in which a thin stripe of contrast within the lumen looks like a string. It may be seen in Crohn's disease, hypertrophic pyloric stenosis, carcinoid tumor and colon cancer. In people with Crohn's Disease, the string sign is caused by incomplete filling of the intestinal lumen, which results from irritability and spasm associated with severe ulceration. In such cases, the string sign is most frequently seen at the terminal ileum. In infants with hypertrophic pyloric stenosis, the pylorus is narrowed and the radio-opaque material will take on the appearance of a thin string as it passes through this narrowed channel. Often, there are several of these strings seen (called the "railroad track sign"). The use of the upper GI series for the diagnosis of HPS, which was the primary diagnostic tool for this condition in the 1980s and 1990s, has been largely replaced by the use of ultrasound, which is less invasive and can visualize the thickened pylorus, giving actual measurements of this thickening.
Key claims
No claims recorded.
Discussion questions
- Summarise the article in your own words. Which single claim would you verify first, and why?
- Which claim in this article is most likely to be revised as the sources update? How would you check its current status?
- If two sources disagreed about one of these facts, what would you need in order to trust one over the other?
Bibliography
No sources recorded.
Key claims and bibliography are generated from the same tracked claims and sources as the article page.