Radiological signs of crohn’s disease:
**Core Concept**
Crohn's disease is a type of inflammatory bowel disease (IBD) characterized by chronic inflammation of the gastrointestinal tract, which can lead to various radiological signs. These signs are crucial for diagnosis and differentiation from other forms of IBD, such as ulcerative colitis.
**Why the Correct Answer is Right**
The correct answer is **Cobblestone appearance of the mucosa**. This radiological sign is due to the presence of superficial ulcers and deep longitudinal and transverse ulcers, giving the mucosa a cobblestone appearance. This is a result of the chronic inflammation and subsequent healing process, leading to the formation of these characteristic ulcers. The cobblestone appearance is a hallmark of Crohn's disease and can be visualized on barium studies or endoscopic examinations.
**Why Each Wrong Option is Incorrect**
**Option A:** **String sign of Cantor** is a sign of Crohn's disease, but it refers to the narrowing of the terminal ileum, not the cobblestone appearance of the mucosa.
**Option B:** **Lead pipe appearance** is more characteristic of ulcerative colitis, which presents with a smooth, featureless colon due to the diffuse inflammation and loss of haustra.
**Option C:** **Thumb printing** is a sign of ischemic bowel, which can be caused by various conditions, including volvulus, thrombosis, or vasculitis, but is not specific to Crohn's disease.
**Clinical Pearl / High-Yield Fact**
Crohn's disease often affects the terminal ileum and the beginning of the colon, known as the ileocolonic junction. This is an important consideration when interpreting radiological findings, as the presence of disease in these areas can help differentiate Crohn's disease from other forms of IBD.
**Correct Answer:** C. Cobblestone appearance of the mucosa.