Diagnosis of Crohn’s disease by ultrasound | Diagnosis of Crohn’s disease

Diagnosis of Crohn’s disease by ultrasound

Ultrasound examination of the abdomen, the so-called sonography of the abdomen, reveals changes typical of Crohn’s disease. This procedure, which is very gentle and non-invasive for the patient, often allows the first suspected diagnosis of Crohn’s disease to be made. Crohn’s disease is characterized by an edematous thickening and swelling of the intestinal wall.

The ultrasound image then shows the so-called cockade or target phenomenon, because the thickened intestinal sections act like the rings of a target in cross-section. Frequently, enlarged lymph nodes present as a reaction to the inflammatory process. In some cases, the fistula ducts or possible accumulation of pus (abscesses) can also be visualized sonographically. If Crohn’s disease has already been diagnosed, ultrasound is the simplest non-invasive examination method to check the success of the therapy.

Diagnosis of Crohn’s disease by MRI according to Sellink

This procedure serves to sift the pattern and extent of the intestinal inflammation. Especially the assessment of the small intestine is unproblematic with this method. A probe is used to introduce a contrast medium into the small intestine.

The contrast agent spreads through the intestinal mucosa in such a way that an optimal assessment of the intestinal mucosa is possible. To prevent the opposite walls of the intestine from sticking together, another fluid is administered via the probe. The entire gastrointestinal tract is visualized with special attention to the small intestine. An edematous thickening of the intestinal wall is typical for Crohn’s disease.

Diagnosis of Crohn’s disease by colonoscopy and biopsy

In a colonoscopy, a camera tube (endoscope) is inserted through the anus into the colon up to the Bauhin’s valve. This valve represents the transition to the last section of the small intestine. It is precisely this last section of the small intestine, the so-called terminal ileum, that is most frequently affected by inflammatory changes in Crohn’s disease.

The pattern of infection in Crohn’s disease is always segmental and discontinuous, i.e. healthy intestinal mucosa is always found next to diseased sections. In an early phase of the disease, superficial injuries of the mucosa, such as reddish spots, can often be detected. In the late stage, constrictions occur more frequently.

During an acute episode, deeper injuries such as ulcers and fistulas occur. The paving stone phenomenon is characteristic of Crohn’s disease. This describes the alternating occurrence of thickening of the mucous membrane and deep ulcers.

The ulcers may look elongated, like snail trails. A further pathognomonic, i.e. typical for chronic disease, is the garden hose. This phenomenon is caused by tissue alteration (fibrosis) of the constrictions.

When sections of the intestine stick together, a conglomerate tumor develops, some of which can be palpated from the outside. During colonoscopy, tissue samples (biopsies) are taken. In Crohn’s disease, these show a large number of immune cells, such as lymphocytes, granulocytes and histiocytes. Also so-called granulomas are a typical finding. Since Crohn’s disease can affect all mucous membranes from the anus to the mouth, a gastroscopy is often recommended