US evaluation of patients affected by IBD: how to do it, methods and findings.

Intestinal US has to be performed very accurately, to obtain an exploration of both small bowel and cholical loops that will be the most complete that is possible; so, this technique requires adequately trained operators. Convex and linear probes with frequency between 3.5 and 7.5 MHz are used: the first ones for the panoramic evaluation and to study the middle-distal sigma and rectum; the second ones to perform a detailed examination of the bowel wall. US allows to evaluate not only the thickness and structure of the bowel wall, but also the content and peristalsis of the loops, their compressibility and movability, the perivisceral spaces and the abdominal organs. In Crohn's disease, US, completed everytime by the color-power-Doppler, shows wall thickening until 20 mm and above, with multi-stratified structure that could be regular, or more and more altered until the hypoechogenic view; the bowel vascularisation could be absent or less or more increased, due to the stadium of the disease itself. Furthermore, US allows to demonstrate the presence of stenosis and various other complications (abscesses inside or outside the walls, fistulas, involvement of other organs, free fluid collections); the use of II generation US contrast media could afford information about the activity of the disease. US has a very important role in the follow-up of patients with diagnosis of Crohn's disease, to monitor the response to the medical therapy and to discover complications; US must be performed as first in subjects with abdominal pain and diarrhea, to select the ones that need more invasive examinations.

Activity of Crohn disease: value of Color-Power-Doppler and contrast-enhanced ultrasonography.

Diagnosis and follow-up of Crohn disease (CD) often require invasive instrumental examinations, with a high risk of iatrogenic damage. Ultrasound (US) examination of bowel walls could be the first choice in managing patients with CD. We evaluated the role of tissue color power Doppler (CPD) and B-mode US with intravenous injection of contrast medium in the detection of disease activity. In our series, 52 patients with CD underwent US examination. Each study was completed with tissue CPD and US with intravenous injection of contrast medium (Sono Vue) to evaluate intestinal wall vascularization as an index of disease activity. We then compared our results with those from clinical and laboratory tests and follow-up. Data from US examination with intravenous injection of Sono Vue partly agreed with clinical and laboratory tests and CPD in disease activity evaluation but were most useful in the follow-up. Bowel US examination associated with CPD and in particular US contrast medium injection can be used to detect CD activity and modulate therapy and follow-up.