Doppler enhancement after intravenous levovist injection in Crohn's disease

Although transabdominal bowel sonography (TABS) has been proposed as a reliable tool to assess increased bowel wall thickness (BWT), the most common sonographic pattern in patients with Crohn's disease (CD), its accuracy is limited in the diagnosis of CD. We therefore tried to assess whether color Doppler enhancement with Levovist, a galactose-based intravenous sonographic contrast agent able to enhance the arterial Doppler signal, increases TABS accuracy. Thirty-one patients with ileal CD, diagnosed by endoscopy and enteroclysis, and 20 healthy volunteers were examined with conventional TABS. Color Doppler of the intramural enteric vessels was then performed before and after intravenous injection of Levovist. Twenty-two CD patients had a BWT >4 mm, and 16 of them presented with active disease. Two of the remaining nine CD patients, all with BWT <4 mm, presented with active disease. By means of color Doppler we identified six patients with inactive disease, normal BWT, and normal basal Doppler signal intensity, who showed an enhanced Doppler signal in intramural vessels after contrast agent bolus. Four of these patients, identified only by color Doppler after Levovist injection, relapsed within 6 months. In our experience, sensitivity and specificity of TABS, integrated with additional stimulated acoustic emission mode, were 96.7% and 100%, respectively. The use of Levovist in color Doppler increases the accuracy of TABS in CD diagnosis and follow-up.