Doppler Sonography of the Mesenteric Circulation

Abstract

The celiac trunk and the superior and inferior mesenteric arteries are responsible for the splanchnic circulation. Normal values for the flow velocities enable the investigator to judge pathologic flow. Pathologic indications are the diagnosis of intussusception, infective bowel disease, vasculitis, ischemic bowel disease, malrotation and volvulus, hypertrophic pyloric stenosis and space occupying lesions of the gastrointestinal tract. Intussusception is characterized by multiple concentric rings on 2d images. If color Doppler shows internal vessels in the intussusceptum the affected bowel is viable. After sonographic reposition reactive hyperemia of the thickened bowel wall and Bauhin’s valve can be shown. Infective bowel diseases are necrotizing enterocolitis, appendicitis and Crohn’s disease. Appendicitis and Crohn’s disease are characterized by thickened bowel walls with increased perfusion. In necrotizing enterocolitis of preterm infants the flow velocities in the celiac trunk and superior mesenteric artery are markedly elevated, often over 1 m/s. Vasculitis of the bowel shows increased vascularity whereas ischemic bowel disease is characterized by absent vascularity. Malrotation can be diagnosed by the inverse relationship between the spleno-portal confluence and the superior mesenteric artery. If volvulus occurs the whirlpool sign is helpful for the diagnosis. Space occupying lesions can be differentiated into cystic and solid tumors. Cystic tumors are gastrointestinal duplication cysts and mesenteric cysts which show no internal perfusion. Solid lesions are juvenile polyps of the colon which show increased vascularization and malignant tumors arising from the bowel. Lymphomas of the gastrointestinal tract are the most frequent abdominal location of lyphomas. They are hypoechoic lesions with minimal perfusion which infiltrate various parts of the intestinal tract.