Professor of Radiology, Paediatric Radiologist. Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands
Diseases of the gallbladder and bile ducts in children are relatively rare and occur at any age. Many pathophysiological mechanisms are involved: inflammatory (cholangitis), trauma (bilioma), autoimmune (sclerosing cholangitis), iatrogenic (inspissated bile caused by TPN) and congenital diseases (biliary atresia, choledochus cyst). Also a variety of hereditary diseases and syndromes can affect the biliary system: cystic fibrosis, spherocytosis, Alagille syndrome and sickle cell anaemia. The imaging characteristics, imaging techniques and pathophysiology will be discussed. Biliary atresia is a congenital obstruction of the intra- and/or extrahepatic bile ducts. It is one of the causes of persistent neonatal jaundice and is two times more frequent in males. The overall incidence is approximately 1:15.000 births. Children with biliary atresia may have similar clinical, biochemical and histological manifestations as neonatal hepatitis and, therefore, diagnostic imaging plays an important role in differentiating these and other causes of jaundice. US, nuclear medicine and magnetic resonance cholangiopancreatography (MRCP) may be used for the evaluation of neonatal jaundice. Choledochal cysts are congenital saccular or fusiform dilatations of the biliary tree (figure). The overall incidence is approximately 1-2:100.000-150.000 live births. Gallstones are relatively uncommon in children but its incidence has been increasing over the past decades. This is mainly due to the more widespread use of US with as a consequence that gallstones are more frequently detected in asymptomatic children. Furthermore, the increase in obesity in the pediatric age-group certainly plays a role. Cholelithiasis may by idiopathic but in the neonate and young infant it is often associated with sepsis, diuretics, and total parenteral nutrition. In older children, gallstone formation may be caused by haemolytic anaemia, cystic fibrosis, and small bowel diseases. A distinct type of cholangitis is the primary sclerosing cholangitis (PSC). This is a chronic and usually progressive cholestatic liver disease of unknown origin, which can result in liver cirrhosis, portal hypertension, and liver failure. PSC is associated with inflammatory bowel diseases (IBD); 70-80% of patients with PSC have IBD, and, conversely, up to 7% of patients with IBD will develop PSC . The diagnosis is based on clinical and typical imaging features, cholestatic biochemical profile and liver histology.