2 Imaging and intervention in patients with acute right upper quadrant disease

Because of the high diagnostic yield, its widespread availability and the possibility of bedside examinations, US has become the imaging modality of choice in patients with acute right upper quadrant pain caused by inflammatory disorders such as liver abscesses, acute cholangitis and acute cholecystitis. Computed tomography (CT) can be reserved for more complex cases. US, often in combination with fluoroscopy, is also widely used to control interventions. In patients with liver abscesses the therapeutic strategy is determined by the size of the abscess, its uni- or multifocal presentation and the causative micro-organisms cultured after diagnostic percutaneous aspiration. Small-sized pyogenic abscesses (<3 cm), most fungal and amoebic abscesses can be treated medically. Large-sized pyogenic abscesses should be drained percutaneously and can be cured in 75–90%. Surgery should be restricted to patients with prolonged sepsis after percutaneous drainage and patients with infected pre-existing hepatic lesions.In patients with acute cholangitis drainage of the infected bile is essential. Invasive imaging such as percutaneous or endoscopic cholangiography should only be done with the intention to drain. The use of endoscopic procedures such as nasobiliary drainage, stent placement and sphincterotomy has decreased mortality rates dramatically. Percutaneous drainage should be considered in patients in whom endoscopic procedures fail. Surgery may have a place in the treatment of bile duct obstruction which causes cholangitis.In patients with suspected acute cholecystitis, imaging modalities such as cholescintigraphy and CT can be reserved for patients with inconclusive sonographic studies and more complex cases. The contribution of percutaneous gallbladder aspiration and culture to diagnose acute cholecystitis seems limited. Percutaneous cholecystostomy is an effective procedure with a low morbidity and mortality for high-risk patients. The drainage catheter in the gallbladder does not interfere with cholecystectomy at a later stage in patients with calculous cholecystitis. In most patients with acalculous cholecystitis, percutaneous cholecystectomy provides a definitive treatment.