title: Hepatic gas: widening spectrum of causes detected at CT and US in the interventional era.
abstract: The spectrum of causes of hepatic gas detected at computed tomography (CT) and ultrasonography (US) is widening. There are many iatrogenic and noniatrogenic causes of hepatic parenchymal, biliary, hepatic venous, and portal venous gas. Hepatic gas may be an indicator of serious acute disease (infarct, infection, abscess, bowel inflammation, or trauma). In other clinical scenarios, it may be an expected finding related to therapeutic interventions (such as surgery; hepatic artery embolization for a tumor or for active bleeding in acute trauma cases; percutaneous tumor ablation performed with radiofrequency, cryotherapy, laser photocoagulation, or ethanol). In some cases, hepatic gas is an incidental finding of no clinical significance. Familiarity with the expanding list of newer intervention-related causes of hepatic gas detected at CT and US, knowledge of the patient's clinical history, and a careful search for associated clues on images are all factors that may allow the radiologist to better determine the clinical relevance of this finding.
authors.affiliation: Department of Diagnostic Radiology and Surgery, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
authors.forename: Priti A
authors.initials: PA
authors.lastname: Shah
authors.forename: Steven C
authors.initials: SC
authors.lastname: Cunningham
authors.forename: Tara A
authors.initials: TA
authors.lastname: Morgan
authors.forename: Barry D
authors.initials: BD
authors.lastname: Daly
mesh_terms: D000007:Abdominal Injuries / Q000000981:diagnostic imaging; D001659:Biliary Tract / Q000000981:diagnostic imaging; D001660:Biliary Tract Diseases / Q000000981:diagnostic imaging; D002483:Cellulose, Oxidized / Q000009:adverse effects; D003113:Colonoscopy; D013505:Digestive System Surgical Procedures; D005740:Gases; D006801:Humans; D007049:Iatrogenic Disease; D033162:Incidental Findings; D007422:Intestines / Q000473:pathology; D007431:Intraoperative Complications / Q000000981:diagnostic imaging; D008099:Liver / Q000000981:diagnostic imaging*; D008107:Liver Diseases / Q000000981:diagnostic imaging; D009336:Necrosis; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011859:Radiography; D014463:Ultrasonography
chemical_list: D002483:Cellulose, Oxidized; D005740:Gases; C013695:Surgicel