CT detection of hepatic and splenic injuries: usefulness of liver window settings

OBJECTIVE. This study was designed to assess the usefulness of liver window settings when performing abdominal CT for the detection and characterization of hepatic and splenic injuries. SUBJECTS AND METHODS. We prospectively evaluated helical abdominal CT scans for hepatic and splenic injuries in 300 consecutive patients with blunt abdominal trauma over a 4-month period. There were 204 males and 96 females with a mean age of 34 years (age range, 1-87 years). For each patient, initial CT diagnosis of hepatic or splenic injury was made from images obtained with standard abdominal window settings. CT scans were then immediately reinterpreted using additional images obtained at narrow window width (liver windows). Changes in conspicuity and characterization of injury were recorded. All CT examinations were performed with helical 7-mm collimation at a pitch of 1.5 after oral ingestion of diluted barium and during bolus IV administration of 125 mL of ioversol at a rate of 2-3 mL/sec. RESULTS. We detected hepatic or splenic injuries in 34 patients (11.3%). There were 19 hepatic injuries and 18 splenic injuries. Three patients had injuries to both liver and spleen. Conspicuity of hepatic or splenic injuries was mildly increased (+1 H) on liver windows in 16 patients, whereas the injury was equally conspicuous on both liver window and standard window images in 19 cases. In no case did review of the liver windows result in a change in grade of injury or reveal an injury that was not seen on standard abdominal window images. The total increased cost for printing liver windows was $5748. CONCLUSION. Routine use of liver window settings for abdominal CT in trauma patients has little clinical usefulness and is not cost-effective.