Detection of hepatic steatosis on contrast-enhanced CT images: diagnostic accuracy of identification of areas of presumed focal fatty sparing.
OBJECTIVE
The purpose of this article is to determine the diagnostic accuracy of identifying focal areas of increased density along the gallbladder fossa or in the periphery of segment IV for diagnosing hepatic steatosis.


METHODS
Five hundred consecutive three-phase CT examinations were retrospectively evaluated. Two reference standards for hepatic steatosis were determined using the unenhanced CT examination: a liver-spleen attenuation difference of greater than 10 HU and the absolute attenuation of the liver less than 40 HU. The portal venous phase was independently analyzed by two radiologists. Hepatic steatosis was diagnosed on the contrast-enhanced images if there was increased attenuation in the liver, either at the gallbladder fossa or in the posterior medial aspect of segment IV, when compared with background liver parenchyma.


RESULTS
The criterion of relative liver-spleen attenuation difference diagnosed 38 cases. The criterion of absolute liver attenuation less than 40 HU diagnosed 44 cases. Of these cases, hepatic steatosis was diagnosed on the portal venous phase in 23 cases (κ = 1.0), with no false-positive cases. The criterion of relative liver-spleen attenuation difference yielded sensitivity, specificity, positive predictive value, and negative predictive value of 60.5%, 100%, 100%, and 96.9%, respectively. The criterion of absolute liver attenuation less than 40 HU yielded sensitivity, specificity, positive predictive value, and negative predictive value of 52.5%, 100%, 100%, and 95.7%, respectively.


CONCLUSIONS
Qualitative evaluation of the liver on a portal venous phase contrast-enhanced CT is highly specific for the diagnosis of hepatic steatosis; the sensitivity of the method, however, is rather low.
Department of Diagnostic Radiology, Yale University School of Medicine, 333 Cedar St, PO Box 208057, New Haven, CT 06520, USA. david.lawrence@yale.edu
David A
DA
Lawrence
Isabel B
IB
Oliva
Gary M
GM
Israel
D003287:Contrast Media; D005234:Fatty Liver / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008111:Liver Function Tests; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011856:Radiographic Image Enhancement / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D003287:Contrast Media