Hypodense liver lesions in patients with hepatic steatosis: do we profit from dual-energy computed tomography?

To evaluate dual-energy CT (DECT) imaging of hypodense liver lesions in patients with hepatic steatosis, having a high incidence in the general population and among cancer patients receiving chemotherapy. One hundred and five patients with hepatic steatosis (liver parenchyma < 40 HU) underwent contrast-enhanced DECT with reconstruction of pure iodine (PI), optimum contrast (OC), 80 kV(p), and 120 kV(p)-equivalent data sets. Image noise (IN), lesion to liver signal to noise (SNR) and contrast to noise (CNR) ratios were quantitatively analysed; image quality was rated on a 5-point scale (1, excellent; 2, good; 3, fair; 4, poor; 5, non-diagnostic) by two independent reviewers. In 21 patients with hypodense liver lesions, IN was lowest in PI followed by 120 kV(p)-equivalent and OC, and highest in 80 kV(p). SNR was highest in PI (1.30), followed by 120 kV(p)-equivalent (0.72) and 80 kV(p) (0.63), and lowest in OC (0.55). CNR was highest in 120 kV(p)-equivalent (4.95), followed by OC (4.55) and 80 kV(p) (4.14), and lowest in PI (3.63). The 120 kV(p)-equivalent series exhibited best overall qualitative image score (1.88), followed by OC (1.98), 80 kV(p) (3.00) and PI (3.67). In our study, the 120 kV(p)-equivalent series was best suited for visualization of hypodense lesions within steatotic liver parenchyma, while using DECT currently seems to offer no additional diagnostic advantage. aEuro cent Hepatic steatosis has high incidence in the general population and following chemotherapy. aEuro cent Hypodense liver lesions can be obscured by steatotic liver parenchyma in CT. aEuro cent Low kV (p) -CT shows no advantage in detecting hypodense lesions in steatotic livers. aEuro cent Additional DECT image information does not improve visualization of hypodense lesions in steatosis. aEuro cent 120 kV (p) -equivalent imaging yields best quantitative and qualitative image analysis results.