Abdominal Imaging - Original Article

Hyperintensity at fat spared area in steatotic liver on the hepatobiliary phase MRI

10.5152/dir.2019.18535

  • Emre Ünal
  • İlkay Sedakat İdilman
  • Ali Devrim Karaosmanoğlu
  • Mustafa Nasuh Özmen
  • Deniz Akata
  • Muşturay Karcaaltıncaba

Received Date: 05.12.2018 Accepted Date: 16.04.2019 Diagn Interv Radiol 2019;25(6):416-420

PURPOSE

We aimed to investigate the reasons for hyperintensity at fat spared area in steatotic liver at hepatobiliary phase (HBP) on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced liver magnetic resonance imaging.

METHODS

Twenty-two patients with focal fat spared area demonstrating hyperintensity on HBP images were included. A region of interest was placed on in- and opposed-phase images at fat spared area and liver to measure the fat. The measurement was also performed on precontrast T1-weighted and HBP images. The signal intensities of spleen, kidney, muscle, intervertebral disc, and spinal cord were also recorded.

RESULTS

The mean fat fraction of liver and fat spared area was 24.86% (8%–46%) and 8.41% (1%–34%), respectively (P < 0.001). There was a significant positive correlation between liver parenchyma fat fraction and delta fat fraction (r=0.74, P < 0.001). The mean signal intensity values of fat spared areas were higher compared with liver on precontrast T1-weighted and HBP images (P < 0.001). The mean relative enhancement ratio of liver and fat spared areas were 0.98 (0.05–1.90) and 1.15 (0.22–2.03), respectively (P < 0.001). However, in 6 patients, the relative enhancement ratio of liver and fat spared areas were almost equal. The uptake of Gd-EOB at fat spared area was not correlated with the degree of steatosis (r = -0.01, P = 0.95).

CONCLUSION

Fat spared area in steatotic liver appears hyperintense on HBP images due to increased relative enhancement ratio and/or baseline hyperintensity on precontrast images.