Macroscopic heterogeneity of liver fat: an MR-based study in type-2 diabetic patients

To assess the heterogeneity of liver fat deposition with MR of the liver in type-2 diabetic (T2D) patients.

We enrolled 121 consecutive T2D patients. The reference standard was 3.0-T (1)H-MR spectroscopy. Hepatic steatosis was defined as liver fat content (LFC) ≥5.56 %. A triple-echo gradient-echo sequence corrected for T1 recovery and T2* decay was used to calculate LFC in left and right livers and hepatic segments. Analyses were performed using a linear mixed model.

Fifty-nine (48.8 %) patients had liver steatosis, whereas 62 (51.2 %) did not. Steatosis was greater in the right than in the left liver (P < 0.0001) [mean difference: 1.32 % (range: 0.01-8.75 %)]. In seven patients (5.8 %), LFC was <5.56 % in one side of the liver, whereas it was ≥5.56 % in the other. Steatosis of the left and right liver was heterogeneous at the segmental level in both non-steatotic (P < 0.001 and P < 0.0001 respectively) and steatotic (P < 0.0001 and P = 0.0002 respectively) patients [mean maximum difference: 3.98 % (range: 0.74-19.32 %)]. In 23 patients (19 %), LFC was <5.56 % in one segment, whereas it was ≥5.56 % in at least one other.

Overall, the mean segmental/lobar variability of steatosis is low. However, segmental variability can sometimes lead to a misdiagnosis.

There is a need for methods quantifying steatosis over a large region. Steatosis is usually greater in the right than left lobe of the liver. Steatosis within both left and right hepatic lobes is segmentally heterogeneous. Segmental variability of steatosis can result in misdiagnosis.