Hepatocellular carcinoma - Correlation between gadobenate dimeglumine-enhanced MRI and pathologic findings

RATIONALE AND OBJECTIVES. TO correlate the appearance of hepatocellular car cinoma on delayed (60 minutes) postcontrast T1-weighted gradient echo image s with the mode of action of gadobenate dimeglumine (Gd-BOPTA) and the anat omic and pathologic characteristics of the lesions. METHODS. A total Of 34 patients with hepatocellular carcinoma and varying d egrees of diffuse liver disease were studied. T2-weighted spin echo and T1- weighted spin echo and gradient echo images were acquired before and 60 min utes after the intravenous administration of 0.1 mmol/kg Gd-BOPTA, Qualitat ive and quantitative evaluations of the images were performed and correlate d with histologic findings. The quantitative evaluation, performed on T1-we ighted gradient echo images, looked at the percentage increase of liver enh ancement after Gd-BOPTA administration, the lesion-to-liver contrast/ noise (C/N) ratio before and after Gd-BOPTA administration, and the C/N variatio n after Gd-BOPTA administration. Qualitative assessment considered the morp hologic features of the lesions as well as the visual variation of contrast before and after Gd-BOPTA administration, Finally, a histologic evaluation was made of the degree of differentiation of the lesions and of the presen ce of fatty metaplasia, necrosis, bile, or intratumoral peliosis, RESULTS. Among the parameters affecting lesion identification were the exte nt of liver function, degree of vascularization, residual functionality of the tumor cells, and characteristics of the neoplastic tissue. Positive cor relations (Spearman coefficients = 0.359 and 0.393, respectively) were obse rved precontrast between the degree of liver failure and the amount of cont rast noise, and postcontrast between the amount of intralesional fatty meta plasia and the extent to which lesion conspicuity worsened after Gd-BOPTA a dministration. An inverse correlation (Spearman coefficient = -0.330) was o bserved between the degree of lesion differentiation and the visible appear ance after Gd-BOPTA administration, with well-differentiated lesions tendin g toward worsened conspicuity postcontrast, A statistically significant dif ference (P = 0.001) was observed in the mean precontrast C/N ratio for lesi ons later showing unchanged conspicuity and worse conspicuity on postcontra st images, respectively. Marked variation (P = 0.019) was also observed bet ween Child A and B cirrhotic patients for the degree of hepatic enhancement on postcontrast images. CONCLUSIONS. The results suggest that liver parenchyma signal intensity is influenced by the extent to which liver function is compromised, that resid ual hepatocytic functionality permits Gd-BOPTA uptake by certain lesions an d that this uptake might subsequently impair the observed C/N ratio on dela yed images, and that the worsening of lesion conspicuity on postcontrast im ages is influenced also by high quantities of intralesional fatty metaplasi a.