Hepatocellular carcinoma: correlation between gadobenate dimeglumine-enhanced MRI and pathologic findings.
Grazioli L, Morana G, Caudana R, Benetti A, Portolani N, Talamini G, Colombari R, Pirovano G, Kirchin MA, Spinazzi A.Invest Radiol 2000 Jan;35(1):25-34
RATIONALE AND OBJECTIVES:
To correlate the appearance of hepatocellular carcinoma on delayed
(60 minutes) postcontrast T1-weighted gradient echo images with
the mode of action of gadobenate dimeglumine (Gd-BOPTA) and the
anatomic and pathologic characteristics of the lesions. METHODS:
A total of 34 patients with hepatocellular carcinoma and varying
degrees of diffuse liver disease were studied. T2-weighted spin
echo and T1-weighted spin echo and gradient echo images were acquired
before and 60 minutes after the intravenous administration of
0.1 mmol/kg Gd-BOPTA. Qualitative and quantitative evaluations
of the images were performed and correlated with histologic findings.
The quantitative evaluation, performed on T1-weighted gradient
echo images, looked at the percentage increase of liver enhancement
after Gd-BOPTA administration, the lesion-to-liver contrast/noise
(C/N) ratio before and after Gd-BOPTA administration, and the
C/N variation after Gd-BOPTA administration. Qualitative assessment
considered the morphologic 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 presence of fatty metaplasia, necrosis,
bile, or intratumoral peliosis. RESULTS: Among the parameters
affecting lesion identification were the extent of liver function,
degree of vascularization, residual functionality of the tumor
cells, and characteristics of the neoplastic tissue. Positive
correlations (Spearman coefficients = 0.359 and 0.393, respectively)
were observed precontrast between the degree of liver failure
and the amount of contrast noise, and postcontrast between the
amount of intralesional fatty metaplasia and the extent to which
lesion conspicuity worsened after Gd-BOPTA administration. An
inverse correlation (Spearman coefficient = -0.330) was observed
between the degree of lesion differentiation and the visible appearance
after Gd-BOPTA administration, with well-differentiated lesions
tending toward worsened conspicuity postcontrast. A statistically
significant difference (P = 0.001) was observed in the mean precontrast
C/N ratio for lesions later showing unchanged conspicuity and
worse conspicuity on postcontrast images, respectively. Marked
variation (P = 0.019) was also observed between 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 residual hepatocytic functionality permits
Gd-BOPTA uptake by certain lesions and that this uptake might
subsequently impair the observed C/N ratio on delayed images,
and that the worsening of lesion conspicuity on postcontrast images
is influenced also by high quantities of intralesional fatty metaplasia.
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