Figure 1.
Details of the homemade support used for the MR elastography examinations.
The picture on the top shows a thin liver sample (A) placed in a plastic insert (B). The bottom illustration shows the way the sample is placed on the homemade support. The vibration is transmitted by a toothpick placed in the center of the liver sample (C). An electromagnetic shaker located outside the MR scanner (not shown) is used to generate mechanical vibrations via a flexible carbon fiber rod to the toothpick (D).
Table 1.
MR acquisition parameters.
Figure 2.
Parametric maps of Gd at 600 Hz performed on thin liver slices with fibrosis ranging from F0 to F4.
With increasing fibrosis, Gd increases as shown by the progressive changes in colors of the parametric maps.
Table 2.
METAVIR score and fibrosis area of the rat population (N = 47).
Figure 3.
Distribution of Gd (kPa) according to METAVIR stages of fibrosis with mechanical excitation of 600 Hz.
There is a progressive increase of Gd according to the METAVIR stage. Line within boxes represents median, lower and upper limits of boxes represent 25 and 75 percentiles respectively. Whiskers represent 10 and 90 percentiles.
Table 3.
Details of the viscoelastic parameters according to the METAVIR score.
Figure 4.
Correlation between Gd and the area of fibrosis with details of the METAVIR stages (A) and the necro-inflammatory activity (B).
Table 4.
Correlations between the viscoelastic parameters on one hand and the METAVIR scores and the percentages of fibrosis on the other.
Figure 5.
ROC curves of the moduli G*, Gd and Gl at 600 Hz for the differentiation of the METAVIR stages.
The AUROCs of Gd are larger than 0.9.