Evaluation of liver T_1rho and T₂ values in acute liver inflammation models using 7T-MRI

We measured the T_1rho and T₂ values the liver of acute liver inflammation model mice administered carbon tetrachloride (CCl₄) after 3 days and 6 days after dispensed, and we compared and examined whether each relaxation time can be used for detect acute liver inflammation.

To create an acute liver inflammation model, a mixture of 0.2 ml / 100 g of CCl₄ with an equal amount of Sesame Oil was administered once intraperitoneally to C57BL / 6JJmsSlc mice (n = 15). On the 3 days and 6 days after administration, we acquired T_1rho mapping images and T₂ mapping images of the liver under respiratory synchronization using for preclinical 7T-MRI, and we measured T_1rho and T₂ values and compared statistically.

The liver T_1rho value of control mice was 33.9 ± 2.5 ms before CCl₄ administration, 43.2 ± 4.9 ms (p < 0.01) on the 3 days post CCl₄ injection, and 41.0 ± 1.2 ms (p < 0.001) on the 6 days post CCl₄ injection. The rate showed a significant increase of 27% on the 3 days after, as well as significant increase of 21% on the 6 days after. On the other hand, the liver T₂ value of control mice was 26.7 ± 1.9 ms before CCl₄ administration, 31.5 ± 3.4 ms (p < 0.05) 3 days post CCl₄ injection, and 29.0 ± 2.0 ms (p = 0.06) 6 days post CCl₄ injection. The rate 3 days after CCl₄ administration showed a significant increase of 18%, after 6 days rate increased 9%, but no significant difference was confirmed compared with normal mice.

The T_1rho value changed significantly compared to the T₂ value, and a continuous change was observed even after 6 days. T_1rho mapping can diagnose acute liver inflammation.