An animal model for the study of liver regeneration by magnetic resonance imaging

Liver regeneration after partial hepatectomy was studied in rats by means of magnetic resonance (MR) imaging and T1 relaxation time. Fourteen hepatectomized rats were compared to sham operated ones and to controls which had not undergone any surgical treatment. The animals were imaged at 0.5 T, and inversion recovery (IR) technique was employed at the T-null of liver before surgery. T1 was determined in vitro with spectroscopy. Regenerating rat liver exhibited a significantly high increase in MR signal intensity and T1 values (p less than 0.05) 24 hours after surgery, returning to baseline values at 2 weeks. Sham operated animals and controls did not exhibit significant changes in signal intensity from baseline values (p greater than 0.05). These findings suggest that MR imaging is able to detect the pathophysiological changes occurring in liver parenchyma during the regenerating process and to monitor different stages of the hyperplastic process.