Acetaminophen overdose is the most common cause of acute liver failure in North America and Europe¹. Gadoxetate disodium (Eovist/Primovist) (Gd-EOB-DTPA) is an FDA-approved contrast agent that is specific to hepatocytes. It is used clinically for detection of liver cancer and cirrhosis, but has not been applied to detect drug-induced liver injury². We propose to use gadoxetate disodium uptake to measure hepatocyte health after acetaminophen toxicity. We have developed a novel method to maintain liver enhancement during the acquisition of T1 maps by infusing gadoxetate disodium intravenously, and applied it in healthy mice and mice with liver damage from acetaminophen.Imaging was performed on a 7T Bruker BioSpec 70/30 USR using a volume transmit coil and 4-channel receive surface coil. Mice (8-10 weeks) were anaesthetized with isoflurane then their tail veins were catheterized. Mice were placed prone on the receive coil. Temperature was maintained through a pad with circulating water. T1-weighted images were acquired every minute at a resolution of 234x234x400 µm. Mice were injected with gadoxetate disodium through the tail vein catheter during acquisition, either with a single injection of 100 µL of gadoxetate disodium (0.625 µmol) at a clinical dose of 0.025 mmol/kg (n=5), or with the injection followed by an infusion of the same dose at 0.13 mL/h (0.81 µmol/h) using an infusion pump (n=5). A series of inversion-recovery images were acquired using the TrueFISP sequence at a resolution of 200x200x400 µm, and T1 maps were processed using non-linear least squares parameter estimation in Matlab³. For acetaminophen overdose, mice were treated with 300 mg/kg acetaminophen IP then imaged 24 h later using the injection/infusion protocol (n=2).After injection of gadoxetate disodium in healthy mice, signal enhancement in the liver followed the expected pattern of a steep increase followed by a slower washout phase. Time to maximum liver enhancement was approximately 10 minutes (Figure 1). The enhancement decreased by 7-20% over the time needed to acquire a T1 map during the washout phase. When gadoxetate disodium infusion was initiated 10 minutes after the initial bolus injection at 0.13 mL/h (0.81 µmol/h), stable signal enhancement was achieved in the liver for over 30 minutes (Figure 2). Rectal temperature was maintained at about 29°C (Figure 3). During the gadoxetate disodium infusion, signal enhancement in healthy mouse liver was homogeneous, while it was heterogeneous in acetaminophen treated livers (Figure 4). T1 of the liver in the healthy mouse was 308 ms. In the two acetaminophen-treated mice, the liver T1 was 510 ms and 560 ms. The appearance of the T1 map is more homogeneous in the healthy mouse than in the acetaminophen-treated mice (Figure 5). It was more difficult to maintain a constant temperature when acquiring T1 maps than with the T1W imaging, because of RF power deposition by the TrueFISP sequence; a modification to our temperature control system may be necessary.Stable signal enhancement of the mouse liver was achieved by using a bolus plus infusion administration of gadoxetate disodium. This enabled the acquisition of T1 maps with consistent amounts of gadoxetate disodium throughout the scan without washout of the contrast agent. The gadoxetate disodium uptake pattern was different in healthy mice and mice with liver damage from acetaminophen. T1 enhancement of the acetaminophen damaged livers was less than that of healthy livers, indicating that there was decreased gadoxetate disodium uptake in the damaged livers.T1 maps with stable gadoxetate disodium concentration will offer the chance to measure gadoxetate disodium uptake and quantify hepatocyte health in drug induced liver injury and other liver disease models. To our knowledge, this is the first description of stable, extended gadoxetate disodium enhancement.