Iron-EHPG as a hepatobillary contrast agent in MR imaging of liver tumors

Fifty-five rats with experimentally induced liver cancer were examined at 2.0 T. Fe-EHPG in five different dosages (iron, 0.01-0.5 mmol/kg) and Gd-DTPA in six different dosages (gadolinium, 0.01-1.0 mmol/kg) were tested in five rats each. The best contrast between liver and tumor was achieved with Fe-EHPG at a dosage of 0.1 mmol/kg and with Gd-DTPA at a dosage of 0.2 mmol/kg. While Gd-DTPA leads to an optimal contrasting only during the first 3 minutes of the dynamic study, Fe-EHPG leads to a significant contrast improvement between 7 and 21 minutes after application. For tumor recognition, Fe-EHPG yielded better results than Gd-DTPA due to the prolonged contrast effect. The perfusion of intrahepatic tumors, on the other hand, can be visualized by means of Gd-DTPA and fast imaging