Native magnetic resonance imaging of morris hepatoma in the rat

Goal of the study presented was to establish an oncological animal model fo r implantable and differentiated hepatoma in the rat and to evaluate imagin g of the tumor induced using MRI. Material and Methods: 20 male buffalo rat s underwent tumor cell implantation of 150000 MH7777-A cells via laparotomy . After 12 days MRI was performed T(1)w SE, T(2)w TSE fs, TIRM) for tumor d etection and measurement of size. Immediately there after all rats were kil led and macroscopic and histological examination performed. Pathological fi ndings were correlated with MRI. Results: In 5 out of 20 animals no tumor w as found. Mean size of the hepatomas in 15 animals was 3.1 mm (+/- 1.7 mm; 1 - 7 mm). On MRO 14 out of 15 tumors were detectable. Mean diameter in MRI was 2.7 mm (+/- 1.5 mm; 1 5 mm). T(2)w TSE was superior for tumor detectio n compared with the TIRM, while the best anatomic depiction was offered by T(1)w SE. Conclusions: The MH7777-A tumor model presents with a rate of 75% even with the small tumor cell amount of 150000 cells. With MRI using T-2 weighted sequences with fat saturation a detection of tumors with diameters of 1 mm is reliably possible in 93 % of the cases.