MedUNAB (Aug 2006)
Magnetic resonance imaging of the liver
Abstract
MR imaging of the liver has gained an important role in the diagnosisand characterization of the hepatic lesions due to the technologicaladvances that have diminished the acquisition time of the images,the use of new sequences and contrast media to show the paternsof vascularización. Cysts and bile duct hamartomas are hypointensein T1 and hyperintense in T2; they are differentiated by a thin ringof gadolinium enhancement, hemangiomas are more common inwomen, they are hypointense in T1 and moderately hyperintensein T2, with a centripetal enhancement in the arterial phase. Focalnodular hiperplasia is iso to slightly hypointense in T1 and iso toslightly hyperintense in T2 and enhances intensely in the arterialphase, and has a central scar that in the delayed images gets tobe isointense to slightly hyperintense. Adenomas are moderatelyhypointense in T1 and isointense to slightly hyperintense in T2, theyhave marked enhancement in the arterial phase but it disappearsin the venous and delayed images, persisting an enhancing ring.Regenerative nodules are isointense in T1 and iso to hypointensein T2, displástic nodules are hyperintense or hypointense in T1 andiso in T2, they differ from hepatocelular carcinoma because they aregenerally less than 2 cm and because carcinoma has noticeableand heterogenous enhancement in the arterial phase.
