Figure 3c. Transverse breath-hold T1-weighted MR images (131/4.1, 80° flip angle) obtained in a patient with focal nodular hyperplasia in the left lobe of the liver. (a) Before contrast enhancement. Note the almost isointense lesion (arrowheads) with a hypointense scar (arrow). (b) Arterial phase image (approximately 25 seconds after contrast material injection). Note the early marked enhancement of the lesion with a nonenhancing central scar (arrow). (c) Portal venous phase image (approximately 60 seconds after injection). Note that the lesion is almost isointense to the liver, and note the delayed enhancement of the central scar (arrow).