38 year old woman underwent an abdominal CT for flank pain, found to have a liver lesion.
The patient subsequently underwent an MRI for further evaluation of the lesion:
Barely discernable on T2-weighted images, a hyperenhancing mass in the anterior right hepatic lobe is seen on arterial phase post contrast images, which fades into the background hepatic parenchyma on venous/delayed phase images.
The MRI appearance is classic for focal nodular hyperplasia (FNH). These lesions are hypervascular on arterial phase images and often “vanish” on venous/delayed phase. A central scar may be present, with enhancement only in the delayed phase.
This lesion has been described as looking like a boutonniere in the arterial phase (Rendon Nelson – Duke University).
Suppose, as in this case, the patient had a Tc99m sulfur colloid study without increased uptake. Does this change our diagnosis?
The short answer is no. Although this lesion does not have the prototypical finding of increased uptake on Tc99m sulfur colloid, up to 1/3 of cases of FNH may have decreased uptake on sulfur colloid imaging.
Please see topic discussion on Functional and Anatomic Imaging of Liver Lesions.