Teenager with abdominal pain

US and MRI of focal nodular hyperplasia
Transverse US of the liver (above left) shows a round hyperechoic lesion in the liver. Coronal T2 MRI without contrast of the abdomen (above right) shows the lesion in the right lobe of the liver to have slightly increased signal intensity aside from the center of the lesion which has high signal intensity. Axial T1 MRI with contrast of the abdomen obtained in early phase imaging (below left) shows near uniform enhancement of the lesion aside from the center of the lesion while delayed phase imaging (below right) shows delayed stellate-like enhancement of the center of the lesion while the rest of the lesion is now isointense to liver.

The diagnosis was focal nodular hyperplasia.