What are the radiologic findings in angiomyolipoma?

Identifying fat is key to confirming the diagnosis. Calcications are nonexistent.
Ultrasound shows a hyperechoic mass, which is nonspecific, as RCC can be echogenic.
CT shows negative HU numbers (-40 to -120 HU), indicating fat. This finding is specific for angiomyolipoma; thin slices may be necessary to demonstrate fat.
MRI can confirm fat as well; it appears bright on T1-weighted images but becomes dark on fat saturation T1-weighted images.
Angiography features are nonspecific; a sunburst pattern is typical.