Rings and arcs enhancement

Rings and arcs enhancement is an MRI enhancement pattern described as curvilinear post-contrast T1-hyperintensities. This pattern is generally observed in hyaline cartilage-containing tumors (e.g. enchondroma, chondrosarcoma)^1,2

Pathology

This pattern is due to the enhancement of the capillaries arising from the septa and perichondrium around the lesions¹.

Radiographic features

CT

This enhancement pattern is not described on CT, probably due to its low contrast resolution, and because the level of enhancement obtained with gadolinium is higher than that with iodinated contrasts².

MRI

This pattern is often seen in the periphery of the lesions and corresponds to the thin curvilinear T2 hyperintensities, and to the T1 hyperintense bands²

Differential diagnosis

This pattern is a typical feature of hylaine cartilage containing tumors such as:

• enchondroma

• chondrosarcoma

It can also be seen in avascular areas with high-water content lesions (e.g. multicystic tumors) such as: ²

• aneursymal bone cyst

• cystic osteoblastoma

• telangiectatic osteosarcoma