Imaging of the nerves of the knee region.

Peripheral neuropathies are a frequent, but often underdiagnosed, cause of pain and functional impairment. The clinical symptoms can be subtle, and other neurologic or non neurologic clinical entities are often evoked. MRI and ultrasonography are the imaging modalities of choice for depicting nerves and assessing neuropathies. Common neuropathies in the knee area involve the saphenous, the tibial, the common peroneal and the sural nerves. The most frequent mechanisms of nerve injury in this area are nerve entrapment and nerve stretching. A perfect knowledge of the normal imaging anatomy is essential for accurate assessment of neuropathies. In this article, we will review the anatomy of the nerves around the knee, and their normal and pathological appearance.

[Mature and immature ovarian teratomas: US, CT and MR imaging features]. / Tératomes ovariens matures et immatures: caractéristiques en échographie, TDM et IRM.

Mature cystic ovarian teratomas, also called dermoid cysts, are one of the most frequent ovarian tumors of younger female patients and are suggested when a fat-containing cystic tumor is identified on imaging. However, the presence of fat is not pathognomonic for dermoid cyst, and it may also be identified in immature teratomas, whose prognosis and treatment are different. Some imaging features are helpful to differentiate between both tumors, including th epresence of enhancement on CT and MRI. Knowledge of the imaging features of these tumors allows for a confident diagnosis to be made in most cases. A few rare and less typical imaging features should also be recognized.