An anal fissure is a tear or cut that extends into the anal canal. While many fissures are small, the area is sensitive, and any tear can be painful. About 11% of people are affected, often ...

An anal fissure is usually a short-term (or acute) problem, with symptoms that last 6 weeks or less. It's considered long-term or chronic when symptoms last more than 6 weeks.

Arachnoid Cyst of the Posterior Cranial Fossa: (Left) T1-weighted axial MRI; (Right) T2-weighted axial image. Note the large cystic lesion in the posterior fossa. As the cyst contains fluid, it is ...