MRI has become the method of choice for evaluating perianal fistulae due to its ability to display the anatomy of the sphincter muscles orthogonally, with good contrast resolution. In this article we give an outline of the classification of perianal fistulae and present a pictorial assay of sphincter anatomy and the MRI findings in perianal fistulae. This study is based on a retrospective analysis of 21 patients with a clinical diagnosis of perianal fistula.

A variety of diffuse diseases affect the calvaria. They may be identified clinically as palpable masses or incidentally in radiologic examinations. The purpose of this study is to illustrate the main diffuse calvarial lesions starting from a case report of fibrous dysplasia of the cranial vault. A 68-year-old male patient who presented with a history of right otalgia and bloody otorrhea was diagnosed to have fibrous dysplasia based on the radiological features. Most diffuse diseases of the calvaria are benign non-neoplastic lesions of unknown origin. The radiologist has a long list of differential diagnosis and their true etiology may be puzzling when the medical evaluation is based only on imaging findings.