Intrathoracic rib demonstrated by helical CT with three-dimensional reconstruction.

Intrathoracic rib is a rare congenital anomaly. An unusual location with atypical pleural tenting is reported. Helical CT with three-dimensional reconstruction seems the best modality for demonstrating the origin and location of these abnormal ribs. The importance of the diagnosis of intrathoracic rib is to rule out pulmonary lesions and prevent unnecessary investigations.