Computed tomography and hypocycloid tomography in lesions of the nose, paranasal sinuses and nasopharynx.

In 31 patients with lesions mainly arising from the nose, paranasal sinuses and nasopharynx comparative evaluation of the results of CT and hypocycloid tomography indicated that CT generally gave a better representation of both the bony structures and the soft parts and alone has the capacity to evaluate intracranial extension. CT should first be performed in the transverse axial plane. If abnormalities in relation to horizontal bony structures are demonstrated, the examination should be supplemented by CT in the coronal plane or, if CT scanning in this plane is not possible, by conventional tomography. Enhancement after intravenous injection of contrast medium does not as a rule seem to add information of diagnostic importance.