A comparative study of the pterygopalatine fossa by computed tomography and magnetic resonance

: The pterygopalatine fossa (PPF) is a narrow, bone lined space containing many major cranial nerves and vessels connecting it to the middle and infratemporal cranial fossa, the oral, nasal and orbital cavities and the rhinopharynx. The internal maxillary artery, the second branch of the V cranial nerve and the sphenopalatine ganglion are the main structures which are found in the PPF. Because of its strategic site, the PPF can be involved in many pathologic conditions originating from the nasal fossa, the orbit, the paranasal sinuses or the rhinopharynx roof. Severe craniofacial trauma can involve the pterygopalatine area too. Consequently, the detailed knowledge of PPF anatomy and the use of the current imaging modalities are necessary in the study of pterygopalatine lesions. We examined a group of 7 patients who underwent CT and MRI for diseases not involving the pterygopalatine area. CT consisted of axial and coronal contiguous 1-mm scans, with post-processing sagittal and 3D reconstructions. MRI was performed with a middle-field unit, using a head coil and high-resolution 3-mm T1- and T2-weighted spin- and fast-spin-echo scans. 3D SPGR pulse sequences were also performed. We found HRCT scans and post-processing 3D studies to be particularly indicated in bone structure analysis. SPGR, spin- and fast-spin-echo MR sequences allowed us to obtained reliable images of the main nervous and vascular structures found in the PPF. Finally, we believe combined CT and MRI to be the method of choice in the study of PPF anatomy and in the assessment of diseases involving the PPF area.