MSCT Imaging Anatomical Study Of The Pterygopalatine Fossa And Its Communications

The pterygopalatine fossa (PPF) is an irregular space between the posterior wall of the maxillary sinus and the anterior surface of the pterygoid process of the sphenoid bone. PPF is an important space because it communicates with the middle cranial fossa, orbit, nasal cavity, oral, cavity, pharynx, foramen lacerum, and the infratemporal fossa via eight foramina and canals. PPF serves in distributing the several neural and vascular connections which embedded in loose fatty tissue. The pterygopalatine fossa and all of its communications represent potential pathway for spread of inflammatory or neoplastic disease among the various abovementioned compartments.The researches of PPF are always difficult and important in human anatomy,imageology, maxillofacial region and basilar region therapeutics.Familiarity with the appearance of the fossa and related connections is necessary for early detection of tumor extension.In this article, particular attentions were given to the normal MSCT anatomy appearance of the PPF and it communicates as well as to its variants . ObjectiveTo investigate the normal anatomic appearance of the pterygopalatine fossa and its communications and to discuss the characteristics of the pathological changes involved the pterygopalatine fossa and its communications on both 2D and 3D images of MSCT. Moreover, the clinical value of MSCT of pterygopalatine fossa were explored in order to provide anatomy data for endoscopic surgery, dentofacial surgery and neurosurgery approach to pterygopalatine fossa and its communications. Materials and MethodsThe normal PPF was studied in 40 volunteers,in 30 patients who had maxillafacial injury while with intact pterygopalatine fossa and in 30 cases undergoing CTA, and pathological changes were observed in 71 cases of various diseases by MSCT scanner( TOSHIBA Aquilion/16s scanner). Additional 3D reconstructed images of the pterygopalatine fossa were obtained in workstation. The volume data were subjected to multiplanar reformation (MPR),Cueved planar reformation (CPR) and volume rendering(VR) in Vitrea-2 working station. All MSCT 2D and 3D Findings were analyzed respectively.Results1 The PPF were well demonstrated on MSCT.On transverse CT sections the PPF displayed different shapes,while on coronal plane usually appeared as a quadrangular space in the anterior portion and as triangle or oval-shap in the poste- rior,and on sagittal plane a funnel—shaped shadow.2 The communicational paths of the PPF,including foramcn rotundum , inferior, orbital fissure, sphenopalatine foramen, pterygoid canal, pterygopalatine canal, pterygomaxillary fissure, greater palatine foramcn and lesser palatine foramcn were also extensively appreciated from different point of view and direction in MSCT transverse scans, MPR and VR images. In this study, using MSCT, anatomical structures and variants of the PPF and its communications are outlined in the hope that this may prove helpful in providing a basis for the diagnosis and treatment of pathological conditions involving the PPF and its communications.3 Secondary malignant tumors were the most common lesion of the PPF. The secondary malignant tumors usually infilitratively destructed the bony wall to involve PPF,the surrounding tissue and the fat within PPF were eroded,and usually poorly defined. the PPF bony wall was slightly enlarged or completely eliminated.4 The center of the tumor can reflect the initiation location in some degree which would help to judge primary or secondary tumor. The primary benign tumors result in the bony wall enlarged obviously, the bone destroy mostly present swelled.5 For the secondary tumor ,the order and appearance of the bone absorption and erosion somewhat explained the origin and growth trend of the tumor.6 The single linetype fracture of PPF and its communications is few, while the comminuted fractures which can put multi bone wall or fabric into trouble can be found frequently and companion the complex basal fracture. The MPR which can observe from more directions is benefit for reveal the fracture line and the bone fragment.7 When the inflammatory pathological changes intrude into PPF, the fattiness image in PPF is blur, the infection of bone wall in PPF is few or slight coarseness.8 The infection of Fibrous dysplasia of bone in PPF and its communications can be represent as straitness and distortion, for the relatively long cranny and canal such as roundum foramen,pterygoid hamulus and inferior orbital fissure, The Fibrous dysplasia of bone can make them straiten as well as increasing the length. ConclusionThe pterygopalatine fossa and its communications can be clearly, wholely and directly Indicated and pathologic features of the PPF and its communications were better defined in MSCT scanning images, MPR and VR images. Early bony lesions of the the PPF and its communications can be easily detected,Which would help for early diagnosis and treatment of these diseases involved PPF and its communications.