MRI chính kịp thời nhưng không có bằng chứng của sự xói mòn xương trên CT, sau đó phẫu thuật thăm dò nên được khấu trừ và các bệnh nhân chỉ theo sau với các phương pháp lâm sàng và X quang để phát hiện các khả năng của một tổn thương tiến bộ. Tài liệu của tiến trình biện minh | 46 Chapter 5 Petrous Apex Lesions 5 Fig. A CT scan in a middle-aged woman with recurrent vertigo revealed an osteolytic lesion arrowhead in the petrous apex Fig. Arteriogram in the same patient as Fig demonstrated an aneurysm of the internal carotid artery. Since neurological deficits were absent observation was recommended. MC middle cerebral artery Fig. Coronal MRI demonstrates a localized enhancement arrowhead in the petrous apex of a middle-aged female with recurrent vertigo and normal labyrinthine function Fig. Axial CT scan demonstrated a cavity with intact bone trabeculae in the petrous apex arrowhead . Transmastoid exploration revealed a venous lake tive MRI but with no evidence of bone erosion on CT scanning then surgical exploration should be withheld and the patients only followed with clinical and radiologic methods to detect the possibility of a progressive lesion. Documentation of progression justifies surgical exploration. Petrositis In the preantibiotic era the most common cystic lesion of the petrous apex was infection either chronic or acute as a result of extension of the inflammatory process from the middle ear and mastoid compartments 11 . Progression of an epidural abscess in Management 47 Fig. a Patient with chronic otitis media and retro-orbital pain. Axial CT scan demonstrates opacification of petrous apex air cells with decalcification of bony trabeculae arrow . The contralateral petrous apex is normal. b Coronal CT of same patient shows erosion of the carotid canal arrow and air in the Eustachian tube arrowhead the air cell system of the petrous apex resulting in bone destruction with dural irritation and involvement of the cranial nerves adjacent to the petrous apex represent Gradenigo s syndrome Figs. . The advent of antibiotics and thorough mastoid surgery has virtually eliminated this complication of suppurative otitis media. Nevertheless this complication does occasionally occur and presents
