History:Ateenagepatientpresentswithheadpain.
病史：青少年患者头痛。
CTimagesareshownbelow.
CT图像如下所示。
Findings
Extensivepansinusdiseasewithathinlayerofabscessalongtheoutertableoftheleftfrontalbone,aswellasextensivesoft-tissueswellingoftheforehead,isseen,consistentwithfrontalboneosteomyelitis.Tinymedialleftfrontalpneumocephalusisconsistentwithintracranialextensionofinfectionandlikelypresenceofatinyepiduralabscess.
影像表现：
广泛鼻窦病变，沿左额骨外侧面可见薄层脓肿形成，前额大量软组织肿胀，提示额骨骨髓炎。左额部颅内少量积气，提示感染延伸至颅内，可见极少量的硬膜外脓肿。
Differentialdiagnosis
Pottspuffytumor
Ewingssar