颌面部解剖及其病变的影像诊断.pptVIP

* 腺囊癌 * 腺囊癌冠状 * Nasolabial cysts. Axial T1-weighted (A) and T2-weighted (B) MR images demonstrating bilateral nasolabial cysts. The cysts are minimally hyperintense in A (arrows) and hyperintense in B (arrows). * Median palatal cyst. Enhanced axial T1-weighted spin-echo image (A) demonstrates cyst extension through the left side of the premaxilla beneath the nasal septum (arrowheads). T1-weighted (B) and T2-weighted (C) images show elevation of the inferior turbinates and depression of the palate. The hyperintensity of the cyst in A and B is presumably a result of the presence of blood products, elevated protein content, or both findings. * Dentigerous cyst. Coned down panoramic view (A) of the left mandible shows cortical expansion (arrows) adjacent to a partially formed tooth. CT scan (B) shows a cystic area, cortical expansion (white arrow), and partially formed crown (black arrow). T1-weighted (C) and T2-weighted (D) images show cortical expansion (white arrows) and a partially formed crown (black arrows). The fluid in the cyst exhibits high signal intensity in D. The bright signal intensity in C reflects the contents of the proteinaceous cyst. * Unicystic ameloblastoma. CT scan (A) shows an osseous defect representing a previous biopsy site (arrow). TI-weighted spin-echo (B) and fat-suppressed T2-weighted fast spin-echo (C) images demonstrate an expansile cystic lesion involving the right maxilla. The lower fluid level is blood from a previous biopsy procedure. The supernatant is cyst fluid * Multicystic ameloblastoma. A, Panoramic view. B, CT shows an expansile lesion in the buccal-lingual area. C, T1-weighted image shows heterogeneous hyperintensity representing highly proteinaceous material within cystic areas. D, T2-weighted image shows both solid and cystic areas as high signal intensity. E, Contrast-enhanced T1-weighted image demonstrates foci of enhancement within the solid component of the lesion (arrows). (Case courtesy L. Van Resenburg an