Postoperative maxillary cysts: Magnetic resonance imaging compared with computerized tomography

Objectives. The aim was to investigate magnetic resonance (MR) and computerized tomography (CT) images and compare MR and CT image features of postoperative maxillary cysts (POMC). Study design. We retrospectively evaluated MR and CT images of 7 POMC patients. Number of the cysts, border, bone expansion, CT value, signal intensity, and contrast enhancement were observed. Results. On CT images, 15 cysts were detected. Fourteen cysts showed smooth border. Bone expansion was found in 10 cysts. Mean CT value of each cyst ranged from 23 to 50 Hounsfield units. On MR images, 18 cysts were detected. Twelve cysts showed smooth border. Bone expansion was not observed. Most cysts showed intermediate signal intensity on T1-weighted images, and high or nonhomogeneous intermediate/high signal intensity on T2-weighted images with the fat suppression technique. No cyst showed contrast enhancement in both examinations. Conclusion. The CT images revealed bony information, and the MR images clearly demonstrated border of POMC. POMC should be evaluated with both CT and MR imaging. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 107: e38-e44)