Computed tomography imaging of the paranasal sinuses: Direct versus reformatted coronal images

Objective: To evaluate the image quality of coronal reformatted CT images compared with direct coronal CT images. Study Design: Cross-sectional. Subjects and Methods: Patients who underwent paranasal sinus CT scans using both direct coronal images (DC) and axially acquired images with coronal reconstructions (CR) were consecutively enrolled. Two reconstruction groups were evaluated: group CR1 with 1-mm axial collimation and group CR2 with 0.625-mm axial collimation. Scans were presented in a randomized, blinded fashion to two sinus surgeons and a neuroradiologist. Results: When compared with CR1, DC images had higher image quality for each of five key anatomic landmarks (P < .0001). DC images were more likely to be adequate preoperative imaging (P < .0001). When compared with CR2, improved DC image quality was noted in the majority of key anatomic landmarks. No difference was noted in the "adequacy rating" between the DC and CR2 (0.625 mm) protocols. Conclusion: The 0.625-mm reformatted images were judged to be adequate preoperative imaging. The additional information provided by multiple-image planes make reformatted 0.625-mm axial images an acceptable approach.