Virtual Endoscopy Using Spiral CT in Head and Neck Lesions

Song, Sang Gook; Seo, Jeong Jin; Chung, Tae Woong; Jeong, Gwang Woo; Jeong, Yong Yeon; Kang, Heoung Keun; Cho, Jae Sik; Park, Seung Jin

Abstract

The purpose of this study was to evaluate the usefulness of the virtual endoscopy using spiral CT compared with laryngoscopy in the detection and evaluation of head and neck lesions. During the last six months, 18 cases with pathologically-proven head and neck lesions underwent laryngooscopy and virtual endoscopy using spiral CT. The cases included 13 cases of malignant lesions(5 cases of hypopharyngeal carcinoma, 3 cases of nasopharyngeal carcinoma, 3 cases of nasomaxillary carcinoma, 2 cases of glottic cancer) and 5 maxillary sinusitis. The source images of virtual endoscopy were reconstructed as three dimensional images within Advantage Windows Workstation and virtual endoscopic images were obtained by using the Navigator Software. On analysis, the grade was given according to image quality (excellent, good, bad). Virtual endoscopic images were interpreted by two radiologists who were blinded to conventional endoscopic findings and were subsequently compared with the endoscopic findings, with regard to similarity to laryngoscopic examiantion and finding of head and neck lesions. The results were as follows. 1) Overall image quality of virtual endoscopy was excellent in 12 cases(67%), good in five cases(28%), and poor in one one case. Of the 13 malignant lesions, image quality of virtual endoscopy was excellent in 8 cases(62%), good in five cases(38%). 2) The detection of lesion was possible in 17 cases(94%). The two cases of hypopharyngeal carcinoma were detected beyond the vocal cord, even if laryngoscope could not be inserted. Of the five maxillary sinusitis, image quality of virtual endoscopy was excellent in 4 cases(80%) and poor in one case. The detection of lesion was possible in four cases(80%). In conclusion, Virtual endoscopy using spiral CT, which is safe and noninvasive method, may be complementary to axial CT in the evaluation of head and neck lesions.