Additive value of "otosclerosis-weighted" images for the CT diagnosis of fenestral otosclerosis. (October 2017)

• Record Type: Journal Article
• Authors: Yamashita, Koji; Hiwatashi, Akio; Togao, Osamu; Kondo, Masatoshi; Kikuchi, Kazufumi; Inoguchi, Takashi; Maehara, Junki; Kyuragi, Yusuke; Honda, Hiroshi
• Is Part Of: Acta radiologica. Volume 58:Number 10(2017:Oct.)
• Page Start: 1215
• Page End: 1221
• Publication Date: 2017-10
• Subjects: Fenestral otosclerosis -- computed tomography (CT) -- computer aided diagnosis; Radiology, Medical -- Periodicals; Radiography, Medical -- Periodicals; Radiotherapy -- Periodicals; 616.0757
• DOI: 10.1177/0284185116687172
• Languages: English
• ISSNs: 0284-1851

Abstract

Background: Otosclerotic foci are usually seen as minute low-density lesions and this may be attributed to relatively low sensitivity on visual assessment using computed tomography (CT). Otosclerotic foci can be detected by using the accurate region of interest (ROI) setting, while small ROI settings by less-experienced radiologists may result in false negative findings. Purpose: To evaluate the diagnostic ability of our proposed method ("otosclerosis-weighted" imaging [OWI]), which is based on reversing the density, compared with conventional CT (CCT) imaging alone. Material and Methods: Temporal bone CTs of consecutive patients with otosclerosis were analyzed. Gender- and age-matched control participants were also included. All CT images were obtained using a 64-detector row scanner. OWI was obtained by extracting the temporal bone region using the threshold technique and reversing the density (black to white). Four independent radiologists took part in two reading sessions. In the first session, the observers read only CCT imaging. In the second session, they read OWI along with the CCT imaging. Sensitivity was assessed for the four readers. Results: Thirty temporal bones of 25 patients with otosclerosis (3 men, 22 women; mean age, 53.9 ± 9.0 years) and 30 temporal bones of 30 control participants (4 men, 26 women; mean age, 44.0 ± 16.2 years) were included. For all observers, reading with a combination of the two methods was associated with a higher sensitivity (63.3–80.0%) than with conventional CT images alone (30.0–60.0%; P < 0.05, each). Conclusion: Application of our proposed method based on threshold value may help detect foci of fenestral otosclerosis.