Minor ossicular anomalies in the middle ear: role of submillimeter multislice computed tomography.
OBJECTIVE
The objective was to elucidate clinical effectiveness of submillimeter multislice 2- and 3-dimensional computed tomography (CT) for diagnosis of congenital middle ear anomaly.


METHODS
Preoperative CT and operative findings were retrospectively analyzed in 36 ears of 33 patients. The distance between the malleal handle (MH) and the incus long process (ILP) was measured in 28 normal ears.


RESULTS
Mean ± SD MH-ILP distance in normal ears was 1.8 ± 0.3 mm. In patients with middle ear anomaly, overall specificity, accuracy, and positive and negative predictive values were 99.7%, 98.7%, 91.7%, and 99.1%, respectively. Overall sensitivity was 82.1%, with relatively low sensitivities for detecting fused incudomalleolar joint, lenticular process defect, stapedial footplate defect, and oval window atresia and high sensitivities (80%-100%) for stapedial crural anomaly and certain fibrous connections.


CONCLUSIONS
Submillimeter CT improved detectability of anomalies of the stapedial superstructure; however, it is still difficult to identify abnormalities of the footplate.
From the *Department of Radiology, and †Department of Otorhinolaryngology, Iwate Medical University School of Medicine, Morioka, Iwate, Japan.
Tatsuhiko
T
Nakasato
Tetsuo
T
Nakayama
Manabu
M
Nakayama
Shigeru
S
Ehara
Hisashi
H
Ohtsuka
Hiroaki
H
Sato
D000293:Adolescent; D000328:Adult; D000465:Algorithms; D002648:Child; D004429:Ear Ossicles / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult