Curved Planar Reformation of the Ossicular Chain in Multislice Spiral CT and Its Clinical Application / 实用放射学杂志

ABSTRACT

Objective Using curved planar reformation(CPR)to delineate the ossicular chain(OC)in one image and evaluate its clinical application. Methods HRCT of temporal bone was performed in 122 cases(165 ears).The CPR of OC was then performed.The main parameters were as followcollimation 0.5mm,pitch 0.875,reformation interval 0.2～0.3mm,reformation matrix 1024?1024.Results (1)CPR of normal OC were performed on 80 ears,the three ossicles and its joints could be showed on one image clearly.(2)Clincal application(72cases)in 39 cases of temporal bone trauma,OCs were normal in 21 cases and abnormal in 18 cases.Subluxation or dislocation of malleoincudal joint(MIJ)(5,5) and incudostapedial joint(ISJ)(5,6),dislocation of MIJ and ISJ with rotation of incus(1 case),fracture of manubrium of malleus(1 case) were found respectively.In 16 cases of external auditory canal dysplasia(EACD),the most commonly associated type of OC deformity was absence of manubrium of malleus(10 cases)。Absence of OC associated with coarctation of middle ear cavity(3 cases) and fusion of the malleus and incus associated with absence of long process of incus represented in 1 case.Congenital ossicular anomalies without associated EACD were found in 2 cases.The long processes of the incus of both side were absent in 1 case.Incudostapedial disconnection was demonstrated in 1 case due to improper development of the long process of the incus.In 15 cases of chronic otitis media(COM),6 cases were complicated cholesteatoma.Destruction of OC was demonstrated in 6 cases.Conclusion CPR of OC with multislice spiral CT is an effective method in the diagnosis of conductive hearing loss.