title: Ultrashort echo time imaging of normal middle ear ossicles: a feasibility study.
abstract: OBJECTIVE
  The aim of this study was to assess the feasibility of ultrashort echo time (UTE) imaging in the visualization of middle ear ossicles in normal subjects.
  
  
  METHODS
  12 young adult volunteers (males/females = 6/6, age 25-44 years, mean 30.3 years) with normal hearing levels underwent MRI studies using a 3.0 T clinical unit with an eight-channel SENSE head coil. For each subject, the whole head was imaged using a three-dimensional dual-echo UTE imaging sequence with radial trajectory and the following parameters: field of view, 240 × 240 × 240 mm; matrix, 320 × 320; flip angle, 7°; repetition time/echo time (TE)1/TE2, 8.0 ms/0.14 ms/1.8 ms; acquisition voxel size, 0.75 × 0.75 × 0.75 mm; number of signals averaged, 1; imaging time, 27 min 20 s. Subsequently, subtraction images were obtained by subtracting long TE (1.8 ms) images from short TE (0.14 ms) images. By using these three images, the visibility of the bilateral middle ear ossicles was evaluated. Moreover, as a reference for the UTE findings, CT images of the temporal bone were obtained in one volunteer.
  
  
  RESULTS
  In all subjects, the middle ear ossicles were clearly visualized as a high signal intensity spot surrounded by a signal void of air on short TE images bilaterally, while they were not visible in long TE images in any of the subjects. The subtraction images provided better contrast of the ossicles.
  
  
  CONCLUSIONS
  We demonstrated the feasibility of UTE imaging of the middle ear ossicle in normal subjects.
authors: Department of Clinical Radiology, Kyushu University, Fukuoka, Japan.
authors: K
authors: K
authors: Yamashita
authors: T
authors: T
authors: Yoshiura
authors: A
authors: A
authors: Hiwatashi
authors: H
authors: H
authors: Kamano
authors: H
authors: H
authors: Honda
mesh_terms: D000328:Adult; D004429:Ear Ossicles / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D017352:Echo-Planar Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011446:Prospective Studies; D013382:Subtraction Technique; D013701:Temporal Bone / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed / Q000379:methods