title: Visualization of Middle Ear Ossicles in Elder Subjects with Ultra-short Echo Time MR Imaging.
abstract: OBJECTIVE
  To evaluate the visualization of middle ear ossicles by ultra-short echo time magnetic resonance (MR) imaging at 3T in subjects over 50 years old.
  
  
  METHODS
  Sixty ears from 30 elder patients that underwent surgical or interventional treatment for neurovascular diseases were included (ages: 50-82, median age: 65; 10 men, 20 women). Patients received follow-up MR imaging including routine T1- and T2-weighted images, time-of-flight MR angiography, and ultra-short echo time imaging (PETRA, pointwise encoding time reduction with radial acquisition). All patients underwent computed tomography (CT) angiography before treatment. Thin-section source CT images were correlated with PETRA images. Scan parameters for PETRA were: TR 3.13, TE 0.07, flip angle 6 degrees, 0.83 × 0.83 × 0.83 mm resolution, 3 min 43 s scan time. Two radiologists retrospectively evaluated the visibility of each ossicular structure as positive or negative using PETRA images. The structures evaluated included the head of the malleus, manubrium of the malleus, body of the incus, long process of the incus, and the stapes. Signal intensity of the ossicles was classified as: between labyrinthine fluid and air, similar to labyrinthine fluid, between labyrinthine fluid and cerebellar parenchyma, or higher than cerebellar parenchyma.
  
  
  RESULTS
  In all ears, the body of the incus was visible. The head of the malleus was visualized in 36/60 ears. The manubrium of the malleus and long process of the incus was visualized in 1/60 and 4/60 ears, respectively. The stapes were not visualized in any ear. Signal intensity of the visible structures was between labyrinthine fluid and air in all ears.
  
  
  CONCLUSIONS
  The body of the incus was consistently visualized with intensity between air and labyrinthine fluid on PETRA images in aged subjects. Poor visualization of the manubrium of the malleus, long process of the incus, and the stapes limits clinical significance of middle ear imaging with current PETRA methods.
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine.
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Toshiki
authors.initials: T
authors.lastname: Nakane
authors.forename: Hisashi
authors.initials: H
authors.lastname: Kawai
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Taoka
authors.forename: Kojiro
authors.initials: K
authors.lastname: Suzuki
authors.forename: Shingo
authors.initials: S
authors.lastname: Iwano
authors.forename: Hiroko
authors.initials: H
authors.lastname: Satake
authors.forename: David
authors.initials: D
authors.lastname: Grodzki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004429:Ear Ossicles / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed