title: Three-dimensional (3D) visualization of endolymphatic hydrops after intratympanic injection of Gd-DTPA: optimization of a 3D-real inversion-recovery turbo spin-echo (TSE) sequence and application of a 32-channel head coil at 3T.
abstract: OBJECTIVE
  To enable volume visualization of endolymphatic hydrops of Ménière's disease via a volume rendering (VR) technique, a three-dimensional (3D) inversion-recovery (IR) sequence with real reconstruction (3D-real IR) sequence after intratympanic injection of Gd-DTPA was optimized for higher spatial resolution using a 32-channel head coil at 3T.
  
  
  METHODS
  Pulse sequence parameters were optimized using a diluted Gd-DTPA phantom. Then, 11 patients who had been clinically diagnosed with Ménière's disease and a patient with sudden hearing loss were scanned. Images were processed using commercially available 3D-VR software. 3D-real IR data was processed to produce endolymph and perilymph fluid volume images in different colors. 3D-CISS data was processed to generate total fluid volume images.
  
  
  RESULTS
  While maintaining a comparable signal-to-noise ratio (SNR) and scan time, the voxel volume could be reduced from 0.4 x 0.4 x 2 mm(3) with a 12-channel coil to 0.4 x 0.4 x 0.8 mm(3) with a 32-channel coil. A newly-optimized protocol allowed the smooth, three-dimensional visualization of endolymphatic hydrops in all patients with Ménière's disease.
  
  
  CONCLUSIONS
  Volumetrically separate visualization of endo-/perilymphatic space is now feasible in patients with Ménière's disease using an optimized 3D-real IR sequence, a 32-channel head coil, at 3T, after intratympanic administration of Gd-DTPA. This will aid the understanding of the pathophysiology of Ménière's disease.
authors.affiliation: Department of Radiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. naganawa@med.nagoya-u.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Shunichi
authors.initials: S
authors.lastname: Ishihara
authors.forename: Shingo
authors.initials: S
authors.lastname: Iwano
authors.forename: Michihiko
authors.initials: M
authors.lastname: Sone
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000368:Aged; D000465:Algorithms; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000295:instrumentation* / Q000379:methods*; D018159:Endolymphatic Hydrops / Q000150:complications / Q000175:diagnosis*; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007267:Injections; D008297:Male; D008575:Meniere Disease / Q000150:complications / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014432:Tympanic Membrane
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA