Three-dimensional imaging of the inner ear by volume-rendered reconstructions of magnetic resonance data.
OBJECTIVE
To evaluate 3-dimensional inner ear visualization by volume rendering of high-resolution magnetic resonance data in patients with clinically suspected inner ear abnormality.


METHODS
Prospective comparative study of different postprocessing techniques, based on blinded film readings.


METHODS
Tertiary referral hospital.


METHODS
Fifty patients (17 females and 33 males) aged 1 to 77 years (average age, 42 years) with sensorineural hearing loss, vertigo, and/or tinnitus.


METHODS
Postprocessing of magnetic resonance data to inner ear reconstructions by the use of volume rendering as well as maximum-intensity projection; caloric testing by electronystagmography.


METHODS
Film was read blindly by 4 radiologists using a 5-point parameter scale for image quality and diagnostic value. The assessibility of inner ear subsegments was evaluated. The specificity of volume-rendered reconstructions for detecting semicircular canal obliterations was assessed in a subgroup of 9 patients by caloric testing. The time required for data postprocessing as well as film reading was recorded by means of a stopwatch.


RESULTS
Volume-rendered inner ear reconstructions were superior in image quality (P<.001), diagnostic value (P<.001), subsegment inner ear assessment (P<.01 to P<.001), and film reading time (P<.001) compared with maximum-intensity projections. The data postprocessing time was comparable for both techniques. Caloric weakness was noted in all patients assessed by electronystagmography.


CONCLUSIONS
Volume rendering is the postprocessing technique of choice for 3-dimensional inner ear visualization, performing better than maximum-intensity projections with respect to various parameters.
Klingebiel
Randolf
R
Neuroradiology Section, Department of Radiology, Charité CM, Schumannstr 20/21, 10098 Berlin, Germany. Randolf.Klingebiel@charite.de
Thieme
Nadine
N
Kivelitz
Dietmar
D
Enzweiler
Christian
C
Werbs
Mechthild
M
Lehmann
Rüdiger
R
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007223:Infant; D007759:Labyrinth Diseases / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014012:Tinnitus / Q000175:diagnosis; D014717:Vertigo / Q000175:diagnosis; D014724:Vestibular Function Tests / Q000379:methods*