title: The role of HRCT and three-dimensional VR CT findings in patients of congenital atresia combined with microtia.
abstract: OBJECTIVE
  To determine the anatomic differences in patients of atresia by using high-resolution computed tomography (HRCT) and 3D volume rendered (VR) CT.
  
  
  METHODS
  High-resolution computed tomography (HRCT) was performed in 43 atresia patients including 34 unilateral atresia patients (n=34, 26 males, 8 females, mean age 13.82 years, range 8-19 years) and 9 bilateral atresia patients (6 males, 3 females, mean age 13.2 years, range 9-19 years). HRCT and 3D VR findings were compared with those in 43 normal ears of the unilateral atresia patients with normal PTA results (n=34, 26 males, 8 females, mean age 13.82 years, range 8-19 years) and 11 patients with sensorineural hearing loss but with no associated aplasia of the middle and inner ear (n=22, 7 males and 4 females, range 8-20.8 years, median age of 13.4 years) by using the independent one sample T test.
  
  
  RESULTS
  On the HRCT images, the angle between the basic line and the tympanic segment of the facial nerve is more acute. And the area of the malleus-incus-joint or the malleus-incus-complex in the diseased ears is smaller than that in the control subjects (P<0.05). The tympanic segment is shorter and the area of the tympanic cavity is smaller in the atresia group, while the diameter of the oval window is also smaller in atresia group than that in the control group (P<0.05). The morphologic differences of the small ossicles and the entire length of the tympanic and mastoid segments can be depicted on a single 3D VR CT image.
  
  
  CONCLUSIONS
  The facial nerve demonstrates abnormal lateral and anterior displacement in the CAA patients and the area of the Malleus-incus-joint and the tympanic cavity are significantly smaller, and the oval window is much narrower in the control group. HRCT and 3D VR CT provide valuable information about preoperative planning of patients with CAA. Measurements of all the angles and length serve as useful adjunct measurements in determining surgical candidacy.
authors.affiliation: Department of Otolaryngology, Peking Union Medical College Hospital, Beijing, PR China.
authors.forename: Ruzhen
authors.initials: R
authors.lastname: Gao
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.forename: Yue
authors.initials: Y
authors.lastname: Fan
authors.forename: Xing
authors.initials: X
authors.lastname: Ai
authors.forename: Xiaona
authors.initials: X
authors.lastname: Zhang
authors.forename: Huadan
authors.initials: H
authors.lastname: Xue
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Chen
authors.forename: Zhengyu
authors.initials: Z
authors.lastname: Jin
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D016022:Case-Control Studies; D002648:Child; D002681:China; D000013:Congenital Abnormalities / Q000175:diagnosis / Q000000981:diagnostic imaging*; D065817:Congenital Microtia; D004423:Ear / Q000002:abnormalities / Q000000981:diagnostic imaging; D004424:Ear Canal / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D005154:Facial Nerve / Q000002:abnormalities / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D061330:Multidetector Computed Tomography / Q000379:methods*; D012016:Reference Values; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult