Reference ranges for atlantodental interval in adults and its variation with age and gender in a large series of subjects on multidetector computed tomography.
BACKGROUND
The atlanto-dental interval measurement in the cervical spine in young adults has been reported on multidetector computed tomography (MDCT), but has not been systematically assessed in all ages.


OBJECTIVE
To evaluate the reference ranges for the atlanto-dental interval (ADI) in a large sample of adult patients on MDCT and to analyze the relationships of these measurements with gender and age of the patients as well as inter-observer performance.


METHODS
First, a consecutive series of 700 Chinese patients aged over 18 years undergoing an upper cervical MDCT scan were divided equally into seven age groups. Second, the mid-sagittal image of the atlanto-dental joint was chosen for measurement and ADI was defined as the distance intercepted from the segment line linking the center of anterior atlas tubercle with that of posterior tubercle. Third, the correlation of ADI with age and gender was analyzed using linear regression analysis. Finally, the inter-observer performance was assessed using Bland and Altman's limits of agreement.


RESULTS
The ADI was 1.77 ± 0.39 mm, 1.61 ± 0.37 mm, 1.58 ± 0.36 mm, 1.41 ± 0.29 mm, 1.31 ± 0.29 mm, 1.34 ± 0.28 mm, and 1.06 ± 0.47 mm in the age groups 18-24 years, 25-29 years, 30-39 years, 40-49 years, 50-59 years, 60-69 years, and older than 70 years, respectively. The range of ADI was 0.85-3.12 mm in the age group 18-39 years, 0.71-2.55 mm in the age group 40-59 years, and 0.00-2.37 mm in the age group older than 60 years. There was no difference between gender and ADI (r = 0.00, P = 1.000). ADI decreased linearly with age (r = -0.511, P = 0.000). The inter-observer performance was reliable.


CONCLUSIONS
ADI measurements on MDCT linearly decrease with increasing age, and these are not affected by gender in adult patients. Different reference values might be used at different ages when diagnosing atlantoaxial anterior dislocation or subluxation.
Shandong Medical Imaging Research Institute, Shandong University, Jinan, PR China.
Kai
K
Liu
Department of Radiology, Qilu Hospital, Shandong University, Jinan, PR China.
Fubo
F
Xie
Shandong Medical Imaging Research Institute, Shandong University, Jinan, PR China.
Daocai
D
Wang
Shandong Medical Imaging Research Institute, Shandong University, Jinan, PR China.
Lingfei
L
Guo
Department of Radiotherapy, Shandong Tumor Hospital, Jinan, PR China.
Yuangang
Y
Qi
Shandong Medical Imaging Research Institute, Shandong University, Jinan, PR China.
Jun
J
Tian
Shandong Medical Imaging Research Institute, Shandong University, Jinan, PR China cjr.zhaobin@vip.163.com.
Bin
B
Zhao
Department of Musculoskeletal Radiology & Orthopedic Surgery, UT Southwestern Medical Center, Johns Hopkins University, Dallas, TX, USA.
Avneesh
A
Chhabra
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D012016:Reference Values; D012189:Retrospective Studies; D012737:Sex Factors; D055815:Young Adult
Atlanto-dental joint; atlanto-dental interval (ADI); multidetector computed tomography (MDCT).