Computed tomography evaluation of the normal craniocervical junction craniometry in 100 asymptomatic patients

Abstract

<jats:sec> <jats:title>OBJECT</jats:title> <jats:p>Most of the craniometric relationships of the normal craniocervical junction (CCJ), especially those related to angular craniometry, are still poorly studied and based on measurements taken from simple plain radiographs. In this study, the authors performed a craniometric evaluation of the CCJ in a population without known CCJ anomalies. The purpose of the study was to evaluate the normal CCJ craniometry based on measurements obtained from CT scans.</jats:p></jats:sec> <jats:sec> <jats:title>METHOD</jats:title> <jats:p>The authors analyzed 100 consecutive CCJ CT scans obtained in adult patients who were admitted at their tertiary hospital for treatment of non-CCJ conditions between 2010 and 2012. A total of 17 craniometrical measurements were performed, including the relation of the odontoid with the cranial base, the atlantodental interval (ADI), the clivus length, the clivus-canal angle (CCA)—the angle formed by the clivus and the upper cervical spine, and the basal angle.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>The mean age of the 100 patients was 50.6 years, and the group included 52 men (52%) and 48 women (48%). In 5 patients (5%), the tip of the odontoid process was more than 2 mm above the Chamberlain line, and in one of these 5 patients (1% of the study group). it was more than 5 mm above it. One patient had a Grabb-Oakes measurement above 9 mm (suggesting ventral cervicomedullary encroachment). The mean ADI value was 1.1 mm. The thickness of the external occipital protuberance ranged from 7.42 to 22.36 mm. The mean clivus length was 44.74 mm, the mean CCA was 153.68° (range 132.32°–173.95°), and the mean basal angle was 113.73° (ranging from 97.06°–133.26°).</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>The data obtained in this study can be useful for evaluating anomalies of the CCJ in comparison with normal parameters, potentially improving the diagnostic criteria of these anomalies. When evaluating CCJ malformations, one should take into account the normal ranges based on CT scans, with more precise bone landmarks, instead of those obtained from simple plain radiographs.</jats:p></jats:sec>

Computed Tomography Evaluation of Craniovertebral Junction in Asymptomatic Central Rural Indian Population

“…CL value of 44.91 mm was comparable to the study conducted by Heiss et al (mean = 43.2 mm, SD = 3.5 mm) 17 and Batista et al 18 (mean = 44.7 mm, SD = 3.5 mm). Dufton et al 19 and Heiss et al 17 have found CL to be shorter in patients with type I Chiari malformation as compared with normal subjects.…”

Cranio-vertebral transition assessment by magnetic resonance imaging in a sample of a northeast Brazilian population

“…Our study showed a CCA with an average of 150.14º ± 11.37º -very close to the values cited by Botelho and Ferreira 11 and Batista et al 19 , which is apparently higher than that suggested by Smoker 1 . Despite Smoker 1 having demonstrated significant correlation between the CCA and DOCL, none was found in this study.…”

“…Despite Smoker 1 having demonstrated significant correlation between the CCA and DOCL, none was found in this study. Thus, it can be speculated that the values of the CCA obtained by MRI or CT of asymptomatic patients seem to be higher than the ones published using radiographs, from which normality standards were defined 1,19 ; or, alternatively, it is possible that each population naturally presents with different values.…”

“…Botelho and Ferreira 11 analyzed the CCA via MRI, obtaining an average of 148º ± 9.8º (with a range from 129º to 179º). Batista et al 19 , analyzing with the use of CT, obtained an average of 153.6º ± 7.6º (varying from 132.3º to 173.9º).…”

“…The WBA has varied broadly, with one reported average of 115.41° (±8.45°) for Netto et al 19 There is still no consensus over the upper limit for DOCL values, which range from 2.0 to 6.6 mm 1,20,21 . This difference is not insignificant when compared to the small dimensions of CVT and hence could lead to considerable changes in specificity in the diagnosis of basilar invagination, as well as in the estimated prevalence 11,22 .…”