Evaluation of osteal posterior cranial fossa in adults by multi-slice CT measurements before and after operation in basilar invagination patients / 中华放射学杂志

ABSTRACT

ObjectiveTo evaluate the clinical effect of MSCT measurements in the pre- and postoperational osteal posterior cranial fossa for the adult patients of basilar invagination.Methods We reviewed the images of a cohort of 31 adult patients with basilar invagination,which were treated by surgical operation.According to the presence of atlantoaxial dislocation,the patients were divided into groups A and B.The basion-dens interval (BDI),atlanto-dental interval (ADI),space available of the spinal cord ( SAC),clivus-canal angle( CCA),Highly index( HI),and Chamberlian line(CBL) of the posterior cranial fossa were obtained in all the patients.Independent-sample Student's t test was used to compare the differences between groups A and groups B.Spearman correlations were analyzed between CT measurement data and effects of operations.ResultsIn Group A,the BDI,ADI,SAC,CCA,HI,CBL before and after surgery were 12.6 mm,8.3 mm,4.5 mm,3.3 mm;18.2 mm,20.8 mm,138.3°,150.4°,28.7 mm,43.4 mm,6.3 mm,3.3 mm respectively.There were significant differences ( t = 5.603,2.323,3.124,5.531,4.278 and 2.375,respectively,P ＜0.05 ).Preoperative JOA score in groups A was 10 points,and was 14 points after surgery.There was significant difference between the JOA scores before and after surgery ( t = 3.526,P ＜ 0.05 ).There were 7 effective cases and 4 stable cases after surgery in group A.Before and after surgery,JOA score and BDI,ADI,SAC,CCA,HI,CBL were significantly correlated( r = -0.667,- 0.673 ; - 0.571,- 0.619 ; 0.642,0.513 ; 0.525,0.558 ; 0.587,0.511 ; - 0.532,- 0.596,respectively,P＜0.05).The SAC,CCA,and CBL before and after surgery in group B were 18.3 mm,19.6 mm,146.8°,150.2°,2.7 mm,1.8 mm.The difference was statistically significant after operation ( t = 5.359,4.126,0.769,P ＜0.05).The BDI,ADI,and HI before and after surgery in group B were 7.2 mm,6.6 mm,2.4 mm,2.1 mm,39.3 mm,41.5 mm.And there were no significant differences (t = 1.482,2.374,0.153,P＞0.05).The preoperative JOA score in groups B was 11 points,and the postoperative score was 16 points.JOA scores before and after surgery were significantly different (t =2.874,P ＜0.05).There were 14 effective cases and 6 stable cases after operation in group B.The JOA score before and after surgery and BDI,ADI,and HI had no correlation (r =0.341,0.387;0.154,0.182; 0.192,0.167,P ＞0.05),and CBL,SAC and CCA were correlated (r = -0.756,-0.728;0.651,0.672; 0.726,0.695,P ＜0.05).ConclusionMSCT measurements for basilar invagination before and after surgery are helpful for understanding changes of osteal posterior fossa anatomy and comprehensive evaluation of surgical treatment.