A New Grading System Based On T2-weighted Axial MRI For Cervical Canal Stenosis

Objective:Cervical Canal stenosis is a common degenerative disease of the Cervical spine in the middle and old age.It is often caused by various anatomical factors such as disc height loss,disc herniation and osteophyte formation,and can be measured by MRI,X-ray,CT and other imaging examinations.Currently,there are a variety of classification systems and evaluation methods of cervical spinal stenosis based on cervical X-ray lateral radiography and cervical CT.After entering the 21st century,with the rise of nuclear magnetic resonance technology,a number of scholars have evaluated cervical spinal stenosis from cervical magnetic resonance T2 imaging,but the research on cervical spinal stenosis still needs to be further studied.The purpose of this study was to find a new measurement based on T2-weight axial magnetic resonance imaging for cervical canal stenosis in order to guide imaging evaluation and clinical treatment.Methods:Cervical canal stenosis was classified into the following grading system according to the MRI on T2-weighted axial images with the most serious oppression:grade 0,absence of canal stenosis without obliteration of Cerebrospinal fluid(CSF)space and no significant change in the morphology of the cervical spinal cord;grade 1,mild canal stenosis with obliteration of anterior or posterior of CSF space;grade 2,moderate canal stenosis with obliteration of both sides of the CSF space but no significant changes in spinal morphology;grade 3,severe canal stenosis with spinal cord deformity,grade3A:the degree of cervical spinal cord compression is below 50%(the cervical spinal cord compression ratio is between 0.4-0.2),grade 3B,the degree of cervical spinal cord compression is within 50%?75%(the cervical spinal cord compression ratio is between 0.2-0.1),grade 3C,severe canal stenosis with spinal cord deformity and the angle of the compressive mass less than 90°;grade 4,severe cervical spinal stenosis with cervical spinal cord malformation,cervical spinal cord compression is over 75%(the cervical spinal cord compression ratio is less than 0.1),grade 4A,the nature of the herniation is non-bony,grade 4B:the herniation is a ossify mass.A total of 100 patients who underwent cervical MRI examination in our hospital from January 2016 to October 2017 were selected.After excluding trauma,other surgical history and major heart and lung diseases,a total of 83 patients were included.At the same time,general information(age,gender)of these patients,preoperative JOA score,surgical methods and main positive signs(pain,numbness,balance disorder,etc.)of the patients were collected.The Effective sagittal spinal canal(ESSC)in patients with stenosis was measured.Three radiologists and three spine surgeons evaluated the patient images according to the classification method,and the inter-observer confidence was assessed using the intra-group correlation coefficient(ICC)method.Results:Primary evaluation showed an almost perfect ICC reliability between six readers(ICC>0.78),and the ICC ranged from 0.792 to 0.859 in the second step with two months.According to our new grading system for cervical canal stenosis,there were a relatively high correlation between stenosis grades and ESSC.Along with the stenosis grades,the ESSC decreased.In addition,our new grading system for cervical canal stenosis is also related to the preoperative JOA score and surgical method selectionConclusion:Our new grading system for cervical canal stenosis has a good consistency,and is helpful for clinical diagnosis and decision.