Correlation Of Signal Intensity Ratio On MRI With Postoperative Prognosis Of Cervical Spinal Cord Injury Without Fracture And Dislocation

Objective: Magnetic resonance imaging(MRI)is the most important examination method,it can not only show the morphology changes of spinal cord but also reflect various intramedullary lesions after spinal cord injury.However,the problem whether the signal intensity ratio of MRI is a prognosis of patients with cervical spinal cord injury without fracture and dislocation(CSCIWFD)remains controversial.The objective of this study was to investigate the correlation of signal intensity ratio(SIR)on preoperative MRI T2 WI with prognosis of the patients with CSCIWFD after surgery.Methods: The retrospective study included 33 CSCIWFD patients who underwent surgical treatment from October 2013 to October 2014.All the patients came from the spinal surgery department in No.3 hospital of Hebei medical university and MRI examination was conducted preoperatively.We obtained the spinal cord signal intensity values(A)at where is the highest signal intensity(or the most severely compressed cord in case without high signal intensity)on sagittal T2 WI and the regions of interests(ROIs)were set with 0.05 cm2.Then,we obtained the spinal cord signal intensity values(B)at C7/T1 disc levels and the ROIs were set with 0.3 cm2.The signal intensity ratio(SIR)was defined as A divided by B.The values were measured double times by the same researcher on the MRI workplace,and finally,the average ratio was calculated.The Japanese Orthopaedic Association(JOA)scale and the American Spinal Injury Association motor scale(AMS)were applied to evaluate the nerve function at admission and at the last time of follow-up.The JOA recovery ratio(JOARR)and the AMS recovery ratio(AMSRR)were also calculated.The difference of spinal cord function between pre-operation and post-operation was analyzed.Preoperative spinal cord function and postoperative recovery ratio were accessed in relation to SIR on T2 WI though Spearman nonparametric correlations analysis.Results: There were 26 males and 7 females.The mean age was 49.33±12.20 years,range from 28 to 71 years.The median following time after surgery was 16(14.5,18)months,ranged from 13-19 months.The nerve function had an improvement in an extent after surgery.The preoperative JOA score was 8(4,12),whereas the postoperative was 12(8,15)(Z=-2.972,P=0.003);the preoperative AMS score was 67(30,87),whereas the postoperative was 90(68,96)(Z=-2.881,P=0.004).The JOARR was 45.45(29.67,58.57)and the AMSRR was 58.33(30.86,69.79).The preoperative SIR was 1.58±0.20.There was a significant correlation between SIR with preoperative JOA score(rs=-0.583,P=0.001),preoperative AMS score(rs=-0.490,P=0.004),with JOARR(rs=-0.490,P=0.015)and AMSRR(rs=-0.486,P=0.004),and when the preoperative SIR was higher,the preoperative JOA score,preoperative AMS score,JOARR and AMSRR were lower.Conclusions: Surgical treatment was effective for patients with CSCIWFD.There was a significant correlation between preoperative SIR and spinal cord function before surgery,as well as the spinal cord function recovery ratio after surgery.When the preoperative SIR was higher,the preoperative spinal cord function and the postoperative spinal cord function recovery ratio were poorer.