Evaluation Of The Value Of Dual-energy CT Virtual Non-calcium Imaging In The Diagnosis Of Lumbar Intervertebral Disc Degeneration

Objectives To assess the diagnostic value of dual-energy CT(DECT)virtual noncalcium(VNCa)technology in lumbar intervertebral disc degeneration through subjective visual evaluation and objective quantitative evaluation.Methods A total of 51 volunteers were recruited.DECT,routine MRI,and magnetic resonance image complication(MAGiC)examination were performed on 51 participants.The interval between CT and MRI examination should not exceed two weeks.The degeneration degree of each lumbar disc was derived from midsagittal T2WI imaging based on modified Pfifirrmann grade(mPG).T2 values of the nucleus pulposus and annulus fibrosus were measured on T2-mapping by setting ROIs of each disc on T2-mapping,ROI3 corresponded to the nucleus pulposus,and ROI1 corresponded to the annulus fibrosus.Two doctors independently classified the discs into three different visual types by comparing the attenuation of the nucleus pulposus and the annulus fibrosus on the color-coded VNCa images,and they independently measured the VNCa CT value and regularCT(rCT)value of the nucleus pulposus and annulus fibrosus by setting ROIs of each disc on the color-coded VNCa images,ROI3 corresponded to the nucleus pulposus,and ROI1 corresponded to the annulus fibrosus.Inter-observer agreement for VNCa visual type was assessed by Kappa analysis,Inter-observer agreement for T2 value,VNCa CT value,and rCT value was assessed by intraclass correlation coefficient(ICC).Spearman’s rank correlation was used to compare the relationship between visual categories for VNCa maps and mPGs,mPGs and VNCa CT values,mPGs and rCT values,visual categories for VNCa maps and T2 values,VNCa CT values and T2 values,rCT values and T2 values.According to whether the data in each group were consistent with normal distribution and homogeneity of variance after grouping by mPG or VNCa visual typing,ANOVA,Kruskal-Wallis,or Welch test were selected to test whether the VNCa CT values and rCT values were significantly different among different mPG grades and whether the T2 values were significantly different among different VNCa visual types.The difference was considered statistically significant when P<0.05.Results 1 A total of 225 lumbar discs were included.Statistically significant difference was observed among mPGs and visual categories for VNCa maps(P<0.001),and a significant positive correlation was observed between visual categories for VNCa maps and mPGs(r_s=0.752,0.701,P<0.001).2 Significant positive correlation between mPGs and VNCa CT values was found(r_s=0.536,0.474,P<0.001),VNCa CT values of nucleus pulposus were significantly different among mPGs(P<0.05 for each)except between grades 1 and 2,grades 1 and 3,and grades 4 and 5(doctor 3:P=0.546,0.136,0.101,doctor3:P=0.999,0.230,0.687).There was no significant difference between rCT values of nucleus pulposus and mPGs(P=0.432,0.116).3 Significant negative correlation between visual categories for VNCa maps and T2 values of nucleus pulposus was observed(r_s=-0.631,-0.636,P<0.001).T2 values of nucleus pulposus were significantly different among different visual categories for VNCa maps(P=0.023 for type 1 and 2,P<0.001 for type 1and 3,type 2 and 3).4 Significant negative correlation between VNCa CT values and T2values of nucleus pulposus was found(r_s=-0.424,-0.437,P<0.001).5 The rCT values of annulus fibrosus were significantly different among mPGs(P<0.001),and a significant negative correlation between rCT values of annulus fibrosus and mPGs was observed(r_s=-0.416,-0.462,P<0.001).The rCT values of annulus fibrosus between grades 2 and 4,grades 2 and 5,and grades 3 and 5 were significantly different.VNCT values of annulus fibrosus were not significantly different among mPGs(doctor 3:F=1.816,P=0.127;doctor4:F=0.916,P=0.455),and no significant correlation was found between VNCT values of annulus fibrosus and mPGs(doctor 3,r_s=-0.115,P=0.86;doctor 4,r_s=-0.066,P=0.323).Conclusions 1 DECT VNCa technology can be used to evaluate lumbar disc degeneration.VNCa visual assessment can be used as an alternative method for MRI mPG grading to evaluate the degree of lumbar disc degeneration in patients with contraindications to MRI examination.2 VNCa CT value of lumbar disc nucleus pulposus can be used as an objective parameter to evaluate lumbar disc degeneration and assist in the evaluation of lumbar disc degeneration.Figure 8;Table 4;Reference 156...