Value Of 3D-medic And 3D-vibe In The Diagnosis Of Multi-segment Lumbar Disc Herniation/bulging

PurposeTo investigate the value of conventional MRI combining with 3D-medic and3D-vibe sequences in the determination of responsible nerve roots and intervertebral discs in multi-segment lumbar disc herniation/bulging,and to provide a more accurate imaging basis for the selection of surgical target segments.Materials and MethodsOn the basis of pre-experiments of 10 healthy volunteers' scanning techniques and radio imaging performance,32 patients with multi-segment lumbar disc herniation/bulging were included.After careful medical history Collection and physical examination,Siemens Avanto 1.5T MR and phased array abdominal coil were used to carry on MRI T1,T2 sagittal and T2 transverse position,3D-medic coronal position and3D-vibe transverse position scan,MRI syngo workstation for image post-processing,PACS workstation for reconstructing and observating.Division,grading and Pffirmann classification of the lumbar intervertebral discs were measured on the conventional MRI and 3D-vibe images.The ROI signal intensity difference of bilateral anterior segment and nerve root,diameter,angle and type of nerve were measured on the 3D-medic images.The clinical symptoms and signs of patients and the surgical results of some patients were used as the standard to compare the advantages of the three sequences.Statistical analysis methods included paired t-test,rank sum test and Pearson correlation analysis.The receiver operating characteristic curve(ROC)of the subjects with nerve root and anterior segment signal difference for diagnosing "responsible nerve" were drawn,and the critical values of the two diagnostic indexes were defined according to the maximum Yoden index.Result(1)In the 77 disks of 32 patients,L4/5 was the most affected(100%),followed by L5/S1(81.25%)and L1/2 was 0%.The coexistence of bulge and protrusion accounted for 37.5%.Multiple simple bulge(21.87%)or protrusion(18.75%)were relatively few.Lumbar spondylolisthesis,ligamentum flavum thickening and spinal stenosis accountedfor about 70%.The proportion of Pffirmann grades 3,2,0 and 1 was 31.17%,28.57%,22.08% and 18.18%,respectively.(2)Among the group of 22 patients with lower limb signs,the majority of partition were multi-zone change(63.63%),in terms of indexing,the change of 2 degree was the main(63.64%),the lowest was 1 degree(4.54%);2 cases of single disc herniation with prolapse compressed 2 nerves,other single disc disease only compress 1 nerve.Of the typing of nerves,root-armpit was the most(54.17%),followed by the root-front type(45.83%),there was no root-shoulder type;Intervertebral disc compressed the same ordinal nerve were mainly 3,4 area herniation/prolapse and gulting,of which 90.9%were root-armpit type;which compressed the lower ordinal nerve were mainly 1,2 area herniation/prolapse and gulting,of which 76.92% were root-front type.(3)Compared the display effects of three MR sequences,3D-vibe was the best method for displaying epidural fat space(grade 1 accounted for 65.63%).Therefore,it has the strongest ability in the division,grading and Pffirmann grading of intervertebral discs(96.88%).3D-medic has the best effect in displaying nerves(81.25% of grade 1).The effect of conventional sequence in displaying nerve and epidural fat space was between the above two.(4)The measurements of nerve signal intensity on 3D-medic images varied greatly among different individuals,but the difference between the two sides of the same body was stable(P > 0.05).Females were higher than males,and nerve roots were higher than anterior segments(P < 0.05).Compared with the group without lower limb sign,the difference of signal of anterior segment was higher in the group with lower limb sign(P< 0.05).There was no significant correlation between the difference of anterior segment and nerve root.ROC curve analysis showed that 17.6 of the signal difference in the anterior segment could be used as the critical value for judging the "responsible nerve".The critical value of the signal difference in the corresponding nerve root was 11.15.The former had higher specificity and lower sensitivity,which might have more clinical value(P < 0.05).The 24 responsible nerves of 22 patients with lower limb syndrome were 13 L5 nerve(54%),7 S1 nerve(29%),3 L4 nerve(13%)and 1 L3 nerve(4%).MRN showed that the changes of nerve diameter and angle had little relationship withnerve compression(P > 0.05).(5)Among the 6 patients who have undergone surgery,3 patients had the same surgical target area as MRN,and the outcome was good;2 patients had a larger surgical target area,but the responsible nerve root judged by MRN were included,and the outcome was still available;1 patient choosed different surgical target area from MRN,after operation he still had low back pain and lower limb pain.Conclusion(1)Display and quantitative analysis of 3D-medic of lumbosacral nerves can be used to judge the responsible nerve of multi-segment lumbar disc bulge/protrusion,and to provide more accurate imaging basis for the selection of surgical target segments.(2)3D-vibe has more advantages in the division,grading and Pfirrmann classification of lumbar disc herniation/bulging,and can reduce the misdiagnosis rate and missed diagnosis rate of 3 and 4 regions of lumbar disc herniation.(3)The combination of 3D-medic and 3D-vibe sequences on the basis of lumbar conventional MRI have practical value in the diagnosis of multi-level lumbar disc herniation.