Lumbar With Dual-source CT Continuous Dynamic Scanning Evaluate The Influence Of Different Curvature On The Lumbar Intervertebral Foramen And Intervertebral Disc

Objective: To study the changes of lumbar spine in patients with lumbar disc herniation underwent dual-source CT continuous dynamic scan and observe the prolapse of lumbar intervertebral discand lumbar intervertebral foramen.Methods: Choose 40 patients’ conventional CT which have been confirmed L4-5 lumbar disc herniation using dual source CT(Siemens SOMATOM definition flash CT) obtained from the lumbar flexion 20 degrees to DICOM image files of different time resolution of 20 degrees of dorsiflexion movement in the process of using VPC Dynmuti 4D scanning. Import the image into Inspace workstation with L4-5 segment Cobb angle measurement method to determine the dynamic scanning process of lumbar curvature, then measure L4-5 vertebral body in the intervertebral movement process and resting supine disc and intervertebral foramen area to analysis the changes and correlationin in the process of intervertebral disc and the intervertebral foramenand.Results:1.40 patients with lumbar disc herniation from bend to hyperextension, L4-5 intervertebral disc prominent degree increased gradually from the trailing edge, the changes of neutral orientation degree of L4-5 segment disc herniation more pronouncedflexion movement(Table 1). In the process of Lumbar flexion motion with lumbar buckling 10 degree, the intervertebral disc is reduced about 0.87±0.26mm; while in the process of Lumbar extension 10 degree, the intervertebral disc is increased about1.24±0.45 mm. 2. All 40 patients were L4-5 lumbar disc herniation, measuring its area of different curvature changes in L4-5 section intervertebral foramen(Table 2). In the prosess of lumbar motion, lumbar stretches 10 degree the intervertebral foramen area will decrease about 8.02±0.34mm2 than the supine static scan; While in the process of flexion with lumbar buckling 10 degree, 90% patients’ intervertebral foramen area decreases about 6.72 mm2 than conventional supine scan; buckling 20 degree, 82% patients with L4-5 section intervertebral foramen area bigger about 6.72 ±0.23 mm2 than static scan; 18% patients of 20 degree buckling without changes in foramen area. From different lumbar curvature of intervertebral foramen area, we know that the intervertebral disc has different effect on intervertebral foramen while buckling, extension can cause intervertebral foramen becomes small, but may cause the intervertebral foramen area bigger or smaller in flexion motion.Conclusion: 1 The dual-source CT lumbar continuous dynamic scanning can be applied to the lumbar disc herniation by routine CT scan negative patients or patients with routine CT scan results and clinical symptoms in differences. 2 Patients with lumbar disc herniation in the lumbar spine in flexion, the degree of protrusion of the intervertebral disc is smaller than the neutral position degree, while lumbar extension degree in the protrusion of intervertebral discis is larger than the neutral position, through different lumbar curvature of lumbar disc herniation cases making accurate judgment, and also having guiding significance for the determination of lumbar disc herniation vertebral. Dual-source CT lumbar dynamic scanning can be more accurately display multiple lumbar curvature protrusion of intervertebral disc and lumbar nerve, blood vessel and the intervertebral foramina change as well as theirs anatomic relationship, the evaluation of the lumbar foramen stenosis changes is much more comprehensive and intuitive, and also provide reference for the treatment of lumbar degenerative disease when selecting the implantation of artificial disc or the height of the Cage to restore intervertebral relatively normal height and foraminal area.