The Study On The Measurement Of The Height Of The Intervertebral Disc Of Cervical Vertibra In MRI

Background: Presently the method of anatomic measurement of intervertebal disc height included measurements on a fresh cadaver, on general specimens, on plastication specimens and measurements of X-ray, CT, and MRI. The MRI was better than X-ray and CT in the measurement on cervical intrevertebral disc. The MRI can show the structures of the cervical intervertebral disc obviously. When a patient position was fixed, the MRI can scan any section by orient change and gradient magnetic selection, such as transverse, sagittal, coronal and oblique sections. That was useful for stereoviewing and measurements of the cervical intervertebral disc. For the past few years the height of intervertebral disc was measured mostly on median sagittal plan, but the new treatment of the protrusion of intervertebral disc were present, and that needed more information except for the median sagittal of the intervertebral disc.Objective: In this study, the height measurements of intervertabral disc on multi-sagittal plans were carried out to present the anatomic data of cervical intervertebral disc for the diagnosis and treatment of the protrusion of cervical intervertebral disc in clinic.Methods: The experiment group was the cervical vertebral MRI images of 20 patients with the protrusion of cervical intervertebral disc. The control group was the MRI images of health adult. The measurements were carried out used a Signa MR/i 1.5T MRI machine. 5 sagittal plans were selected including the median sagittal plan and 2 plans on each side in 4mm interval. The anterior and posterior marginal heights of the disc were measured on each sagittal plan. And the data were processed by SPSS 11.5software. P<0.05 was statistical significance.Results:⑴There was significant 85% diffrence (P<0.05) between two group people in the height of intervertebral discs at C4-5, C5-6 and C6-7, which were liable to the protrusion. There was only 30% difference (P<0.05) between two group at C2-3and C3-4, which were not liable to the protrusion.⑵The data of measurements (Table 1-4). Table 1 Average heights of cervical intervertebral discs of the health adult(mm) A, anterior. P, posterior. Sagittal plan, 1-5 from right to left side.Table 2 Average heights of cervical intervertebral discs of the protrusion (mm) A, anterior. P, posterior. Sagittal plan, 1-5 from right to left side.Table 3 Average heights of cervical intervertebral discs of the two group (mm). A, anterior. P, posterior. Sagittal plan, 1-5 from right to left side.Conclusion:⑴The height of protrusion intervertebral discs were lesser than that of normal disc at cervical vertebra in MRI.⑵The anatomic indexes were presented about the normal and abnormal cervical intervertebral discs in MRI.