Correlation Of Water Concentration On Spectral CT With The T2 Relaxation Time On MRI Of Cervical Intervertebral Discs

BackgroundWith the heads-down trib creasingly,the incidence of cervical spondylosis is also increasing,and the age of onset of cervical spondylosis is also becoming younger.At present,there are many clinical methods to check the degree of cervical disc degeneration.Generally,cervical MRI scan is preferred.In particular,T2 mapping images of MRI can quantify the water content in the nucleus pulposus of the cervical intervertebral disc,and then detect problems in the early stage of disc degeneration.However,in the presence of contraindications to examination,another examination method is urgently needed to replace its early detection of degeneration.When performing computed tomography angiography(CTA)of the head and neck,vascular subtraction angiography is often used.This examination requires a set of plain scan images to subtract bones.At the same time,head and neck CTA imaging using gemstone spectral imaging(GSI)mode scanning can effectively reduce the radiation dose and improve the detail display.The purpose of this article is to use the plain scan images to observe the morphology of the cervical spine and intervertebral discs,and to study whether the material separation map can accurately and quantitatively analyze the water content in the intervertebral discs and compare them with the T2 value on the T2 mapping image to study the correlation between the two.ObjectiveTo investigate the correlation between the water concentration in the cervical intervertebral disc and the T2 relaxation time value on the T2 mapping image in the water-based map obtained from the energy spectrum CT material separation.Objective to study the feasibility of diagnosing cervical spondylosis with water-based image in spectral CT material separation.MethodsA total of 74 patients who underwent continuous energy spectrum head and neck CTA and cervical spine MRI in one day were retrospectively collected.The images of 70 ke V,water(iodine),water(calcium),water(HAP)and T2 mapping were obtained.All cases of disc herniation were evaluated subjectively,and Chi square test was used to compare the condition of cervical disc detected by four groups of images.CT values of cervical intervertebral discs were measured in 70 ke V images.The water concentration values of cervical intervertebral discs were measured in the water iodine map,water calcium map,and water HAP map obtained from the material separation.The T2 relaxation time of each disc was measured on the T2 mapping image.The Friedman test was used to compare the differences in the water concentration values of the intervertebral discs in the three groups of water(iodine)map,water(calcium)map,and water(HAP)map.Pearson correlation analysis was used to determine the correlation between the CT value of the intervertebral disc in the 70 ke V image,the concentration of the disc water in the water(iodine)map,water(calcium)map,and water(HAP)map and the T2 relaxation time value on the T2 mapping image.ResultsThere was no significant difference between water(iodine),water(calcium)and 70 ke V images in evaluating the morphology of cervical intervertebral disc,and there was no significant difference between them and MRI.However,there were differences between HAP and MRI in evaluating the morphology of intervertebral disc.The results of water(iodine),water(calcium)and water(HAP)were better than those of 70 ke V.The image quality of water(HAP)is the best,and there is no difference between water(iodine)map and water(calcium)map.There were no statistically significant differences in CT values between C2-7 intervertebral discs,water concentration values on three water-based maps,and T2 relaxation time.The water concentration value of each intervertebral disc is different between the water(iodine)map,the water(calcium)map,and the water(HAP)map.The water(iodine)map is the highest,the water(calcium)map is the second,and the water(HAP)map is the lowest,the differences were statistically significant,and the P-values of pairwise comparisons were all <0.05.Except that the CT value measured on the C4/5 intervertebral disc 70 ke V image is related to the T2 relaxation time(r=-0.474,P=0.022),there is no correlation between the CT values of the other 70 ke V discs,the water concentration values on the three water-based maps,and the T2 relaxation time values on the T2 mapping map.ConclusionWater(iodine)diagram and water(calcium)diagram can better show the degree of cervical disc degeneration..And there is no correlation between the water concentration of the cervical intervertebral disc obtained from the water-based map and the T2 relaxation time,which indicates that the separation of the water-based map from the spectral imaging material cannot quantitatively reflect the degeneration of the cervical disc.