Diagnostic Value Of Dual-energy CT Scan In Lumbar Traumatic Bone Marrow Edema

Objective: To investigate the diagnostic efficacy of Dual-energy computed tomography(DECT)on lumbar traumatic bone marrow edema(BME),and to evaluate the diagnostic value of virtual noncalcium(VNCa)technology and virtual monoenergetic imaging(VMI)technology on lumbar traumatic bone marrow edema.Methods: The imaging data of Dual-energy CT and MRI examination of the lumbar spine in 51 patients with lumbar trauma were retrospectively analyzed.A total of 250 vertebrae were included in the study,of which 59 were diagnosed as acute compression fractures with bone marrow edema by DECT and MRI examination.The DECT scan data of51 patients were reconstructed by VNCa technique and VMI technique to obtain VNCa images and 9 sets of single-energy images with energy levels ranging from 40 ke V to 120 ke V,respectively.DECT VNCa images and VMI images of different energy levels were analyzed by two imaging physicians using a double-blind method for subjective evaluation and imaging diagnosis,respectively.Using the diagnostic results of MRI examination as a reference standard,the diagnostic results of visual assessment of VNCa images were compared and analyzed with the diagnostic results of MRI,and the VMI images with the optimal energy level were also selected.Two additional imaging diagnostic physicians were responsible for measuring VNCa CT values and r CT values of vertebrae with bone marrow edema versus vertebrae without bone marrow edema on VNCa images,as well as measuring CT values of vertebrae with acute compression fractures versus normal vertebrae on VMI images at optimal energy levels.The weighted Kappa analysis test was used to evaluate interobserver agreement,and the Mann-Whitney U test was used to explore the differences between the CT values of the groups.Receiver operating characteristic curve(ROC)was used to evaluate the visual evaluation of VNCa images and the diagnostic efficacy of different CT values quantitatively measured on VNCa images for lumbar bone marrow edema,and to evaluate the efficacy of CT values measured on VMI images in the diagnosis of acute lumbar compression fractures.Results: Visual qualitative assessment of VNCa images: the agreement between the diagnostic results of vertebral bone marrow edema on VNCa images by both imaging physicians and the display of vertebral bone marrow edema on MRI images was significant(K=0.877,K=0.888);the sensitivity(Sen),specificity(Spe),positive predictive value(PPV),negative predictive value(NPV),and accuracy(Acc)of the diagnosis of vertebral bone marrow edema on VNCa images by both diagnostic physicians were 89.83%,97.38%,91.37%,96.88%,95.60% and 89.83%,97.91%,92.98%,96.89%,96.00%,respectively.The quantitative measurement results showed that the VNCa CT value(-0.36±-21.43)HU and r CT value(160.10±41.63)HU of the vertebral body with bone marrow edema were higher than those of the vertebral body without bone marrow edema,with a statistically significant difference(P<0.05);The AUC of the ROC curve for quantitative diagnosis of vertebral bone marrow edema based on VNCa CT value and r CT value were0.985 and 0.776,respectively.The optimal cutoff values calculated were-38.1 HU and125.8 HU,respectively,with corresponding accuracy of 96.80% and 68.80%,respectively.The difference in the ability to diagnose bone marrow edema between VNCa CT values and r CT values was statistically significant(Z=6.242,P<0.0001),and combined with the AUC and accuracy results showed that VNCa CT values were superior to r CT values in their ability to detect bone marrow edema.Subjective assessment of VMI images:both imaging physicians had good agreement in subjective scoring of image quality at all energy levels of DECT VMI(K=0.806),and the results indicated that single-energy images at an energy level of 80 ke V had the highest subjective assessment scores of(3.88±0.38)and(3.90±0.36)for diseased vertebrae,respectively,agreeing that single-energy images at80 ke V had the best quality.The quantitative measurement results on the best single energy level 80 ke V images showed that the CT value of acute compression fracture vertebral body(177.74±39.47)HU was significantly higher than that of normal vertebral body(131.38±30.77)HU.With CT value 161.3 HU as the critical value,the AUC for the diagnosis of acute compression fracture was 0.829 and the accuracy(Acc)was 81.2%.Conclusion: Dual-energy CT VNCa technology has good diagnostic efficacy for detecting lumbar traumatic bone marrow edema,and VMI technology can provide a reference basis for diagnosing acute compression fractures of the lumbar spine in clinical practice.The combined application of the two imaging technologies can effectively improve the diagnostic value of dual-energy CT for lumbar traumatic bone marrow edema.