Detection Of Different Degree Traumatic Vertebral Bone Marrow Lesions By Virtual Noncalcium Technique Of Dual-source CT With Comparison To MR

Objective: To evaluate the diagnostic performance of dual-source computed tomographic(DSCT)virtual noncalcium(VNCa)technique for detection of different degree traumatic vertebral bone marrow lesions with magnetic resonance(MR)imaging as the reference standard.Methods: Our prospective study was approved by the institutional ethics committee.Informed consent was obtained from all patients.Twenty consecutive patients suspected with posttraumatic vertebral compression fractures(VCF)were studied between October 2016 and May 2017(thoracic 88,lumbar 93).All patients underwent both DSCT(100 k V and 140 k V with tin filter)and MR imaging.DSCT data were postprocessed by using a three-material decomposition algorithm for generating VNCa images.Vertebral bodies on VNCa images were visually graded by two blinded,independent radiologists using a three-point classification system(0 = normal bone marrow,1 = subtle abnormal bone marrow attenuation,2 = distinct abnormal bone marrow attenuation).CT values in VNCa images were calculated by a third radiologist.Vertebral bodies on MR images were graded by a forth radiologist using the same classification as DSCT(0 = normal bone marrow,1 = subtle abnormal bone marrow signal,2 = distinct abnormal bone marrow signal).MR imaging findings served as the reference standard.Results: The interobserver agreement for visual grading of bone marrow lesions on VNCa images was substantial(? = 0.695),and the agreement between VNCa and MR images for the grading of bone marrow lesions was also substantial(? = 0.694).If MR imaging at grade 2(distinct abnormal bone marrow signal)was regarded as positive for bone marrow lesions and served as the reference standard,VNCa images achieved an overall sensitivity of 85.0%,specificity of 97.5%,PPV of 81.0%,NPV of 98.1%,and accuracy of 96.1%.There was no statistical difference in CT values obtained from VNCa images between thoracic and lumbar vertebrae with and without bone marrow lesions on MR images(both P > 0.05).CT values obtained from VNCa images were significantly different between vertebrae with and without bone marrow lesions on MR images(P < 0.001).Receiver operating characteristic(ROC)analysis based on CT values for the diagnosis of distinct bone marrow lesions according to MR imaging revealed an area under the curve(AUC)of 0.950.A cutoff value of-11.80 HU provided sensitivity of 95.0%,specificity of 86.3% for the diagnosis of distinct vertebral bone marrow lesions at DSCT.Conclusion:1 Compared with MR images,DSCT VNCa images have shown good diagnostic performance for detecting traumatic vertebral bone marrow lesions on both visual and quantitative analysis,especially for detecting distinct traumatic vertebral bone marrow lesions.2 Not only can radiologists diagnose or exclude VCF by observing the integrity of bone structure on traditional CT bone reconstruction images,they can also detect or exclude bone marrow lesions on VNCa images in cases of morphogically nonfractured vertebral bodies.3 In comparison to the traditional single-energy CT,DSCT could provide additional diagnostic information to help radiologists depict the recent fractures,thereby preventing more associated complications.4 DSCT might provide an alternative option for patients who are suspected of acute VCF and need a one-shop-stop examination to quickly clarify the diagnosis or for whom with contraindications to MR imaging.