The Value Of Energy Spectrum CT In The Differential Diagnosis Of Benign And Malignant Muscle

Objective To explore the value of spectral curve in the differential diagnosis of benign and malignant tumor of musculoskeletal system.Methods100patients with mass of musculoskeletal system which were confirmed by MRI underwent Discovery HD750Gemstone CT scan and the images acquired were processed. Areas with homogenous density which do not contain necrosis, cyst, hemorrhage and calcification were chosen as region of interest(ROI). Select the optimal Kev on single energy images, then the Kev-CT curve was automatically generated. All100patients proved by histological examination were divided into four groups,38cases as group A with benign tumor,10cases as group B with borderline tumor,49cases as group C with malignant tumor and3cases of lipoma (that were analyzed separately since its curve was arc shaped). Average slope rate of every group was calculated according to the formula: K40-80keV=(HU40keV-HU80keV)/80-40. Kruskal Wallis test was applied for statistical analysis, P value of less than0.05was considered statistical significant.Results The spectral curve of group C was sharply falling type with a mean slope rate of1.64±1.00, that of group A was gradually falling type with a mean slope rate of0.75±0.30, and the slope of group C was1.34±0.45. The difference of slope rate between group A and C(p<0.05), between A and B was of statistical significance(p<0.05). The spectral curve of3lipomas showed arc shaped rising type with a mean slope rate of-2.00.Conclusion Spectral curve is useful in the differential diagnosis of benign and malignant tumor of musculoskeletal system. Arc shaped curve is a specific sign for tumors containing abundant fat.