Application Study Of Quantitative Parameters Of Double-layer Detector Spectral CT In The Differentiation Of Spinal Multiple Myeloma And Osteolytic Metastasis

Objective:To explore the application values of double-layer detector spectral CT(SDCT)in the differential diagnosis of multiple myeloma(MM)and spinal osteolytic metastasis by measuring and analyzing the CT value of virtual monoenergetic images(VMI),the effective atomic number Z value and the k value of the spectral curve slope of two kinds of lesions on the SDCT.Methods:The images of 21 patients with MM and 25 patients with spinal osteolytic metastases who underwent SDCT scanning in the second Hospital of Shanxi Medical University from October 2020 to October 2021 were collected and analyzed retrospectively.The CT value of 40-140 ke V(energy interval 10 ke V),and 200 ke V VMI,the effective atomic number Z value and the k value of the spectral curve slope of the two groups were compared.The Mann Whitney U test,the student T test and ROC curve were used to compare the difference of the two groups of data and the differential diagnosis power.Results:In the spinal bone metastasis group,the CT value of 40-80 ke V VMI,k value and Z value were higher than those of the MM group(P<0.05),while the CT value of 90-140 ke V200,ke V VMI had no significant difference(P>0.05).The ROC curve results show that the area under the curve(AUC)of the CT value of 40 ke V VMI is the largest,0.957(critical value: 90.95 HU),the slope k value and the effective atomic number Z value have higher diagnostic efficiency.Conclusion:SDCT can measure and compare the CT value at different energy levels of VMI,the effective atomic number Z value and the k value of the spectral curve slope of MM and spinal bone metastases,which provides rich imaging information for clinical differential diagnosis of MM and spinal osteolytic metastases,and has certain application value in the differential diagnosis of two kinds of lesions.