Comparison Of Whole-body PET/CT And PET/MR In Clinical Diagnosis Of Lymphoma

Objective: The main objective was to compare the diagnostic efficacy of PET/MRI and PET/CT in adult 's lymphoma.Secondary objective is to evaluate the maximum Standardized uptake value and intravoxel incoherent motion(IVIM)model index of correlation.Methods: A prospective study was conducted on 45 pathologically confirmed lymphoma patients who underwent systemic PET/CT and PET/MR examinations.Two experienced readers independently evaluated the PET/MRI studies,and two other experienced readers independently evaluated PET/CT.Site of lymphoma involvement and SUVmax at all nodal sites more avid than background liver were recorded.The D,D* and f value corresponding to the most avid PET site of disease was recorded,and the differences in the diagnostic efficacy and staging of the two diagnostic modes were analyzed by using imaging follow-up and pathology as the gold standard.Results: Both PET/CT and PET/MR detected 55 nodal and 5 extranodal sites,In addition,2 nodal were identified on PET/MRI.thirty-nine sites were identified on IVIM.For positive lesion detection,reader agreement was perfect between the two readers and almost perfect between PET/CT and PET/MR(k=0.956).Intermodality agreement between PET/CT and PET/MRI was also near-perfect to perfect for staging(k =1.000).SUVmax from PET/CT and PET/MRI correlated significantly,(Spearman's rho correlation coefficient 0.892,P<0.0001).A weak correlation was demonstrated between D and SUVmax(Spearman's rho correlation coefficient r-0.312,P<0.005),A Moderate correlation was demonstrated between f and SUVmax(Spearman's rho correlation coefficient r 0.520,P<0.0001).Conclusion: PET/MR is comparable to PET/CT in the ability of Diagnosis and staging in lymphoma.It has a good diagnostic efficacy.Because of its higher tissue resolution,it can improve the accuracy of the diagnosis and staging of lymphoma.Moreover,through the combination of multiple parameters,the heterogeneity of tumor can be predicted and evaluated,which has important clinical application value.