The Whole Body Magnetic Resonance IVIM Functional Imaging Was Compared With ¹⁸F-FDG PET/CT In Lymphoma Staging

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MULTI-B VALUE DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING AND INTRAVOXEL INCOHERENT MOTION MODELING:DIFFERENTIATION OF AGGRESSIVE LYMPHOMA LESIONS ON INITIAL TREATMENT AND ACTIVITY ASSESSMENT AFTER CHEMOTHERAPYOBJECTIVE: This study investigated the efficiency of DWI with different b values and the application of an IVIM model to identify benign or malignant lymph nodes and malignant residual lesions of lymphomas after chemotherapyMATERIALS AND METHODS: Thirty patients?16 males and 14 females?and sixty patients?33 males and 27 females?were enrolled in this study.They received 3.0 T MRI conventional sequences And DWI imaging with multiple b-values ??b = 0,30,50,100,150,200,400,800 s / mm²?.The newly diagnosed group received follow-up biopsy,and the completed chemotherapy treatment group received biopsy or follow-up?18 22 months?.The Longest transverse Diameter and mean apparent diffusion coefficient?m ADC?of the target lymph nodes were measured by reference to T2-weighted images and diffusion-weighted images?DWI?.The standard apparent diffusion coefficientvalues ??in the IVIM single exponential model were obtained,and the D,D* and f values ??in the double exponential model were obtained.The differences of m ADC,s ADC,D,D * and f in patients with newly diagnosed and chemotherapy were compared with the pathology or follow-up.The logistic regression model was established to screen the clinical and imaging parameters of benign and malignant lymph node lesions and lymphoma.RESULTS: A total of 32 clinically diagnosed lymph nodes were found in30 newly diagnosed patients,including 13 benign lymph nodes and 19 invasive lymphomas.When the b value = 200 s / mm²,m ADC value of benign lymph node disease(2.42 × 10^-3mm² / s)> lymphoma(0.67 × 10^-3mm² / s)?P <0.01?,can get the best diagnostic performance(diagnosis Threshold: 1.11 × 10^-3 mm² /s,AUC area: 0.992,95% confidence interval: 0.973-1,sensitivity: 94.7%,specificity: 100.0%,accuracy of 96.9%).Completed chemotherapy treatment group: a total of 60 patients,which can analyze the target lymph nodes 60,5cases pathology confirmed CR,8 cases pathology confirmed no CR?PR?,10follow-up confirmed CR,37 not CR.The f value in IVIM has the best diagnostic performance.?56.5% of PR residual group > 21.5% of CR residual group?P <0.01?,Diagnostic threshold: 42.1%,AUC area: 0.931,95%confidence interval: 0.869-0.995,sensitivity: 93.3%,specificity: 82.2%,accuracy: 85.0%?.The newly diagnosed patient group could not establish the logistic regression model.The logistic regression model of completed chemotherapy treatment group was: Logit?Q?=-12.83 + 4.45?LDi?+19.60?f?,Q ? 0.5 was CR,Q> 0.5 was PR,the accuracy was 93.0%.CONCLUSION: The mean apparent diffusion coefficient is different from benign lymph node lesion and malignant lymphoma.When b = 200 mm² / s,the diagnostic efficiency is the largest,and the diagnostic accuracy is about96.7%.The f value of IVIM was the highest in the benign and malignant lesions of lymphoma after chemotherapy,and the accuracy was 85.0%.The establishment of a multivariate logistic regression model helps to improve the accuracy of residual disease identification after chemotherapy.The Longest transverse Diameter of the lymph nodes,f value lesions is the important parameters of benign and malignant for the identification of lymphoma after chemotherapy residual.PART ? COMPARISON OF WHOLE BODY MRI IVIM WITH ¹⁸F-FDG PET/CT OF FUNCTIONAL IMAGING STAGING IN LYMPHOMA RESEARCHOBJECTIVE: To explore the value of MRI in Lymphoma stage,compare differences between FDG PET/CT and MRI in the staging of lymphomas.MATERIAL AND METHODS: A total of 66 newly diagnosed patients with malignant lymphoma were enrolled in the study cohort.A total of 48 patients achieved a study endpoint?25 males and 23 females?in a prospective,self-controlled cohort study.They received the whole body 3.0T MRI: T1 WI,T2WI,DWI multi-b?b = 0,30,50,100,150,200,400,800 s / mm²?imaging and the same machine 18 FDG PET/CT scan.Two independent radiographs reading groups evaluated the nodes regions,lymph node organs and external lymph node regions,and the Lugano Staging System was performed on MRI and PET/ CT using qualitative and semi-quantitative methods.Result: In the region-based analysis,Forty-eight patients had a total of1436 PET/CT and MRI-corresponding analytic lymph nodes regions and 268?semi-quantitative analysis of 138?external lymph node regions were included in the analysis.The concordance rate of qualitative diagnosis of lymph node regions was 96.3%?Kappa = 0.914,P <0.0001?.The concordance rate of qualitative diagnosis of external lymph node regions was 97.3%?Kappa =0.815,P <0.0001?.With the qualitiative diagnosis methods of PET/CT and MRI,The sensitivity,specificity and accuracy of lymph node regions were 93%,90%,91%,and 94%,88%,90% respectively.There was no significant difference in the sensitivity of the two methods,and the specificity was statistically different.Sensitivity,specificity,accuracy were 80,99%,97% and 90%,98%,98% in external lymph node regions.Their sensitivity and specificity were statistically different.The sensitivity,specificity and accuracy of PET/CT and MRI semi-quantitative method were 90%,98%,96% and 91%,95%,94%respectively in the diagnosis of lymph node area.There was no significant difference in the sensitivity of the two methods,and the specificity was statistically different.The sensitivity,specificity and accuracy of the diagnosis were 85%,97%,96% and 84%,82%,83% respectively in the diagnosis of external lymph node regions.The sensitivity was not statistically significant,the specificity was statistically different.In the patient-based qualitative analysis,four patients?8.3%?in PET/CT did not match the gold standard staging.MRI has 3 patients?6.3%?inconsistent with the gold standard staging.There was no significant difference in Lugano staging system by PET qualitative method and PET/CT qualitative method?Mc Nemar's chi-squared =6,P= 0.4232?.They were well consistent?Kappa = 0.774,P <0.001?.Three patients?6.3%?changed the overall treatment strategy because of the staging.Conclusions: Both PET/CT and MRI methods have similarity to PET /CT sensitivity in lymph node area and the specificity is slightly lower.The sensitivity of MRI to qualitative method was superior to that of PET/CT in external lymph node regions and the specificity is similar.Patients with MRI and PET/CT in the initial stage of lymphoma good consistency.But whether MRI can replace PET for lymphoma staging also need more data to verify.