| This study was divided into two parts:Part One was clinical cases study, to evaluatethe correlation between the quantized indexs SUV and ADC values of18F-FDG PET/CTand MRI DWI in diffuse large B-cell lymphoma;Part Two was Animal experiments,toassess the value of PET/CT and MR DWI in discrimination between benign and malignantlymph nodes in rabbits model.Part One: The correlation between SUV and ADC values in diffuse largeB-cell lymphoma——18F-FDG PET/CT and MRIObjective: To evaluate the correlation between the quantized indexs SUV and ADCvalues of18F-FDG PET/CT and MRI DWI in diffuse large B-cell lymphoma, accordinglyto reflect the glucose metabolism and water molecular diffusion of tumor tissue.Materials and Methods: Twenty-four diffuse large B-cell lymphoma patientsunderwent18F-FDG PET/CT and MRI examinations within a week.MRI DWI wasperformed with b-values of0,500,and1000s/mm2. All patients were onset patients,nopatients received chemotherapy or radiotherapy. The lesions of diameter larger than2cm,and the location was uniform on PET/CT and DWI, were selected to mesure the SUVmax,ADCminand ADCmeanvalues, then measured the SUVmaxof cerebellums, and calculated theSUVbri. Correlation analysis was used linear regression analysis.The final diagnoses of allthe patients were confirmed by pathology.Results: Eighty-two lesions were included into statistical ananlysis according to theinclusion standard. The SUVmaxand SUVbriwere7.82±4.24and1.17±0.63respectively.When b value was500s/mm2, ADCminand ADCmeanwere （0.59±0.21）×10-3mm2/s, （0.85±0.23）×10-3mm2/s respectively; low negative correlation was found between SUVmaxand ADCmin, SUVmaxand ADCmean（r=-0.304,P=0.005;r=-0.389,P<0.001）, moderatenegative correlation was found between SUVbriand ADCmin, SUVbriand ADCmean（r=-0.439,P<0.001;r=-0.559,P<0.001）. When b value was1000s/mm2, ADCminandADCmeanwere （0.56±0.18）×10-3mm2/s and （0.77±0.21）×10-3mm2/s respectively; lownegative correlation was found between SUVmaxand ADCmin（r=-0.346,P=0.001）, andmoderate negative correlation was found between SUVmaxand ADCmean, SUVbriandADCmin, SUVbriand ADCmean（r=-0.462,P<0.001;r=-0.477,P<0.001;r=-0.638,P<0.001）.Highly positive correlation was found between SUVmaxand SUVbri（r=0.929,P<0.001）.Conclusion: Low to moderate negative correlations were found between SUV and ADCvalues in large B-cell lymphoma, and SUVbri better than SUVmax, which meant there wasnegative correlation between glucose metabolism and water molecular diffusion of tumortissue.Part Two: Values research of18F-FDG PET/CT and MR DWI indiscrimination between benign and malignant lymph nodes in rabbitsmodel.Objective: to investigate the value of18F-FDG PET/CT and MR DWI in evaluation ofreactive and tumor metastatic lymph nodes.Materials and Methods:36healthy adult New Zealand rabbits were randomlydivided into three groups. Reactively hyperplastic lymph node（RLN） model wasestablished in15animals by intramuscular injection of1ml egg yolk emulsion into thebilateral hindleg, and tumor-bearing lymph node（MLN） model was established byintramuscular injection of0.5ml VX2tumor tissue mass suspension in another15rabbits,and the other6rabbits were chosen as normal（NLN） control group. RLN wereperformed18F-FDG PET/CT and MRI after2weeks, MLN were performed18F-FDGPET/CT and MRI after3～4weeks, two examinations were all finished within one day. Measured the SUVmaxof lymph nodes on PET images, the diameter of lymph nodes on CTand MRI T1WI images, measured the ADC and eADC values of lymph nodes on ADCmaps. Calculated the SUVrand ADCr, and measured the CPM and quality of lymph nodes.The lymph nodes diameter among NLN, RLN, and MRN were compared using one-wayANOVA. The SUVmax, ADC and eADC values between RLN and MLN were comparedusing t-test. Correlation analysis was used linear regression analysis. Base on pathology,Receiver Operating Characteristic curves（ROC） were drawn to evaluate the diagnosticperformance of lymph nodes diameter, SUVmax, ADC and eADC values.Results: ANOVA analysis: there was statictical difference among the three groups lymphnodes diameter measured on the PET/CT, MRI and sample（P<0.001all）. t-test: the samegroup lymph nodes diameters were measured on PET/CT and MRI, but there was nostatictical difference（P>0.05all）. The SUVmaxof RLN and MLN were1.35±0.61and3.03±1.85respectively, and there was statictical difference. When b-value was500s/mm2,the ADC values of RLN and MLN were （1.20±0.33）×10-3mm2/s and （1.01±0.18）×10-3mm2/s respectively, and the eADC velues of RLN and MLN were （0.29±0.11）×10-3mm2/s and （0.38±0.07）×10-3mm2/s respectively, there were statictical differencebetween RLN and MLN in the ADC and eADC（t=2.57,P=0.014;t=3.70, P=0.001）. Whenb-value was1000s/mm2, the ADC values of RLN and MLN were （0.99±0.26）×10-3mm2/sand （0.83±0.25）×10-3mm2/s respectively,and the eADC velues of RLN and MLN were（0.37±0.12）×10-3mm2/s and （0.46±0.14）×10-3mm2/s respectively, there were staticticaldifference between RLN and MLN in the ADC and eADC（t=2.33,P=0.024;t=2.70,P=0.009）. Correlation analysis:When b-value was500s/mm2and1000s/mm2, moderatenegative correlation was found in MLN between SUVmaxand ADC（r=-0.636,P<0.001;r=-0.547,P=0.002）, moderate positive correlation was found in MLN betweenSUVmaxand eADC（r=0.604,P<0.001;r=0.698,P<0.001）; while in RLN there was nocorrelation between SUVmaxand ADC, SUVmaxand eADC.There were all high negativecorrelation between ADC and eADC in MLN and RLN（r=-0.926～-0.806, P<0.001all）.ROC curve analysis:The Az values of lymph nodes diameter on PET/CT and MRI were 0.823and0.852respectively, the sensitivity and specificity were86.7%and73.3%,83.3%and76.7%respectively, the diameter threshold was9.95mm and8.89mm respectively. TheSUVmaxhad a higher diagnostic performance than SUVr, Az value were0.855and0.698,the sensitivity and specificity were92.9%and65.4%,96.4%and46.2%respectively, thethreshold was2.22and5.92. The CPM with the highest diagnostic performance, its Azvalue was0.939, sensitivity and specificity were96.2%and79.2%. When b-value was500s/mm2and1000s/mm2, the eADC had a moderate diagnostic performance, the Azvalue was0.759and0.717, the sensitivity and specificity were82.1%and61.5%,92.9%and50.0%respectively, and the threshold was0.31×10-3mm2/s and0.34×10-3mm2/srespectively; while ADC had a low diagnostic performance, the Az value was0.693and0.677, the sensitivity and specificity were75.0%and61.5%,78.6%and57.7%respectively, the threshold was1.11×10-3mm2/s and0.97×10-3mm2/s respectively. Whenb-value was500s/mm2, ADCr with the lowest diagnostic performance, Az value was0.676,the sensitivity and specificity were69.2%and66.7%.Conclusion:①The lymph nodes diameter, SUVmax, ADC and eADC all had a certainvalue in discrimination between benign and malignant lymph nodes, but they had differentlimitations of theirselves.②The diagnostic performance of SUVr and ADCr was lowerthan SUVmax and ADC respectively, CPM with the highest diagnostic performance.③There were moderate negative correlation between SUVmax and ADC in MLN, andthere were moderate positive correlation between SUVmax and eADC in MLN.④Therewas no anything correlation between SUVmax and ADC, SUVmax and eADC in RLN. |
PDF Full Text Request