| Objective: To study the value of18F-FDG PET/CT-MR in diagnosis and in differentiationbetween benign and malignant pulmonary lesions.Materials and Methods: Thirty-two cases of patients who accept PET/CT-MR examination forpulmonary diseases were from our hospital during March2013to January2014. All patientsvoluntarily signed the informed consent form and the study was approved by the HumanResearch Ethics Committee of our University. As the investigated targets, the pulmonary lesions(nodules, mass or consolidation) only with diameter larger than1cm are selected.22cases weremalignancy and the others were benign lesions．Among all the patients,25of them are males and7of them are females. They are all at age between35and77, with mean56.28±10.38year.There are22patients with lung carcinomas (11cases of squamous cell carcinoma,8cases ofadenocarcinoma, and3cases of small cell lung carcinoma), and there are10benign lesions (5cases of tuberculosis,3cases of pneumonia, and2cases of inflammatory pseudotumor). Allcases are confirmed pathologically by operation, biopsy or bronchoscopy, and clinical Follow-up.They all received MR chest examinations with GE Discovery3.0T MR, and the Sequenceincluding T1WI, T2WI and DWI (diffusion factors of500s/mm2). And then, they all receivedwhole body PET/CT test with GE Discovery Elite690PET/CT scanners. The value of ADC andSUV of lesions were respectively measured on corresponding DWI and PET/CT imaging. Afterall completion, the following analyses were done:1. to make a quantitative analysis of the ADCvalues of the benign or malignant lesions and compare the differences of ADC values betweenthose two;2. to make a quantitative analysis of the SUV values of the same items above andcontrasts the differences of SUV values between the benign and malignant lung lesions;3. toanalyze the relationship between ADC and SUV value of the pulmonary lesions;4. to comparethe diagnostic efficacy of the three diagnostic methods (MRI, PET/CT, PET/CT-MR). Statisticalanalysis was determined by using Independent-Samples t test, linear correlation, X2test and theFisher’s Exact test.Result:1. When b=500s/mm2, ADC values of malignancy were1.07±0.31×10-3mm2/s. ADCvalues of benign lesions were1.60±0.23×10-3mm2/s. There was statistical significance betweenADC values of malignant pulmonary tumors and benign lesions (p=0.000). ADC values ofmalignant tumors were significantly lower than those of benign lesions. 2. SUV values of pulmonary malignancy were8.32±3.80, while those of benign lesions were3.50±1.25. There was statistical significance between SUV values of malignant pulmonarytumors and benign lesions (P=0.000). SUV values of malignant tumors were significantly higherthan those of benign lesions.3. ADC values of pulmonary malignancy were1.07±0.31×10-3mm2/s. SUV values of pulmonarymalignancy were8.32±3.80.The ADC was minus correlated with the SUV (p=0.021＜0.05) andthe Correlation coefficient was－0.65.4. The diagnostic sensitivity, specificity and accuracy of PET/CT-MR for pulmonary malignancywere95%,90%and93%respectively. The diagnostic sensitivity, specificity and accuracy ofPET/CT for pulmonary malignancy were86%,80%and84%, respectively. The diagnosticsensitivity, specificity and accuracy of single MR for pulmonary malignancy were72%,60%and68%, respectively.Conclusion: ADC values and the SUV values of lung lesions are significantly different in lungbenign and malignant lesions, therefore the identity of lung lesions can be determined by thosetwo values. The higher of glucose metabolism in lung cancer (larger of the SUV), the morelimited of the diffusion presented (smaller of the ADC), so there is a minus correlation betweenthe ADC and SUV. PET/CT–MR is more effective than PET/CT and single MR in respect ofdifferentiating benign and malignant pulmonary lesions. |
PDF Full Text Request