Diagnosis value of trimoality PET/CT-MR in digestive tract disease

Objectives The aim of the study was to assess the diagnosis value of trimodality PET/CT-MR in digestive tract disaeses., to evaluate quantitative correlation between standardized uptake value with [18F]fluoro-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) and apparent diffusion coefficient with MRI in digestive tract malignant tumors.

Methods Fifteen consecutive patients with pathologically confirmed digestive tract adenocarcinoma or inflammation were included in this study, who all carried out [18F]FDG-PET/CT and MR. MR convention sequences plus multi b value diffusion weighted imaging (DWI) sequences exams were performed after PET/CT exams through a transfer bed. Two blind and independent readers assessed all images randomly for the nature of the digestive tract diseases. SUVmax (maximum SUV), SUVmean (average SUV) and ADC maps were generated to calculate ADCmean (average ADC), ADCmin (lowest ADC) of fast，slow and super high b value on GE AW4.6 work station. Pearson’s correlation test was used to detect the relationships between quantitative indices of DWI and PET.

Results 1.Sensitivity, specificity，precision ,positive predictive value and negative predictive value of PET/CT for fifteen digestive tract disease patients is respectively 79.2%, 100%, 80.8%, 100% and 28.6%, is 80%, 100%, 80.8%, 100% , 16.7% and 80% of MR. The value for PET/CT-MR is respectively 92%, 100%, 92.3%,100% and 33.3%. Youden’s indexs of PET/CT, MR and PET/CT-MR are 83.3%、80% and 92%. 2. The correlation between fast ADCav and SUVmax(r=-0.669，P=0.009), SUVmin(r=-0.679，P=0.008)of digestive tract malignant tumors is negative correlation.

Conclusions Trimodality PET/CT-MR can help improve diagnosis efficacy of digestive tract disease, compared with single mode PET/CT or MR. The significant negative correlations between fast ADC and SUV suggest an association between tumor perfusion and metabolic activity in digestive tract malignant tumors.

Research Support No