Diagnosis of lymph node metastasis on rectal cancer by PET-CT computer imaging combined with MRI technology

To compare the diagnostic efficacy and clinical application value of Positron Emission Tomography-Computed Tomography (PET-CT) metabolic computer Imaging imaging and Magnetic Resonance Imaging (MRI) diffusion imaging technology for regional lymph node metastasis in rectal cancer, 41 patients with rectal cancer confirmed by colonoscopy were collected and underwent 3.0T pelvic MRI and PET-CT examination, respectively. PET-CT/MRI fusion software was used to fuse magnetic resonance images and PET-CT images and accurately locate the rectal cancer lesions and lymph nodes, and image-operation-pathology control method was used to identify the lymph nodes around the rectum. In addition, independent sample t-test or Mann-Whitney U test were used to compare the differences in the values of various parameters between the two groups of metastatic lymph nodes and non-metastatic lymph nodes, Spearman correlation was used to analyze the correlation between SUV value and ADC value of metastatic lymph node, and the diagnostic value of SUV value and ADC value was evaluated by drawing ROC curve. The results showed that when SUV took 2.0 as the diagnostic threshold, the accuracy of PET-CT in diagnosing metastatic lymph nodes was 90.1%; when the diagnostic threshold of ADC was 1.0×10^-3mm²/s, the accuracy of DWI in diagnosing metastatic lymph nodes was 84.2%; the accuracy of the combination of the two methods for the diagnosis of metastatic lymph nodes was 94.4%. Therefore, it can be concluded that both PET-CT and MRI diffusion images were of high diagnostic value in the diagnosis of lymph node metastasis of rectal cancer, and their diagnostic results were highly consistent. When combined, the diagnostic accuracy can be further improved.