Colorectal Cancer Lymph Node Metastasis And High Field Magnetic Resonance Diffusion Weighted Imaging The Pathological Control Study

Purpose: Study MRI（Magnetic Resonance Imaging） small bvalue and b value of Diffusion weighted Imaging （coursing togetherweighted Imaging） rate of lymph node and multiple DWI the accuracy ofthe diagnosis of rectal cancer lymph node metastasis can b values, so asto improve the accuracy of preoperative N staging of rectal cancer.Materials and methods: This study60cases were retrospectivelyanalyzed by colonoscopy pathological biopsy and postoperativepathological diagnosis of colorectal cancer patients （45cases were male,15female, mean age,59.3years）, both in the preoperative routine MRIsequence （T2WI sagittal position, T2fat suppression like, T1WI, T2WI shaftaxis, T2WI, coronal position）, DWI （b=0s/mm²ã€b=20s/mm²ã€b=30s/mm²ã€b=50s/mm²ã€b=600s/mm²ã€b=800s/mm²ã€b=1000s/mm²ï¼‰ check.（1） According to the b value of DWI images can divided into twogroups, namely: the small values of b group （b=50s/mm²ï¼‰, more than group bvalue （b=0s/mm²ã€b=20s/mm²ã€b=30s/mm²ã€b=50s/mm²ã€b=600s/mm²ã€b=800s/mm²ã€b=1000s/mm²ï¼‰, respectively the small b value set of imagesand more than b group is shown on the image number of lymph nodes with pathology and T2WI sequence comparison.（2） according to theresults of the pathological lymph nodes can be divided into the metastasislymph nodes and the metastasis lymph nodes, and then a retrospectivesurvey and analysis of two groups of lymph node b value of ADC values,calculate the sensitivity and specificity of ADC value in the diagnosis oflymph node metastases, ROC curve drawing.Asaresult:1), pathology and T2WI images as reference standard,small b value of lymph node detection rate was98%, more than b valueof lymph node detection rate was90%, the average of9.91±5.879.94±5.759.75±5.469.56±5.42. statistical differences between groups （p<0.05）.2), through the measurements we get high field strength b morevalue of metastatic lymph nodes was the average ADC values for（1.06±0.30）×10^-3mm²/s, average ADC values of metastatic lymph nodes（0.74±0.21）×10^-3mm²/s, statistically difference between the two.3), when the value of ADC values of0.98×10^-3mm²/s is the bestcut-off point for diagnosis of lymph node metastasis or not, its sensitivitywas63.7%,93.2%.Conclusion:（1） high field strength small b value DWI with higherdetection rate of lymph nodes. Can （2） high field strength b value of ADCvalues can more effective identification of lymph node metastasis, highlyspecific degrees and moderate sensitivity.（3） more than high field strength b value combined with a small b DWI imaging can on clinicalpatients with rectal cancer operation method, treatment and prognosisjudgment provides effective information.