Preoperative Staging By MRI In The Diagnosis Of Rectal Cancer And Correlation With Histopathology

Background: Rectal carcinoma is one of the most frequent cancers in the world,as well as one of the leading causes of cancer-related death.Stereotactic radiotherapy,neoadjuvant therapy,molecular targeted therapy,and surgical resection are considered to be commo n therapies for rectal cancer.Accurate tumor staging plays a vital role in implications for the choice of treatment options as well as in the prognosis of patients and has a good impact on patient prognosis and parental quality.Magnetic resonance imaging（MRI）routine imaging examination is of utmost importance in the diagnosis,evaluation of preoperative staging,and prognosis of rectal cancer.Preoperative staging can be done by observing the location,size,shape,depth of invasion,and relationship with surrounding tissues,and then provide a guide to the choice of clinical surgical methods.Objective: To investigate the value of MRI in preoperative staging and correlation with histopathology.Methods: In this study,a total of 76 patients having rectal cancer were taken as a treatment group for gastrointestinal surgery and were selected for prospective study and analysis in the Hospital of Dali University from May 2017 to December 2018.All patients were imaged with3.0T MRI and phased-array surface coil.Less residue diet 2-3 days before the examination,fasting time > 6 hours on the day of the examination,and empty the contents of jejunum as far as possible;do not use drugs to inhibit intestinal peristalsis;do not use intestinal contrast agents.Then each patient was independently diagnosed by MRI and pathological diagnosis after the operation,and the key data were recorded in real-time by their specific personnel.Finally,the accuracy of preoperative MR diagnosis of TN staging,distances from the lower margin of tumors up to anal margin of all patients was analyzed.Data analysis was done by using PASW Statistics 19.0 statistical software,in which the measurement data were expressed as mean（x±s）Matched sample t-test was used for comparison;Kappa test was used for consistency between MRI and pathology in diagnosis of T staging and paraintestinal lymph node metastasis,and Kappa > 0.7 was considered to be more consistent;P < 0.05 was a significant difference.Results:There were 9 cases of stage T1 followed by cases of stage（15）T2,（32）T3,（14）T4a and（2）T4b diagnosed by MRI,9 cases of stage T1 followed by cases of stage（22）T2,（28）T3,（15）T4a and（2）T4b diagnosed by pathology,and the sensitivity and specificity of stage T1,T2,T3,T4 a and T4 b diagnosed by MRI were 67% and 100%,68.2% and 92.6%,89.3% and 85.4%,80.0% and96.7%,100%,and 100%,respectively,with a good steadiness（Kappa=0.708,P<0.05）.)The sensitivity and specificity of MRI in diagnosis of 4 paraintestinal lymph node metastasis were85.2% and 83.3%（Kappa = 0.701,P < 0.05）.In 12 patients who come in for anal resection,there was no major difference in the space between the lower margin of the tumors and the anal margin measured by MRI and the gross specimen after the operation（<7 mm）（P > 0.05）.Conclusions:MRI can accurately stage and evaluate rectal cancer patients before operation,and provide help for clinical diagnosis and treatment.Among the harmful growths is colorectal disease is quite possibly the most well-known cancer,its bleakness mortality actually continue to increment step by step.With the headway and improvement of individuals’ wellbeing mindfulness and the consistent advancement of clinical levels,the identification of colorectal malignant growth essentially higher than previously.Patients frequently don’t have commonplace clinical appearances and are not entirely obvious by patients.Most patients are in the center and late stages when they are analyzed,and around 25% of patients have far off metastases when they are found.