ObjectiveTo investigate the value of rectumaerated MSCT examination in diagnosis of mesorectal infiltration of rectal cancer and lymph node metastasis staging. MethodsFrom January 2010 to July 2010, the data of 68 patients with rectal cancer confirmed by pathology were analyzed in the First Affiliated Hospital of Liaoning Medical University. All the patients underwent rectumaerated MSCT preoperatively and postoperative pathology was taken as the gold standard for evaluation of the accuracy, sensitivity, specificity, positive or negative predictive values of MSCT in diagnosis of mesorectal infiltration and lymph node metastasis.ResultsIn rectum-aerated MSCT scanning, rectum and sigmoid colon was fully expanded, perirectal fat space was clear between perirectal fat space and relatively high density rectal wall and very low density enteric cavity. For mesorectal infiltration of degree Ⅰ, Ⅱ, and Ⅲ, the accuracies were 92.6%(63/68), 91.1%(62/68), and 95.6%(65/68), respectively; sensitivities were 91.2%(31/34), 85.0%(17/20), and 92.9%(13/14), respectively; specificities were 94.1%(32/34), 93.8%(45/48), and 96.3%(52/54), respectively; positive predictive values were 93.9%(31/33), 85.0%(17/20), and 86.7%(13/15), respectively; negative predictive values were 91.4%(32/35), 93.8%(45/48), and 98.1%(52/53), respectively. For lymph node metastasis in N0, N1, and N2, the accuracies were 92.6%(63/68),85.3%(58/68), and 92.6%(63/68), respectively; sensitivities were 86.2%(25/29), 90.0%(27/30), and 66.7%(6/9), respectively; specificities were 97.4%(38/39), 81.6%(31/38), and 96.6%(57/59), respectively; positive predictive values were 96.2%(25/26), 79.4%(27/34), and 75.0%(6/8), respectively; negative predictive values were 90.5%(38/42), 92.1%(35/38), and 95.0%(57/60), respectively. ConclusionsRectumaerated MSCT scaning can clearly show the depth of rectal carcinoma infiltration in the mesorectum, and N staging of mesorectal lymph node metastasis of MSCT has a higher consistency with that of pathological staging. Rectumaerated MSCT scanning is an important referenced method for clinical preoperative staging and individualized chemotherapy regimen.