Department of Radiology, College of Medicine, Hallym University
ABSTRACT
To evaluate the accuracy of preoperative staging of rectal cancer by transrectal US(7.5MHz linear arraytransducer), 17 cases with primary rectal cancer who were examined by transrectal US and histopathologicallyproven, were analyzed. We correlated the sonographic features of the depth of rectal wall invasion, perirectal fatinfiltration and perirectal lymph node metastasis with histopathologic findings. The tumor staging was analyzedaccording to the TNM classification. The depth of rectal wall invasion was in accordance with histopathologicfindings in 15 of 17 cases (accuracy;88.2%). The sensitivity and specificity of transrectal US in predictingperirectal lymph node metastasis were 20% and 75%, respectively (accuracy ; 58.8%). The sensitivity andspecificity in predicting perirectal fat infiltration were 92.9% and 100%, respectively (accuracy ; 94%).Perirectal fat infiltration and depth of rectal wall invasion were preoperatively diagnosed with relatively highaccuracy, while perirectal lymph node metastasis with low accuracy. In conclusion, transrectal US is a usefulimaging modality for preoperative staging of rectal cancer.