Comparison of Imaging Modalities in the Diagnosis and Tumor Staging of Colorectal Adenocarcinoma



Colorectal cancer is a malignancy that affects the gastrointestinal tract. Clinical diagnosis has routinely been done with colonoscopy in conjunction with digital rectal and histological examinations.



We show that CT, MRI, and MRI-DWI are all effective in T-staging colorectal adenocarcinoma when compared to pathology examination. However, differences in the detection and diagnostic agreement rates between the imaging modalities for the specific T-stages were observed.



Fifty-six patients diagnosed with colorectal adenocarcinoma and underwent contrast-enhanced abdominal CT, non-contrast MRI, or MRI-DWI between January 2014 and March 2020 were retrospectively examined and compared to a biopsy or postoperative pathological T-stage.



The total diagnostic agreement rate for CT, MRI, and MRI-DWI were 58.93%, 76.79%, and 85.71%, respectively. T-staging was statistically and significantly different across all four stages analyzed for all imaging modalities. The T1-stage for MRI and MRI-DWI compared to pathology rates were statistically significant, whereas MRI-DWI and CT both demonstrated statistical significance for T3 and T2 stage comparison, respectively. Furthermore, a statistical and significant difference between the total stage comparison of MRI, MRI-DWI, and CT compared individually to pathology was also observed. All imaging modalities were able to statistically and significantly identify tumors based on tumor size according to the ROC analysis.



These data suggest that CT, MRI, and MRI-DWI can identify and aid visually in the diagnosis of adenocarcinoma colorectal cancer. MRI-DWI is more specific and sensitive in the diagnosis and staging of colorectal tumors.
