The value of diffusion-weighted imaging in combination with T2-weighted imaging for rectal cancer detection

ObjectiveTo evaluate the clinical value of diffusion-weighted imaging (DWI) in combination with T2-weighted imaging (T2WI) for the detection of rectal cancer as compared with T2WI alone.Materials and methodsForty-five patients with rectal cancer and 20 without rectal cancer underwent DWI with parallel imaging and T2WI on a 1.5 T scanner. Images were independently reviewed by two readers blinded to the results to determine the detectability of rectal cancer. The detectability of T2W imaging without and with DW imaging was assessed by means of receiver operating characteristic analysis. The interobserver agreement between the two readers was calculated with kappa statistics.ResultsThe ROC analysis showed that each of two readers achieved more accurate results with T2W imaging combined with DW imaging than with T2W imaging alone significantly. The Az values for the two readers for each T2WI and T2WI combined with DWI were 0.918 versus 0.991 (p = 0.0494), 0.934 versus 0.997 (p = 0.0475), respectively. The values of kappa were 0.934 for T2WI and 0.948 for T2WI combined with DWI between the two readers.ConclusionThe addition of DW imaging to conventional T2W imaging provides better detection of rectal cancer.