Differentiating metastatic mucinous colorectal adenocarcinomas from simple cysts of the liver using contrast-enhanced and diffusion-weighted MrI

Objective: To determine the value of contrast-enhanced and diffusion-weighted (DW) MRI for differentiating metastatic mucinous colorectal adenocarcinomas from simple cysts of the liver. Methods: 29 patients with 47 metastatic mucinous colorectal adenocarcinomas and/or 19 simple cysts of the liver who underwent contrast-enhanced and DW MRI were included in this retrospective study. Two radiologists assessed the MRI findings by consensus. Qualitative and quantitative analyses were conducted. Significant MRI findings on univariate and multivariate analyses were assessed, and their diagnostic performances for predicting metastatic mucinous colorectal adenocarcinomas were analyzed. results: The presence of rim enhancement (odds ratio, 28.43; p = 0.008) and intracystic enhancement (oddsratio, 180.15; p = 0.001) were independently significant factors for predicting metastatic mucinous colorectal adenocarcinomas. The sensitivity and specificity of rim enhancement, intracystic enhancement, and their combination for detecting metastatic mucinous colorectal adenocarcinomas were 83% (39/47) and 63.2% (12/19), 87.2% (41/47) and 89.5% (17/19), and 72.3% (34/47) and 94.7% (18/19), respectively. Compared to simple cysts, meta-static mucinous colorectal adenocarcinomas showed significantly lower mean apparent diffusion coefficient (1.92 ± 0.81 vs 2.99 ± 0.75 × 10^-3 mm² s^-1; p = 0.001) and lesion-to-liver apparent diffusion coefficient ratio (1.66 ± 0.75 vs 2.44 ± 0.56 × 10^-3 mm² s^-1; p = 0.004) and higher mean signal intensity (400.3 ± 216.3 vs 222.4 ± 99.3; p = 0.039) and lesion-to-liver signal intensity ratio on hepatobiliary-phase images (0.58 ± 0.16 vs 0.30 ± 0.14; p < 0.001). Conclusion: Contrast-enhanced and DW MRI may be helpful for differentiating metastatic mucinous colorectal adenocarcinomas from simple cysts of the liver. advances in knowledge: On contrast-enhanced and DW MRI, rim and intracystic enhancement can be helpful for differentiating metastatic mucinous colorectal adeno-carcinomas from simple cysts of the liver.