Objectives: To compare diagnostic performance in the detection of colorectal liver metastases between 64-detector-row contrast-enhanced CT (CE-CT) alone and the combination of CE-CT and gadoxetic acid-enhanced MRI (EOB-MRI) at 3.0T, and to assess whether EOB-MRI in addition to CE-CT results in a change to initially planned operative strategy.
Methods: A total of 39 patients (27 men, mean age 65 years) with 85 histopathologically confirmed liver metastases were included. At EOB-MRI, unenhanced (T1- and T2-weighted), dynamic, and hepatocyte-phase images were obtained. At CE-CT, four-phase dynamic contrast-enhanced images were obtained. One on-site reader and three off-site readers independently reviewed both CE-CT alone and the combination of CE-CT and EOB-MRI. Sensitivity, positive predictive value, and alternative free-response receiver operating characteristic (AFROC) method were calculated. Differences in therapeutic strategy before and after the EOB-MRI examination were also evaluated.
Results: Sensitivity and area under the AFROC curve with the combination of CE-CT and EOB-MRI were significantly superior to those with CE-CT alone. Changes in surgical therapy were documented in 13 of 39 patients.
Conclusions: The combination of CE-CT and EOB-MRI may provide better diagnostic performance than CE-CT alone for the detection of colorectal liver metastases, and EOB-MRI in addition to CE-CT resulted in changes to the planned operative strategy in one-third of the patients.
Key points: • Accurate preoperative imaging is essential for surgical planning and successful hepatic resection. • Combination of CE-CT and EOB-MRI is useful to detect colorectal liver metastases. • EOB-MRI combined with CE-CT contributes to determine the correct therapeutic strategy.