Liver MRI for Colorectal Cancer Liver Metastasis: Comparative Effectiveness Research for the Choice of Contrast Agents

Magnetic resonance imaging (MRI) has been widely used for problem-solving tool in the evaluation of hepatic lesions, and it has been shown to have better sensitivity than CT for detection of colorectal liver metastases, especially for lesions which are smaller than 1 cm. After introduction of a liver-specific hepatobiliary MR contrast agent, gadoxetic acid, gadoxetic acid-enhanced MRI (Gd-EOB-MRI) has been increasingly used for evaluation of liver lesion including CRLM. However, compared to conventional MRI with extracellular contrast agent (ECA-MRI), Gd-EOB-MRI has different pharmacodynamic characteristics, and is more expensive due to higher cost of gadoxetic acid and needs longer scan time to obtain hepatobiliary phase which is generally acquired 15 to 20 minutes after contrast injection. The purpose of this study was to compare the clinical outcome and diagnostic performance of Gd-EOB-MRI and ECA-MRI for evaluation of focal hepatic lesion in newly diagnosed colorectal cancer.

Inclusion Criteria:

1. patients with surgically proven colorectal adenocarcinoma
2. patients who underwent abdominopelvic CT and liver MRI for initial staging before any treatment
3. no past or concurrent malignancy other than colorectal adenocarcinoma.

Exclusion Criteria:

1. precontrast abdominopelvic CT
2. precontrast liver MRI
3. liver MRI using contrast other than extracellular agent or gadoxetic acid
4. the interval between CT and liver MRI was longer than 4 weeks
5. patients who had suspected multiple hepatic metastases (> 10) on CT
6. distant metastasis other than liver and
7. unavailable reference standard of their hepatic lesions with no pathologic confirmation or follow up imaging.