Colorectal liver metastases on gadoxetic acid-enhanced MRI: Typical characteristics decrease after chemotherapy

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• Colorectal liver metastases (CRLM) are common in advanced colorectal cancer.
• Accurate imaging is crucial for diagnosis and treatment monitoring.
• Gadoxetic acid-enhanced MRI offers detailed liver imaging.

Purpose of the Study:

• To assess the frequency of typical imaging characteristics of CRLM on gadoxetic acid-enhanced MRI.
• To evaluate how these characteristics change after chemotherapy.

Main Methods:

• Retrospective analysis of 258 patients with CRLM undergoing gadoxetic acid-enhanced MRI.
• Evaluation of 722 CRLMs based on six defined typical imaging characteristics.
• Comparison of imaging features in chemotherapy-naïve and post-chemotherapy CRLM.

Main Results:

• 49% of chemotherapy-naïve CRLM displayed all six typical characteristics; this decreased to 25% post-chemotherapy.
• Hypovascularity (98%) and non-enhancement in the hepatobiliary phase (100%) were highly prevalent.
• Post-chemotherapy, T2W mild hyperintensity (95% to 79%) and diffusion restriction (87% to 65%) significantly decreased.

Conclusions:

• CRLM exhibit multiple typical imaging characteristics on gadoxetic acid-enhanced MRI.
• Arterial rim enhancement is the least common characteristic.
• Chemotherapy alters typical MRI features, notably reducing T2W hyperintensity and diffusion restriction.