Initial imaging for suspected colorectal liver metastases should include which of the following?

Initial imaging for suspected colorectal liver metastases should include which of the following?

• A. Abdominal ultrasound only
• B. Chest radiograph
• C. Chest, abdomen, and pelvis CT with contrast
• D. Brain MRI

Answer: (C)

The key idea is comprehensive staging with cross-sectional imaging. Colorectal cancer commonly spreads to the liver, but an initial evaluation should also assess for extrahepatic disease to plan treatment. A chest, abdomen, and pelvis CT with IV contrast provides the most complete picture in one study: it accurately detects liver metastases, gauges their number and size, evaluates resectability, and surveys the chest and other abdominal/pelvic structures for additional metastatic sites. Other options fall short. Abdominal ultrasound alone may miss small or multifocal liver metastases and cannot assess the chest or pelvis thoroughly. A chest radiograph is insensitive for detecting early or small pulmonary metastases and won’t stage liver disease well. Brain MRI is not part of initial staging because brain metastases from colorectal cancer are less common and would only be pursued if neurologic symptoms arise.

The key idea is comprehensive staging with cross-sectional imaging. Colorectal cancer commonly spreads to the liver, but an initial evaluation should also assess for extrahepatic disease to plan treatment. A chest, abdomen, and pelvis CT with IV contrast provides the most complete picture in one study: it accurately detects liver metastases, gauges their number and size, evaluates resectability, and surveys the chest and other abdominal/pelvic structures for additional metastatic sites.

Other options fall short. Abdominal ultrasound alone may miss small or multifocal liver metastases and cannot assess the chest or pelvis thoroughly. A chest radiograph is insensitive for detecting early or small pulmonary metastases and won’t stage liver disease well. Brain MRI is not part of initial staging because brain metastases from colorectal cancer are less common and would only be pursued if neurologic symptoms arise.