American Board of Internal Medicine (ABIM) Certification Practice Exam

According to the 2015 guidelines, what additional imaging is recommended for high-risk patients after colorectal cancer resection?

1. MRI of the abdomen

2. Annual abdominal/pelvic CT scan

3. Chest X-ray

4. Ultrasound of the abdomen

The correct answer is: Annual abdominal/pelvic CT scan

The recommendation for an annual abdominal/pelvic CT scan for high-risk patients after colorectal cancer resection aligns with established guidelines aimed at early detection of recurrence. High-risk patients, defined by factors such as the presence of lymph node involvement, poorly differentiated tumors, or local complications, have higher chances of cancer recurrence. Regular imaging using CT scans allows for thorough evaluation of the abdominal and pelvic cavity, where recurrences might occur, particularly in lymph nodes or the liver. The sensitivity of CT scans makes them particularly effective in identifying these recurrences compared to other imaging modalities. Thus, the annual CT scan serves as a crucial tool in the post-operative management of these patients, supporting ongoing surveillance and timely intervention. Other imaging modalities listed in the choices, such as MRI, chest X-rays, or ultrasound, may have roles in certain contexts but do not hold the same level of recommendation or efficacy in routine surveillance for colorectal cancer recurrence as the annual abdominal/pelvic CT scan does for high-risk patients.