American Board of Internal Medicine (ABIM) Certification Practice Exam

For an abdominal aortic aneurysm (AAA) measuring between 4.5 to 5.4 cm, the recommended interval for ultrasonography is every 6 to 12 months. This frequency of monitoring is grounded in the need for regular assessments to evaluate the aneurysm's size and to detect any changes that may indicate an increased risk of rupture.

The rationale for monitoring these aneurysms at this interval is based on research indicating that AAAs in this size range carry a significant risk of progression. Smaller aneurysms less than 4.5 cm might be monitored less frequently, and larger aneurysms (greater than 5.5 cm) typically require more frequent evaluations and prompt surgical intervention.

In summary, regular ultrasonography every 6 to 12 months provides an optimal balance between risk assessment and timely intervention needs, ensuring patient safety while facilitating effective management of the aneurysm.