American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the imaging study of choice for secondary headaches?

1. CT scan

2. X-ray

3. MRI

4. Ultrasound

The correct answer is: MRI

The choice of MRI as the imaging study for evaluating secondary headaches is based on its superior ability to visualize soft tissue structures, including the brain and spinal cord. Secondary headaches often arise from underlying pathological conditions, such as tumors, vascular issues, infections, or structural abnormalities, which can all be better characterized with MRI. MRI provides detailed images that help identify these conditions, including detection of intracranial masses, vascular malformations, or significant infections. Additionally, MRI avoids the radiation exposure associated with CT scans, making it a safer option for repeated assessments, especially in cases where chronic headache conditions require ongoing evaluation. While CT scans can also be useful, especially in acute settings to rule out emergencies like hemorrhagic strokes, they are not as effective as MRI for capturing detailed brain anatomy and detecting subtle lesions that may be responsible for secondary headaches. X-rays and ultrasound are generally not useful for evaluating intracranial issues, as they do not provide the necessary detail for diagnosing conditions related to headaches. Thus, MRI stands out as the imaging method of choice for secondary headaches due to its comprehensive structural assessment capabilities.