Which imaging study is most appropriate if a brain lesion is suspected in a child with headaches?

When a brain lesion is suspected in a child experiencing headaches, an MRI of the brain is the most appropriate imaging study to conduct. MRI provides detailed images of the brain's structures and is particularly effective in visualizing soft tissue, which is essential for identifying any discrepancies, lesions, or abnormalities in brain tissue that may be causing the child’s symptoms.

MRI has several advantages over other imaging modalities when it comes to evaluating potential brain lesions. It is non-invasive, does not involve exposure to ionizing radiation, and offers superior resolution, allowing for better differentiation between various types of brain tissue. This capability is crucial for accurately diagnosing conditions such as tumors, abscesses, or other lesions.

While an X-ray of the skull might be useful in assessing for fractures or bony abnormalities, it does not provide the detailed information needed about the brain itself. A CT scan of the abdomen is irrelevant to the evaluation of brain lesions, as it focuses on the abdominal organs and structures. An ultrasound of the head can be helpful in certain situations, particularly in younger children with open fontanelles, but it is limited in diagnosing brain lesions compared to an MRI, particularly in older children where the fontanelles have closed. Therefore, an MRI stands out as the best option