American Board of Internal Medicine (ABIM) Certification Practice Exam

Which MRI feature is associated with meningiomas?

1. Ring enhancement

2. Homogeneous contrast enhancement and a dural tail

3. Prominent cystic changes

4. Calcifications with no enhancement

The correct answer is: Homogeneous contrast enhancement and a dural tail

Meningiomas are typically characterized by specific MRI features that help in their identification. One of the hallmark features of meningiomas on MRI is homogeneous contrast enhancement, which means that the tumor takes up contrast uniformly, indicating that the blood supply within the tumor is well-vascularized. This is often accompanied by the presence of a "dural tail," which refers to the extension of the contrast-enhanced lesion along the dura mater. The dural tail reflects the tumor's dural origin and is a classic MRI finding associated with meningiomas. The other choices represent characteristics that are not specific to meningiomas. For example, ring enhancement is commonly seen in other conditions, such as abscesses or metastases. Prominent cystic changes are typically more indicative of a different type of tumor, like a schwannoma or other neoplastic processes. Calcifications with no enhancement can occur in a variety of lesions, including certain low-grade tumors or even benign conditions, but they do not specifically point to meningiomas. Thus, the presence of homogeneous enhancement along with a dural tail is the definitive feature that helps diagnose a meningioma.