An MRI of the skull base visualizes soft-tissue structures there, including the brainstem, cranial nerves, pituitary gland, meninges, and nearby sinuses. It detects tumors, inflammation, infections, vascular abnormalities, nerve compression, and marrow or soft-tissue invasion; contrast-enhanced scans highlight abnormal enhancement. MRI is superior for soft-tissue and nerve pathology, while CT is better for acute bone fractures.

A skull base MRI typically takes about 30–60 minutes. Non-contrast studies are often 20–45 minutes, while contrast-enhanced exams (gadolinium) and additional sequences can extend scanning to around an hour. Allow extra time for check-in, positioning and paperwork; total appointment time may be 60–90 minutes. Motion and complexity of the case can also lengthen the exam.

Symptoms of a skull base defect include persistent clear, watery (often unilateral) nasal discharge or ear drainage that worsens with leaning forward; salty or metallic taste; headaches that are positional; recurrent meningitis or unexplained fevers; signs of cerebrospinal fluid leak; reduced sense of smell, visual changes, cranial-nerve-related facial numbness or weakness, hearing loss, and tinnitus. New focal neurologic deficits may also occur.

A skull base tumor grows at the underside of the skull where brain, cranial nerves and blood vessels meet. Some skull base tumors are brain-related (e.g., meningiomas, schwannomas, pituitary tumors) while others arise from bone, cartilage, or metastases, so they aren’t strictly brain tissue. Their location affects nearby brain structures and cranial nerves, and treatment depends on tumor type and size.

Skull base disease refers to disorders affecting the bones and tissues at the base of the skull, where the brain meets the face and spine. Conditions include congenital anomalies, tumors (benign or malignant), infections, inflammatory disease, trauma, and cranial nerve disorders. Symptoms can include headaches, hearing or vision changes, facial numbness, and swallowing or breathing problems. Diagnosis often uses imaging and specialist surgical or medical treatment.

Seek a brain MRI for new or worsening focal neurological signs (sudden weakness, numbness, vision loss, speech problems), unexplained or severe or new persistent headaches (especially with vomiting or altered consciousness), sudden severe "thunderclap" headache, new-onset seizures, unexplained cognitive or behavioral changes, persistent dizziness or balance problems, head trauma, or suspected stroke, tumor, or infection.