Correlation between computed tomography and magnetic resonance imaging in Graves' orbitopathy

Area of Science:

• Ophthalmology
• Radiology
• Endocrinology

Background:

• Computed tomography (CT) has been the standard for imaging patients with severe Graves' disease and potential optic neuropathy.
• The increasing availability of magnetic resonance imaging (MRI) necessitates evaluating its role in managing Graves' disease.
• Severe Graves' orbitopathy can lead to optic nerve compression and vision loss.

Purpose of the Study:

• To compare the effectiveness of CT and MRI in imaging severe Graves' orbitopathy.
• To determine which imaging modality is superior for assessing optic nerve involvement and orbital apex changes in Graves' disease.

Main Methods:

• A comparative study involving 39 orbits from 20 consecutive patients with severe Graves' disease.
• Patients were assessed clinically, and both CT and MRI scans were performed.
• Radiologic images were evaluated using five specific measures, focusing on muscular changes, orbital apex, optic nerve, and proptosis.

Main Results:

• MRI demonstrated significantly higher reliability than CT in assessing two key measures: degree of fat effacement and minimal optic nerve index.
• These measures are crucial for evaluating optic nerve compression and thickness at the orbital apex.
• CT scans were less reliable in visualizing these critical aspects of the orbital apex.

Conclusions:

• Magnetic resonance imaging (MRI) is a more effective imaging technique than computed tomography (CT) for evaluating the orbital apex in patients with Graves' optic neuropathy.
• MRI provides superior visualization of structures critical for diagnosing and managing optic nerve compression in severe Graves' orbitopathy.