Orbital MRI 3D Reconstruction Based on Volume Rendering in Evaluating Dysthyroid Optic Neuropathy

Area of Science:

• Ophthalmology
• Radiology
• Medical Imaging

Background:

• Dysthyroid optic neuropathy (DON) is a vision-threatening complication of thyroid-associated ophthalmopathy (TAO).
• Accurate assessment of orbital soft tissue changes is crucial for diagnosing and managing DON.

Purpose of the Study:

• To utilize magnetic resonance imaging (MRI) three-dimensional (3D) reconstruction with volume rendering to analyze orbital soft tissue changes in DON patients.
• To evaluate the reliability of MRI 3D reconstruction for quantifying orbital fat volume (FV) and extraocular rectus muscle volume (EOMV).

Main Methods:

• Orbital MRI scans were acquired and processed using 3D volume rendering for reconstruction.
• Orbital model parameters, FV, and EOMV were calculated and compared with observer measurements.
• Visual functions were assessed, and receiver operating characteristic (ROC) curves were analyzed to correlate measurements with DON presence.

Main Results:

• MRI 3D reconstruction demonstrated high correlation (ICC > 0.950) with observer measurements.
• Significantly greater FV and EOMV were observed in DON patients compared to healthy and non-DON TAO patients (p < 0.05).
• EOM enlargement was the most significant factor associated with DON (OR = 2.79), with an EOMV > 4.035 ml indicating probable DON.

Conclusions:

• MRI 3D reconstruction using volume rendering is a dependable technique for assessing orbital soft tissues in TAO.
• Elevated EOMV is the key indicator for diagnosing dysthyroid optic neuropathy.