Improved detection of active multiple sclerosis lesions: 3D subtraction imaging

Area of Science:

• Radiology
• Neuroimaging
• Medical Imaging Analysis

Background:

• Multiple sclerosis (MS) diagnosis and monitoring rely on detecting active brain lesions.
• Current imaging techniques, particularly two-dimensional (2D) subtraction imaging, face challenges with artifacts and lesion detection sensitivity.

Purpose of the Study:

• To evaluate the efficacy of near-isotropic single-slab three-dimensional (3D) magnetic resonance (MR) imaging for creating subtraction images.
• To compare the performance of 3D subtraction images against 2D subtraction images in detecting active MS brain lesions.

Main Methods:

• 14 patients with MS and 9 healthy controls underwent repeated 3D and 2D MR sequences (including MP-RAGE).
• Active lesions were identified and counted by two independent raters, with consensus reading.
• Statistical analysis included negative binomial regression for lesion counts and intraclass correlation for interrater agreement.

Main Results:

• 3D subtraction images exhibited reduced misregistration and fewer artifacts compared to 2D.
• Significantly more active MS lesions were detected using 3D MP-RAGE subtraction imaging versus 2D (2.8 vs 1.7).
• Improved detection of infratentorial and small MS lesions was observed with 3D techniques.

Conclusions:

• 3D subtraction imaging, particularly 3D MP-RAGE, offers superior image quality and increased detection of active MS lesions.
• This method enhances interobserver agreement and shows promise for improving sensitivity in lesion detection and evaluating treatment efficacy in clinical trials.