A systematically designed study to investigate the effects of contrast medium on diffusion tensor MRI

Area of Science:

• Neuroimaging
• Oncology
• Radiology

Background:

• Diffusion tensor magnetic resonance imaging (DTI) is crucial for characterizing brain tissue.
• The impact of contrast medium administration on DTI parameters in malignant brain tumors requires clarification.

Purpose of the Study:

• To determine if contrast medium administration influences DTI metrics over time in patients with malignant brain tumors.
• To assess the temporal relationship between contrast injection and DTI changes.

Main Methods:

• DTI scans were acquired five times in 12 patients with malignant brain tumors: twice before, once during, and twice after contrast injection.
• Diffusion indices were analyzed in regions of interest within the tumor, peritumoral edema, and normal brain tissue.
• Repeated-measures ANOVA was employed to evaluate temporal effects of contrast medium on diffusion indices.

Main Results:

• Averaging precontrast scans confirmed no significant inter-scan differences.
• Statistically significant temporal differences were observed in the edema ROI for fractional anisotropy and the largest eigenvalue, but not for trace or the second-largest eigenvalue.

Conclusions:

• The influence of contrast medium on DTI in malignant brain tumors is time-dependent, particularly for anisotropic diffusion indices.
• DTI parameters remain stable beyond 6 minutes post-contrast injection, indicating minimal impact on isotropic and anisotropic values at later time points.