Brain Tumor Imaging with Iopamidol CEST MRI: In Vivo Detection and Validation.

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Radiology

Background:

• Gadolinium-based contrast agents (CAs) are standard for brain tumor detection.
• Diamagnetic chemical exchange saturation transfer (CEST) molecules offer potential alternatives.
• Direct comparisons of CEST agents in brain tumors are limited.

Purpose of the Study:

• To evaluate Iopamidol, a CT contrast medium, for brain tumor detection and delineation using MRI-CEST.
• To compare Iopamidol's performance against a conventional gadolinium-based CA (Gadoteridol).
• To assess diagnostic accuracy and delineate tumor borders in a murine glioblastoma model.

Main Methods:

• Utilized MRI-CEST technique in a murine glioblastoma model (GL261 cells in C57BL/6 mice).
• Administered Iopamidol and Gadoteridol as contrast agents.
• Quantified tumor detection and delineation using Contrast-to-Noise Ratio (CNR) and Lesion-to-Brain Ratio (LBR).
• Assessed diagnostic accuracy using Tanimoto, DICE, and volume similarity coefficients.

Main Results:

• Iopamidol demonstrated effective contrast enhancement for detecting and delineating brain tumors.
• Lesion-to-Brain Ratio (LBR) was 2.7-fold higher for Iopamidol than Gadoteridol.
• High similarity coefficients indicated strong agreement in tumor region segmentation between Iopamidol and Gadoteridol.
• Moderate to excellent intra- and interobserver agreement was observed.

Conclusions:

• Iopamidol exhibits comparable capabilities to Gadoteridol in detecting and contouring brain tumors.
• Iopamidol shows good diagnostic performance for tumor border delineation in brain tumors.
• Iopamidol presents a promising alternative for brain tumor imaging using MRI-CEST.