Cell tracking using (19)F magnetic resonance imaging: technical aspects and challenges towards clinical applications

Area of Science:

• Medical Imaging
• Biophysics
• Cell Biology

Background:

• Fluorine-19 MRI (19F MRI) is an emerging technique for cell tracking.
• Its potential for direct and precise cell quantification makes it attractive for in vivo applications.
• Sensitivity, or the detection limit within a reasonable imaging time, is the primary challenge for widespread clinical use.

Purpose of the Study:

• To introduce the 19F MRI technique, focusing on sensitivity.
• To review the current state-of-the-art and clinical developments of 19F MRI.
• To analyze detection limits for preclinical and clinical 19F MRI studies.

Main Methods:

• Review of existing literature on 19F MRI techniques, compounds, hardware, and acquisition methods.
• Calculation and comparison of 19F detection limits in terms of tissue concentration (millimoles per litre) within a 1 cm³ voxel.
• Analysis of preclinical cell tracking and clinical drug studies using 19F MRI.

Main Results:

• Optimal sensitivity in 19F MRI relies on dedicated 19F compounds, adapted hardware, and specific acquisition methods.
• Detection limits vary across studies, necessitating standardized comparison metrics.
• A tissue concentration of a few millimoles per litre (mM) of 19F is estimated as necessary for human studies at 1 cm³ resolution.

Conclusions:

• Sensitivity remains a critical factor for advancing 19F MRI towards routine clinical application.
• Standardized methods for assessing detection limits are crucial for comparing different 19F MRI approaches.
• Further development in 19F compounds and imaging technology is needed to achieve the required sensitivity for in vivo human studies.