¹H NMR Relaxation Processes in Lung Tissues at Low Magnetic Fields

Area of Science:

• Biophysics
• Medical Physics
• Biochemistry

Background:

• Nuclear Magnetic Resonance (NMR) relaxometry offers insights into molecular dynamics.
• Tissue characterization using NMR relaxation properties is an active area of research.
• Understanding water and macromolecule dynamics is crucial for diagnosing diseases.

Purpose of the Study:

• To evaluate the diagnostic potential of low-field NMR relaxometry in lung tissues.
• To investigate the dynamics of water and macromolecules in tumor versus reference tissues.
• To identify potential NMR-based biomarkers for pathological changes.

Main Methods:

• Proton spin-lattice and spin-spin NMR relaxation measurements were performed on lung tissue samples from 10 patients.
• Relaxation properties of tumor tissue were compared with corresponding reference tissue.
• Spin-lattice relaxation was measured over a wide frequency range (10 kHz–10 MHz), complemented by data at 18.7 MHz.

Main Results:

• Spin-spin relaxation exhibited bi-exponential behavior, analyzed using dedicated models.
• Frequency dependence of spin-lattice relaxation rates followed a power-law (exponent ~0.3), consistent with polymer reptation dynamics.
• Specific NMR relaxation parameters, including rate ratios and component amplitude ratios, differentiated tissue types.

Conclusions:

• Low-field NMR relaxometry holds diagnostic potential for lung tissues.
• NMR relaxation parameters can serve as sensitive markers of altered molecular dynamics in pathological tissues.
• The study provides insights into water and macromolecule dynamics in lung tissues compared to solutions.