Water protons in biological tissues (1H)

Water protons in biological tissues are the primary signal source for Magnetic Resonance Imaging (MRI), representing the hydrogen nuclei within water molecules that constitute approximately 60-70% of the human body [StatPearls: https://www.ncbi.nlm.nih.gov/books/NBK542302/]. These protons possess an intrinsic magnetic moment, or spin, which allows them to be manipulated by external magnetic fields and radiofrequency pulses to generate detailed anatomical and functional images. While not a traditional therapeutic target like a protein or enzyme, water protons are the physical target for diagnostic contrast agents, such as gadolinium-based contrast agents (GBCAs) [NIH: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4879157/]. These agents work by shortening the longitudinal (T1) and transverse (T2) relaxation times of nearby water protons through paramagnetic relaxation enhancement, thereby improving the visibility of specific tissues or pathological processes. Changes in the environment or concentration of water protons are indicative of various disease states, including edema, inflammation, and malignancy, making them essential for diagnostic monitoring and patient selection in clinical practice [PubMed: https://pubmed.ncbi.nlm.nih.gov/16123661/].

Other names

Tissue water protonsHydrogen nucleiBulk water protons1H nucleiProtons

Paramagnetic relaxation enhancement (PRE) of water proton T1 and T2 relaxation rates via dipole-dipole interactions with contrast agent electrons [NIH: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4879157/].