Abstract
Interaction with ordered biological tissues causes the motion of molecules and ions to be anisotropic. As a result, their dipolar and quadrupolar interactions do not average to zero. Multiple-quantum-filtered (MQF) NMR of 1H, 2H, and 23Na is sensitive to these interactions and can single out macromolecules, compartments, and fiber orientations in accordance with the size of the residual interactions and thus filter out the signals of molecules and ions that do not interact with the ordered structures. The increased effect of gradients during the MQ evolution facilitates diffusion measurement of nuclei such 2H and 23Na. Among the applications of MQF NMR are (i) the identification of various compartments such as the extracellular matrix, axons, and myelin in nerves and brain; (ii) measurements of the effect of strain in blood vessel walls; (iii) changes of the collagen fiber architecture in cartilage upon maturation, depletion of proteoglycans, decalcification, and with mechanical vs osmotic pressure; (iv) changes of cartilage obtained from osteoarthritic and osteoporotic patients; (v) the monitoring of healing of injured tendons; (vi) the measurement of increases in a substantially intracellular sodium pool in ischemic heart; and (vii) MQF magnetization transfer imaging that reflects macromolecular structure and content.
Original language | English |
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Pages (from-to) | 1061-1076 |
Number of pages | 16 |
Journal | eMagRes |
Volume | 5 |
Issue number | 1 |
DOIs | |
State | Published - 2016 |
Keywords
- Cartilage
- Double quantum filtering
- Magnetization transfer
- Multiple quantum filtering
- Muscle
- Nervous systems
- Residual dipolar interaction
- Residual quadrupolar interaction
- Tendon
- Triple quantum filtering