Nuclear magnetic resonance (NMR) phenomena

started, as a curiosity research,

more than half a century ago.

It translated into a routine MRI tool,

attending the diagnostics of brain disorders,

only recently.

Where it will go, towards the end of this century,

depends on the investment, in the research and development,

and the education about it world wide.

Health is an area, where there is, less commercial gain.

It can also serve, in, the security

of the society at large.

May be the MRI research, will be lucky,

and get the timely attention of the leaders.

The resonance phenomenae are in common use in many technologies, we enjoy today. Use of RF (radio frequency) electromagnetic radiation, magnetic resonance of molecules, for the human body, to produce an image, deserves special recognition. MRI is a non invasive application of science, to the diagnostics of various diseases and disorders in human body and is particularly challenging, in the human brain arena. The renounce phenomena used in MRI is little different in principle from other applications. The well known applications are the radio broadcast, the production of television picture, Lases, etc. The subtle difference lies in the selection of the frequency band of radiation, out of the very wide electromagnetic radiation band. TV broadcast uses the visible (light) part of the electromagnetic, radiation spectrum, to produce pictures, and the microwaves are used, to carry it and broadcast over large distances. On the receiving end, electrical resonance phenomena, in the electrical circuits, is used to produce the picture. This picture is about the movement of the external parts of an object or of a living body. The TV picture is clearly visible to the naked eye. MRI uses the dark (invisible) RF radiation. It brings out the behavior of internal molecular movements which are not visible to the naked eye.

The internal topological structure in the brain on a macroscopic (mm-cm) scale is made visible to the naked eye through a photographic pictur produced, through a computer on the screen after the scanning process. It is then printed as a hard copy on a cellulose film, which acts as tool of diagnostics of disorders, if any for the doctor. One can also view the picture in real time on the computer. In the radio broadcast, we use the RF (radio frequency) and the microwaves as carriers of message. These are dark (invisible) radiations. They carry the electrical signals over long distances which are converted into sound, in the radio at the receiver end, e.g. in a car. The differences in various applications of the resonance phenomena, being used in many technologies, also arise, in the different forms of matter being resonated by the incident radiation to produce the desired result. The medium may be e.g., the gas or solid-state in the case of lasers it is liquid crystal display in a Lap Top computer, etc., etc. It can be a biological medium of magnetic spins e.g. in the human brain (The MRI), etc.

The soft-condensed matter, tissues, cells, etc., used as a medium of imaging in the MRI are of specific interest, for analysis in MRI. One need to be careful for the high risk involved about the dose, of the irradiated medium. Here a human i.e., a patient is the subject of investigation. MRI is considered as a non-invasive tool, for all practical purposes, but in fact is not totally invasive. However standard practices and procedures are in place in MRI radiology practice to take care of the risks involved. The word resonance in MRI basically means RF (radio frequency) energy absorption, in tune with the binding energy of the electrons, atoms and nuclei (the micro-particles) as part of the quantum energy structure, of a group of molecules, which may be a part of a cell, tissue, etc. One may ask a question, why particularly RF radiation is used in the case of human body? The answer is simplified as follows. Our body is made of tissues, cells, very many organic, inorganic molecules, macro-molecules, chemicals, various fluids, and above all, the most important ingredient, the water. There is an intrinsic quantum (atomic-nuclear) potential energy stored inside, in various macromolecules, the building block of our body It is due to the chemical and physical bonding structure produced by the electrons, atoms and molecules, and is called, as the biding energy.

The atoms and molecules which are the lowest level building blocks of our body, inherit with them, the micro-particles i.e. the electrons in an atom, protons and neutrons in the nucleus, etc. When spread over a broader perspective of macromolecules, which forms the dynamics of action, in our body, the binding energy is seen to be in the RF part of the electro-magnetic radiation spectrum. The RF radiation used in MRI, is basically used to excite (break the binding energy of) the molecules, in a local small volume (called a voxel). The energy of interaction (breaking the biding energy) involved is around meV (milli electron volt). The returned back electrical signal, has the signatures, of the local medium, in which the magnetic spins (tiny molecular magnets) reside and function. The repetition of this process voxel-to-voxel and coordination in space and time of the electrical signals received over the whole brain results into the picture (the MRI) the doctors use for diagnostics of diseases.