Blood is a complex fluid  that transports a variety of molecules around the body. It carries diatomic Oxygen and the nutrients essential for the organism to function, but it also carries the wastes  produced by these same organs (Carbon Dioxide, nitrogenous wastes).

It also carries the many molecules associated with the immune system, and diffuses hormones throughout the organism.

Veins and arteries are the largest blood vessels in the human body. An artery can become clogged by fatty deposits, called plaques, that form on its internal walls. Th flow of blood is thus reduced and surgical intervention becomes necessary.

Angioplasty is a relatively non-invasive technique that permits dilation of the artery at the point of narrowing (also known as “stenosis”).

Scintigraphy is an imaging technique that involves tracking the distribution, in a patient's body, of very low doses of radioactive elements.

Each element is chosen according to its affinity for the organ under study.

In addition to the progression of the radioactive elements through the human body, their fixation in the interior of certain tissues is detected.

Because they are radioactive, these elements  disintegrate, releasing a gamma photon. This radiation is detected by one or more gamma detecting cameras.

This technique permits a highly targeted exploration of certain organs or pathological processes.

Scintigraphy is a method that produces images of the functioning of organs, as opposed to merely anatomical images (as in X-rays), which show only the contours and the densities of organs.

The examination is painless, and has no side effects.

The word « scanner » designates the apparatus used to carry out the examination.

It is made up of a mobile table on which the patient lies and an x-ray tube which moves around the patient.

Detectors measure the intensity of the rays emitted by the tube.

Opposite these,   receptors, made up of digital detectors, register received intensities, after the rays have passed through the patient's body.

This  device is linked to a computer which analyzes the digital data. The intensity difference between the incident rays and those emerging from the patient's body, calculated for different angles, enables us to produce an image in grayscale (a more complex form of "black and white".)

 Even though the rays penetrate the patient's body perpendicular to that body's main axis, the images obtained are horizontal sections.

ELISA, Enzyme Linked Immunosorbent Assay, is a is an immuno-enzymatic technique that enables the detection of antigen-antibody reactions thanks to a reaction with colored products. ELISA is a technique currently used in the process of screening for HIV infections.

Radiography  is based on the use of x rays.

These rays were discovered in the 19^th century . They are electromagnetic waves, just like the microwaves used in portable telephones, or the light that we perceive with our eyes.

The apparatus is made up of an x ray tube (an emitter of x rays) , an examination table and a receptacle that contains the radiographic film.

For a chest x ray, the patient stands upright with his or her chest pressed against the examination table, which is in a vertical position.

The x ray tube is placed to the rear of the patient.

One asks the patient to inhale so as to fill his/her lungs, then  submits him/her to x rays so as to make a record on the radiographic film.

The film cassette is then removed and the film is developed in the same way that traditional photographic film is developed.  Current technology tends to replace radiographic film with digital recording plates.

MRI, or « Magnetic Resonance Imagery », is a relatively new technique that rests on the electromagnetic properties of atomic nuclei.

The patient is placed at the center of a very powerful magnet which forces the nuclei of Hydrogen atoms in the pateint's body to align themselves with the magnetic field. Then, a radio wave, perpendicular to the main field,  is sent to excite the Hydrogen atoms, which then begin to resonate.

At this stage, the Hydrogen atoms absorb the energy.

Then the radio source is turned off. The Hydrogen atoms return to their original positions, releasing the stored energy in the form of a new radio wave.

It is this wave,  released  by the atoms,  which is detected and then analyzed by a computer in order to convert it to an image.

ELISA, Enzyme Linked Immunosorbent Assay, is a is an immuno-enzymatic technique that enables the detection of antigen-antibody reactions thanks to a reaction with colored products. ELISA is a technique currently used in the process of screening for HIV infections.

Scintigraphy is an imaging technique which enables one to trace the distribution, in  a patient’s body, of radioactive elements that have been introduced there in minute quantities. In the case of bone scintigraphy it is a matter of observing the skeleton via a scan of the entire body.  The tracer used (Technetium 99) has an affinity for bone.
As cancer cells have a higher rate of metabolic activity than normal ones, areas of hyperfixation reveal the presence of metastases.

Scintigraphy is an imaging technique which enables one to trace the distribution, in  a patient’s body, of radioactive elements that have been introduced there in minute quantities.
For the thyroid, for example, which is an endocrine gland situated at the base of the neck, one uses a radioactive isotope of Iodine (Iodine 123), or, sometimes Technetium. The image obtained tells us about the morphology of the gland, but also, most importantly, about its physiological activity.