Scan: WHAT IS IT, HOW IT WORKS, REQUESTED FOR, PROBLEMS, PRECAUTIONS

Scan

WHAT IS IT?

It is a functional medical imaging technique that uses radioactive isotopes to study the functionality of various organs

HOW IT WORKS

The different tissues of the body capture the different chemical elements selectively.

Using radioactive isotopes of these, you can get information on how to purchase the various tissue elements they need for their function, by quantifying the radiation emitted (with a gamma camera; set of radiation detectors located in a grid), and obtain an idea of the functioning of organs.

The classic example is the assessment of thyroid gland function, which selectively accumulates iodine that enters the body.

It also serves to detect ectopic activity (misplaced) and in thyroid cancers in which the metastases (planting distance) also capture the radioactive iodine, visualizing early with this technique.

In other cases, exploits the tendency of certain processes such as inflammation or accumulate certain metastases certain products that are concentrated in normal circumstances, so you can monitor the activity of inflammatory processes of bone metastases from breast cancer or extension of a heart attack.



In all these cases the two main advantages of scintigraphy lies in its functional nature, demonstrating ongoing processes and its high sensitivity, demonstrating some lesions much earlier than other media.

In turn, the two biggest disadvantage is the small risk posed by the introduction into the body of radioactive substances, but with the improvement in sensitivity of the cameras and the use of short-lived isotopes of low intensity and this is today At present, small, and the relative anatomical imprecision obtained, the blurring of radiation on the uptake zone.

REQUESTED FOR

As already mentioned, the scan is essential today in functional studies of specific physiological processes (normal) and pathological conditions such as:

Exploration of thyroid function and, within this, the valuation of solid nodules (for the study of cysts are used ultrasound and fine needle aspiration).

In the evaluation of metabolically active bone processes, such as Paget's disease or ankylosing spondylarthritis in its early stages, which is more sensitive than conventional radiography.

In cardiology, in assessing the extent of the stroke, if this information is necessary.

In the proof of metastasis of solid tumors such as breast cancer, which provides a global information and early.

In kidney and liver function studies.
HOW DOES THE EXPLORATION ADVANCE PREPARATION
Normally needed no preparation.
Pregnancy is a contraindication of this test.
TO LEAVE TO DO THE TEST
It should go without metal objects of a certain size.

He probably put a nightgown at the time of detecting radiation to improve sensitivity and reduce the administered dose, although in many cases not necessary to undress.

There is no need for gonadal protection, since the radiation, unlike in radiology, from inside your body, not outside, so that you can not dazzle.

WHAT IS THE EXPLORATION
The doctor, nurse or technician will be injected into a forearm vein using a syringe surrounded by lead, the calculated dose (for its weight and specific exploration) of the radioactive element concerned.

After a variable period of time (about which you report), must undergo the study with the gamma camera, of which there are several models, usually consisting in a kind of plate that he passes along the body, front and behind, or that is placed on the body to explore. Can be integrated into an examination table, which you then will move.

PROBLEMS
They are not expected.

The chances of harmful effects of a radionuclide scan is minimal given that the doses used are too.

LONG DOES
It depends on the study to be conducted in particular, the waiting time between the injection and passage through the radiation detector (the gamma camera) is variable. Consult in advance.

The injection itself will take less than a minute, and exploration with the gamma camera for ten minutes.

TELL YOUR DOCTOR IF
Are afraid or unaware of the technique.

PRECAUTIONS
Generic Scan
They are not expected.

Children and pregnant
It is not advisable, except in very special cases. Check with your doctor.

Special Diseases
Could pose problems in patients with alterations in DNA repair mechanisms (genetic code), such as ataxia telangiectasia patients.

Electrocardiography: What is it, How it works, techniques, Problems, Precautions, Generic Scan, Children and pregnant, Special Diseases

Electrocardiography

WHAT IS IT?

It is the study from outside the heart's electrical activity.

HOW IT WORKS

The heart contracts because the electrical signals of their pacemaker and conduction system neatly spread across the same from the left atrium, causing the muscle to contract.

This signal causes a change in the electrical properties of heart muscle contraction preamble, which produces a "wave of depolarization," as a continuous front of activity, starting from the left atrium is displaced to the apex of the heart.

Einthoven, Belgian physiologist, discovered that the heart's electrical activity can be collected from outside the body, which gave rise to the ECG.



REQUESTED FOR

To study the electrical conduction disorders of the heart, important in two areas:

Study of cardiac conduction abnormalities, such as in heart block.

On the principle that the heart muscle without sufficient intake of oxygen presents an abnormal electrical signal for the diagnosis of ischemic heart injury, angina and myocardial heart.

HOW DOES THE EXPLORATION ADVANCE PREPARATION
Usually not necessary.

TO LEAVE TO DO THE TEST
You have to undress from the waist up, placing electrodes on both ankles, so it is recommended not to wear "panties".
If it is too hairy, you should shave your chest (if not shave in the office).

WHAT IS THE EXPLORATION
He placed a series of electrodes (one at each end, usually by forceps, and six in the anterior and left lateral chest, around, around, the left breast, usually held up by a suction cup). For skin that transmit better signal can be spread with pasta or alcohol. Rarely performed a study with an esophageal electrode, placed in the same from the mouth.

Subsequent to the electrodes is the recording, for which the device is manipulated. Twelve combinations are usually studied with them, called derivatives "standard" and precordial increased.

There are two main variations of the technique.
The first, called "stress test" or "Bruce protocol" the record is done while the patient exercises on a formal, on a bicycle or treadmill. It is used to determine exercise tolerance after an episode of angina or heart attack.

In the second, "permanent monitoring" of 24 hours or Holter protocol, the patient wears for a long time (one or two days) is a device that continuously recorded the ECG. Used in cases of sporadic arrhythmias and angina-type pains. Currently, the emergence of mobile devices (credit card size) for specific event recording technique may become obsolete, but remains the standard.

PROBLEMS
It is a completely passive system for collecting electrical signals, so you are not foreseen.

LONG DOES
A normal ECG, about three minutes.

PRECAUTIONS

Generic Scan
Not necessary.

Children and pregnant
They can be performed without difficulty, although in children requires interppretación personnel.

Special Diseases
No difficulties are expected with any disease.