Magnetic field

Introduction

A magnetic field is the magnetic effect of an electric current or a magnetic material.The magnetic effect of a substance is the force on moving electric charge and magnetic dipoles.An electric current is the movement of charged particles.Magnetic materials or permanent magnets are objects that produce their own persistent magnetic fields and are made up of ferromagnetic materials such as iron and nickel that have been magnetized. Permanent magnets have both North and a South Pole.The magnetic field at any given point around an electric current or a magnetic material is specified by both a direction and the magnitude. Therefore it is a vector quantity.Tesla (T) is the unit of measurement of the strength of a magnetic field.A magnetic field is represented by magnetic field lines which show the direction of the field at different points.In a permanent magnet like a bar magnet, magnetic field lines are taken to be outward from the North Pole and into the South Pole of the magnet.

Importance of magnetic fields in medicine

Magnets are utilized in a wide range of branches in medicine. The human body and the earth that we live in produces magnetic fields naturally. Artificially created magnetic fields such as radio waves and microwaves are found in the environment that we live in. Most importantly magnetic fields are made use of in medical imaging in radiology.Magnetic resonance imaging (MRI), Nuclear magnetic resonance imaging (NMRI) or magnetic resonance tomography (MRT) is a medical imaging technique used in radiology to image the anatomy and the physiological processes of the body in both health and disease. These instruments use magnetic fields to form images of the body. MRI is used in neuroimaging, cardiovascular imaging, musculoskeletal imaging, liver and gastrointestinal imaging and in oncology for diagnosis, staging & follow-up of other tumours. It.It uses a magnetic field scanner to detect the positively charged ions of water throughout the human body. The resulting radiographs display stark contrasts between the various soft tissues throughout the body, which has made it the preferred radiology technique for neurological and musculoskeletal imaging. Magnetic resonance microscopy (MRM)	is magnetic resonance imaging at a microscopic level.Magnetic Resonance Elastography (MRE) is another use of magnetic fields in medicine.

There is also a pseudo scientific alternative medicine practise the use of static magnetic fields called magnetic therapy which uses magnetic fields to treat diseases such as joint problems, pain, depression, cancer, overstretched muscles, injured muscles or ligaments & migraine headaches. It is also used in magnetic therapy for detoxification by attracting the positive charges of various toxins created by the body's immune system when fighting infection. The increased blood flow will then escort the toxins to the liver for speedy detoxification and eventual elimination from the body through the kidneys.

Advantages of using magnetic fields in medicine Disadvantages of magnetic fields in medicine Present state
 * Magnet therapy is not thought to have negative side effects or complications when it is combined with conventional medical treatment.
 * Since it does not expose the body to ionizing radiation, magnetic resonance imaging is widely used in hospitals for medical diagnosis.
 * It is painless.
 * The MRI machine produces a very strong magnetic field which can exert a very powerful force on any metallic object found in the body such as pacemaker, medicine pumps and aneurysm clips & cochlear implants.
 * Since the MRI machine is a very confined space, it can be problematic to have a patient with claustrophobia using the machine.
 * Since the technology used is relatively new, there are no known long term side effects of magnetic fields in the human body.
 * It can lead to very expensive medical bills.

Since the new generation has shown an increasing preference for alternate medicine, treatment methods like magnetic therapy is becoming widely popular around the world.About 25,000 MRI machines are thought to be in operation throughout the world providing much needed images of internal tissues for proper diagnosis and treatment.

Safety Precautions

As mentioned earlier, since the MRI machine uses very powerful magnetic fields, patients are instructed to remove all metallic devices from their body.

Eg: wrist watches, jewellery etc.Most medical implants produced in modern times are MRI compatible. Therefore it is necessary to talk with your radiologist/doctor about the nature of your medical implant and whether it is safe to use the MRI machine.It is necessary for patients to lie down quietly for clear images to be produced. Therefore sometimes sedatives are given to small children and adults who are in a lot of pain and find it difficult to remain in one position during the course of the scan. Therefore it is essential to notify your doctor/radiologist about possible allergies to sedatives.

Conclusion

With the advancements in physics and the understanding of magnetic waves and its properties, new imaging methods that are more accurate and clear in helping medical professionals properly diagnose an ailment are being researched. Clear imaging is essential for proper diagnosis and the advancement in imaging could lead to the early diagnosis and treatment of cancer, tumours and many other ailments which could save millions of lives throughout the world.

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References

http://www.webmd.com/pain-management/tc/magnetic-field-therapy-topic-overview

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http://www.nps.org.au/medical-tests/medical-imaging/for-individuals/types-of-imaging/mri-magnetic-resonance-imaging/for-individuals/risks-and-benefits

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https://en.wikipedia.org/wiki/Magnetic_field#Magnetic_field_shape_descriptions

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