Magnetic resonance imaging (MRI) 1.5 Tesla

MRT-top-01-859

 

The MRI is an examination in radiologic and nuclear medical diagnostics. In medical imaging, magnetic fields and radio waves are created to produce tomographic images of the human body. This allows an assessment of the structure and function of tissues and organs in the body and therefore also many pathologic changes. This process does not use radiation.

Other names: Magnetic resonance tomography (MRT 1.5 Tesla)

 

What is a Magnetic Resonance Imaging (MRI)?

Magnetic resonance imaging (MRI) is an examination method in radiology and nuclear medicine creating images of internal organs. In contrast to an X-ray or computed tomography, X-rays magnetic fields and radio waves are used rather than x-rays.

How does magnetic resonance imaging (MRI) work?

Basis of the MRI are very strong magnetic fields, in which patients are examined. By electromagnetic fields in the form of radio waves in the VHF frequency range, certain atomic nuclei (hydrogen nuclei) are stimulated selectively in the body utilizing the fact that there are many hydrogen atoms are present in the human body. The MRI device records the physical response of the excited nuclei. A powerful computer converts signals by a very complex calculation method and combines them to very detailed 2 - or 3-dimensional images. These can then be evaluated by a physician. The images show particularly well the condition of the soft tissues or organs of the body and joints and provide information on their structure and function. Tissue having a high water content and fat are light colored while tissue with low water content is darker.

For which indication is the method useful?

Practically all areas of the body can be imaged by the MRI:

  • Brain and cranium
  • Facial and Eye
  • Spine and spinal cord
  • Soft tissues of the chest (for the lungs, currently the computed tomography is still more appropriate.)
  • Upper abdomen and pelvic organs
  • All joints, particularly with respect to cartilage, ligaments and capsule structures
  • Muscle processes
  • Vessels by means of a special technique, the so-called MR angiography

Equipment technology

So-called "closed devices" still have a greater advantage over open systems because they allow stronger magnetic fields. This is an important factor for the image quality and scan speed. Our unit of the brand Siemens Symphony Quantum (field strength of 1.5 Tesla) has the form of a short Tunnel of 60cm in diameter and open at the front and the back, meaning it is well lit and ventilated. At the systematic variation of the magnetic field (see "What is it?") very loud sometimes compressed air-hammer-like noise are caused by a so-called gradient. Unfortunately currently the rule of thumb: "The louder the noise, the better the device" is still dominating. This noise level is counteracted with suitable hearing protection. However, the patient should be carefully monitored during the exam. The patient can also use an "emergency bell" any time during the exam. Depending on the medical issue and the body region to be examined, we use different "antennas"/coils. 

How is the examination performed?

Patientengespraech-897

Der patient lays in a lockable, spacious cabin with all metallic objects, such as technical equipment, valuables, and bankcards, etc. removed. Complete undressing is not required. The radiographer (specially trained assistant) will help to position you on the examination table. He or she may still bring some corresponding coil (see above).

Depending on the medical issue, a thin indwelling cannula is placed in a vein in your arm and a special contrast agent is injected. These MRI contrast agents are characterized by good compatibility. They are not radioactive, and have an extremely low tendency to trigger an allergy or harm the patient in any other way. The contrast agents leave the body chemically unchanged and completely unnoticed by the kidneys. The radiologist selects the contrast agent specifically according to the medical problem.

The patient is then moved slowly into the unit or "the tunnel" - in studies of the legs with feet first. The examinations take, depending on individual planning between about 15 - 30 minutes.

Subsequently, the physician evaluates the images and discusses the results with the patient.

Who cannot be examined (contraindications)?

Naturally, all metal objects located in the body can be affected by the magnetic field (e.g. pacemakers, dentures, prostheses, vascular grafts (STENT), surgical material, insulin pumps, artificial heart valves, metallic foreign body). Most of today’s implanted prosthetic joints, heart valves and surgical metallic materials do no longer exclude an MRI scan, however, this must always be evaluated carefully in each individual case. Patients with pacemakers may general not be examined. However, if the cause is very serious this is possible in specialized centers with a cardiology department. A relative contraindication is a pregnancy. However, the relevant professional association as well as the Radiation Commission demands a very close indication.

Claustrophobia - fear of narrowness?

A significant part of the population has trouble staying in tight spaces. Are you affected? Trust us; you are not the only one! Talk to us. With proper planning, we can help you with a rapid and intense acting sedative. This can be administered in individualized dose - and because we have many such cases, we have a great deal of experience.

When being administered a sedative, you need to be accompanied by a companion for your personal safety since you will not be able after the exam to cope with the road traffic or operate a motor vehicle.  

Who pays for the examination?

The MRI is a standard benefit of all statutory and private health insurance.