Tesla (T) is the SI derived unit of measurement used to quantify the strength of a magnetic field.

MRI, or Magnetic Resonance Imaging, is a non-invasive way to allow physicians to “see” inside the body. Unlike x-rays and CT scans, MRI does not rely on radiation to produce high resolution images. MRI exams use a strong, constant magnetic field and radiowaves to create very clear images of the body.

MRI scanners are categorized by their design and magnetic field strength.

The classification of an MRI scanner is often related to its overall appearance and field strength.

  • Closed MRI scanners are designed with an imaging bore that encircles the patient. These scanners can further be broken down into two categories: conventional and wide-bore. Wide bore MRI scanners allow more room for patients and are a comfortable alternative for individuals who do not need an open MRI scanner but would like a little more room.
  • Open MRI scanners are designed to be open along the sides with the patient positioned beneath the magnet.
  • Low /Mid Field MRI – magnet strengths are 0.2 to 0.7 Tesla
  • High Field MRI – magnet strengths are greater than 1.0 Tesla

The resolution – or image detail – of an MRI exam is linked to the strength of the magnet. High field strength MRI scanners provide better resolution allowing subtle abnormalities to be visible – which may impact clinical treatment. And better image quality allows for more accurate interpretations.

At MRI of Reston, we offer four (4) high field MRI options including a 1.2 Tesla Open MRI, a 1.5 Tesla MRI, a 3 Tesla MRI and a 3 Tesla Wide Bore MRI.

Is an MRI Exam for Everybody?

Almost anyone can benefit from the advanced imaging techniques offered by an MRI system. However, we advise caution if one of the following conditions applies to you:

  • Are you pregnant? Although MRI does not use X-rays and there are no known harmful effects on pregnancy, we recommend postponing the study until the second trimester, unless absolutely necessary.
  • Do you have a cardiac pacemaker, neurostimulator, or cochlear implant? Many of these devices are not compatible with MRI. It is important to know what type of device (manufacturer, model) is implanted to determine if an MRI is the right exam for you.
  • Do you have a cerebral aneurysm clip, cardiac or carotid stent, or mechanical valve replacement? Some of these are compatible with MRI but only under specific conditions. It is important to know exactly what type of implant was used before undergoing the study.
  • Do you have any metal fragments in your eyes? A metal fragment could move and cause damage to the eye. If you have had a metal eye injury, we will obtain X-rays prior to the MRI scan to make sure no fragments remain in the eye.