What is an MRI?

MRI at Southwest DiagnosticMagnetic resonance imaging (MRI) uses a magnetic field and radio waves to create detailed images of the soft tissues and organs in your body. The magnetic field temporarily aligns the water molecules in your body and radio waves cause these aligned particles to produce very faint electrical signals. These signals are used to create the MRI images. The powerful system delivers images with the diagnostic clarity that physicians need. Since this new machine does not emit x-rays there is no fear of radiation.




High-Field MRI

High Field MRI at Southwest DiagnosticThe Vantage 1.5 Tesla HiField MRI represents the next generation in High Field imaging. Designed with patients in mind, the Vantage opens new possibilities for fast, comfortable scanning while delivering superior image quality.

  • Ultra-Short length - the industry's shortest High Field magnet

  • Ultra-Wide bore - wide opening

  • Ultra-Quiet - Pianissimo technology, cutting MRI noise by 90%

  • Powerful gradient system combined with powerful computer system

  • Advanced RF system

  • Patient-friendly gantry and couch system

We are glad to offer state-of-the-art High Field and Open MRI systems to the community with expanded diagnostic capabilities catering to all patient criteria and preferences.

Southwest Hi-Field MRI  is Accredited

Open MRI

Open MRI at Southwest DiagnosticOpen MRI combines the superior diagnostic performance with the comfort of an open environment and incorporates latest advances in gradiant, radio frequency and computer technology permitting very sophisticated clinical applications. The powerful system delivers images with the diagnostic clarity that physicians need. Since this new machine does not emit x-rays there is no fear of radiation.

Most importantly, Open MRI allows all-round patient access and therefore increased ability to scan pediatric, claustrophobic, and large patients up to 400 lbs.

The large aperture and floating table allow for accurate patient positioning, improving signal to noise ratio and in-plane resolution by permitting a smaller field of view with minimal offset.

Open MRI offers physicians the latest enhancements in MRIs, facilitating fast and accurate patient diagnosis. Copies of MRI studies can be made available on request for a nominal copying charge. For more information, contact us.

Southwest Open MRI in San Antonio is Accredited.



Is MRI safe?

The strength and frequency of radio waves used in MRI are believed at this time to have no harmful effects. Many units monitor the amount of radio frequency energy used, called SAR, to prevent from heating patient tissue. SAR limits are set at a small fraction of what is considered safe. Strong magnetic fields have been used for separating iron from aluminum ore for years. The health of employees in this industry has been carefully monitored by researchers with no ill effects identified from this exposure.

Is MRI comfortable?

There are many aspects of comfort during an MRI examination.

Pain from lying in one position is sometimes a problem when exams run for 1/2 to 1 hour. Often patients are instructed to keep all or part of his or her body still for the entire procedure. If you think you may be in pain, take some medication prior to your test. Over-the-counter medications such as Aspirin or Tylenol help a great deal.

Noise produced by the gradients (strong electromagnets being turned on and off) can bother some patients during the test. This banging noise is reduced at our facility with ear plugs or specially designed noise suppression systems which also allow music to be played. You can bring your favorite CD. Our "Open" MRI unit produces much less noise than high field units, and ear protection is not required.

Claustrophobia, or that closed-in feeling, is sometimes a problem for many patients during MRI. Even though most patients tolerate the magnet enclosure with little problem, many are anxious because of stories they have heard. A mild tranquilizer (Diazapam) is very effective in alleviating claustrophobia, and makes the examination in any magnet tolerable.

Why is the test so long?

Each MRI scan consists of several sequences or collections of data gathered over 2 to 10 minute periods. The time varies with the number and type of sequences the radiologist requires.

Why do I have to wait for the results?

The typical MRI examination results in approximately 50-150 images which must be processed and carefully reviewed by a radiologist specially trained in MRI. Sometimes the radiologist may want to consult with another physician for a second opinion with no additional charge to you. While usually ready in a day or two, results for difficult cases can take more days. If your radiologist identifies a condition requiring emergency treatment, your doctor will be notified immediately.

Can I have an MRI if I have metal in or on my body?

There are a few instances when MRI cannot be attempted on patients with metal in their bodies. Patients with pacemakers or other implanted electronic devices cannot be examined. Your technologist will carefully assess your situation and prepare you for your procedure. You can help by not wearing clothing containing metal.

Is there any preparation needed?

No special preparation is usually needed for MRI examinations. Patients should avoid clothing with metal and should not wear eye makeup.

Is there any dye used?

For some tests, Gadolinium is injected to help answer questions about specific conditions. Usually the need for Gadolinium is determined at the time of the examination by the radiologist. This use of contrast media can help to identify scar tissue from previous spine surgery.

Gadolinium has been used for many years and has proved to be very safe with few incidences of side effects. As with any medication or food, it is possible to experience an allergic reaction; however very few serious reactions have been reported. This contrast media is NOT related to the xray dye you may have heard about, and has no relationship to shellfish allergies.

Can MRI examine my whole body at once?

No. The quality of the images produced increases as the area of examination becomes smaller. Because of limitations on signal to noise, the number of image pixels is finite, and they become too large for accurate diagnosis if the field of view is too large.