An MRI is a non-invasive scanning process that produces three-dimensional images of a targeted part of the body. Unlike X-ray or CT (computed tomography) scans, MRI does not use ionizing radiation, which makes it especially useful for scanning sensitive patients such as pregnant women or young children.
According to USA Today, more than 35 million MRIs are performed each year. The first use of MRI technology on humans occurred in 1977, and in the years since, MRIs have grown steadily more popular in health systems as they become safer, faster and capable of producing more detailed, higher-resolution images.
If your doctor prescribed an MRI exam for you or a loved one, Memorial Hermann has the experience and advanced technology necessary to meet your diagnostic imaging needs.
MRI machines generate magnetic and radio waves that react with water molecules in your body on a microscopic level. From this reaction, the machine electronics assemble a clear image of the specific bone, organ or tissue being scanned. Several images are taken during the course of an MRI exam, which the imaging technician compiles to produce a workable scan.
MRIs are often used to examine patients for conditions like internal bleeding, infection, tumors and injuries to tendons and ligaments. They are also used to scan the heart and arteries for defects, and to check the liver and gastrointestinal tract for lesions or diseased tissue.
MRIs are most often used to scan:
MRI exams are also a useful tool to investigate different types of cancer. They provide an alternative to tests or procedures that require painful or invasive incisions, and can help identify cancer at an early stage, when treatments can be most successful.
At Memorial Hermann locations throughout the Greater Houston area, our imaging technicians are skilled and trained to perform the following MRI exams:
Breast MRI exams are recommended for people at a higher risk for breast cancer or for patients recently diagnosed with the disease. At Memorial Hermann, our 3 Tesla (3.0T) MRI machines have twice the signal strength of standard machines, helping to cut down on false positives and unnecessary breast biopsies. Pairing a screening MRI with yearly mammograms may improve the ability to diagnose certain cancers.
Cardiac magnetic resonance imaging (cMRI) scans are like a standard MRI scan, except a special coil is placed on your chest to provide vivid, highly detailed images of the heart. The cMRI exam is most often used in conjunction with other specialized imaging techniques to assess cardiovascular disease, congenital heart defects and overall cardiac health.
Certain MRI scans may require the use of contrast, a special medication or dye administered through an IV that helps provide information about blood vessels and organs during the scanning process. Your imaging technician will let you know if they need to give you contrast before the exam begins and will ask if you have any known allergies. Less than one percent of all patients experience an allergic reaction to MRI contrast, while the vast majority do not notice any significant symptoms.
MRI exams may allow your physician to better diagnose and treat any potential health issues. They are increasingly common and designed as an alternative to invasive surgery, and compared to more complex diagnostic medical procedures, MRIs require relatively little preparation or recovery time.
As always, if you do not agree with your current course of treatment, you have the option to get a second opinion from another physician.
Minimal preparation is needed before a typical MRI exam. It is important, however, to notify your doctor and imaging technician of any implants, tattoos or other metallic objects on, or in your body, including the following:
These items may react negatively to the MRI machine’s high-powered magnetic field and interfere with the imaging process. Before the scan, you’ll be instructed by the imaging technician to remove items capable of being removed and to change into a hospital gown. A locker will be provided so you can safely store your belongings until the MRI exam is complete.
Prior to your exam, an imaging technician will ask you a series of screening questions to determine if you have any medical conditions or devices, implants or metallic items that may prevent you from receiving an MRI. You will then lie down on a table that will move automatically into position inside the MRI machine.
During the scanning process, it’s important that you remain completely still so the images being taken are not blurred. The magnets inside the MRI machine may make loud clicking or tapping noises as scans are taken. If you prefer, your technician can provide you with earplugs or play music to help drown out the noise.
You will also be given an “emergency ball” before the exam starts. If you feel anxious or claustrophobic at any time, you can squeeze this ball to stop the exam.
Once the exam is complete, the imaging technician will compile and send your scans to an affiliated radiologist, who will interpret the images and provide a report to your doctor. The technician conducting your MRI is not allowed to interpret or discuss what they are viewing before or after the exam.
Standard single MRI exams last about 30 to 40 minutes, while specialty MRI exams can take up to an hour. Ask your doctor about the specific scans you need, so you can plan your schedule accordingly.
Advances in MRI technology have significantly decreased the time it takes for scans to be developed. In most cases, MRI results will be presented to your doctor within one to two business days. You will need to schedule an appointment with your doctor to discuss the results.
MRI exam costs depend on several factors, including:
Hospitals and health systems like Memorial Hermann are required to meet rigorous safety standards for equipment and staff and will update their imaging technology more often to provide cutting-edge care for patients.
While choosing an outpatient imaging center for your MRI exam may seem like a budget choice, you should consider all your options before making a decision, especially when it comes to your health.
According to a study by the Radiology and Biomedical Imaging Department of UC – San Francisco Hospital, no known biological risks to humans exist from magnetic fields of the strength currently used in MRI machines. As long as you follow the directions of your imaging technician, your MRI experience should be a smooth one.
For some patients, MRI exams may not be an option for economic or health-related reasons. If this is the case, you may wish to undergo another type of exam. There are alternatives to the MRI, but you will need to speak to your doctor to find out if they are viable options for you, based on your unique circumstances.
Alternative procedures include:
There are many important factors to consider when choosing an imaging provider, including cost, equipment, type of facility and hospitality. Only you can make the right healthcare choice for you or your family.
At Memorial Hermann, we are focused on exceptional patient service. Each of our locations features comfortable waiting rooms, warm gowns to wear during the procedure and care from our friendly, knowledgeable staff.
No matter where you decide to have your MRI exam, you can count on our imaging technicians to be courteous, knowledgeable and well-trained. Safety protocols are updated regularly to keep pace with advances in imaging technology, and we continue to improve turnaround times on MRI results.
If this is your first experience with an MRI exam, we understand it can feel intimidating. It doesn’t have to be. We’re here to help you through the process, and we’re focused on making this an experience that is as stress-free as possible.
The highly skilled team at Memorial Hermann utilizes the most advanced imaging tools and technology available.
The streamlined processes performed at our imaging centers are designed to maximize your comfort and minimize stress.
Learn how to request a copy of your results for imaging performed at a Memorial Hermann Imaging or Breast Care location.