* These important forms should be printed out and completed and brought in with you on the day of your appointment.
In this section of our website, patients will find a great deal of information about MRI and the examination process. We have tried to answer questions and concerns you may have in a clear and jargon free manner. There are also forms and questionnaires included in this section that you can open and print out to save time in preparing for your visit. If you have questions or concerns not covered here or are uncertain about anything regarding the MRI process please let us know. Please also tell us if there are ways we can make this web site more helpful for you.
How MRI Works top
MRI (Magnetic Resonance Imaging) provides an unparalleled view inside the human body. The level of detail is extraordinary compared with any other imaging modality. MRI is the method of choice for the diagnosis of many types of injuries and conditions because of the incredible ability to tailor the exam to the particular medical question being asked. By changing exam parameters, the MRI system can cause tissues in the body to take on different appearances.
This is very helpful to the radiologist (who reads the MRI) in determining if something seen is normal or not. We know that when we do “A,” normal tissue will look like “B” — if it doesn’t, there might be an abnormality. MRI systems can also image flowing blood virtually any part of the body. This allows us to perform studies that show the arterial system in the body, but not the tissue around it. In addition the radiologist may wish to have a contrast media (dye) injected into the patient during the scan.
This is a very safe procedure and gives the radiologist additional information. MRI scanners vary in size and shape but the basic design is the same. Using a strong magnetic field in conjunction with RF (radiofrequency) pulses of energy, the MRI scanner can pick out a very small point inside the patient’s body and ask it, essentially, “What type of tissue are you?” This point may be extremely small. The MRI system goes through the patient’s body point by point, building up a 2-dimensional or 3-dimensional map of tissue types. It then integrates all of this information together to create 2-D images or 3-D models.
The patient, typically lying on his or her back, slides into the bore of the magnet on a special table. Whether or not the patient goes in head first or feet first, as well as how far into the magnet they will go, is determined by the type of exam to be performed. Once the body part to be scanned is in the exact center of the magnetic field, the scan can begin.
Physics For The Faint Hearted top
The MRI machine contains a very large and powerful magnet. This magnet is rated using a unit of measure known as a tesla (T). Another unit of measure commonly used with magnets is the gauss (1 tesla = 10,000 gauss). The magnets in use today in MRI are in the 0.5-tesla to 2.0-tesla range, or 5,000 to 20,000 gauss. Magnetic fields used in MRI generally range between 0.2T and 3.0T, compared with the Earth’s magnetic field of 0.5-gauss. Magnets up to 9.0T are currently being investigated at academic and research centers.
Everyone’s body is primarily made up of water. Water contains one hydrogen molecule and two oxygen molecules. Because hydrogen is the most abundant element in the body, it is this element that we are imaging. These hydrogen molecules or protons possess two nuclear properties, an electrical charge and spin or precession. As you walk around, the protons in your body are spinning or precessing in a random manner. This means that some are pointing up, some down, some left, and some right. Each of these spinning protons also has an electrical charge (+1). Because all the protons are spinning randomly all the charges cancel each other out. Simply put you are a walking magnet with zero charge.
As the technologist places you inside the bore of the MRI system magnet your random protons begin to align parallel to the magnetic field. This happens very fast. Once you are in the middle of the magnet all of your protons are either aligned with (parallel) or against (anti-parallel) the main magnet with a slight majority of protons aligning with the main magnet. These slight majorities of protons give you a small charge and produce the MRI signal. You are no longer a magnet with zero charge but a magnet with a slight positive charge.
As you lie comfortably on the MRI table inside the magnet you begin to hear the loud knocking sound that is the hallmark of MRI. This knocking sound is caused by a part of the machine called gradients. Gradients are smaller magnets that are responsible for affecting the main magnet in order to tell where your protons are in relation to each other. There are three sets of gradients, one responsible for right to left, one for top to bottom and one for front to back. With the addition of these three gradients we have now split your body into three planes.
We can now tell the machine to image anywhere in the body. If we want to image the brain all we have to do is to turn on and off the appropriate gradients. Now that we know where the protons are in relation to each other, we need to find out what type of environment those protons are in. Are the protons in fat? Muscle? Flowing blood?
We first discussed the main magnet and then the gradients, we are now going to add the third piece called RF (radiofrequency) energy or radio waves. These radio waves will be transmitted into the bore of the magnet at a certain frequency. The radio energy is absorbed by the protons and causes them to be very energetic. Recall that we have a slight majority of protons aligned with the main magnet that give you a slight charge. These protons are so excited by the radio waves that they move out of alignment. The radio waves are then turned off and the protons lose all the absorbed energy (relax) and become aligned once again with the main magnet. As the protons relax, the absorbed energy is released into the surrounding tissue.
This rate at which the energy is released and the protons move back into alignment with the main magnet is influenced by the surrounding tissue. Some tissues, such as fat, absorb the released energy very quickly causing the protons to back to alignment very quickly. Water absorbs energy very slowly so the protons take a long time to align with the main magnet. Simply by measuring the relaxation time of the protons we can determine what tissue that proton is in.
Using the various parts of the MRI system mentioned above we can now localize where the protons are and what specific tissue they are in. These relaxation times are different for all tissues. Normal tissue relaxation times are also affected by most disease states. The technologist can adjust the parameters of the system to take advantage of, or weight, certain relaxation times. This allows the radiologist to see differences in these relaxation times caused by pathology.
In order to measure the proton’s relaxation time and listen to where the protons are, a listening device called a “receiver” coil is used. The body part being imaged is surrounded by this receiver coil. The closer and smaller the receiver coil is the easier it is to “listen” for these signals. The coil acquires all the information, location, relaxation times, and number of protons then sends this information to the computer. This information is used by the computer to create images. The image is a computer generated black and white or color coded image that represents the anatomy imaged.
Breast MRI top
We know that you are concerned about the health care you receive. That is especially true when a diagnosis of breast cancer may be on your horizon. We think that having sensitive and compassionate female MRI technologists performing your breast MRI results in the best possible imaging experience. The more relaxed and comfortable you are the better and more diagnostic your images will be. This will facilitate the radiologist in reading your exam and your physician in interpreting the results.
We chose to utilize only female MRI technologists to perform your exam at Corvallis MRI. These technologists have had specialized training in breast imaging. They provide compassionate and confidential care from the pre exam interview through the imaging process. Your privacy and emotional well being are a priority.
Having A Breast MRI – What To Expect top
Although the actual imaging time will usually be no more than 45-60 minutes you should plan on spending approximately 90 minutes at our facility. When you arrive you will be asked to fill out a safety questionnaire (or save time and complete the forms provided below). This will allow us to determine whether or not it is safe for you to have an MRI.
It is important to answer all questions accurately and completely. You will be escorted from the waiting room to a small dressing room where you will be asked to change your clothes. It is very important that you remove all types of metal such as earrings, rings, hair clips, etc.
The MRI technologist will then sit down with you and record your medical history paying special attention to any prior breast imaging or issues you may have. The more complete history we compile the more accurate your imaging interpretation will be. Once this process is completed the technologist will start a small IV in your arm or hand. Breast MRI uses an intravenous contrast material to help visualize normal and abnormal blood flow. This IV will remain in place until the examination is completed.
You will be positioned face down on your stomach with your breasts hanging freely into cushioned openings and your arms will be above your head. Your breasts will be surrounded by a breast coil, a signal receiver that works with the MRI unit to create the images. Straps and bolsters may be used to help you stay still and maintain the correct position during imaging.
Your will be given a signal ball to assist you in the event you need to alert the technologist during the exam. You may also be given headphones so you can listen to your favorite music. Your IV will be attached to a device called a “power injector” that allows contrast material to be injected remotely at a constant pressure and rate. Once positioned correctly and comfortably you will be moved into the bore of the MRI magnet and the technologist will leave the room. She will be in constant contact both visually and verbally with you throughout the entire exam.
During the exam you will hear the machine make various loud bangs, clicks, and thumping noises. This can be quite loud. Several sequences or sets of pictures will be acquired before, during and after the administration of the contrast material. These sets of pictures will be matched up, or subtracted from each other so it is of the utmost importance that you hold very still the entire time you are in the magnet.
Once the examination is complete the technologist may ask you to wait for a few minutes without moving while they review your images. Once they have done this you will be removed from the magnet and the IV removed from your arm. The technologist will then escort back to your dressing room and answer any additional questions you might have. Once you are dressed you may leave and resume normal activities.
A radiologist that specializes in women’s or breast imaging will interpret the approximately 2800 images. A detailed report will go to the doctor that ordered your exam. You will need to contact that doctor in order to get your results. This process usually takes about 2-3 days.
Please print out and fill-in the below forms and bring them with you on the day of your appointment.
Patient Comfort & Safety top
At Corvallis MRI the comfort of our patient is second only the safety of our patient. Patients undergoing any medical test, especially imaging procedures, typically do not feel well, are uncomfortable and quite apprehensive about the test and/or the results. We understand that your comfort is paramount to obtaining the high quality diagnostic images necessary for your physician to determine the best and most efficient method of treating you.
Most MRI exams take approximately 30-45 minutes. During this time it is extremely important that you do not move or shift your body in any way from beginning to end. As the technologist positions you on the table the computer is told “where you are”. Once this is done any movement will result in pictures being taken of the wrong area. In addition, while we are in the process of collecting the information to make our pictures, movement will cause the images to be blurry. Think of the MRI process as taking a picture with a very long exposure; any movement during the time the “shutter” is open (typically 3-5 minutes) causes the pictures to be out of focus.
When you arrive for your exam the technologist will do everything possible to ensure that you are comfortable prior to beginning the exam. Please keep in mind however that sometimes a particular exam dictates that you be in a certain position. This position may be uncomfortable but will result in the best diagnostic images. In these instances we ask for your patience and that you help us in getting you as comfortable as we can.
The new 3T system that you will be placed in for your exam generates heat as part of the normal imaging process. Some patients depending on body shape and size and what exam is being performed may get very warm and may even perspire. This is a normal byproduct of the scanning process and you shouldn’t be concerned. The machine has fans within the bore that will blow cool air past you during scanning. This should keep your discomfort at a minimum.
You will be able to communicate with the technologist at all times and stop the exam should you get too uncomfortable. The technologist will also give you a “panic button” prior to enter the magnet. This squeeze ball will assure that you can contact the technologist at any time. The technologist will also speak to you throughout the exam informing you of the length of each set of pictures and how much time is left.
Hearing Protection top
If you have had an MRI in the past you know that the hallmark of the MRI scanner is the loud knocking sound heard during the imaging process. This sound, although dampened somewhat in the new generation scanners, can be very, very loud especially with some of the newer imaging techniques. You will be required to wear some type of hearing protection while in the scanner. The technologist, depending on your exam, will give you earplugs or headphones (see music below). This will make you more comfortable in the noisy environment, as well as protect your hearing.
Although the clothes you wear to your appointment may or may not contain metal snaps or fasteners you will be asked to change your regular clothes into our facility attire (pants and top). This serves a dual purpose. First, it provides you with the best possible safety margin. Many of today’s clothing can have metal threads, small snaps or zippers that could be dangerous for you or interfere with the imaging process.
Many of the undergarments that women wear also contain metal snaps or fasteners. In addition, even the best intentioned individuals may forget to remove items from their pockets. Changing your clothes ensures that no contraindicated items (keys, change, etc.) will be brought into the magnet room. Second, our attire is loose fitting which will hopefully be more comfortable than you regular clothes.
You will be asked to remove all your jewelry including all piercings. Even though the majority is made from non ferrous (MRI safe) metals such as gold, platinum or silver the exact composition is difficult to ascertain. Many piercings contain very ferrous metal and attachments which can be attracted to the magnetic field. Additionally, loops of any conductive metal can heat up or vibrate during the imaging process. If it is impossible for you to remove an item jewelry please inform the technologist prior to entering the magnet room so appropriate steps can be taken to ensure your safety.
You may be given headphones and allowed to listen to the music of your choice during your exam. This will depend on the type of exam you are having and what type of surface coil (receiving antennae) must be used. Typically you may listen to music for the following exams:
- Upper and lower musculoskeletal exams such as knees, ankles, feet, shoulders, elbows and wrists
- Abdominal and pelvic exams
Typically you may NOT listen to music for the following exams:
- Brain exams
- Spine exams
Many patients undergoing MRI suffer from claustrophobia. There are many ways to approach this problem. Our MRI system has the traditional open bore configuration. We have had a very low percentage of patients unable to complete the exam.
As you can see it is a round tube approximately 1½ meters long and 60 cm in diameter. Like a tennis racket or baseball bat an MRI magnet has a “sweet spot”, a place the where magnetic field is as perfect as possible. This area in all magnets, regardless of type, is in the middle of the bore or magnet. It is crucial to producing highly diagnostic pictures that the part we are imaging be at this “sweet spot”. For example if you are having a brain MRI your brain must be in the center of the magnet. Depending on the exam ordered, you may enter the magnet head first or feet first. Head first exams are typically :
- Most exams for anatomy above the belly button
Feet first exams are typically:
The magnet bore has adjustable lighting and airflow. If you think you may have a problem with claustrophobia please inform your physician. He or she may decide to prescribe a light sedative or anti-anxiety medication that will help you relax. If you take any of these types of medications you must have someone drive you to and from your appointment. Other things that help in reducing claustrophobia are:
- Listening to your favorite music (see above)
- Placing cloth over your eyes
- Bringing a friend with you for comfort
Frequently Asked Questions top
- Q. Why do we ask so many questions?
- A. An MRI is one of the safest imaging techniques available. No ionizing radiation (x-rays) is used. Instead magnetic fields and radio frequency (RF) energy (radio waves) are used to produce the images. The magnetic fields used during the imaging process produce no known adverse effects to the tissues of the human body.
Although MRI is considered safe a number of potential safety issues exist, some related to potential direct effects from the imaging environment, and others related to indirect hazards.
The most important safety issue is the introduction of objects containing ferrous or magnetic metals (e.g. iron, nickel). These items will be strongly attracted to the powerful magnetic field within the MRI exam room. Patients and personnel can be injured by these flying metal objects.
This strong magnetic field may also interfere with metal implants placed inside the body. Some of these items such as brain aneurysm clips may become dislodged causing additional injury.
Implants containing electrical parts such as pacemakers or cochlear implants may be temporarily rendered ineffective or damaged beyond repair.
Long standing, firmly implanted metal items such surgical clips and artificial joints do not pose any safety issues for the patient. In addition, loops of metal such as rings, bracelets and necklaces can induce electrical currents from interactions with the radio frequency energy used. These electrical currents can be uncomfortable as well as potentially causing burns on the patient.
Q. What if I have an implanted device? Can I have an MRI?A. Many patients today have implanted devices placed there either through surgery or through wires (catheters) placed in the blood vessels. It is important to furnish as much information as possible so that the MRI technologist can ascertain the safety of the implant. Please bring the card that the doctor gave you to your appointment.Q. My friends have told me stories about arriving at the MRI office and having to wait or be rescheduled because of insufficient information. Will that happen to me?A. At Corvallis MRI we do our best to make sure that we have all the necessary information on each patient prior to their arrival. We depend on your referring physician to inform us about the presence of any items that may be a danger to you in the MRI environment.If this information is missing or not adequately provided we depend on you, to inform us about what is inside your body. If we don’t know ahead of time then we must take time to make sure you are safe prior to proceeding. We understand that you are sometimes in a hurry or on a schedule but please remember that your safety always comes first. Items that WILL prevent you from undergoing an MRI exam:
- Implanted cardiac defibrillator
- Spinal cord or brain stimulator
- Cochlear (inner ear) implants
- Metal fragments in eyes
- Magnetic implants
- External pacer wires
Items that MAY prevent you from undergoing an MRI exam:
- Brain aneurysm clips
- Shrapnel, bullets, etc. – depends on location
- Intravascular stents, filters, etc. – depends on location and date of implantation
- Prosthetic devices
- Tattooed makeup
Once the technologist has determined that your implant is safe you will be escorted into the MRI exam room. You will be placed within the magnet. The technologist will be in constant verbal and visual contact. You will also be given a small rubber “panic” ball to signal the technologist if you need something.
Q. If I am claustrophobic and unable to complete the exam will I be charged?A. No. You will only be charged for an exam if we are able to get diagnostic results.Q. What if I can’t get a piece of jewelry off?A. For your safety we ask that you remove all your jewelry. Sometimes this is not possible especially with wedding rings. Rings are usually not an issue other than they may vibrate and/or heat up a small amount. Other piercings and earrings will be dealt with on a case by case basis. It is possible that we will deny you access to the magnet room or make you sign a release informing you of the dangers of having the exam with these items in place.Q. How long will the exam take?A. MRI exams vary in length depending on patient cooperation and the exam ordered. Most exams last approximately 30-45 minutes. There are a few exams that may take up to one hour.Q. Why do most MRIs take 30-45 minutes?A. The amount of protons used to make our image is a very small percentage of the protons in your body. In order to get enough signal data we must repeat the imaging process many times and average the result to obtain a diagnostic image. In addition, we obtain multiple sets of pictures, each one reflecting different relaxation times. In a typical exam we may produce anywhere from 200 – 3000 images, depending on what we are looking at. The number of images is dependent on what is needed to adequately image the body part.Q. Why can’t they make the machine quieter?A. The loudness of the machine is directly related to the strength of the magnet and how “hard” the machine has to work to acquire the data necessary to produce the image. Typically the thinner the slices, the higher the resolution and the faster the scans, the louder the machine. As MRI systems have gotten stronger (for example Corvallis MRI’s 3T) this is leading to louder exams. However, technical advancements have reduced the noise somewhat making these stronger magnets less noisy than they would have been.Q. Is it OK to wear my shoes?
A. We would prefer that you remove your shoes. It is possible that you could track in metal fragments or shavings that could be pulled into the magnet affecting its performance.
Q. I have heard that you need to be really still during the MRI. Is it OK to blink, swallow, chew, etc. during the exam?A. Although MRI is very sensitive to motion, normal movements such as blinking and swallowing should not compromise image quality. On some of the exams such as a cervical spine (part of your neck) we will ask you to keep your swallowing to a minimum or as gently as possible. If we are imaging your eyes we would like your eyes to be as still as possible.Q. My friend told me he got really warm during the exam. Will I get warm and why?A. The new 3T system that you will be placed in for your exam generates heat as part of the normal imaging process. Some patients depending on body shape and size and what exam is being performed may get very warm and may even perspire. This is a normal byproduct of the scanning process and you shouldn’t be concerned.Q. Will I be given an injection of dye (contrast material)?A. Some exams require the use of an intravenous injection of a contrast material to image or improve the diagnosis. Your physician and the radiologist will decide if this is necessary.
If you have questions or concerns not covered here or are uncertain about anything regarding the MRI process please contact our office at 541-768-5187.
Patient Insurance Rights top
All patients are entitled to certain insurance rights as outlined by the U.S. Department of Labor, Employee Benefits Security Administration (EBSA). You can find out more about your insurance rights and other related healthcare topics by searching the EBSA Consumer Information on Health Plan website.
Patient Billing top
Clear and accurate billing is one of our priorities since patients are commonly confused by healthcare bills. Therefore, please understand that you will receive two (2) bills when you are seen at Corvallis MRI:
- TECHNICAL COMPONENT is for the resources used to perform the MRI scan & billed by CORVALLIS MRI
- PROFESSIONAL COMPONENT is the radiologist’s interpretation of the exam & billed by CORVALLIS RADIOLOGY
Still Have Questions?
Read all bills carefully to find the phone number to call for assistance. Or call your employer’s human resources or benefits office for explanations. If you have a question about the TECHNICAL COMPONENT of your bill, have a copy of your bill in hand and call (800) 640-5339. If you have a question about the PROFESSIONAL COMPONENT of your bill, have a copy of your bill in hand and call (800) 672-7210. If you would like to pay your bill online, click here.