Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging (MRI) is a medical imaging technique which produces detailed images of organs, soft tissues, bone and virtually all other internal body structures. MRI provides a stark contrast between the different soft tissues of the body making it especially useful in neurological (brain), musculoskeletal, cardiovascular, and oncological (cancer) imaging.

Unlike CT or X-ray, MRI uses no ionizing radiation, but instead uses a powerful magnetic field to align the magnetization of hydrogen atoms in the body. Radio frequency (RF) fields are then used to systematically alter the alignment of this magnetization, causing the hydrogen nuclei to produce a rotating magnetic field that is detectable by the scanner. Signals created by this rotating magnetic field are then manipulated by a computer to construct a very detailed image of the body.

What To Expect

MRI machines are shaped like large cylinders with openings on both ends.  Patients will lie on an examination table that will then travel into the scanner to properly align the anatomy of the patient with the MRI scanner. MRI scanners create audible noise levels during operation which requires patients to wear hearing protection during their exam. Patients will wear headphones during their procedure that, along with protecting their hearing, allows for communication with the technologist and the listening of music during their MRI exam. The typical MRI exam takes between 30 to 45 minutes to complete, depending on the type of study being performed.

Safety

For most individuals, MRI is a very safe medical imaging procedure. However, for individuals who have certain medically implanted devices, exposure to the strong magnetic field present in the MRI environment may pose a very severe risk to their health. People with the following implants should never enter the MRI scanning area unless instructed to do so by a radiologist or technologist who is aware of the presence of these implants:

• Pacemaker or internal (implanted) defibrillator
• Certain vascular stents
• Cochlear (ear) implant
• Brain aneurysm clips
• Implanted drug infusion pumps or ports
• Implanted nerve stimulators
• Continuous Glucose Monitor
• History of metal in the eye

All patients are required to fill out a safety screening sheet prior to admittance into the MRI scanning area. During this time it is important that you inform the technologist of any implanted medical devices you might have. The technologist will verify that it is safe for you to enter the MRI area prior to your exam.

Exam Preparation

• Prior to your scheduled appointment, Overlake will call you to discuss specific instructions, review your health and insurance information and answer any questions.
• Follow the specific preparation instructions listed above for your particular type of MRI exam.
• If you’ve had an allergic reaction to a contrast agent in any prior medical imaging exam, please notify our staff before your appointment.
• Prior to the exam, eat normally (unless otherwise instructed) and take your medication as usual (unless your physician has given you other instructions).
• Leave your valuables at home. All jewelry and any metal objects must be removed prior to the exam.
• You will be asked to change into a hospital gown or scrubs after arriving.
• Please notify the technologist if you are pregnant, or could be pregnant.
• If sedation is requested, please call your provider for instructions. You will need to arrange for someone to drive you home.
• Please arrive 30 minutes prior to your exam.

Breast MRI

Breast MRI is a non-invasive procedure using magnetic resonance imaging (MRI) that allows doctors to see inside the breast to diagnose and treat medical conditions. It provides valuable information about breast tissue and potential lesions/tumors that cannot be obtained by other imaging modalities, such as mammography or ultrasound.

There are two kinds of breast MRI exams — with contrast or without contrast. Contrast is a special dye that helps highlight breast tissue.

With Contrast

• Provide further data after an inconclusive mammogram, ultrasound or physical exam
• Screen certain high-risk patients
• Detect breast cancer and/or determine the extent of the disease
• Assist with the consideration of treatment options
• Monitor breast cancer chemotherapy

Without Contrast

• Evaluate breast implants
• Determine if rupture or leakage has occurred

MRI of the breast is not a replacement for mammography or ultrasound imaging, but rather a supplemental tool for detecting and staging breast cancer and other breast abnormalities. However, ongoing medical studies have shown that MRI is substantially more accurate for early diagnosis of breast cancer than digital mammography or breast ultrasound.

Special Precautions

A breast MRI exam is safe, simple and painless. However, please notify us for further instructions if:

• You are pregnant or could be pregnant.
• You have a pacemaker, defibrillator, heart valve, cochlear implant, drug pump or neuro-stimulator.
• You have a history of metal in the eyes.

Some heart valves, aneurysm clips and neuro-stimulators are not safe. Bring the implant certificate with you so the technologists can refer to the manufacturer’s information about MRI compatibility.

Exam Preparation

• Prior to your scheduled appointment, you will receive a call from Overlake to discuss specific instructions, review your health and insurance information and answer any questions you may have.
• If you’ve had an allergic reaction to a contrast agent in any prior imaging exam, please notify our staff before your appointment.
• Contrast breast exams are best performed between day seven to 12 of your menstrual cycle.
• Prior to the exam, eat normally and take your medication as usual unless your physician has given you other instructions.
• Leave your valuables at home. All jewelry and any metal objects must be removed prior to the exam.
• You will change into a hospital gown or scrubs after arriving.
• Please notify the technologist if you are pregnant or could be pregnant. Or, if you are breastfeeding.
• If sedation is requested, please call your provider for instructions. You will need to arrange for someone to drive you home.
• Please arrive 30 minutes prior to your exam.

During the Exam

• Allow between 60 and 90 minutes for the procedure.
• For your comfort, you may have someone accompany you to the exam. 
• If necessary, your physician may prescribe medication to help you relax during the exam.
• A technologist will help position you on the cushioned scanning table. You will lie face down on your stomach with both breasts hanging freely in a padded depression in the table containing a breast coil which detects magnetic signals from the MRI machine. Your head will be positioned on a headrest. Your arms will be positioned above your head or at your sides.
• If a contrast material will be used, the technologist will insert an intravenous (IV) line into a vein in your hand or arm. A saline solution may be used. The solution will drip through the IV to prevent blockage of the IV line until the contrast material is injected.
• To minimize scanner noises, you will be given earplugs and you can listen to music through an audio headset.
• The scanner bed will slide into the magnet of the MRI unit. The technologist will leave the room during the scan, but you will remain in contact via an intercom.
• As the scan begins, you will hear knocking sounds for a few minutes at a time as images are captured. It is important to lie as still as possible and breathe normally during this imaging process. Some movement is allowed between sequences.
• After an initial series of scans, if contrast is to be used, Gadolinium (an FDA-approved, non-radioactive contrast agent) will be injected into the IV. You may feel a warm or cold sensation and may experience a metallic taste in your mouth that lasts a few minutes.
• An additional series of images will be taken during or following the injection.

After the Exam

• You may leave as soon as the exam is completed and resume normal activities.
• Your normal diet may be resumed.
• If IV contrast was used, it will rapidly be cleared from the body by the kidneys. However, women who are breastfeeding may consider discarding milk for 24 hours following the exam.
• Your imaging study will be interpreted by a board-certified radiologist who specializes in breast imaging.
• Your referring physician will receive a report and pictures detailing the findings of your exam within 24 hours. Plan to contact your doctor to discuss the exam results.

Common Indications

• Breast cancer staging. Extent of disease evaluation prior to breast conservation surgery or mastectomy.
• Contralateral breast examination in patients with breast malignancy. MRI can detect unsuspected disease in the opposite breast in at least 4-5% of breast cancer patient — often with negative mammography and physical examination.
• Lesion characterization. When conventional breast imaging studies such as mammography, ultrasound or physical examination are inconclusive for the presence of breast cancer.
• Monitoring chemotherapy treatment. To evaluate chemotherapeutic response and the extent of residual disease prior to surgical treatment.
• Evaluating patients with positive surgical margins for residual disease. To help determine which patients could be effectively treated by re-excision or whether a mastectomy is required due to the presence of more extensive disease.
• Silicone and non-silicone breast implant evaluation. Evaluating breast implants for rupture and detecting cancer in women with breast implants.
• Evaluating post-operative scar versus tumor recurrence.
• Occult breast cancer. Locating the very small, undiagnosed breast cancer (occult cancer) when a malignant axillary node is found and the origin cannot be determined with mammography or physical examination.
• Surveillance of high risk patients. Breast cancer screening in patients with a genetic predisposition to breast cancer.

Referrals & Insurance Pre-Authorization

Most health plans and insurers require a referral and pre-authorization. Plan to check directly with your health insurance carrier regarding your policy. If pre-authorization is required, let us know when you schedule an appointment and we will gladly take care of the next steps.

Prostate MRI

A diagnostic prostate MRI creates a detailed cross-sectional image of the prostate and surrounding tissues. The image is examined by one of our board-certified radiologists. At Overlake Medical Imaging, we use multiparametric magnetic resonance imaging (MRI) as a new option for detecting and locating prostate cancer in men with abnormal PSA levels.

You should always speak to your primary care physician or urologist if you believe you could benefit from a prostate MRI. Below is the primary criteria used to determine whether a patient is a candidate for prostate MRI:

• Patients with negative prior trans-rectal ultrasound-guided (TRUS) biopsy and continued elevated prostate-specific antigen (PSA) level.
• Patients with positive digital rectal examination (DRE) and a negative trans-rectal ultrasound-guided TRUS biopsy.
• Patients requiring prostate surgery or radiation therapy.

Exam Preparation

Prostate MRI is a noninvasive imaging technique that does not require exposure to ionizing radiation.

• An IV will be started to administer contrast.
• A multiparametric MRI is performed and computer aided detection (CAD) is used to help the radiologist identify prostate cancer.
• The entire exam is usually completed within 45 - 60 minutes.

After Your Exam

One of our board-certified radiologists will interpret your images and send your referring provider a written report and pictures detailing the findings of your exam. Your referring provider will go over your results with you.