Magnetic Resonance Imaging (MRI)
Magnetic Resonance Imaging is an imaging technique that uses a magnet to generate a magnetic field and thus obtain images of the human body. No radiation is produced. The patient lies on a table and the part of the body that is examined enters into the magnetic field. This is done safely and comfortably.
Images are then obtained of the body, and the part in question is examined in any plane. The resolution of the MRI is excellent for soft tissues in the body (in fact, the best of all imaging techniques). Therefore, it is the ideal imaging modality to evaluate the brain, the spinal cord, the abdominal organs (liver, kidneys, pancreas), and the genital organs. MRI is the imaging modality of choice to evaluate the musculoskeletal system. Thus, one can appreciate the different tendons and ligaments in all joints, and see the menisci in the knees.
When going for an MRI examination, you must answer a questionnaire to see whether there are any contraindications to undergoing such an examination, (for example, a pacemaker or metal shards in the eyes). When coming into an Magnetic Resonance Imaging suite, any metal you have (a ring, coins, etc.) is removed. If you are claustrophobic, our staff will take care of you to help you get through your examination.
The technologist installs a coil on the body part to be examined (e.g. the knee). This coil will produce detailed images in this area. During the examination, you may communicate at any time with the technologist via a microphone.
The studies last on average between 20 and 50 minutes. Some studies will require the injection of a contrast medium (dye) intravenously. Each examination produces an average of 100 images that one of our MRI radiologists will analyze. A prepared report will then be sent to your physician.
Radimed at Pointe-Claire has an MRI device for the examination of the extremities. This device is unique in Quebec. Only your wrist, elbow, knee or ankle penetrates into the small magnet while you are sitting in a very comfortable chair. The magnet is a miniature one but with the same magnetic force (1.5 Tesla) as the large magnet.
Questionnaire:
A questionnaire must be completed beforehand by you or your doctor stating the following elements: implants, jewelry and the presence of metal in your body. When making the appointment and then with the technologist, you will review the magnetic resonance compatibility questionnaire.
This questionnaire is very important for your safety as well as for the realization of good images (click HERE).
Remember to tell the technologist if you are pregnant.
Exam offered:
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Abdominal MRI
Do not drink or eat anything 3 hours before the examination
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Cardiac MRI
Fast 4 hours before the examination, no caffeine for 12 hours before.
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MRI msk (musculoskeletal)
No preparation
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MRI of the breasts – Diagnostic
Full Breast MRI (Diagnostic MRI)
Breast cancer is the most common form of cancer among Canadian women, excluding non-melanoma skin cancer. This type of cancer is extremely rare in men. Breast cancer develops in the cells of the mammary gland. Breast tissue includes not only the breast itself but also the area between the collarbone, the armpit, and the sternum.
MRI can be used as a screening tool for women at very high risk of breast cancer. MRI is also indicated when there is a suspected rupture of a silicone breast implant. For detecting implant ruptures, gadolinium injection is not required. A full breast MRI is indicated for:
- Assessing the extent of known breast cancer in the preoperative phase
- Evaluating the spread of known breast cancer
- Screening in high-risk patients
- Monitoring for patients who have had breast cancer
- Preoperative planning (to help the surgeon target the surgery)
- Evaluating the response to chemotherapy, hormone therapy, and/or surgery
- Assessing local recurrence of breast cancer
- Metastasis to axillary lymph nodes with an unknown primary cancer
- Assisting in the follow-up of patients with breast implants
Why Use a Contrast Agent?
A contrast agent is essential in medical imaging, especially during a full breast MRI, as it enhances the visibility of internal structures. The injection of gadolinium, a contrast agent, offers several benefits for diagnosis. Here’s why its use is important:
- Highlighting Abnormalities: Gadolinium improves the detection of suspicious areas by focusing on tissues with increased vascularization, such as tumors or inflammations. This helps identify abnormalities that might go unnoticed without contrast.
- Differentiating Tissues: The injection of a contrast agent makes it easier to distinguish between normal and pathological tissues. This is especially useful in diagnosing conditions like cancer by allowing the identification of lesions, masses, or other abnormalities.
- Assessing Vascularization: In certain conditions, the vascularization of tissues can provide crucial information. Gadolinium helps evaluate this vascularization, which can indicate the aggressiveness of a tumor or the presence of other lesions.
- Improving Image Quality: Using a contrast agent results in more detailed and clearer images, facilitating precise diagnosis. This helps doctors make informed clinical decisions regarding treatment and disease management.
Procedure
The patient lies face down, similar to a massage table, on a special platform designed to position the breasts for imaging. She enters the machine feet-first, and headphones are provided to protect against the noise.
A contrast agent is injected during the procedure.
The exam lasts approximately 45 minutes, including the injection of gadolinium.
Do not wear deodorant or antiperspirant before the examination (bring your previous films and reports)
Do not drink or eat anything 3 hours before the examination
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MRI of the breasts – Screening
Abbreviated Breast MRI: A Complementary Tool for Breast Cancer Detection
The abbreviated breast MRI, also known as “fast MRI,” differs from the diagnostic breast MRI. This screening exam is designed to detect abnormalities in breast tissue, including small tumors that mammography or ultrasound may miss, particularly in women with dense breasts. The abbreviated MRI is primarily aimed at women with a moderate risk of breast cancer and is increasingly used as a complement to traditional screening methods.
How Does Abbreviated Breast MRI Work?
Abbreviated breast MRI uses the same magnetic resonance imaging (MRI) technology as the full MRI. A contrast agent is injected into a vein to enhance the visibility of breast tissue and facilitate the detection of potential abnormalities.
In summary, abbreviated MRI provides a simplified and rapid approach to screening, while full MRI allows for a more in-depth and detailed evaluation in a diagnostic context. Your doctor will determine the most suitable exam for your situation.
Why Inject a Contrast Agent?
A contrast agent is a substance used in medical imaging to improve the visibility of internal structures during exams, such as MRI. In the case of abbreviated breast MRI, the injection of gadolinium, a type of contrast agent, is particularly beneficial. Here’s why:
- Improved Detection of Abnormalities: Gadolinium highlights areas with increased vascularization, such as tumors, which is crucial for breast cancer screening.
- Distinction Between Normal and Abnormal Tissue: This helps identify suspicious lesions or anomalies, making MRI more effective for diagnosis.
- Monitoring Vascularization: Evaluating vascularization is particularly important in oncology, as it can indicate the presence and severity of cancers.
- Accuracy in Diagnosis: The use of a contrast agent allows for higher quality images, improving diagnosis and aiding in informed clinical decisions.
Examination Procedure
The patient lies face down on a special camera that positions the breasts for imaging, similar to a massage table. She enters the machine feet first, and headphones are provided to protect her from noise.
A contrast agent injection is performed.
The exam lasts approximately 15 minutes.
Do not wear deodorant or antiperspirant before the examination (bring your previous films and reports)
Do not drink or eat anything 3 hours before the examination
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Neurological MRI
The preparation depends on the exam to be done so our staff will advise you of the necessary preparation when making an appointment
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Pelvis MRI
Do not drink or eat anything 3 hours before the examination
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MRI-cholangiography
MRCP is a dedicated MRI examination of the biliary ducts and system. This examination can help in identifying malformations and anatomical variants of the biliary ducts and assess pathologies of the biliary system.
This study can also detect the presence of gallstones or tumors of the biliary system. This MRI study also helps in assessing extrabiliary anomalies, i.e. within other organs such as the pancreas. It is a non invasive examination.Technique
The patient is lying on his back, with an antenna acting as a camera, placed on the front of the abdomen to see the different organs.
Small speakers are given to the patient so that he can listen to the instructions of the technologist especially to control his or her breathing, and to diminish the sound of the MRI machine. For most of the images, the patient must stop breathing for about 15-20 seconds.
We can sometimes inject a dye or contrast ferromagnetic agent such as gadolinium to complete the examination.
The examination lasts for about 30 minutes without contrast injection and 45 minutes with contrast injection.
Do not drink or eat anything 3 hours before the examination
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Prostate MRI
Prostate cancer is a common occurrence in men similarly to breast cancer in women. However, men do not have the reliable screening tools, such as mammogram for women, for accurate detection of the disease.
A multiparametric magnetic resonance imaging of the prostate is a new, non-invasive and highly reliable technique in detecting prostate cancer. In addition to producing high resolution of the anatomy, this procedure evaluates the health of the vessels and the density of the cells. The procedure also allows reliable differentiation between clinically significant aggressive cancer and non-significant lesions. It is recommended to perform this procedure before a biopsy in order to focus more on areas visible on MRI, thereby reducing the possibility of non-essential detection benign cancers and differentiating between artefacts on specialized imaging. Biopsy targeted by MRI could limit unnecessary diagnosis and treatment.
Technique
The procedure is performed in the supine (lying on the back) position. A catheter, which is used to administer the contrast medium, is inserted into a vein in the arm or hand. An antispasmodic agent is injected intramuscularly through the biceps before the examination to decrease peristalsis of the intestines.
It is recommended to do the following before the examination:
- Refrain from sexual activities for 72 hours.
- Fast 4 hours before the examination (3 hours before leaving home).
- Administer a rectal enema (Fleet enema). This can be purchased at a pharmacy.
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Dynamic pelvic floor MRI / Defeco MRI
Pelvic floor dysfunction (PFD) is a common disorder present in 25 percent of women aged 30 to 70 years. The diagnosis of PFD begins with a detailed collection of medical history and physical examination. When imaging is required, some doctors prefer a dynamic pelvic MRI in lieu of fluoroscopy.
Procedure
At first, the acquisition is carried out at rest followed by a trust sequence with evacuation.
It is, indeed, important to push until is a complete evacuation from the rectum is attained in order to have a clear image of any anomalies or shape and position of the rectum and other organs of the small pelvis.
At the end of the different sequences, a quick wash is performed before the patient gets dressed.
The technologist will insert a catheter (a small plastic tube) into the rectum and inject about 100ml of gel. The gel makes it easier to differentiate the organs. The gel, which is situated in the rectum, will be evacuated during the acquisition of the images. One the gel is inserted, the catheter is removed.
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MRI Quantification of Iron Overload
Hemochromatosis is an inherited disease characterized by absorption of too much iron by the body through dietary intake, and it is among the more frequently occurring genetic diseases in Canada, affecting 1 in 300 Canadians. To contract this disease, you have to inherit two defective genes, one from each parent. A brother or sister has a 25 percent chance of having the disease.
It is important to have a non-invasive method to determine the degree of impairment. The most recent studies have shown that MRI can be used to determine iron level in the blood with an equivalency of what is determined by biopsy.
Different sequences are performed to morphologically analyze the liver, spleen and pancreas correctly and to locate any hypointense lesion in the liver. The total duration of a scan, including placing the patient in the machine, is approximately 15 minutes.
Early detection and treatment of hemochromatosis is essential in preventing complications from this potentially fatal disease.
Procedure
You will be placed in supine position (lying on your back), and the technologist will put a camera on you. You will be placed in the center of the machine. You will have to follow breathing instructions. It is important to follow the instructions. For each image, you will need to hold your breath for about 15 seconds.
No preparation is necessary.
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MRI quantification of liver fat
This test helps to quantify the fat contents of the liver. During this test, the technologist obtains a series of special images then measures the liver in order to determine the percentage of fat
Procedure
You will be placed in supine position (lying on your back), and the technologist will place a camera on you. You will be placed in the center of the machine. It is important to follow the breathing instructions. For each image, you will need to hold your breath for about 15 seconds.
No preparation is necessary.
