Melbourne Radiology Clinic

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Oct 20th
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MRI (Magnetic Resonance Imaging)

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The information below is intended for patients who are planning to undergo a MRI Scan at Melbourne Radiology Clinic. An Magnetic Resonance Imaging (MRI) scan uses a powerful magnet and radiowaves to produce superbly detailed views of the human body, particularly soft tissues, such as the brain, spinal cord and muscles. Unlike other imaging tests, MRI does not use radiation. Though some discomfort may occur from having to lay still, MRI is otherwise a painless procedure and typically takes approximately 20 to 30 minutes to perform.

Download PDF Information Sheet on MRI Melbourne Radiology Clinic - Magnetic Resonance Imaging (MRI) Patient Information Sheet

Preparation

  • No preparation is necessary for an MRI scan. You can eat and drink normally.
  • As a strong magnet is used, all metallic devices MUST be removed before entering the MRI room.
    Please consult the MRI Consent Form and Safety Questionnaire also available on the Melbourne Radiology Clinic website or ask that it be emailed to you. Otherwise, when you arrive, you will receive a detailed information sheet prior to entering the scanner.
  • On arrival at Melbourne Radiology Clinic, you will be asked to complete an MRI Consent Form and Safety Questionnaire before the scan to thoroughly understand your overall health.
  • Patients with cardiac pacemakers and cochlear implants cannot undergo MRI scans. Other metallic implants may prohibit patients from having an MRI scan. This includes people with certain types of cerebral aneurysm clips, vascular stents, infusion pumps and neurostimulators.
  • The scan occurs in an enclosed space, so if you have problems with this and may experience claustrophobia or anxiety, please inform us in advance. We can offer a light sedative that may relax you, however, you will require a responsible adult to drive you home and you must refrain from any significant activity for the remainder of the day. In particular, you should not drive a car or any other machinery, nor make important decisions, such as signing legal documents.
Preparing for your MRI scan at Melbourne Radiology Clinic
  • You will be asked to wear the examination gown provided. You will then lie on a movable scanning table that moves into the bore of the MRI. The body part to be scanned will be positioned in the centre of the tunnel. A device, known as a coil, which improves the quality of the images, may be placed over the body region to be examined during the scan.
  • Information for Female Patients
    • Female patients are requested not to wear eye make-up for brain scans as this can affect image quality.
    • If you are or might be pregnant, please call the Clinic in advance of your appointment so that the radiologist can discuss your situation with yourself and/or referring doctor. As a general rule, MRI scans are usually not conducted in the first trimester of pregnancy unless it is deemed by the referring doctor or radiologist that is an absolute medical necessity to do so and that the benefits of the test outweigh the risks. This of course assumes that there is no other test available that can provide similar information.

Procedure

Once the scan is under way as you will hear a loud vibrating or knocking sound. Noise cancelling headphones are provided for you to use and you may wish to listen to music or radio of your choice during the scan.

It is very important that you keep your body extremely still during the scan. Movement during a scan will result in lower quality or blurred images, similar to the blurring effect that occurs when taking a photograph of a moving object.

Usually four or five different types of MRI scans called sequences are taken with each one lasting about 2–8 minutes. Overall, you will be in the scanner for about 20 minutes. A sequence or sequences may need to be repeated if there is bluring of the images due to excessive movement.

You will be in constant communication with the technician who conducts the MRI. Their role is to ensure that you are comfortable and kept up-to-date with the progress of your scans. As an additional safety mechanism, you will be provided with a buzzer to hold during the scan. Press this at anytime should you feel exceedingly uncomfortable or anxious to gain the attention of the MRI technician. The scan at this point will be stopped and you will be immediately attended to by our staff.

MRI Contrast Dye (Gadolinium)

Some patients undergoing an MRI scan may require an injection of an intravenous (IV) dye (contrast) known as Gadolinium, which is a paramagnetic substance that is visible on MRI scans. The contrast is delivered into your body through a small plastic tube known as an intravenous cannula, which is placed into a vein in your arm by a nurse or radiographer who are both experienced in performing this procedure. This will result in a minor discomfort, usually no more than taking blood from your arm. The IV contrast is NOT radioactive.

The benefit of administering intravenous contrast for an MRI examination is enormous. The use of contrast greatly improves the accuracy of the examination and assists in excluding many life threatening conditions, such as cancer.

As for all medical procedures, there are risks associated with the administration of any substance, including IV contrast, however the benefit, such as an accurate diagnosis, outweighs the small risk of suffering from the side effects (discussed below). The decision to administer IV contrast is not taken lightly and is carefully made by your referring doctor and is based on your signs, symptoms, past medical history as well as the suspected diagnosis. If after reading the information below you are not willing to undergo a study with IV contrast, the test may still be performed without it, however you must be aware that the information from the examination may not accurately answer your doctor’s question. It is possible that another test may be appropriate, such as CT scan or Ultrasound, and this can be discussed with your referring doctor or our radiologist.

Most injections of IV contrast occur uneventfully. So that you are fully informed of the risks prior to the examination, Melbourne Radiology Clinic would like to inform you that:

  • The most common side effect is a minor contrast reaction, which occurs in less than 0.05% of cases. Symptoms include headache, sneezing, nausea, vomiting, hives and swelling and usually settle rapidly. Occasionally medications may be required to help alleviate the symptoms if they persists for some time and typically involve using an anti-emetic and promethazine (phenergan) for hives and swelling. Phenergan unfortunately results in drowsiness, so is usually administered only if the swelling or hives is particularly severe. In this instance, you would need a responsible person to drive you home.
  • Less commonly, a severe (anaphylactoid) contrast reaction occurs in approximately 0.03–0.1% of cases. This includes a rapid or slow heart rate, low blood pressure, an asthma attack (bronchospasm) and complete circulatory collapse/shock. Such reactions require urgent medical treatment and immediate transfer to an appropriate facility, such as an emergency department or intensive care unit. Despite medical intervention and rapid treatment, a person may die from a severe reaction, however this is fortunately rare, occurring in 0.0000001% (1 in 10 million) of cases. Melbourne Radiology Clinic possesses the equipment and trained medical staff to assist in providing immediate life saving treatment should this be required.
  • Patients with kidney (renal) impairment or failure should not undergo an injection of gadolinium unless this has been cleared by a specialist in this field (renal physician) in order to avoid a potentially life threatening condition known as NSF (Nephrogenic Systemic Fibrosis).
  • Patients who have had a contrast reaction to the dye used in CT, IVP and angiographic examinations are at a 3.7 times increased risk of an adverse reaction.

Otherwise, there is no way of predicting who will be allergic to contrast until the dye is given. A patient who becomes allergic will usually develop their symptoms within 10 minutes, typically within the first one or two minutes and therefore will be still on our premises where assistance and medical treatment may be provided.

Results

A radiologist, a medical doctor specialising in the interpretation of medical images for the purposes of providing a diagnosis, will then review the images and provide a formal written report. If medically urgent, or you have an appointment immediately after the scan to be seen by your doctor or health care provider, Melbourne Radiology Clinic will instantly have your results ready. Otherwise, the report will be received by your doctor or health care provider within the next 24 hours.

  • Please ensure that you make a follow up appointment with your referring doctor or health care provider to discuss your results.

REMEMBER ...

  • Please bring to the clinic any prior scans (eg. X-rays, ultrasounds, MRI, CT) and reports as these will assist the radiologist in assessing your condition.
  • If you have any further queries please call Melbourne Radiology Clinic on (03) 9667 1667 – we are only too happy to help.
  • Please note that any referral for a scan is valid at Melbourne Radiology Clinic, even if it has been written on a referral form from another radiology provider.

Whilst every effort is made to keep your appointment time, the special needs of complex cases, elderly and frail patients can cause unexpected delays. Your consideration and patience in these circumstances is appreciated.

Patients will also need to read and complete:
Melbourne Radiology Clinic - MRI Consent Form and Safety Questionnaire

References:

Last Updated ( Wednesday, 29 October 2014 16:09 )  
 
MEDICAL DISCLAIMER The Melbourne Radiology Clinic web site is not intended as a substitute for your own independent health professional’s advice, diagnosis or treatment. Always seek the advice of your physician or other qualified health provider within your country or place of residency with any questions you may have regarding a medical condition. Any surgical or invasive procedure carries risks. Before proceeding, you should seek a second medical opinion.