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A Patient’s Guide to Magnetic Resonance Spectroscopy

Magnetic Resonance Spectroscopy

Learn what magnetic resonance spectroscopy (MRS) is and how it differs from an MRI to help diagnose cancerous tumors and other diseases.

An MRI or magnetic resonance imaging is a procedure that allows your doctor to view and capture images of your internal organs. An MRI uses a strong magnet and radio waves to provide clear, detailed images of your organs, including variances in tissue.

Magnetic resonance spectroscopy (MRS), also known as MR spectroscopy or MRI spectroscopy, works similarly to an MRI but uses additional technology to indicate which tissues are functioning normally and which are not.

Both types of diagnostic imagery can help doctors explore the health of your internal organs and tissues. MRS can provide a more in-depth look by tracking how well the cells in that tissue are functioning by assessing their energy output or metabolic function. These outputs are known as tissue metabolites and can be measured by MRS. This information can indicate a growing or shrinking tumor or suggest tumor recurrence.

Keep reading to learn how MRS works, what your doctor is looking for, how to prepare for your appointment and how to gain access to your MRI and MRS imaging results through PocketHealth. Access your records here.

How does magnetic resonance spectroscopy work?

MR spectroscopy uses the same machine as an MRI and the two scans may be done in parallel to produce a more detailed understanding of the health of your body tissues.

An MRI scan uses magnets and radio waves to create detailed images of your internal organs, which are subsequently interpreted by a radiologist. MRS is used in conjunction with an MRI to measure the function of the cells in the tissue captured by the MRI.

MRS analyzes either protons or hydrogen ion activity within cells, which indicates the rate at which the cells create energy and metabolites, the energy production byproduct. Proton magnetic resonance spectroscopy is more commonly used to help compare normal tissue to cancerous tissue. Cancerous tissue is likely to show aggressive cell growth and excess metabolite production.

MRS assesses metabolite peaks by looking at the frequency of the metabolites generated by cells by analyzing the parts per million or ppm of each metabolite. That information then determines whether that particular tissue is acting normally. This is particularly helpful in determining tumor growth or decline or the type of cancer present based on the metabolites produced.

Your cells produce many different metabolites, including:

  • Adenosine triphosphate
  • Alanine
  • Choline
  • Creatine
  • Myoinositol
  • N-acetyl aspartate
  • Lactate
  • Lipids

Is magnetic resonance spectroscopy safe?

Yes, MRS is safe. MRI and MRS don’t use ionizing radiation like CT scans or X-rays. There are no known serious health risks associated with MRS, but some types of implanted medical devices can affect the magnets used in the test. Also, a contrast dye agent is often used during an MRI or MRS; in rare cases, patients can react to this dye. Your doctor will go over these risks with you.

According to the American College of Obstetricians and Gynecologists (ACOG), pregnant women should avoid MRS unless medically necessary for their health or the health of the fetus.

What is the difference between an MRI and magnetic resonance spectroscopy?

An MRI captures the structure and general components of soft internal organs and tissues, including the fat or water content, as well as blood flow and artery damage. This information can give your medical team insight into the health of those tissues, but MRS takes exploration a step further.

During an MRI, strong magnets help push the body’s protons out of regular alignment so they align in the same direction. Once the magnets are turned off, an MRI machine produces radio waves to push the protons back to normal alignment, and a computer assesses how long that process takes.

This amount of time is called T1 or T2 relaxation time and indicates the health of the cells. MRIs can assess any soft body structure this way and are used to examine organs all over the body, including the spine and brain.

Although MRIs are comprehensive tests for many illnesses, they may also be used in conjunction with MRS to track the metabolite or byproduct production of cells as they break down nutrients into energy. By analyzing metabolism, MRS can help doctors track cancer and other diseases, particularly of the brain.

MRS uses contrast dye alongside magnets and radio waves to assess cellular metabolism or energy production. The rate of energy produced within a cell is shown by the metabolites created as it produces energy. The type and rate of this metabolite production can be assessed using contrast dye, giving doctors a better understanding of the health of the tissue and indicating disease progression.

Once the scan is complete, a computer will create a graph showing the metabolite activity within the tissue. This data can give your medical team information about whether the tissue is behaving abnormally or how treatment is progressing.

Magnetic Resonance Spectroscopy

MR spectroscopy showcasing the activity of brain metabolites with low levels of N-acetyl aspartate (NAA) metabolite signals and increased levels of the metabolite Choline (Cho).

What does magnetic resonance spectroscopy detect?

Since MRS can observe the growth, death and activity of cells through their metabolites, the test is used to track whether cells within a certain area of tissue are healthy. Normal cells produce a specific range of metabolites, but cells growing aggressively, like tumor cells, produce different metabolites at different rates. MRS can also detect a low concentration of metabolites, indicating radiation necrosis, which occurs when cells die due to radiation treatment.

For example, studies have found that almost all brain tumors have decreased N-acetyl aspartate (NAA) metabolite signals and often have increased levels of the metabolite Choline (Cho). Using MRS data to analyze metabolite ratios within normal brain tissue, scientists can compare it to the brain metabolism of tissue containing brain tumors. This allows doctors to determine the health of the cells in the human brain and assess for disease, illness or damaged tissues due to:

  • Alzheimer’s disease (a progressive disease of the brain that causes dementia)
  • Brain cancer (cancer found within the tissues of the brain)
  • Glioblastoma abscess (an aggressive form of brain cancer)
  • Glioma (a brain tumor)
  • Lymphoma (cancer that affects the lymphatic system)
  • Meningioma (a tumor that grows in the brain or spinal membranes)
  • Tissue necrosis (the death of body tissue, which can be a side effect of some cancer treatments)

What is contrast and when is it used?

A contrast agent or dye allows a radiologist to view your organs, tissues and cell metabolite activity in more detail during an MRI or MRS. Contrast agents are typically injected into a vein before a diagnostic imaging test. As the contrast agent moves through your system, it clearly shows areas of contrast within tissues.

Gadolinium-based contrast agents are typically used for imaging tests, but because they contain low levels of radiation, they are not recommended for pregnant women unless medically necessary.

How to prepare for MRS imaging

A combined MRS and MRI procedure is simple, but some preparation is required before your appointment.

  • Bring your requisition. Your requisition contains essential information for the imaging clinic, including a description of the area to be scanned and notes from your referring practitioner. Having the form on hand will make the check-in process easier.
  • Wear comfortable clothing. You’ll be taken to a separate room to change into a hospital gown for your scan, so wear comfortable clothing you can easily change out of.
  • Remove metal jewelry and body piercings. Metal items can be pulled toward the strong magnets used in the test.
  • Disclose any implants. The scan may impact some metal implants. You should alert your doctor if you have an implant or worked with metal in the past, or if there’s a possibility any metal shrapnel or bullets are in your body. Your doctor will clarify whether you have any metallic implants before your appointment, including some types of metallic joint prostheses, fillings and hearing aids, contraceptive devices or drug fusion pumps.
  • Refrain from eating (in some cases). Depending on what part of the body is being imaged, MRS may require an empty stomach. If you’re unsure, check your requisition form or confirm with the imaging clinic or hospital before your appointment.
  • Drink only clear fluids. Even if you’re not required to fast before your appointment, you should drink only clear liquids. And if your scan requires a contrast agent, avoid caffeine for 24 hours before your appointment.
  • Complete any necessary bloodwork. Bloodwork may be required if a contrast agent will be used for your scan. The blood test ensures your kidneys are working properly and will be able to clear the contrast agent from your system.
  • Clarify medication safety. While regular medications can generally be taken, it’s a good idea to come prepared with your prescription information.

What happens during the MRS imaging procedure?

After you check in for your appointment, you’ll be taken to a private room and be asked to change into a hospital gown. You’ll be required to remove any metal jewelry or hearing aids as they can interfere with the magnetic field of the scan. Let the technician know if you are anxious; a mild sedative may be available.

Before your exam begins, a nurse will inject you with a contrast agent and you’ll be asked to lie down on a table that can be moved into the MRI machine. The MRI machine is a long, rounded machine containing a large, open-ended enclosure for the table to move through.

You’ll be given earplugs or headphones to reduce the loud, intermittent pulse sequences of the machine during the exam. Depending on the body part being scanned, you may also have a cage-like structure fitted over that particular area. For example, if you’re having a brain scan, you’ll have a special mask fitted around your face and head. This is to help focus the magnetic field onto that specific area, to ensure the best images possible.

Once you’re comfortable, the procedure will begin. The technician will communicate with you while you’re inside the MRI machine and ask you to position your body in certain ways to capture the best images. You’ll be required to lie completely still for the exam and may have to hold your breath for short periods of time. You may also be given a button to press if you’re uncomfortable, anxious or need to take a break between imaging sequences.

The technician will let you know when the MRS procedure is complete and you will be moved out of the machine. You’ll be able to dress right away, but let the technician know if you feel nauseous or want to sit down for a moment.

How long does the procedure take?

An MRI scan typically takes around 45 minutes to an hour to complete. It may take slightly longer to capture specific images for an MRS procedure, depending on the complexity of the exam and the area being scanned.

Are there any risks associated with an MRS procedure?

Magnetic resonance procedures are generally safe and don’t release radiation or damage surrounding healthy tissue, but a small number of patients may experience minor discomfort during their scan, due to:

  • Anxiety or claustrophobia: Patients who have a fear of enclosed spaces should share any concerns with their doctor or radiologist before their MRS scan. Mild sedatives can be provided if you have anxiety about the procedure.
  • Tattoos: Body art can be a problem because some tattoo ink contains magnetic particles that may heat up inside the powerful magnetic field used for the scan. Let the technician know if you start to feel warmth in any of the areas you’re tattooed.
  • Pregnancy concerns: It’s crucial to inform the technologist if you are pregnant or suspect you might be. An MRI can be performed on a pregnant patient under specific circumstances, but generally doctors will avoid any sort of imaging on pregnant women unless deemed medically necessary for the health of the mother or fetus.
  • Allergies: Some patients may feel flushed or warm after being given contrast fluid but very few patients will have an allergic reaction requiring medical treatment. If you have an allergy to contrast fluid, certain medications or iodine, discuss these allergies with your doctor before your scan.

How long does it take to access your MR spectroscopy results?

Your MR spectroscopy results are interpreted by a radiologist (or a neuroradiologist if you had brain MRS) and are recorded in a report provided to your referring physicians. Your doctor will usually receive the results of your MR spectroscopy within a week of your imaging appointment, at the same time as your MRI results, and will share them at a follow-up consultation. If you booked your appointment privately, you’ll need to proactively reach out and schedule an appointment with your doctor to learn the results.

You can easily access your MRS images and report with PocketHealth, often before your follow-up appointment. PocketHealth allows you to securely access, share and store your medical images and information in one place. If you had your procedure at a private clinic, you can share your records with your doctor directly through PocketHealth. Access your records here.

Additionally, PocketHealth Report Reader can help you understand the terms in your MR spectroscopy report and spotlight any further follow-up recommendations. The better informed you are, the more confident you can feel when discussing the results with your doctor.

Understanding your magnetic resonance spectroscopy report

Your MRS report will indicate areas of concern by showing the radiologist different cross-sectional images and combining those images or “slices” into one complete view.

Your MRS data tracks the levels of metabolites used by cells for energy. These metabolites will be weighted as ppm or parts per million and will appear on a graph or chart depicting the different concentrations and ratios of metabolites.

The radiologist will use this information in conjunction with the data from your MRI scan to assess the health of the tissues viewed during the scan. MRI data contains complicated medical terminology, but you can learn more about interpreting your scan here.

You can gain fast access to your MRS and MRI results through PocketHealth, as soon as they are released by the imaging clinic or hospital department. These reports contain the radiologist’s expert opinion on your case, as well as all data collected during your scan. Even with this information, it is imperative that you review your report with your referring physician at your follow-up appointment.

How PocketHealth can help you better understand your MRI and MRS results

Medical terminology is highly technical and can be difficult to understand without a medical degree. Report Reader gives you the base knowledge required to read and understand your MRS results by providing medical terminology definitions. With a full understanding of your results, you’ll be able to have confident, informed discussions with your healthcare team and better understand your next steps.

MyCare Navigator is an additional tool that goes beyond terminology to help you get the most out of your report. It flags follow-up recommendations, provides questions to ask your doctor at your appointments and offers preventative screening tools, giving you greater control over your health.

Expand your knowledge to advocate for your health

Knowledge is powerful. Learning how to prepare for your MRS appointment, what to expect, what to do after your scan, and how to access and understand your scan results lets you attend your appointments with confidence.

Understanding your MRS report allows you to thoroughly discuss your results and next steps with your medical team, ask informed questions about your treatment options and gain control during your healthcare journey.

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