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Are MRI Scans Bad For You?

Also Known As: Magnetic Resonance Imaging



Short answer

While MRIs are generally safe and do not use ionizing radiation like X-rays or CT scans, it's vital to take certain precautions. People with metal implants, tattoos with metallic ink, or those who require sedation due to claustrophobia might face additional risks. MRI contrast agents are generally safe, but those with poor kidney function or those who've had multiple scans may experience complications. Always report your medical history to health professionals before an MRI.



Long answer

Magnetic Fields and Radio Waves: Understanding MRI Technology

Magnetic Resonance Imaging (MRI) is a diagnostic tool that combines strong magnetic fields and radio waves to generate detailed images of the body's internal structures. Unlike X-rays or CT scans, MRI does not use ionizing radiation, which can cause damage to DNA and potentially lead to cancer. Instead, MRI relies on the magnetic properties of atoms within the body to produce clear, high-resolution images.

To understand the safety aspects of MRI technology, it's essential to know how these magnetic fields and radio waves interact with our bodies:

  • Strong Magnetic Fields: MRI machines utilize a powerful magnet, usually measured in tesla (T) units. Most clinical MRIs operate at 1.5T or 3T, although there are specialized systems that use higher strengths. These magnetic fields temporarily realign hydrogen atoms in the body, which are abundant due to the high water content of human tissue.
  • Radiofrequency Pulses: Once the magnetic field is established, MRI utilizes radiofrequency (RF) pulses that are absorbed by the realigned hydrogen atoms. When the RF pulse is turned off, the atoms return to their original alignment, releasing energy in the process. It's this energy release that is detected and converted into the images that health professionals use for diagnosis.

Concerns about the effects of magnetic fields on health have been raised, but research shows that the temporary exposure during an MRI scan is generally safe. The World Health Organization's International Agency for Research on Cancer (IARC) has stated that static magnetic fields are 'not classifiable as to their carcinogenicity to humans.' Furthermore, extensive reviews of the literature by regulatory agencies, such as the U.S. Food and Drug Administration (FDA), have concluded that MRI is safe when guidelines are followed.

However, while the magnetic fields themselves do not pose a significant health risk, there are safety considerations during an MRI scan:

  • Individuals with certain metal implants, such as pacemakers, cochlear implants, or some types of aneurysm clips, may be at risk because the magnet can affect these devices.
  • Some tattoos contain metallic compounds that could theoretically interact with the magnetic field, although adverse reactions are exceedingly rare.
  • The RF pulses generate heat, which can lead to an increase in body temperature. MRI protocols are designed to manage this and keep heating within safe limits.

It's also worth noting that during an MRI scan, the body's exposure to radio waves is regulated. The Specific Absorption Rate (SAR), which measures the RF energy absorbed by the body, is limited to ensure patient safety. While high levels of RF energy can lead to tissue heating, compliance with recommended SAR limits makes this a negligible concern.

In conclusion, the technology behind MRI is complex but is designed with patient safety in mind. By understanding the interplay of magnetic fields and radio waves, we can appreciate the innovation that allows clinicians to peer inside the body without the risks associated with ionizing radiation.

Contrast Agents in MRI: Safety and Side Effects

When it comes to getting an MRI, a contrast agent might sometimes be used to improve the clarity of the images produced. This agent, usually containing gadolinium, is administered intravenously. It's important to discuss the safety and side effects associated with these contrast agents, as they can offer significant benefits whilst carrying a low, but not negligible, risk for certain individuals.

Safety of Contrast Agents:

Overall, MRI contrast agents are considered safe for most people. Gadolinium-based contrast agents (GBCAs) are less likely to cause an allergic reaction than iodine-based agents used in other types of imaging tests. However, as with any medical procedure, there are safety considerations to be aware of:

  • Kidney Function: Patients with impaired kidney function need special consideration. Gadolinium can cause a rare condition called nephrogenic systemic fibrosis (NSF) in those with severe renal impairment. Therefore, kidney function should be assessed before the administration of GBCAs.
  • Allergic Reactions: While rare, some individuals may experience mild to moderate allergic reactions to contrast agents, including hives, itching, or short-term nausea. Severe reactions like anaphylaxis are exceedingly uncommon but require immediate medical attention.
  • Pregnancy and Breastfeeding: There's limited data on the effects of gadolinium during pregnancy and breastfeeding. Potential risks to the fetus or infant are not completely understood, so the use of contrast is typically avoided unless absolutely necessary.

Side Effects of Contrast Agents:

Despite the low-risk profile of GBCAs, some patients do experience side effects, which can range from mild to severe. These may include:

  • Mild reactions, such as coldness or warmth at the injection site, headaches, or dizziness.
  • Intermediate reactions like vomiting, hives, or a feeling of tightness in the throat.
  • Rare but severe side effects, such as difficulty breathing or cardiac arrest, may occur and constitute a medical emergency.

Recent concerns about the deposition of gadolinium in the brain and other tissues have also been raised. According to a 2015 study published in Radiology, gadolinium deposition has been noted following repeated use of certain types of GBCAs. While no definitive harmful effects have been proven, research is ongoing to determine any potential long-term consequences.

Patients are typically monitored during and after their MRI with contrast to manage any immediate side effects. It's important for patients to inform radiologists of any history of kidney issues, previous reactions to contrast material, or allergies to medications before undergoing an MRI with contrast. Open communication with healthcare professionals and informed consent are key to mitigating risks and ensuring patient safety.

If you have any concerns about an upcoming MRI scan with a contrast agent, don't hesitate to discuss with your doctor or radiologist. They can provide the information tailored to your health history and current condition, giving you the assurance you need for a safe imaging experience.

The Risk of Claustrophobia and Anxiety During MRI Scans

Magnetic Resonance Imaging (MRI) is a widely used diagnostic tool that allows doctors to see detailed images of the organs and structures inside the body. While MRIs do not involve radiation, and are generally considered safe, they can pose risks for certain individuals, particularly those prone to claustrophobia or anxiety.

For some people, the thought of being in a confined space for an extended period can be daunting. In the MRI setting, patients are typically required to lie still inside a narrow tube, which can trigger claustrophobia. Reports suggest that about 5% of patients may experience severe claustrophobia during an MRI procedure. This can sometimes result in the need to sedate the patient or even cancel the scan altogether.

Here are some of the factors that could increase anxiety during an MRI:

  • Loud Noises: MRI machines produce loud banging and buzzing noises during operation, caused by the powerful magnets and radio waves used to create images. These sounds can be unsettling for patients and may exacerbate anxiety.
  • Physical Restrictions: Patients are often required to lie very still within the MRI machine for up to an hour. For those with anxiety, the inability to move freely can be a significant stressor.
  • Feeling of Isolation: Being enclosed in the MRI tunnel, some patients may feel isolated from others, including the comforting presence of healthcare professionals.

To mitigate these risks, healthcare providers often use a variety of strategies:

  • Pre-scan counseling focused on educating patients about the procedure and setting realistic expectations.
  • Providing earplugs or headphones to help block out the MRI machine’s noises.
  • Using open MRI machines or those with a wider bore, which can feel less confining and more comfortable for patients.
  • Offering a “panic button” to allow patients to easily alert staff if they become too uncomfortable.
  • Employing relaxation techniques before and during the scan, which may include guided imagery or breathing exercises.
  • In some cases, the use of sedative medication may be considered to help ease severe anxiety. This option should be discussed in advance with healthcare providers.

Studies have also shown that interventions like cognitive-behavioral therapy (CBT) can significantly reduce MRI-related anxiety. A 2015 study published in "Behavioural and Cognitive Psychotherapy" provided evidence that CBT interventions can help patients manage claustrophobic fears.

Remember that not everybody will experience claustrophobia or anxiety during an MRI scan, but it's important to communicate any concerns you might have to your healthcare provider ahead of time. This way, they can make appropriate accommodations to ensure that the experience is as comfortable as possible. The key takeaway is that while the MRI itself is not inherently "bad" for you, individual experiences may vary, and for some, the psychological stress can become a real concern that warrants attention and compassionate care.

Comparing MRI with CT and X-ray: Radiation Exposure Considerations

Radiation exposure is a significant factor to consider when comparing Magnetic Resonance Imaging (MRI) with CT (Computed Tomography) scans and traditional X-rays. While all these imaging techniques provide valuable diagnostic information, their approach to capturing images of the body's internal structures vastly differs, leading to divergent radiation risks associated with each procedure.

Firstly, it's important to note that MRI scans operate using strong magnetic fields and radio waves to generate detailed images of organs and tissues. One of the strongest advantages of MRI is that it does not use ionizing radiation, which can cause damage to DNA and potentially lead to cancer. Therefore, from a radiation exposure standpoint, MRI is generally considered safer than CT scans and X-rays, which both rely on ionizing radiation to produce images.

Let's delve into the specifics of how CT scans and X-rays work:

  • CT Scans: During a CT scan, the patient is exposed to a series of X-ray beams that rotate around the body to create detailed cross-sectional images. Although CT scans are highly precise and useful for diagnosing various conditions, they expose the patient to a much higher level of ionizing radiation compared to a standard X-ray.
  • X-rays: Traditional X-rays emit a small amount of ionizing radiation to capture images of the body's dense structures, like bones. The level of radiation is relatively low but can accumulate over time with repeated exposure.

According to a study by Smith-Bindman et al. (2012), published in Archives of Internal Medicine, the typical radiation dose for a single CT scan can be equivalent to about 200 chest X-rays. This is a substantial amount of radiation, especially considering that the National Cancer Institute highlights the cumulative effects of ionizing radiation as a potential risk factor for cancer.

When considering the necessity of an imaging test, healthcare providers weigh the potential benefits against the risks of radiation exposure. They factor in the patient's history, the urgency of the diagnosis, and the potential for alternative methods, such as MRI or ultrasound, which do not use ionizing radiation.

While radiation from medical imaging is a concern, it's also helpful to put this into perspective. According to the American Cancer Society, we are all exposed to background radiation in our daily lives from natural sources like radon in the air, cosmic rays, and the Earth itself. A balance must be struck between necessary medical procedures and minimizing unnecessary exposure.

In conclusion, when it comes to radiation exposure, MRI scans are considered a safer alternative to CT scans and X-rays. However, this does not mean MRIs are appropriate for all types of diagnostic imaging. The choice of procedure is a medical decision based on the patient's specific circumstances and the diagnostic needs at hand.

Remember, if you have concerns about radiation exposure during medical tests, don't hesitate to discuss them with your healthcare provider. They can provide guidance on the risks and benefits of each type of imaging study, tailored to your situation.

Gadolinium Retention and Its Long-Term Implications

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool that provides clear images of the body's internal structures. In some MRI procedures, a contrast agent containing gadolinium is used to enhance the clarity of these images. While the use of gadolinium-based contrast agents (GBCAs) has revolutionized the detail and accuracy of MRIs, concerns have arisen regarding the long-term effects of gadolinium retention in the body.

Gadolinium is a rare earth metal that, due to its paramagnetic properties, serves to improve the visibility of internal structures by altering the magnetic properties of nearby water molecules during an MRI scan. It's important to note that GBCAs are chelated, meaning gadolinium is bound to a ligand to prevent it from being freely deposited in the body.

Despite this chelation, studies and clinical reports have indicated that gadolinium can remain in the body, particularly in the brain, bones, and skin. The term "gadolinium deposition disease" has been used to describe the set of symptoms experienced by patients who have had multiple gadolinium-enhanced MRI scans.

  • Study Findings: A study published in Radiology in 2015 found evidence of gadolinium residues in the brains of patients who had undergone four or more contrast-enhanced MRIs, even though the patients had normal renal function.
  • Symptoms of Gadolinium Retention: Some individuals report varied symptoms, including but not limited to persistent headaches, bone and joint pain, and cognitive disturbances. However, it is currently unclear whether these symptoms are directly attributable to gadolinium deposits.
  • Risk Factors: Patients with impaired kidney function are at a higher risk for gadolinium accumulation, as the kidneys are the primary pathway for GBCA elimination.

The FDA has taken actions to ensure greater scrutiny when using GBCAs. They have categorized the agents into groups based on their potential for gadolinium retention, advising more caution with agents shown to result in higher retention levels.

Long-term implications of gadolinium retention are still actively researched. As of now, the evidence is not conclusive enough to establish a direct relationship between gadolinium retention and severe health conditions. Nonetheless, the medical community remains vigilant, and researchers continue to explore the mechanisms behind gadolinium retention and its possible effects on health.

For patients concerned about gadolinium exposure, it is recommended to discuss the risks and benefits of contrast-enhanced MRI with their healthcare provider. Alternative imaging methods without gadolinium or with agents known to have lower retention rates may be considered, depending on the diagnostic needs and patient history. It's all about making an informed decision under the guidance of a medical professional, ensuring the benefits of precise diagnosis and monitoring outweigh the risks of gadolinium exposure.

In the spirit of embracing a holistic approach to health, when contemplating any medical procedure, it is crucial to weigh the pros and cons. As with any medical decision, educating oneself on the potential risks and employing a cost-benefit analysis tailored to one's individual health situation is a responsible approach to take.

Special Considerations for Patients with Implants and Devices

When it comes to Magnetic Resonance Imaging (MRI), a scan that utilizes powerful magnetic fields and radiofrequency pulses to generate detailed images of the inside of the body, certain groups of individuals need to approach with extra caution. Patients with implants and devices, in particular, face specific risks and considerations that must be accounted for to ensure their safety and the integrity of the diagnostic process.

Metallic Implants: The strong magnetic field of an MRI can cause metal objects to move or heat up, potentially leading to injury or malfunction. For patients with metallic implants such as artificial joints, stents, or screws, it's crucial to inform the healthcare provider before the scan. Not all implants are MRI-safe, and some may require a specialized protocol or a different imaging modality entirely.

Pacemakers and Defibrillators: Traditional pacemakers and defibrillators can be affected by MRI scans. The magnetic field may interrupt their function, pose health risks, or damage the device. However, technology has evolved - MRI-conditional pacemakers and defibrillators are designed to withstand an MRI environment when certain guidelines are followed. Patients should always carry their device identification card, which contains critical safety information for healthcare providers.

Neurostimulators: Patients with implanted neurostimulation systems must also take precautions. The MRI can alter the device settings or its operation. If a neurostimulator is involved, a thorough evaluation by a healthcare specialist is essential to determine the safety and feasibility of MRI scanning.

Drug Pumps: Implantable drug infusion pumps can malfunction or deliver drugs improperly during an MRI procedure. It's important to check if the pump is MRI-compatible and if specific steps must be taken to mitigate risks.

Implanted Clips: While most implanted surgical clips used today are made of non-ferrous materials and are deemed safe for MRI, older clips may pose a risk. Any clip placed for aneurysm repair requires a careful review before proceeding with an MRI.

Medical Tattoos and Cosmetic Procedures: Emerging research indicates that certain medical tattoos made with metallic or iron-based inks, as well as cosmetic procedures involving metal particles, might heat up during an MRI. A detailed medical history should be provided to avoid complications.

Overall, the likelihood and severity of risks associated with MRI scans for patients with implants and devices depend on various factors including the type of implant, its location, and the strength of the MRI's magnetic field. Clear and open communication with the healthcare team, a review of the implant's safety data, and if necessary, consultations with the device manufacturer, can help make informed decisions.

Healthcare professionals typically follow established guidelines, such as those provided by the American College of Radiology and the MRI Safety Committee, to determine the compatibility of an implant or device with MRI. These protocols have been developed through clinical research aimed at maximizing patient safety while still leveraging the diagnostic power of MRI technology.

Patients with implants should not entirely shy away from MRI diagnostics. When carefully planned and executed by a knowledgeable medical team, an MRI scan can offer invaluable insights into a patient's health without compromising safety.

MRI Safety Guidelines for Optimal Patient Care

When it comes to obtaining an MRI scan, the question of safety generally comes to the forefront. Good news for patients and healthcare providers alike: MRI scans are considered safe for most people and do not use ionizing radiation, which is associated with X-rays and CT scans. Instead, MRIs use a powerful magnetic field and radio waves to generate images of the body’s internal structures. Nevertheless, to ensure optimal patient care and safety during an MRI procedure, there are essential safety guidelines that should be adhered to.

Screening for Metal Objects: Since MRI machines use a powerful magnetic field, it’s critical that patients remove all metal objects before entering the MRI suite. Common items such as jewelry, watches, eyeglasses, and hearing aids can become dangerous projectiles. Furthermore, patients with metal implants, such as pacemakers, cochlear implants, or certain types of metal clips in the brain, might be at risk if proper precautions are not taken. Be sure to discuss any implants or metal in your body with the MRI technologist or radiologist before the procedure.

Assessing Kidney Function: In the case of MRIs that require a contrast agent, typically a substance called gadolinium, assessing kidney function is imperative as individuals with kidney impairment may be at higher risk for a rare condition called nephrogenic systemic fibrosis (NSF). Pre-screening for renal function typically involves blood tests to measure creatinine levels and determine the glomerular filtration rate (GFR).

Reviewing Medical History: A thorough review of the patient's medical history can identify potential risks or contraindications for an MRI scan. Factors such as pregnancy, recent surgeries, and the presence of medical devices need to be known to tailor the procedure to each individual’s needs.

Communication During the Scan: It’s important for patients to have the ability to communicate with the MRI technologist during the scan. This may be through a call button or intercom system. Clear and concise instructions from the technologist can assist the patient in staying still during the scan, which is vital for high-quality images.

Maintaining a Calm Environment: Some patients may experience claustrophobia or anxiety during an MRI scan. Techniques to alleviate discomfort can include providing headphones with music, using blankets to make the patient comfortable, employing relaxation techniques, or, in some cases, administering mild sedatives. Open or wide-bore MRI machines are also available at some facilities to help reduce feelings of confinement.

Emergency Preparedness: MRI facilities should be prepared for any medical emergencies. This includes having safety protocols in place for allergic reactions to contrast agents and readily available emergency equipment that is MRI-compatible.

Following these safety guidelines can make the difference between an unsettling experience and one that integrates seamlessly into our health journey. Remember, while MRI scans are incredibly powerful diagnostic tools, the ultimate goal is to ensure that they are conducted in a manner that prioritizes patient care and safety above all else.

Frequently asked questions

Yes, there are several strategies to assist patients with claustrophobia during an MRI scan. These can include providing a calm and relaxing environment, using open or wide-bore MRI machines which are less confining, offering headphones or earplugs to block out the noise, employing relaxation techniques such as guided imagery or deep breathing exercises, providing a means of communication with the technologist, and in some cases, administering anxiolytic or sedative medications under medical supervision.

While MRI scans are generally considered safe and do not utilize ionizing radiation, there is limited research on the effects of strong magnetic fields and radio waves on fetal development. Therefore, healthcare providers typically avoid MRI scans during the first trimester of pregnancy unless absolutely necessary. If an MRI is required, it is conducted without the use of gadolinium-based contrast agents to minimize any potential risks to the fetus. Pregnant women should always consult with their healthcare provider to weigh the potential benefits and risks of the scan.

Kidney function is particularly important when considering an MRI scan with contrast because the kidneys are responsible for excreting gadolinium from the body. Patients with severe renal impairment are at higher risk for developing nephrogenic systemic fibrosis (NSF), a rare but serious condition associated with gadolinium use. Pre-screening for renal function, usually through blood tests to determine glomerular filtration rate (GFR), is part of the safety protocols before administering gadolinium-based contrast agents.

Yes, while uncommon, it is possible to have an allergic reaction to gadolinium-based contrast agents (GBCAs). Reactions can range from mild, such as hives and itching, to more severe responses like anaphylactic shock. Patients with a history of allergies or prior reactions to contrast material should inform their radiologist before the procedure. Steps can be taken to minimize risks, including premedication with antihistamines or corticosteroids, or selecting an alternative imaging method if necessary.

Ask a question about MRI Scans and our team will publish the answer as soon as possible.

Possible short-term side effects

  • nausea
  • vomiting
  • headaches
  • dizziness
  • claustrophobia
  • anxiety
  • temperature rise
  • allergic reactions
  • injection site coldness or warmth

Possible long-term side effects

  • nephrogenic systemic fibrosis (nsf) in those with renal impairment
  • gadolinium tissue deposition

Ingredients to be aware of

  • gadolinium-based contrast agents


  • detailed internal body imaging
  • non-invasive diagnostic tool
  • no ionizing radiation exposure
  • enhances disease diagnosis and monitoring

Thank you for your feedback!

Written by Desmond Richard
Published on: 02-13-2024

Thank you for your feedback!

Written by Desmond Richard
Published on: 02-13-2024

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