Though most people have heard of MRIs, CT scans, and X-rays, the differences between these diagnostic strategies are not always clear. To add to their complexity, each of these tests may be conducted in various ways and used for a number of purposes. MRIs, in particular, come in two distinct forms: contrast and non-contrast. Consider the answers to a few frequently asked questions that may give you peace of mind and help you prepare for your upcoming MRI with or without contrast.
What Is an MRI?
Magnetic resonance imaging is a technique physicians use to non-invasively examine different tissues within your body. The region of your body being scanned is converted to a black-and-white image, with different shades corresponding to distinct types of tissue. Your doctor may examine several scans that form cross-sections of the area being studied. This allows the viewer to analyze the precise location and extent of a particular concern. Alternatively, physicians may be able to combine these cross-sections to view a three-dimensional image.
How Do MRIs Work?
As their name suggests, MRIs utilize magnetic fields to capture images of internal tissues. The magnetic fields first cause the hydrogen atoms in your body’s water molecules to align in a certain direction. Then, a radiofrequency disturbs this alignment, causing these atoms to move against the magnetic field in a different direction. When the machine stops emitting radio waves, the hydrogen atoms throughout your body revert to the position they were in when they were only subjected to the magnetic field. Atoms readjust at different speeds and emit varying amounts of energy depending on the makeup of the tissue they belong to. These characteristics are what cause some tissues to appear dark on MRI scans while others appear light. In general, soft tissue is lighter than bone.
What Is the Difference Between Contrast and Non-Contrast MRIs?
Depending on your condition, your physician may recommend that you undergo a contrast MRI. The principles involved in an MRI with contrast are much the same as those described above; however, a dye made of the element gadolinium is injected into the bloodstream prior to the scan. Some tissues will receive this dye more readily than others. Gadolinium will cause these components to appear much lighter on the final scans. Thus, the dye can improve the MRIs clarity, making it easier for physicians to distinguish between different types of tissues.
Contrast MRIs are often ordered when a patient is experiencing a problem involving things like soft-tissue tumors and central nervous system injuries. The added image quality these scans provide gives doctors greater insight into a tumor’s stage and even the underlying cause of neurological problems.
Are There Risks Associated With MRIs?
Unlike CT scans and X-rays, MRIs do not expose patients to radiation. As such, MRIs can be conducted on multiple occasions without fear of damage from repeated radiation exposure. MRIs are not completely risk-free, however. For one thing, you may not be able to undergo an MRI if you have a medical implant with metallic features, as the magnetic field the machine creates could forcefully pull on these materials. These devices may include cochlear implants and pacemakers, for example.
There are also some potential side effects associated with contrast MRIs, which is why physicians only order contrast images when absolutely necessary. Namely, people with kidney problems could develop nephrogenic systemic fibrosis, a condition that can cause damage to your organs as a result of dye that your kidneys cannot efficiently clear from your system. On rare occasions, the gadolinium dye also can lead to allergic reactions and may be harmful to unborn infants.
Which Conditions Call for an MRI?
There are numerous medical concerns that may be better diagnosed and treated after a patient undergoes an MRI. If you were injured on the job or during an athletic event, for instance, a non-contrast MRI may be helpful when examining the cause of back, knee, or shoulder pain. These scans may reveal damage to tendons, muscles, and ligaments. MRIs without contrast also work well when a doctor suspects a patient has an aneurysm or a blocked blood vessel.
Other soft tissues, including nerves, the spinal cord, the brain, and various major organs may be studied using contrast MRIs. A herniated disk or pinched nerve, for example, can be diagnosed using an MRI with contrast. Even complex health issues such as seizures, multiple sclerosis, and dementia can be analyzed using this technique. Doctors can also examine the size and location of tumors in order to stage their progress appropriately.
What Can You Expect During Your MRI?
Even once you know how MRIs work and what they do, you may still feel a bit anxious as your upcoming scan approaches. Most importantly, bear in mind that this imaging technique is non-invasive and should cause little to no physical discomfort. On occasion, patients report experiencing muscle twitches while the magnetic field is in place.
The nature of the MRI machine itself, however, can be bothersome for some people. Many MRIs consist of a large tube that a patient may have to enter in part or in full. These machines can be loud and often feel confining, which may be especially difficult for those with claustrophobia. Fortunately, many healthcare providers now offer what are known as open MRIs. These machines are designed to feel more like an examination table and less like a tunnel, as they do not include walls on each side as traditional MRIs do.
Schedule Your MRI Today
If you are looking to complete an MRI scan in Brooklyn NY at your doctor’s recommendation, our team at Brooklyn Open MRI may be able to help. We conduct MRIs and X-rays for patients with a wide range of medical concerns. We provide Open MRIs if your physician suggests this option. Learn more about our services online today, or give us a call at (718) 400-6369 with any questions you may have. We look forward to helping you navigate the next step of your medical care as smoothly as possible.