What Does An MRI Detect?

Oncologists use MRIs to discover whether a tumor is cancerous or benign, look for new metastases (cancerous spread), and help your doctor plan a course of treatment to fight cancer. The scan will reveal whether the tumor has clear or irregular boundaries, which is usually the first step in deciding whether or not the tumor is cancerous.When scanning a tumor to check if it is malignant, you may be required to get an MRI with contrast. This means you will be injected with contrast dye to see if the mass has spread to blood vessels. 

An MRI can show enlarged lymph nodes after a lymphoma diagnosis to monitor the potential spread of cancer. For breast and prostate cancer, it is common for cancer to spread through the lymph nodes. By using a full-body MRI scan, your oncologist can discover new metastases early and prepare to fight them faster. MRIs are integral to diagnosing and staging cancer, as well as monitoring the patient’s response to treatment such as radiation or chemotherapy.

If you are getting an MRI of your head and neck, there are many conditions it could detect: aneurysms, eye and inner ear disorders, spinal cord disorders, brain tumors, traumatic brain injuries, developmental anomalies, multiple sclerosis, dementia, infection, and even diagnosing causes of headaches. These injuries will appear on your MRI scan as white spots or areas on your brain. These white spots can be dense tissue, concentrated infection, or symptomatic of brain disorders. Depending on the size and placement of these spots, your doctor can figure out what is wrong and how to treat it.

Don’t let that list of potential conditions frighten you. 82% of brain MRIs turn up normal results, meaning there is an 18% chance of abnormal results. An abnormal result means that the scanned brain is not perfectly healthy – there could be structural damage, swelling, bleeding, or lesions. Your doctor will let you know if you have received an abnormal result and will schedule you for a follow-up appointment to address your concerns and condition.

Nerve damage commonly stems from pressure on your nerves. An MRI can discover where the lesions are before permanent nerve damage sets in. When paired with a neurological examination, an MRI can diagnose nerve damage and help your doctor create a treatment plan for the future. On your MRI, your radiologist will see your nerves as they show up in white or gray, and can check for anything that is affecting them – pinching them, cutting them off, or causing inflammation somehow. Your doctor will be able to take this information and turn it into a diagnosis in order to create a treatment plan. 

Sciatica, or pain along the sciatic nerve, is also diagnosable by an MRI. Pinched nerves will also show up on an MRI scan and help your radiologist pinpoint exactly where the pinched nerve is and how to treat it. Permanent nerve damage is not only painful but can limit movement and motor function. Early diagnosis is the best way to combat these issues.

An MRI can show inflammation or infection of soft tissue or bone marrow, will help pinpoint where the inflammation is located, and if there is a treatable cause. Not only would an MRI scan help in the diagnostic process, but it would also be a key tool in monitoring the patient’s response to treatment. You may be required to get an MRI with contrast to see if there are any obstructed blood vessels or joints. Inflammation will show up on your MRI as large areas of white or gray that obstruct movement or press down on joints. Inflammation fluid will show up as solid white areas. 

If you are getting an MRI, you should stop taking your anti-inflammatory 3 days before your exam. If you have questions or concerns, be sure to bring them up with your doctor. Anti-inflammatory drugs will reduce swelling in the area of your body that is causing you problems, making it difficult for your radiologist to see the issue on the scans.

Muscle damage shows up on an MRI, especially muscle damage affecting the liver or bile ducts, kidneys, spleen, pancreas, uterus, ovaries, and prostate. MRIs are also able to show blood clots. Bone damage like torn cartilage or ligaments, disk abnormalities, bone infections, or bone tumors will show up on an MRI scan, although bone damage would show up clearer on a CT scan. CT scans offer an accurate outline of bones, especially in the chest, while MRIs are better suited for soft tissue examination, brain, and spinal cord issues.

Doctors might recommend you first get a CT scan because it takes longer to perform an MRI – if you need results fast, a CT scan would be the way to go. If you get abnormal results, your doctor is likely to request a more detailed look with an MRI scan. MRIs and CTs each have pros and cons, so trust your doctor’s recommendation, but be sure to ask questions if you have them. CT scans can capture a larger amount of the body compared to MRIs. MRIs may take longer, but they produce more precise images and detect more diseases. 

MRIs use safe magnets to capture their scans but often require patients to lie still inside a metal tube for that whole time. CT scans also use ionizing radiation to take their images, which comes with minimal exposure to radiation that could cause an increased potential for cancer in some patients. 

CT scans can be a better option for patients who experience claustrophobia or have metal inside their bodies (pacemakers, clips, hearing aids, etc.) that could interfere with the MRI’s magnets. Talk with your doctor if you have concerns about which scan they recommend.