How to Understand Your Brain MRI Results
How to Understand Your Brain or Spine MRI Results: A Guide for Patients with Cancer
If you or someone you love has brain or spine cancer, getting an MRI can be one of the most stressful parts of the journey. The scan itself can be intimidating, but the real anxiety usually starts when you’re waiting for, or reading, the results. The report is often filled with complex medical terms, and it’s natural to worry.
This guide is here to help you better understand what your MRI results are saying, so you can feel more informed, confident, and prepared for conversations with your care team.
What Is an MRI?
An MRI (Magnetic Resonance Imaging) is a detailed scan that uses magnets and radio waves to create images. It does not use radiation. Radiologists rely on MRI to:
- Detect and locate tumors
- See if a tumor has grown, shrunk, or remained stable
- Check how well treatment is working
- Look for swelling, bleeding, or other changes
For people with brain or spine cancers, MRIs are usually done at regular intervals to monitor progress.
Why One MRI Doesn’t Tell the Whole Story
An MRI is a snapshot in time. Doctors do not interpret it in isolation. They also consider:
- Your symptoms
- Your physical and neurological exam
- Your treatment history
- Your past scans
- Any surgical or biopsy results
- Your overall health
Sometimes, scans may look worse temporarily due to treatment effects like inflammation. This is known as pseudoprogression, and it can mimic true tumor growth even when treatment is working. That’s why patterns over time matter more than any single result.
Common Words You Might See in Your MRI Report
MRI reports are written in technical language for doctors. Seeing that language can be scary, but many terms are more neutral than they sound.
1. Lesion or Mass
These words simply mean an area that looks abnormal. In the context of brain cancer, they often refer to the tumor but don’t automatically describe whether it is growing or shrinking.
2. Tumor Size (Measurements)
You might see measurements such as “2.4 cm x 1.9 cm”. These numbers describe the size of the area the radiologist measured.
- Stable: No significant change in size
- Increased: Possible growth
- Decreased: Possible shrinkage
It is normal to have some variability in measurements between scans, so a bigger number doesn’t always mean a bigger tumor. Trends over time matter most.
3. Enhancement
This refers to how the area looks after contrast dye is given. Enhancement does not automatically mean your cancer is worse. It is only one part of the overall picture. Some types of tumors do not enhance. Some treatments provided by your oncologist can make the enhancement increase or decrease.
4. Edema (Swelling)
Edema is swelling caused by irritation or pressure around the tumor. It may contribute to symptoms such as headaches, nausea, or vision changes. This is often treated with medications like steroids (for example, dexamethasone).
5. Midline Shift
This means pressure (from swelling or a mass) is pushing the brain slightly to one side. The amount of shift matters, and your doctor will pay close attention to this. If you have no new symptoms or if the shift is small (less than 1 cm), this may not require any treatment.
6. Necrosis
Necrosis means “dead tissue.” This can happen when tumor cells die, often as a result of effective treatment. While the word sounds alarming, necrosis can actually be a sign of treatment response in some cases.
What If the MRI Report Sounds Different Than What You Discussed with Your Doctor?
It can be distressing to read your MRI report and feel like it tells a different story than what your doctor explained. Words such as “worsening,” “concerning,” “progression,” “mass effect,” or “suspicious” may appear in your written report even if your doctor seemed more positive or calm.
This disconnect is actually very common. Here’s why it happens:
1. Radiology reports use a different “language”
Radiologists are doctors who primarily communicate information to other doctors. Radiology reports describe image details in technical terms that have specific meanings to medical professionals. Your oncology doctor integrates that information together with your symptoms, history, and response to treatment. The radiology report is important, but it's only part of the information that goes into your comprehensive assessment.
2. Medical reports are written to be cautious
Phrases like “cannot rule out” or “possibly represents” don’t mean something is definitely happening, they mean it should be interpreted carefully. It’s up to your oncology doctor to determine whether or not these possibilities are relevant for your care.
3. Radiology doctors don’t directly evaluate your whole clinical picture
While radiologists can see your medical record and your MRIs, they don’t know how you are actually feeling and how your symptoms are changing over time.
4. You might see the report before your oncology doctor does or after your visit has taken place
This gap in timing can create stress and confusion, but remember, the radiology report is only one part of the information that your oncology doctor uses to figure out if your current treatment is working.
Radiology doctors and oncology doctors work together to understand the status of your cancer. If there is ever any doubt, your oncology doctor can and will contact your radiology doctor directly. The end goal is to give you the best possible care through a multi-disciplinary approach.
What You Can Do If You Feel Confused About Your MRI Results
If the report seems different from what you were told:
- Highlight or write down the parts that worry you
- Bring them to your provider at the next visit
- Ask: “Can you explain this section in simpler terms for me?” or “Can you pull up my MRI images and show me what the report is talking about?”
You are not causing trouble. You are advocating for your understanding, and that’s important.
Helpful Questions to Ask Your Doctor
Consider bringing these to your next visit:
- Has the tumor changed since my last scan?
- Could this be pseudoprogression or treatment effect?
- Could this be related to my immunotherapy?
- Does this change my current treatment plan?
- What symptoms should I watch for?
- When is my next MRI?
Writing them down can be very helpful, especially if you feel overwhelmed.
Understanding BT-RADS
You may see a BT-RADS (Brain Tumor Reporting and Data System) score in your MRI report. BT-RADS is a standardized scoring system used by radiologists to describe what they see on MRI in patients with brain tumors.
Think of BT-RADS as a structured “status update” that helps your medical team track changes over time.
BT-RADS Categories Explained
- BT-RADS 1 – Imaging Improved: The tumor is getting smaller or is not visible. Often used after starting an effective treatment.
- BT-RADS 2a, b – Stable: The tumor looks unchanged compared to your last scan. This is usually a positive result and means that your treatment is working.
- BT-RADS 3a, b, c – Imaging Changes of Unclear Significance: There may be a small change, but it’s unclear whether this represents tumor growth or treatment effects (like inflammation or scarring). 3a means that the radiologist thinks the change is more likely to be a normal result of treatment. 3b means that the radiologist is unsure. 3c means the radiologist is concerned that the change might be tumor growth. For all versions of BT-RADS 3, your oncology doctor will likely monitor more closely, but a change in treatment is usually not needed.
- BT-RADS 4 – Likely Tumor Growth or Recurrence: The scan is concerning for tumor growth. This may lead to discussion about treatment changes, surgery, or other options.
What Is Pseudoprogression?
Pseudoprogression is when an MRI scan appears to show that a tumor is growing, but in reality, it is not true tumor growth. Instead, the changes are caused by inflammation and treatment effects, most commonly after radiation and chemotherapy.
In simple terms: The scan may look worse, but the cancer is not actually getting worse.
These treatment-related changes can occur because therapy may cause:
- Temporary swelling in the brain or spine
- Inflammation in the area that was treated
- Tissue breakdown where tumor cells were damaged or destroyed
Pseudoprogression is most common in the first 3-6 months after radiation, but it can sometimes occur later as well.
Why is Pseudoprogression Important to Know?
Pseudoprogression can:
- Trigger fear and confusion
- Lead to dramatic-sounding words in an MRI report
- Look concerning even to experienced doctors
When this is suspected, your medical team may:
- Compare your scan with previous MRIs
- Monitor you closely over time
- Order a repeat scan in a shorter timeframe
- Consider advanced imaging techniques
- Focus on your symptoms and neurological exam
The key point to remember: Imaging worsening does not mean tumor worsening. Imaging can look worse as a normal part of your treatment. Time and context are essential.
What Is Immunoprogression (or Immune-Related Pseudoprogression)?
If you are receiving immunotherapy, your MRI can show changes that look like tumor growth even when your treatment is actually working. This effect is sometimes called immunoprogression or immune-related pseudoprogression.
Immunotherapy works by stimulating your own immune system to attack tumor cells. When immune cells rush into the tumor area, they can cause:
- An increase in the size of the lesion
- More enhancement (brightness) on MRI
- Swelling and inflammation around the tumor
On imaging, this can look very similar to real tumor growth, but it may actually be a sign that your immune system is actively fighting the cancer.
When immunoprogression is a possibility, your care team may:
- Continue treatment for now
- Closely monitor your symptoms
- Schedule another MRI in a few weeks
- Use specialized imaging techniques to gather more information
- Base decisions on your overall neurological function and quality of life
Once again, the trend over time is far more important than a single scan.
Move Forward with Confidence in Your Cancer Care
Understanding your brain MRI results is an important step in managing your brain cancer journey, but you don’t have to navigate it alone. Connect with the experts at The Preston Robert Tisch Brain Tumor Center to discuss your results, ask questions, and explore personalized treatment options. Our team is here to guide you through every step of your care, from interpretation to next steps and ongoing support.
Learn more about our innovative cancer therapies, research programs, and patient support resources. You can also support the clinic by donating funds directly to patient care, research, education, and treatment for brain tumors. We also provide access to innovative clinical trials and the latest education & training to ensure you and your loved ones receive the most advanced care possible for brain tumors.
Visit our website to request an appointment and learn more about the different therapies and recovery methods available to you and your loved ones.
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