Can an MRI detect cancer anywhere?

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An MRI scan can assist doctors in detecting cancer in various parts of the body due to its ability to distinguish between different types of tissues. For example, these scans can detect:

• brain tumors
• primary bone tumors
• soft tissue sarcomas
• spinal cord tumors
• prostate cancer
• bladder cancer
• ovarian cancer

MRIs can also check for signs that cancer has spread from its original location. Analyzing MRI results helps doctors plan cancer treatments, such as surgery or radiation therapy.

Despite its versatility, MRI has limitations. For example, it is less effective in detecting lung cancer or examining the mediastinum, which is the central compartment of the chest cavity. It is also less common as a test for stomach cancer than other methods.

This is because air and bowel motion in these areas can interfere with image clarity. That said, technological advancements and breath-holding techniques may help make the images more accurate.

MRI may have less success in accurately detecting tiny tumors than other imaging techniques.

Learn about screening for lung cancer using CT scans.

Full-body scans can detect cancer, but doctors typically reserve them for specific medical situations.

Whole-body MRI (WB-MRI) is a scanning method that does not use harmful radiation and can cover the entire body in less than 40 minutes.

WB-MRI is often more effective than bone scans and CT scans for finding and assessing lesions, checking how well treatments are working, and screening people at high risk. Doctors may use additional scans to focus on specific areas if necessary.

Because of its effectiveness, doctors can perform WB-MRI to manage:

• multiple myeloma
• prostate cancer
• melanoma
• genetic cancer risks

Doctors are using it increasingly to identify:

• metastatic breast cancer
• ovarian cancer
• lymphoma

However, the Food and Drug Administration (FDA) does not recommend full-body scans as a routine screening tool for cancer in individuals without symptoms due to the lack of proven benefits and the potential for unnecessary follow-up tests.

WB-MRIs should not replace routine screening procedures or targeted imaging tests.

Learn whether a biopsy or MRI is better for prostate cancer.

An MRI requires very little preparation. Before the procedure, a health professional will check there is no medical reason that a person cannot undergo the scan. They may do this by asking them to fill out a questionnaire.

Then, they may ask the person to change into a hospital gown and remove any metal from their body, such as jewelry. As an MRI involves strong magnets, it is critical there are no metal objects in the scanner.

Once ready, the scan will involve the following steps:

1. The person will lie on a motorized table. A technician may place blocks around the part of the body they are focusing on to ensure it stays still. They may also give a person a button they can press if they need help and may provide earplugs to reduce the noise of the scanner.
2. Next, the table slides into a large tube-shaped MRI machine, and the scan will begin.
3. The machine generates a strong magnetic field around the area of interest and sends radio waves through the body. This process takes some time and can be loud.
4. The machine’s sensors detect the energy emitted by hydrogen atoms in the body’s cells. These signals are processed to create detailed images of the internal structures.

The procedure is noninvasive and typically lasts 45 to 60 minutes, depending on the area a doctor is examining. Sometimes, it may take up to 2 hours.

Sometimes, medical professionals inject a contrast dye through the vein to enhance the visibility of certain tissues or blood vessels.

It is important to remain still during the scan to ensure high-quality images. If a person feels uncomfortable during the procedure, they can speak to the MRI technician or press the button in their hand to stop it.

Learn about the side effects of MRI contrast.

MRI and CT scans are valuable tools for detecting cancer, each having distinct advantages and limitations.

MRI

MRI scans can produce clearer images than CT scans. These images can show how deep a tumor has grown into body tissues, or whether there is tissue left behind after treatment.

An MRI is ideal for scanning the brain, spinal cord, and musculoskeletal system. Additionally, it does not use ionizing radiation, making it a safer option for multiple uses.

However, it can be less effective for imaging structures that contain air, such as the lungs, or structures that move.

CT

CT scans use X-rays to create detailed cross-sectional images of the body. They are highly effective for visualizing the chest, lungs, and abdomen, which is where MRIs can fall short.

CT scans are also faster than MRIs, and doctors often prefer them in emergency settings. However, a CT scan involves exposure to ionizing radiation, which can accumulate if a person has many scans over time.

The choice between MRI and CT depends on various factors, such as the area of the body a doctor is examining and a person’s specific needs. Doctors will consider these factors when deciding whether to use an MRI or CT scan.

Learn about the differences between MRI and CT scans.

While MRIs are highly effective in detecting and characterizing tumors, they may not confirm whether a tumor is benign (noncancerous) or malignant (cancerous). This usually requires additional testing.

However, MRIs can provide clues as to whether the tumor might be cancerous based on certain factors, such as its:

• size
• shape
• location
• interaction with surrounding tissues

Benign tumors often have well-defined borders, whereas malignant tumors may appear more irregular and invade nearby structures.

A firm diagnosis typically requires a biopsy, where a doctor examines a tissue sample from the tumor under a microscope. MRI findings can guide the biopsy by identifying the areas of a tumor to sample.

Learn more about the different types of tumors.

If an MRI detects a mass that could be cancer, the next steps usually involve further diagnostic testing and a consultation with a specialist. This may include additional imaging tests, such as CT or PET scans, or a biopsy to gather more information about the tumor.

A multidisciplinary team of healthcare providers will use these findings to develop a tailored treatment plan. Treatment options may include:

• surgery
• radiation therapy
• chemotherapy
• targeted therapy
• a combination of these approaches

It is important to note that the outlook for cancer varies widely depending on the type and stage. Some types are highly treatable and are rarely fatal with appropriate care. Others are more difficult to treat, particularly if they are more advanced.

People can speak with their doctor about what their MRI results mean, what their diagnosis might be, and the available treatments.

Learn how to cope after a cancer diagnosis.

MRI is a powerful imaging tool that can help detect cancer in various parts of the body. It is particularly effective for scanning soft tissues in the brain, spinal cord, and musculoskeletal system.

However, its effectiveness varies, and it can be less effective for detecting lung and gastrointestinal cancers. It also may not confirm whether a tumor is cancerous. For this, a person will usually need a biopsy.

The choice between MRI and CT scans depends on an individual’s needs, with each imaging type offering unique strengths. While full-body MRI scans are available, doctors generally do not recommend them for people without any symptoms.

If a doctor detects cancer, further tests and consultations will guide the treatment plan. Individuals should discuss their specific medical needs with their healthcare team.