Imaging Scans for Mesothelioma

Expert Fact Checked

This page was medically reviewed by James Stevenson, M.D. on April 19, 2019. For information on our content creation and review process read our editorial guidelines. If you notice an error or have comments or questions on our content please contact us.

James Stevenson, M.D. Thoracic Medical Oncologist

Imaging scans are an important initial step in diagnosing mesothelioma. X-rays, CT scans and MRIs can help doctors identify mesothelioma tumors and the extent of disease. With other tests, imaging scans can help doctors diagnose mesothelioma and determine treatment options.

01. Imaging Scans for Mesothelioma Diagnosis

How Are Imaging Scans Used to Help Diagnose Mesothelioma?

Doctors may use a variety of imaging scans to help diagnose mesothelioma. For example, a chest X-ray may be performed initially to look for any abnormalities in the lungs or chest. A PET scan might be ordered later in the process to help determine the patient’s stage of mesothelioma.

Imaging scans are often the first step in the process of diagnosing mesothelioma. Imaging scans alone do not provide enough information for a mesothelioma diagnosis. Therefore, doctors may also recommend a blood test or biopsy to make an accurate diagnosis.

Depending on the doctor’s assessment, they may recommend multiple types of imaging scans. Each type of imaging test has its own advantages and limitations.

In addition to aiding in a mesothelioma diagnosis, imaging scans also help doctors determine how far the mesothelioma has progressed. In other words, these tests can help identify the cancer stage, such as whether it’s localized or spread to other organs.

Although imaging scans are helpful for doctors to visualize the patient’s internal organs, a biopsy is the only definitive way to diagnose mesothelioma.

02. Mesothelioma X-Rays

X-Rays: The First Step of a Mesothelioma Diagnosis

As a first step in diagnosing mesothelioma, a doctor typically orders an X-ray.

An X-ray is a common medical imaging test that generates images of bones and soft tissue. Doctors often use X-rays as a first-level diagnostic tool to view the inside of the patient’s body and discover any abnormalities.

X-rays usually take no longer than 10 – 15 minutes. Some specific X-ray procedures, such as those involving contrast dye, may take longer. Regardless of the specific procedure, X-rays use low levels of radiation. As a result, X-rays are unlikely to cause serious side effects.

When diagnosing mesothelioma, X-rays help doctors rule out other potential illnesses. For example, if a patient has difficulty breathing or chest pain, a physician may order a chest X-ray. The chest X-ray can help narrow down the cause of the patient’s symptoms from several conditions including pneumonia, emphysema and heart issues.

Can You See Mesothelioma on an X-Ray?

An X-ray can help a doctor detect abnormalities in many parts of the body. For instance, a chest X-ray can help a doctor detect tumors or excessive fluid buildup around the lungs. This excess fluid is called pleural effusion, a common symptom of pleural mesothelioma.

On an X-ray, healthy lungs appear black. When a mesothelioma tumor is present on the membrane of the lungs, it may appear as an abnormally white area.

03. Mesothelioma CT Scans

CT Scans

A CT scan, sometimes called a CAT scan, can also help doctors diagnose mesothelioma. Similar to X-rays, CT scans are commonly used to view organs, tissues and tumors. Instead of a flat, 2D image, CT scans provide a series of images from different angles. The result is a detailed 3D model image of the scanned tissue.

Some CT scans may use a dye called contrast material to enhance the captured images. Contrast material makes it easier for doctors to visualize specific organs or tissues.

CT scans provide clear, specific information on the imaged tissues. They are also relatively fast and capable of imaging small or large areas within a single session. As such, CT scans are useful in determining the stage of mesothelioma.

What Does Mesothelioma Look Like on a CT Scan?

If a CT scan shows mesothelioma, it may appear as a series of tumors along the pleura. The CT scan may also show pleural thickening or pleural effusion, both of which are consistent with a pleural mesothelioma diagnosis.

In peritoneal mesothelioma, a CT scan may show tumors within the peritoneum, the lining of the abdominal cavity. A CT scan may also reveal fluid accumulation within the abdomen (ascites) or tumors on the liver or colon.

Studying a CT scan can also help doctors determine the proper course of mesothelioma treatment, such as whether surgery is needed or possible.

04. Mesothelioma MRI Scans

MRI Scans

An MRI scan creates detailed images of organs, tissues and tumors in the body using radio waves and a strong magnetic field. It’s a painless, non-invasive procedure that does not use radiation.

Depending on the area being scanned, an MRI can take anywhere from 15 minutes to an hour or longer. The doctor may be able to tell the patient how long they expect it to take based on the images needed.

An MRI scan effectively highlights abnormalities in the body, including tumors and cysts. MRI scans may also show doctors how far the cancer has spread and if surgery for removal is possible.

05. Mesothelioma PET Scans

PET Scans

PET scans provide doctors with information on how individual organs are functioning. For this type of imaging scan, the patient receives radioactive glucose. Cancerous cells absorb more sugar than healthy cells. Thus, cancer cells appear brighter compared to surrounding tissues and other cells.

Images from a PET scan are collected in the same way as CT scan images, by using a rotating cylinder that gathers pictures from all angles.

A PET scan is useful for doctors in diagnosing mesothelioma because it can show the presence of tumors and assist with identifying the stage of cancer. It also can show whether the cancer has metastasized.

Doctors may also use PET scans to measure the efficacy of treatment. For instance, doctors may use a PET scan after or during a patient’s course of chemotherapy to look for tumor progression. This can help doctors modify the treatment plan, if needed.

06. Mesothelioma Ultrasounds


An ultrasound uses high-frequency sound waves to view internal body structures. Ultrasound waves cannot transmit properly through air. This means ultrasound produces inferior images of structures in the chest and abdomen.

However, a doctor might opt for an ultrasound in certain instances, such as:

Sometimes physicians order a fluid biopsy to assist in mesothelioma diagnosis. This procedure involves using a needle to remove a small fluid sample for analysis. In these cases, an ultrasound may be used to help guide the needle so it can extract the fluid.

07. Diagnosis Next Steps

What Are the Next Steps for a Mesothelioma Diagnosis?

Imaging scans are often the first step in diagnosing mesothelioma. Although imaging scans can provide valuable information to the doctor, they are not enough on their own to make a definitive diagnosis.

Other tests are typically ordered after imaging scans are reviewed. These may include blood tests and a biopsy.

A biopsy is the only definitive method of diagnosing mesothelioma. Once the doctor confirms the mesothelioma diagnosis, they will develop the patient’s treatment plan.

Imaging scans may be used again during treatment. These scans can help doctors monitor the efficacy of treatment, such as looking for any cancer progression after chemotherapy.