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 doctor may initially order a chest X-ray to look for any lung or chest abnormalities. The mesothelioma doctor may use a PET scan 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. Depending on the type of scan, doctors can get information to:

  • Estimate how the treatment is affecting the tumors
  • Help understand how much cancer there is or how far it has spread
  • Monitor a patient for cancer recurrence
  • Show possible suspicious tissues or areas that might be cancer

Doctors may recommend several different imaging scans. While each has advantages and limitations, imaging scans alone do not provide enough information to allow a doctor to diagnose mesothelioma. Instead, doctors may recommend a blood test or biopsy. Testing a biopsy sample is the only definitive way to diagnose mesothelioma.

Radiology and Mesothelioma

Radiology is a medical field that uses technology to get images of the inside of the body to help diagnose an injury or disease. Specialized doctors, called radiologists, use these images to help make a diagnosis. For example, radiology at a mesothelioma cancer center uses imaging tests to detect possible tumors in the thin lining around organs.

02. Mesothelioma X-Rays

X-Rays: An Early Step of a Mesothelioma Diagnosis

A doctor may order an X-ray early in the diagnostic process for mesothelioma. An X-ray sends electromagnetic radiation through a person’s body to capture images of structures inside the body.

X-rays are common medical imaging tests. Doctors often use X-rays as first-level diagnostic tools to see inside the patient’s body and discover any abnormalities.

X-rays usually take no longer than 5 – 10 minutes. However, some specific X-ray procedures, such as those involving contrast dye, may take longer.

Doctors use X-rays to help rule out other illnesses. For example, patients with difficulty breathing or chest pain may have 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.

Quick Facts About X-Rays

  • Standard X-rays take 5 – 10 minutes to complete, but the results may take time to review.
  • X-rays use low levels of radiation, so they are unlikely to cause serious side effects.
  • The radiation from one chest X-ray amounts to about what people naturally get over 10 days of being on earth.
  • There are different types of X-rays, including some that use special contrast dyes to highlight a specific part of the body.
  • Newer technology, called digital radiography, does not use film. Instead, it takes an X-ray image like a digital camera and saves it on a computer.

Can You See Mesothelioma on an X-Ray?

An X-ray can help a doctor detect abnormalities in many parts of the body. Those abnormalities appear white on the X-ray, and healthy tissues appear black.

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.

While a doctor can see the abnormalities, they will not be able to diagnose them as mesothelioma. The only way to diagnose mesothelioma is by testing a biopsy sample.

Chest X-Rays (CXR)

In cases of pleural mesothelioma, chest X-rays are the most common X-ray. Doctors order chest X-rays to look for abnormalities in the chest and around the lungs. Some common things a doctor looks for in a mesothelioma chest X-ray include:

  • Pleural effusion or thickening
  • Loss of space in the chest cavity
  • Lung compression

These findings may suggest additional tests are needed. The patient’s doctor can explain more about chest X-rays for pleural mesothelioma.

03. Mesothelioma CT Scans

Computed Tomography (CT) Scans

A CT scan, sometimes called a CAT scan, can also help doctors diagnose mesothelioma. Like X-rays, CT scans are commonly used to view organs, tissues and tumors. Instead of a single image, CT scans provide a series of images from different angles.

CT scans use multiple X-rays that doctors can look at individually or stack on top of each other to create a 3D model. Complete results from a CT scan can take 24 hours. Doctors may use a CT scan for patients with signs of pericardial mesothelioma.

Contrast material, or contrast dye, is a substance that helps show abnormalities in the body. Contrast dyes are given by injection or orally. Doctors may use them during CT scans, MRIs or X-rays.

Some CT scans use a dye, or contrast material, to enhance the captured images. The 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.

Quick Facts About CT Scans

  • Some mesothelioma specialists prefer the CT scan for staging pleural mesothelioma cases.
  • A typical CT scan usually takes between 10 and 30 minutes, depending on if the scan needs a contrast dye.
  • Results may take 24 hours or longer, as a radiologist has to review and parse the image.
  • Patients lie on a table that moves in and out of a ring-shaped scanner during the quiet imaging scan procedure.
  • CT scans can help doctors determine if a mesothelioma patient is eligible for surgery.
  • The radiation a person gets from a CT scan is about what they naturally get over 2 years of living on earth.

What Does Mesothelioma Look Like on a CT Scan?

A CT scan of pleural mesothelioma may show tumors along the lining around the lung (the pleura). The CT scan may also show pleural thickening or pleural effusion, which are both consistent with a pleural mesothelioma diagnosis.

X-rays and CT scans both provide images of structures inside the body. However, CT scans show greater detail and allow the doctor to see it in 3D. CT scans cannot diagnose mesothelioma, but they may help lead a doctor to that diagnosis.

For example, peritoneal mesothelioma CT scans may show tumors within the abdominal cavity lining. A CT scan may also reveal fluid accumulation within the abdomen (ascites) or tumors on the liver or colon.

After diagnosis, studying a CT scan can also help doctors determine the best mesothelioma treatment, such as whether surgery is needed or possible.

04. Mesothelioma MRI Scans

Magnetic Resonance Imaging (MRI) Scans

An MRI scan can help diagnose mesothelioma by creating detailed images of structures inside the body. An MRI may show organs, bones, blood vessels and soft tissues like muscle or tumors. Doctors use these images to evaluate whether further tests, such as a biopsy, are needed.

MRI scans use radio waves and a strong magnetic field. It’s a painless, non-invasive procedure that does not use radiation. Some MRI scans may use an injectable contrast dye to help make tissues appear more clearly in the images.

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.

Quick Facts About MRI Scans

  • Usually, patients do not have to prepare for an MRI, but the doctor will have complete instructions.
  • An MRI machine is a large tube that holds a powerful magnet and does not use radiation.
  • Patients uncomfortable with tight spaces can ask about an open MRI, which provides more space.
  • Doctors use MRI scans to determine if the mesothelioma tumor has spread to the diaphragm or chest wall.
  • An MRI scan will not diagnose mesothelioma but can help doctors determine if the cancer has spread after a biopsy confirms it.
05. Mesothelioma PET Scans

Positron Emission Tomography (PET) Scans

PET scans show tissues and cells that use a lot of energy, like cancer cells. For this type of imaging scan, the patient receives radioactive sugar. Cells that use a lot of energy absorb more sugar than other cells. Thus, cancer cells appear brighter compared to surrounding tissues.

A PET scan cannot show if a tumor is mesothelioma, but it does show abnormal tissue. Doctors can use that information to help determine:

  • The size, location and growth speed of the tumor
  • Whether thickening found in a CT scan is likely to be from cancer or scar tissue
  • If the cancer has spread, or metastasized, to other parts of the body, like lymph nodes

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.

Quick Facts About PET Scans

  • A PET scan finds cells that use sugar (energy) more quickly, such as cancer cells.
  • Cancer cells show up as bright spots on PET scans.
  • Doctors use PET scans to find cancer, see if and where it has spread and how well treatment is doing.
  • A mesothelioma PET scan may help a doctor determine if the thickening of the pleura or peritoneum is from scar tissue or tumors.
  • Some PET scan machines can also do CT scans.

PET Scans vs. CT Scans

PET scans and CT scans are collected the same way, using a rotating cylinder that gathers pictures from all angles. These scans differ mainly in the information they provide. CT scans create still images of tissues and bones. PET scans show which tissues are using a lot of energy. PET scans use radioactive sugar and CT scans do not. PET scans generally take longer than CT scans.

06. Mesothelioma Ultrasounds


Ultrasounds do not use radiation like X-rays, CT scans or PET scans. Instead, they use sound waves to travel through a person’s body and bounce back when they hit organs. The sound waves bounce off structures at different rates, allowing the machine to create images.

Ultrasound waves cannot transmit properly through air, which is found in the lungs and abdominal organs. 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:

For mesothelioma, doctors may use an ultrasound to pinpoint where a tumor or excess fluid, like a pleural effusion, is in the body. They may also use ultrasound to help guide a needle during certain procedures, like a thoracentesis or biopsy.

Quick Facts About Ultrasounds

  • Ultrasounds are not as detailed as CT scans or MRI scans.
  • Ultrasounds do not work well in tissues that hold air, like the lungs.
  • Doctors often use ultrasounds to guide needles during procedures, like biopsies, to help collect samples.
  • An ultrasound can show the direction and speed of blood flow, which can help identify tumors.
  • Most ultrasounds do not require preparation, but patients should speak with their doctors for instructions.
  • Most ultrasounds take between 20 and 30 minutes to complete.
07. Image Testing by Type

Image Testing for Mesothelioma by Type

Image testing varies by mesothelioma type. Certain imaging tests may work well for some mesothelioma types but not others. For example, doctors commonly use ultrasounds for testicular mesothelioma. However, they typically do not use them for peritoneal mesothelioma.

Image Testing for Pleural Mesothelioma

  • X-ray: Chest X-rays and abdominal X-rays are both used.
  • CT scan: Doctors may use a CT scan of the chest during diagnosis.
  • MRI: Doctors may recommend an MRI for patients if they are being considered for surgical treatments.
  • PET scan: Patients eligible for surgery may have a PET scan to help the doctors stage the cancer.
  • Ultrasound: Doctors may use an ultrasound to find pleural effusions or to examine lymph nodes to determine if the mesothelioma has spread.

Image Testing for Peritoneal Mesothelioma

  • X-ray: Testing includes abdominal X-rays, and may include chest X-rays.
  • CT scan: Doctors may use a CT scan of the abdomen during diagnosis.
  • MRI: Patients may get an MRI if the doctor thinks surgery and HIPEC, a type of multimodal treatment, would be beneficial.
  • PET scan: While uncommon, a PET scan may be used to help stage the mesothelioma or monitor treatment.
  • Ultrasound: Doctors do not generally use ultrasounds in peritoneal cases.

Image Testing for Pericardial Mesothelioma

  • X-ray: Doctors may order a chest X-ray but less often than CT scans or MRIs.
  • CT scan: Doctors may use a CT scan of the chest during diagnosis.
  • MRI: MRI scans are common among patients diagnosed with pericardial mesothelioma.
  • PET scan: It is unclear if PET scans are used to diagnose pericardial mesothelioma.
  • Ultrasound: Doctors use a type of ultrasound called an echocardiogram to find pericardial effusion or pericardial tumors. They may also use them to guide needles for pericardiocentesis and/or a needle biopsy.

Image Testing for Testicular Mesothelioma

  • X-ray: Patients may have a chest X-ray to check for metastasis.
  • CT scan: Because testicular mesothelioma is rare, not much evidence shows up on standard imaging scans. However, patients may have abdominal or pelvic CT scans.
  • MRI: It is unclear if MRI is used to diagnose testicular mesothelioma.
  • PET scan: It is unclear if PET scans are used to diagnose testicular mesothelioma.
  • Ultrasound: Doctors use ultrasounds as one of the primary diagnostic tools for testicular mesothelioma. These ultrasounds may lead to additional procedures to definitively diagnose testicular mesothelioma.
08. Diagnosis Next Steps

What Are the Next Steps for a Mesothelioma Diagnosis?

Imaging scans can provide doctors with valuable information during and after a mesothelioma diagnosis. For instance, imaging scans may help doctors classify cancer spread or clinical stage using the TNM system. However, imaging alone is not enough to make a definitive diagnosis.

A mesothelioma doctor may use an imaging scan as one of the early tests during diagnosis. After doctors review the imaging scans, they may order other tests, including blood tests and a biopsy.

Testing tissue from 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 how well the treatment works, such as looking for any cancer progression after chemotherapy.

09. Common Questions

Common Questions About Mesothelioma Image Testing

Does asbestos show up on a CT scan?

Asbestos fibers are very small and do not appear on a CT scan. However, the damage and scarring caused by the fibers may show. For example, abnormal tissues in the lungs or the lining around them can show up on the CT scan. If doctors believe the CT scan shows possible signs of an asbestos-related illness, they may order additional tests.

Do asbestos fibers show up on an X-ray?

Asbestos fibers are very small and do not appear on an X-ray. However, the damage caused by the fibers may appear. Conditions like pleural or peritoneal effusion, pleural thickening or mesothelioma tumors may be seen. Doctors may order additional tests if they suspect mesothelioma after reviewing an X-ray.

If an image scan shows cancerous cells, do I still need a biopsy?

Imaging scans do not identify cancerous cells, but they do identify suspicious tissues. If a doctor sees abnormal tissue in an imaging scan, they may order additional tests, such as a biopsy. The tissue collected from the biopsy goes to a pathology lab for testing that may reveal cancer cells.

Are image scans covered by insurance?

Insurance coverage for imaging scans varies by each carrier and individual insurance plan. Patients should speak with their insurance providers to understand their coverage. Financial assistance may be available if their plans do not cover diagnostic test costs.