Written By: Devin Golden
Imaging Tests for Diagnosis
Imaging tests are an integral part of diagnosing mesothelioma. The specific tests used will depend on a detailed history of the patient’s symptoms and a physical exam.
Medically Reviewed By
Dr. Stephen Williams
Precision Oncology Scientist
Medically Reviewed By
Dr. Stephen Williams
Precision Oncology Scientist
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Important Facts About Imaging Tests for Mesothelioma
- There are several imaging tests used in the diagnosis of mesothelioma, but none of them are definitive on their own. A biopsy is the only way to confirm mesothelioma.
- The initial imaging test used is an X-ray, followed by more detailed studies such as a CT scan, PET scan and MRI. These help identify abnormalities linked to mesothelioma symptoms and guide doctors toward the next steps.
- Imaging tests are non-invasive and are typically well tolerated by the patient. Doctors will select the most appropriate scans depending on the patient’s symptoms and suspected type of mesothelioma.
How Are Scans Used for Mesothelioma?
Mesothelioma imaging tests provide detailed visualization of the lungs, heart, and abdomen. These imaging scans are essential for doctors to evaluate the likelihood of mesothelioma cancer, detect abnormalities, and begin assessing potential biopsy needs. While imaging cannot confirm mesothelioma, it plays a crucial role in the early detection and diagnostic process.
The two most common types of mesothelioma are pleural mesothelioma (lining of the lung cavity) and peritoneal mesothelioma (lining of the abdominal cavity). Malignant pleural mesothelioma is the most common type. Standard imaging tests including X-ray, CT, PET, and MRI scans can assist in evaluating both pleural and peritoneal disease.
A much rarer form, called pericardial mesothelioma, affects the lining around the heart. For this type of mesothelioma, patients typically undergo an echocardiogram, an ultrasound used to evaluate the structures and function of the heart. An even rarer type is testicular mesothelioma, which forms in the lining of the testes.
Patients must have a mesothelioma biopsy to receive a definitive diagnosis.
What Are the Tests for Mesothelioma?
There are four tests often used to evaluate and help diagnose mesothelioma. If doctors suspect you have this cancer, you will likely undergo at least one of them:
- X-ray
- CT scan (computed tomography)
- PET scan (positron emission tomography)
- MRI scan (magnetic resonance imaging)
X-rays and CT scans are the most common initial imaging tests used for mesothelioma. MRI scans and PET scans are typically used to obtain details about the extent of the disease and metastatic disease.
How Doctors Determine the Usefulness of Mesothelioma Scans
Imaging scans are measured by sensitivity, specificity and accuracy. These three measurements are used by researchers and doctors to determine the usefulness of imaging scans in detecting mesothelioma. Studies are conducted to determine the:
- Sensitivity – Ability to correctly identify people with mesothelioma (true positives versus false negatives)
- Specificity – Ability to correctly identify people without mesothelioma (true negatives versus false positives)
- Accuracy – Overall percentage of correct results
Here is an explanation of the four possible outcomes of an imaging scan for mesothelioma:
- True positives – Scan helps doctors correctly believe mesothelioma is present
- True negatives – Scan helps doctors correctly believe mesothelioma is not present
- False positives – Scan leads doctors to incorrectly believe mesothelioma is present
- False negatives – Scan leads doctors to incorrectly believe mesothelioma is not present
Physicians must be able to rely on the accuracy of imaging scans to guide decisions about the need for additional testing and biopsies when determining if mesothelioma is present. Inaccurate results, false positive or false negative, can lead to unnecessary procedures and delay in treatments.
X-rays for Mesothelioma
An X-ray uses electromagnetic beams to capture two-dimensional images inside the body. X-rays can examine structures in the chest and abdomen and are usually one of the first imaging tests used in the mesothelioma diagnostic process.
An X-ray can help doctors identify abnormalities of the bones, lung conditions (like pneumonia), and tissue linings. They can reveal thickening of tissues, abnormal fluid accumulation, and tumors, which all may be early signs of pleural or peritoneal mesothelioma.
What to Expect Before, During, and After X-rays
- Before the scan: No preparation needed
- After the scan: More images may be needed at a later time.
Scan time:
Approximately 15 minutes
Does it hurt?
No.
CT Scans for Mesothelioma
A CT scan generates detailed three-dimensional images of the body. This test uses X-rays and computer technology to capture multiple images of the same area from different angles. These images are then combined into a cross-sectional view of the bones, blood vessels, and soft tissues.
During the scan, the patient lies on a table that moves slowly through the circular opening, which is often called the “donut.” The resulting images help doctors identify tumors, pleural thickening, fluid buildup, or other abnormalities associated with mesothelioma.
Iodine-based contrast (radiocontrast) is often used to improve visibility. Patients may drink the iodine solution and/or receive it through an IV to enhance image clarity and provide more details of the organs and tissues.
CT scans are the primary imaging tool for investigating the possibility of pleural mesothelioma. Research shows that CT imaging detected pleural thickening in 94% of pleural mesothelioma patients and pleural effusion (fluid around the lungs) in 74% of patients, demonstrating its effectiveness in early evaluation.
What to Expect Before, During, and After CT Scans
- Before the scan: Patients may need to drink and/or receive an IV of a contrast liquid so images can be seen clearly.
- After the scan: More images may be needed at a later time.
Scan time:
Between 15 and 60 minutes
Does it hurt?
No, but patients may experience discomfort during the IV placement and lying flat for an extended period of time.
PET Scans for Mesothelioma
A PET scan uses a small dose of radioactive sugar (FDG), or tracer, to show how tissues in the body are functioning. Because cancer cells absorb sugar more rapidly, they appear brighter on PET images. The tracer is injected into a vein and a rotating scanner, similar to a CT machine, captures metabolic activity throughout the body.
Why PET Scans Are Used for Mesothelioma
What to Expect Before, During, and After PET Scans
- Before the scan: An IV is placed and a radioactive tracer is injected 1 hour before the scan.
- After the scan: Additional scans may be needed to obtain more images.
Scan time:
20-30 minutes, but some time is needed before scanning to allow for the tracer to circulate in the bloodstream
Does it hurt?
No, but some patients may experience discomfort during IV placement and lying flat for an extended period of time.
MRI Scans for Mesothelioma
An MRI scan uses powerful magnets and radio waves to create detailed images of soft tissues, organs, bones, and blood vessels. For mesothelioma, an MRI is especially useful for identifying the exact location and extent of tumors, helping doctors accurately evaluate and stage the disease, and develop an individualized treatment plan.
How MRI Scans Work
Patients lie on a table that slides into a cylindrical scanner. A magnetic field and radio signals generate high-resolution images. Patients are required to remain completely still during the scan so the images are clear.
What to Expect Before, During, and After MRI Scans
- Before the scan: All metal must be removed before entering the MRI exam room and an IV may need to be started if the test is ordered with contrast.
- After the scan: Follow-up scans might be needed.
Scan time:
40-80 minutes depending on the part of the body being scanned
Does it hurt?
No, but patients may experience discomfort from the IV placement and lying flat for extended periods of time. This procedure also requires the patient to be placed in a tube like machine, which may cause anxiety or claustrophobic symptoms. Sedation might be needed.
Why Are Mesothelioma Tests So Important?
Imaging tests are typically one of the first steps in diagnosing mesothelioma. Patients experiencing symptoms of mesothelioma are examined to find abnormalities in the body. Mesothelioma is difficult to diagnose due to symptoms that are often non-specific and can mimic common non-life threatening conditions, like the flu.
These tests can reveal the presence of tumors but cannot determine the exact disease or if the tumors are malignant. Surgical procedures called biopsies are used to provide a definitive diagnosis of mesothelioma.
Mesothelioma may be misdiagnosed or confused with other types of cancer, such as adenocarcinoma or lung cancer. If mesothelioma is suspected after a tissue biopsy it may be advised to consult with a mesothelioma specialist. Specialists have the knowledge and experience needed to accurately examine imaging scans and biopsy results to determine if tumors are mesothelioma. Connect with a mesothelioma specialist to get an accurate mesothelioma diagnosis.
Sources & Author
- The role of imaging in diagnosis and management of malignant peritoneal mesothelioma: a systematic review. Abdominal Radiology. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/35257201/. Accessed: 03/28/2022.
- Sensitivity and Specificity. Radiopaedia. Retrieved from: https://radiopaedia.org/articles/sensitivity-and-specificity?lang=us. Accessed: 03/28/2022.
- Part 1: Simple Definition and Calculation of Accuracy, Sensitivity and Specificity. Archives of Academic Emergency Medicine. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4614595/. Accessed: 03/28/2022.
- CT (Computed Tomography) Scan. Healthline. Retrieved from: https://www.healthline.com/health/ct-scan. Accessed: 06/23/2020.
- CT in Differential Diagnosis of Diffuse Pleural Disease. American Journal of Radiology. Retrieved from: https://www.ajronline.org/doi/pdfplus/10.2214/ajr.154.3.2106209. Accessed: 06/23/2020.
- X-Ray/Radiology Frequently Asked Questions. St. Mary’s Health System. Retrieved from: https://www.stmarysmaine.com/departments-services/x-ray-imaging/x-rayradiology-frequently-asked-questions.. Accessed: 06/23/2020.
- Medical Imaging. St. Michael’s. Retrieved from: http://www.stmichaelshospital.com/programs/imaging/ctscan/faq.php. Accessed: 06/23/2020.
- PET/CT Cancer Imaging: Cancers Eat a lot of Sugar. UCLA Center for Integrative Oncology. Retrieved from: https://www.simmsmanncenter.ucla.edu/center_events/petct-cancer-imaging-cancers-eat-a-lot-of-sugar/. Accessed: 06/23/2020.
- The role of imaging in the management of primary pleural malignancies. Cancer Imaging. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4448635/. Accessed: 06/23/2020.
- Positron Emission Tomography – Computed Tomography (PET/CT). Radiologyinfo.org. Retrieved from: https://www.radiologyinfo.org/en/info.cfm?pg=pet. Accessed: 06/23/2020.
- How long does an MRI take? WebMD. Retrieved from: https://www.webmd.com/multiple-sclerosis/qa/how-long-does-an-mri-take. Accessed: 06/23/2020.
- Tests for Malignant Mesothelioma. American Cancer Society. Retrieved from: https://www.cancer.org/cancer/malignant-mesothelioma/detection-diagnosis-staging/how-diagnosed.html. Accessed: 06/23/2020.
- Mesothelioma Imaging and Diagnostics, What to Look For. Imaging Technology News. Retrieved from: https://www.itnonline.com/article/mesothelioma-imaging-and-diagnostics-what-look. Accessed: 06/23/2020.
AI Summary of Imaging Tests for Diagnosis
Imaging tests play a vital role in the diagnosis of mesothelioma, a serious cancer that affects the lining of the lungs, abdomen, or heart. While these tests cannot confirm mesothelioma on their own, they provide important visual information that helps doctors understand the extent and location of abnormalities in the body. The initial imaging often begins with a simple X-ray, which can reveal signs such as tissue thickening or abnormal fluid accumulation. From there, more detailed scans like CT, PET, and MRI are used to gain a clearer view of the disease and guide further testing, such as biopsies, which are necessary for a definitive diagnosis.
Each imaging method offers unique benefits. A CT scan creates detailed three-dimensional images, allowing doctors to assess tumor size, spread, and structure within the chest or abdomen. PET scans provide insight into how tissues are functioning by detecting areas with high sugar absorption typical of cancer cells, which aids in distinguishing malignant from benign growths. MRI scans use powerful magnets and radio waves to produce highly detailed images of soft tissues, helping to determine the precise location and extent of tumors without exposing patients to radiation. These scans are crucial for staging the disease, planning treatment procedures, and monitoring disease progression or response to therapy.
The use of these imaging tools involves minimal discomfort, but some procedures might require contrast agents, IV placement, or lying still for extended periods, which can cause some minor discomfort or anxiety, especially in enclosed spaces. The accuracy of these tests is assessed through measures such as sensitivity, specificity, and overall accuracy, which help determine how well they identify true positive or negative cases. Because false results can lead to unnecessary procedures or delays in treatment, doctors interpret these imaging results carefully and often combine them with biopsy findings for an accurate diagnosis. Overall, imaging tests are essential in the early detection and ongoing management of mesothelioma, helping patients receive the most appropriate care based on detailed and precise information about their condition.