Imaging Scans for Pleural Mesothelioma

Imaging Scans for Pleural Mesothelioma

Imaging scans and other tests are imperative to making an accurate diagnosis of pleural mesothelioma. When a patient presents with shortness of breath or a constant cough, the first test most doctors perform is a chest X-ray.

While a chest X-ray may indicate an asbestos-related disease, the results are less detailed than those of more advanced imaging tests. However, chest X-rays will sometimes capture several signs of pleural mesothelioma, including pleural effusion, thickening of the pleural lung lining and calcium deposits on the lining.

The imaging scan of choice for the initial diagnosis of pleural mesothelioma is a computed tomography (CT) scan, also known as a CAT scan. Instead of taking one picture of the patient’s body like an X-ray, a CT scan takes many detailed cross-sectional images. A computer then combines these images, allowing doctors to look at the patient’s chest in slices.

Although CT scans take longer than traditional X-rays, they produce images that more clearly display the size and location of mesothelioma tumors and the extent to which they have spread throughout the body. A CT scan will commonly find pleural thickening, one sign that suggests pleural mesothelioma.

An even higher level of detail can be attained with a magnetic resonance imaging (MRI) scan, which produces an image with magnets and radio waves. This scan is generally better for detecting pleural mesothelioma that has spread into vital structures of the chest, such as the diaphragm (breathing muscle) or mediastinum (a group of structures located behind the breast bone and between the lungs). This type of scan is valuable because it can help identify the patients who will benefit most from surgery.

In some cases, doctors may confuse scar tissue for cancer on imaging scans. Positron emission tomography (PET) scans allow doctors to clearly distinguish between the two. This imaging technique uses a radioactive form of sugar that cancer cells absorb in large amounts. Although not very detailed, a PET scan can clearly display where mesothelioma cancer has spread.

A relatively new technique called the PET-CT scan, which combines PET and CT scan technologies into one machine, overcomes the limitations of the PET scan. Because studies demonstrate the PET-CT scan can gauge a patient’s response to chemotherapy better than either scan alone, it is a highly useful tool in pleural mesothelioma treatment.

Imaging scans are essential to determining a cancer’s stage. Staging assesses the growth and spread of a person’s cancer. Imaging scans are the primary diagnostic tool that allows doctors to evaluate the growth and spread of pleural mesothelioma.

An MRI scan can show whether the cancer has spread locally throughout the chest, which helps distinguish between stages I through III. A PET-CT scan is especially helpful at showing spread to distant organs, which can help determine if the cancer is in stage IV yet. To this end, imaging scans are crucial to reaching a prognosis because staging is the biggest determinant of prognosis.