OSF Saint Anthony's Health Center

Alton, Illinois

Diagnostic testing

The following diagnostic tests are available at OSF Saint Anthony’s:

Pulmonary function tests

These non-invasive tests show how well the lungs are working. The tests measure lung volume, capacity, rates of flow, and gas exchange. This information can help your health care provider diagnose and decide the treatment of certain lung disorders.


This measures the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. The most common measurements used are: Forced expiratory volume in one second (FEV1). This is the amount of air you can blow out within one second.

Six-minute walk tests

A pulmonary function test in which the distance a patient can walk over a six-minute period is measured, usually including pulse oximetry, a device that clips on to your finger tip and measures the amount of oxygen in the blood. The six-minute walk test is used for prognosis, diagnosis, and in response to therapy.

Sleep studies

Sleep studies can reveal sleep-related breathing disorders, such as sleep apnea.


An echocardiogram is a non-invasive test that looks at the heart's activity and muscles through ultrasound waves. Echocardiograms also are used to diagnose blood clots in the heart and fluid buildup in the sac around the heart, as well as monitor heart valve functioning. It is used when doctors need to diagnose heart conditions such as heart disease or monitor a heart condition.  

Right heart catheterizations

A heart catheterization is an invasive imaging test that allows doctors to see the vessels and arteries that supply the heart with blood. It is used to evaluate a patient's heart muscle function or to determine if a patient needs intervention treatment. During the procedure, the patient lies underneath an X-ray machine. After being given a mild sedative, a doctor threads a small catheter through the patient's artery in their groin or in their arm. The catheter injects dye into the patient's artery in order to allow the doctor to see the patient's heart and vessels on X-ray.