The primary purpose of this study is evaluate the VRI device's accuracy in diagnosis of pleural effusion (in comparison to chest x-ray and ultrasonography), and to assess the pleural effusion location and size. The VRI system uses pressure sensors (electronic stethoscopes) to record the energy created by the airflow in the lungs during breathing.

The accumulation of excess fluid in the pleural cavity of the lungs, known as pleural effusion, is a common clinical condition that may be the result of trauma or disease. Diagnosis and management of pleural effusion can be done by X-Ray or ultrasound; however X-Ray emits radiation, requires a special room and expert personnel, while ultrasound requires a high level of expertise to perform and analyze. The VRI device is non-invasive and radiation free. The VRI device is a simple method to image the lungs in a regional manner to examine changes that occur during pleural effusion.

Comparison: X-ray and ultrasonography evaluations of pleural effusion, compared to VRI acoustic imaging evaluations.

Inclusion Criteria:

• Able and willing to read, understand, and provide written Informed Consent;
• Male or Female in the age range of 18-85 years;
• Subject is suspected to have pleural effusion;
• Body mass index (BMI) > 21.

Exclusion Criteria:

• Chest wall deformation;
• Spine deformation (including severe scoliosis);
• Hirsutism;
• Potentially contagious skin lesion on the back;
• Skin lesion that would interfere with sensor placement;
• Cardiac pacemaker or implantable defibrillator;

Patients diagnosed with pleural effusion