The goal of this clinical trial is to learn if a new computed tomography (CT) lung perfusion imaging method is as effective as standard of care (SOC) CT imaging. The main question it aims to answer is:

• Does the new contrast-free method provide more information about lung perfusion than SOC?

Participants will undergo a 30 minute chest CT.

The purpose of the study is to evaluate X-ray Pulsatility Index using prospectively acquired dynamic CT, which is different from conventional static CT scans.

The primary objective of this study is to collect dynamic CT scan data with human participants using high frame rate imaging methods to produce a map of lung perfusion.

Inclusion Criteria:

• Age 18 years or older
• Able to sign and date the informed consent form
• Will undergo a clinically-indicated CT exam of the head, neck, chest, abdomen, pelvis, or extremities

Exclusion Criteria:

• Pregnant or lactating
• In need of urgent or emergent care
• Have any conditions that, in the opinion of the PI or designee, would interfere with the evaluation of the results or constitute a health hazard for the participant