Overview

We are doing the research to see if a CT scan without the dye can help find pulmonary emboli. If you agree to join the study, you will be asked to sign this consent form before we do any research procedures. If you join the research, we will ask you to blow into a small device known as a spirometer to train you to hold your breath after you inhale and exhale. Spirometer is a small handheld device to find out how well your lungs work when you inhale and exhale. For this research, we will obtain two extra sets of CT images at very low levels of radiation dose. The two extra sets of images will take less than 1 minute. Your total participation time is about 5 minutes. We will also review your medical record for up to 30 to 90 days after your CT scan.

The main risks of being in the study are exposure to ionizing radiation which may have health risks, and minor inconvenience from the spirometer test.

You will not benefit from taking part in this research study. If you take part in this study, your participation may help people in the future. If you decide not to be in the study, you will still have the standard-of-care chest CT with the dye ordered by your doctor. You will not be paid for taking part in this research study.

Eligibility

Inclusion Criteria:

1. Patients undergoing CTPA for suspected aPE
2. Patients who provide written informed consent to participate
3. Adults patients \>/= 21 years of age
4. Mini Mental State Exam (MMSE) score of 18 or more.

Exclusion Criteria:

1. Patients who decline informed consent
2. Patients with known chronic PE
3. Patients with known interstitial lung diseases
4. Patients who cannot raise their arms above their shoulders (arms can cause serious artifacts)
5. Women of child-bearing potential (\< 55 years) who test positive for pregnancy test
6. Patients \< 21 years of age (to avoid research radiation dose in young patients)
7. Patients with any EMR documented cognitive impairment or diseases such as dementia, recent head injury, psychiatric disorders, or other neurological diseases that impair decision-making.
8. Pregnant subjects
9. Women of child-bearing potential (21-55 years) who refuse to take a urine pregnancy test prior to their CT examination
10. Mini Mental State Exam (MMSE) score of less than 18.