NCT07527117 · Massachusetts General Hospital
Role of n On-contrast Chest CT (NCCT) Based CT V: Q in Patients With Acute Pulmonary Embolism (aPE)
What this study is about
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.
View original scientific description
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.
Interventions
DIAGNOSTIC_TEST
Additional CT acquisition at low dose (1- 2 mSv)
In addition to their CTPA, we will acquire low-dose CT images in inspiration and expiration breath hold or in free breathing phase.
Primary outcome measures
NPV for ruling out PE on non-contrast CT
Time frame: 2 years
Negative predictive value
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Patients undergoing CTPA for suspected aPE
- Patients who provide written informed consent to participate
- Adults patients \>/= 21 years of age
- Mini Mental State Exam (MMSE) score of 18 or more.
Exclusion criteria
- Patients who decline informed consent
- Patients with known chronic PE
- Patients with known interstitial lung diseases
- Patients who cannot raise their arms above their shoulders (arms can cause serious artifacts)
- Women of child-bearing potential (\< 55 years) who test positive for pregnancy test
- Patients \< 21 years of age (to avoid research radiation dose in young patients)
- 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.
- Pregnant subjects
- Women of child-bearing potential (21-55 years) who refuse to take a urine pregnancy test prior to their CT examination
- Mini Mental State Exam (MMSE) score of less than 18.
Where
- Boston, Massachusetts
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Sep 11, 2026 · Source of record for eligibility and locations