An interventional study of Additional CT acquisition at low dose (1- 2 mSv) in Pulmonary Embolism (Diagnosis) and Pulmonary Embolism Acute, sponsored by Massachusetts General Hospital. Recruiting at 2 sites in United States. Open to participants aged 21 Years and older. Per ClinicalTrials.gov, last updated 2026-09-11.
Sponsored by Massachusetts General Hospital · Not applicable, Interventional, and Diagnostic
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.
832 studies on the registry are indexed under Pulmonary Embolism; 171 are open to participants now.
This study's planned enrollment of 750 is above the median of 174 across 429 interventional studies indexed under Pulmonary Embolism.
Browse Pulmonary Embolism studies →Massachusetts General Hospital is the lead sponsor of 2,586 studies on the registry; 447 are open to participants now.
Of its 222 completed or terminated interventional studies of FDA-regulated products, 168 (76%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
MMSE and MoCA
Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients will undergo an additional low dose CT image acquistion without contrast prior to CT pulmanary angiogram. The low dose CT will be performed in both inspiration and expiration.
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.
Also known as: CT
NPV for ruling out PE on non-contrast CT
Negative predictive value
Time frame: 2 years
Plan to share: Undecided — To protect patient privacy and comply with hospital guidelines, we will not share IPD.
No publications or documents are linked to this record.
Started Jul 2026 (actual). Primary completion is estimated for Jun 2028, 23 months after the start.
Of 125 non-industry interventional studies with no phase under Pulmonary Embolism, half reached primary completion within 27 months of starting (the median), counting those still running; a quarter within 15 and three quarters within 55. This study's planned 23 months is below that.
Counting every sponsor, half of 150 studies reached it within 25 months; a quarter within 15 and three quarters within 51.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Massachusetts General Hospital →