Role of n On-contrast Chest CT (NCCT) Based CT V: Q in Patients With Acute Pulmonary Embolism (aPE)

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Pulmonary Embolism Acute; Pulmonary Embolism (Diagnosis)
• Intervention / Treatment: Diagnostic test: Additional CT acquisition at low dose (1- 2 mSv)

• Study Type: Interventional
• Enrollment (Estimated): 750
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Shivangi JHA, MD, MPH; Phone Number: 16176434583; Email: sjha7@mgh.harvard.edu

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02420
      • Massachusetts General Hospital
      • Contact: Shivangi JHA, MD MPH; Phone Number: 6176434583; Email: sjha7@mgh.harvard.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Non-contrast CT for diagnosis of acute pulmonary embolism; 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.; Other Names: CT

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
NPV for ruling out PE on non-contrast CT	Negative predictive value	2 years

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): June 30, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: April 7, 2026
• First Submitted That Met QC Criteria: April 7, 2026
• First Posted (Actual): April 14, 2026

Study Record Updates

• Last Update Posted (Actual): April 14, 2026
• Last Update Submitted That Met QC Criteria: April 7, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: CT ventilation perfusion pulmonary embolism CT pulmonary angiogram
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Respiratory Tract Diseases; Lung Diseases; Embolism and Thrombosis; Embolism; Pathological Conditions, Signs and Symptoms; Pulmonary Embolism; Disease
• Other Study ID Numbers: 2026P000652

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: To protect patient privacy and comply with hospital guidelines, we will not share IPD.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes