Cannabis UseNCT03909477
Longitudinal Study of Xenon-129 MRI Imaging Effects of Cannabis Smoking
An observational study of Cannabis Use and Cannabis Smoking, run by Western University, Canada at 1 site in Canada.
Trial summary
This is a longitudinal study of the long-term health impact of cannabis smoking on the lungs. Participants will be followed over a period of 3 years, and impacts of cannabis smoking on the lungs will be measured with magnetic resonance imaging (MRI) using hyperpolarized xenon-129 gas, pulmonary function tests… Read more about this study
- Who is it for?
- Ages 18 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Cannabis Use, Cannabis Smoking, Marijuana Smoking
- What is being tested?
- Hyperpolarized Xenon-129 MRI of the lungs, Computed Tomography (CT) and Pulmonary Function Tests (PFTs)
- How many people
- 200 participants
- Where
- 1 siteCanada
- Study dates
- 1 Jun 2022to 1 Dec 2030
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Current and former smokers of cannabis
Who may be able to join
- Patient understands study procedures and is willing to participate in the study as indicated by the patient's signature
- Provision of written, informed consent prior to any study specific procedures
- Males and females aged 18-85
- Current or former cannabis smoker (medicinal or recreational) with or without concurrent tobacco smoking history
- Participant is able to perform reproducible pulmonary function testing (i.e. the 3 best acceptable spirograms have Forced Expiratory Volume in 1 second (FEV1) values that do not vary more than 150 millilitres)
- Participant is able to perform a breathhold for 16s
- FEV1 > 25% predicted
- Forced Vital Capacity (FVC) > 25% predicted and >0.5 litres
Who cannot join
- Participant is, in the opinion of the investigator, mentally or legally incapacitated, preventing informed consent from being obtained, or cannot read or understand written material
- Participant is medically unstable in the opinion of the Principal Investigator
- Participant has a daytime room air oxygen saturation <90% while lying supine
- Participant is unable to perform spirometry or plethysmography maneuvers
- Patient is pregnant at time of enrolment
- In the opinion of the investigator, patient suffers from any physical, psychological or other condition(s) that might prevent performance of the MRI, such as severe claustrophobia
- Patient has implanted mechanically, electrically or magnetically activated device or any metal in their body, which cannot be removed, including but not limited to pacemakers, neurostimulators, biostimulators, implanted insulin pumps, aneurysm clips, bioprosthesis, artificial limb, metallic fragment or foreign body, shunt, surgical staples (including clips or metallic sutures and/or ear implants) - at the discretion of the MRI Technologist.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
Robarts Research Institute; The University of Western Ontario; London Health Sciences Centre
London, Ontario, N6A 5B7
Grace E Parraga, PhD, 519-931-5265, gparraga@uwo.ca
About this study
Official title: Longitudinal Study of Xenon-129 MRI Imaging of Effects of Cannabis Smoking on Lung Structure and Function
This is a longitudinal study of the long-term health impact of cannabis smoking on the lungs. Participants will be followed over a period of 3 years, and impacts of cannabis smoking on the lungs will be measured with magnetic resonance imaging (MRI) using hyperpolarized xenon-129 gas, pulmonary function tests, exercise capacity, computed tomography images and questionnaires.
Read the detailed description
This is a longitudinal study of the long-term lung health impact of cannabis smoking in adults using xenon-129 (129Xe) MRI over three years.
Males and females between the ages of 18 to 85 years with a history of cannabis smoking will be screened, and those who satisfy all inclusion and exclusion criteria will undergo study visits for up to 3 years, with visits every 12 ± 3 months, for a total of up to four study visits. Each study visit will include collection of patient smoking history and vital signs. At Visit 1 and 4, 129-Xe MRI, spirometry, plethysmography for airways resistance (Raw) and lung volumes, forced oscillation technique (FOT) and multiple breath nitrogen washout (MBNW) for the lung clearance index (LCI) will all be performed pre- and post-bronchodilator. Blood will be drawn for blood eosinophil count, and sputum induction will be done to measure sputum eosinophils. A CT will also be done at Robarts Research Institute, or at University Hospital, London Health Sciences Centre next door to Robarts. Visit 2 will be a telephone call to complete questionnaires. Visit 3 will include spirometry and questionnaires only. Participants 35 years of age or older will complete a six minute walk test (6MWT) for the distance walked (6MWD), pre and post oxygen saturation, perceived dyspnea (Modified Borg Scale) and perceived exertion (Borg's rating of perceived exertion). These participants will complete the St. George's Respiratory Questionnaire (SGRQ).
Participants under the age of 35 will complete Cardio Pulmonary Exercise Testing to assess exercise capacity, and the American Thoracic Society Questionnaire (ATSQ).
- Conditions
- Cannabis Use, Cannabis Smoking, Marijuana Smoking, Marijuana Usage
- Being tested
- Hyperpolarized Xenon-129 MRI of the lungs, Computed Tomography (CT), Pulmonary Function Tests (PFTs), Six Minute Walk Test (6MWT), Cardiopulmonary exercise testing (CPET)
- Medical subject headings
- Marijuana Smoking
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hyperpolarized Xenon-129 MRI of the lungsDiagnostic test
Participants will be imaged using MRI using hyperpolarized xenon-129 gas as a contrast gas
Computed Tomography (CT)Diagnostic test
Also called CT
Participants will undergo a CT scan of the thoracic cavity
Pulmonary Function Tests (PFTs)Diagnostic test
Also called PFTs
Participants will have their lung function evaluated using PFTs
Six Minute Walk Test (6MWT)Diagnostic test
Also called 6MWT
Participants >35 years of age will perform the six minute walk test as a measure of exercise capacity
Cardiopulmonary exercise testing (CPET)Diagnostic test
Also called CPET
Participants <35 will perform cardiopulmonary exercise testing as a measure of exercise capacity
Sputum analysisDiagnostic test
Participants will provide a sputum sample that will be analysed for eosinophils
Blood analysisDiagnostic test
Participants will have their blood drawn and analysed for eosinophil count.
| Study group | Role | What they receive |
|---|---|---|
| Cannabis Smoker | Participants in this group will be current or former cannabis smokers Receives: Diagnostic Test: Hyperpolarized Xenon-129 MRI of the lungs; Diagnostic Test: Computed Tomography (CT); Diagnostic Test: Pulmonary Function Tests (PFTs); Diagnostic Test: Six Minute Walk Test (6MWT); Diagnostic Test: Cardiopulmonary exercise testing (CPET); Diagnostic Test: Sputum analysis; Diagnostic Test: Blood analysis |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes in airways over time
Measured using Xenon-129 (129-Xe) MRI
Measured: 3 years
Changes in parenchyma over time
Measured using Xenon-129 (129-Xe) MRI
Measured: 3 years
Differences in lung ventilation in cannabis smokers compared to never-smokers and tobacco smokers
Measured using 129-Xe MRI
Measured: 3 years
Differences in perfusion in cannabis smokers compared to never-smokers and tobacco smokers
Measured using 129-Xe MRI
Measured: 3 years
Differences in parenchyma integrity in cannabis smokers compared to never-smokers and tobacco smokers
Measured using 129-Xe MRI
Measured: 3 years
Differences in airways between cannabis-only smokers and cannabis and tobacco smokers
Measured using 129-Xe MRI
Measured: 3 years
Differences in parenchyma between cannabis-only smokers and cannabis and tobacco smokers
Measured using 129-Xe MRI
Measured: 3 years
Dose-response of cannabis use to changes in airways over time
Measured using 129-Xe MRI
Measured: 3 years
Dose-response of cannabis use to changes in parenchyma over time
Measured using 129-Xe MRI
Measured: 3 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Apr 2019
- Study start1 Jun 2022
- Primary completion1 Dec 2030 (estimated)
- Study completion1 Dec 2030 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Cannabis UseStudies of the same condition, open and under way.
- More trials run by Western University, CanadaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Western University, Canada
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Grace E Parraga, PhD, Principal investigator, Robarts Research Institute, The University of Western Ontario
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03909477
- Sponsor's protocol ID
- ROB0043
- Status last verified
- Aug 2025
- First submitted
- 25 Mar 2019
- Last updated
- 15 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Longitudinal Study of Xenon-129 MRI Imaging of Effects of Cannabis Smoking on Lung Structure and Function
- ClinicalTrials.gov ID
- NCT03909477
- Acronym / sponsor ID
- ROB0043
- Conditions
- Cannabis Use, Cannabis Smoking, Marijuana Smoking, Marijuana Usage
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Western University, CanadaUniversity, hospital or other
- Study start
- 1 Jun 2022 (actual)
- Primary completion
- 1 Dec 2030 (estimated)
- Study completion
- 1 Dec 2030 (estimated)
- First posted
- 10 Apr 2019 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a longitudinal study of the long-term health impact of cannabis smoking on the lungs. Participants will be followed over a period of 3 years, and impacts of cannabis smoking on the lungs will be measured with magnetic resonance imaging (MRI) using hyperpolarized xenon-129 gas, pulmonary function tests, exercise capacity, computed tomography images and questionnaires.
Detailed description
This is a longitudinal study of the long-term lung health impact of cannabis smoking in adults using xenon-129 (129Xe) MRI over three years.
Males and females between the ages of 18 to 85 years with a history of cannabis smoking will be screened, and those who satisfy all inclusion and exclusion criteria will undergo study visits for up to 3 years, with visits every 12 ± 3 months, for a total of up to four study visits. Each study visit will include collection of patient smoking history and vital signs. At Visit 1 and 4, 129-Xe MRI, spirometry, plethysmography for airways resistance (Raw) and lung volumes, forced oscillation technique (FOT) and multiple breath nitrogen washout (MBNW) for the lung clearance index (LCI) will all be performed pre- and post-bronchodilator. Blood will be drawn for blood eosinophil count, and sputum induction will be done to measure sputum eosinophils. A CT will also be done at Robarts Research Institute, or at University Hospital, London Health Sciences Centre next door to Robarts. Visit 2 will be a telephone call to complete questionnaires. Visit 3 will include spirometry and questionnaires only. Participants 35 years of age or older will complete a six minute walk test (6MWT) for the distance walked (6MWD), pre and post oxygen saturation, perceived dyspnea (Modified Borg Scale) and perceived exertion (Borg's rating of perceived exertion). These participants will complete the St. George's Respiratory Questionnaire (SGRQ).
Participants under the age of 35 will complete Cardio Pulmonary Exercise Testing to assess exercise capacity, and the American Thoracic Society Questionnaire (ATSQ).
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Cannabis Smoker | – | Diagnostic Test: Hyperpolarized Xenon-129 MRI of the lungs, Diagnostic Test: Computed Tomography (CT), Diagnostic Test: Pulmonary Function Tests (PFTs), Diagnostic Test: Six Minute Walk Test (6MWT), Diagnostic Test: Cardiopulmonary exercise testing (CPET), Diagnostic Test: Sputum analysis, Diagnostic Test: Blood analysisParticipants in this group will be current or former cannabis smokers |
Who may qualify
- Ages
- 18 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Current and former smokers of cannabis
Key inclusion criteria (8 listed)
- Patient understands study procedures and is willing to participate in the study as indicated by the patient's signature
- Provision of written, informed consent prior to any study specific procedures
- Males and females aged 18-85
- Current or former cannabis smoker (medicinal or recreational) with or without concurrent tobacco smoking history
- Participant is able to perform reproducible pulmonary function testing (i.e. the 3 best acceptable spirograms have Forced Expiratory Volume in 1 second (FEV1) values that do not vary more than 150 millilitres)
Key exclusion criteria (7 listed)
- Participant is, in the opinion of the investigator, mentally or legally incapacitated, preventing informed consent from being obtained, or cannot read or understand written material
- Participant is medically unstable in the opinion of the Principal Investigator
- Participant has a daytime room air oxygen saturation <90% while lying supine
- Participant is unable to perform spirometry or plethysmography maneuvers
- Patient is pregnant at time of enrolment
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hyperpolarized Xenon-129 MRI of the lungsParticipants will be imaged using MRI using hyperpolarized xenon-129 gas as a contrast gas | Diagnostic test | Cannabis Smoker |
| Computed Tomography (CT)Also: CTParticipants will undergo a CT scan of the thoracic cavity | Diagnostic test | Cannabis Smoker |
| Pulmonary Function Tests (PFTs)Also: PFTsParticipants will have their lung function evaluated using PFTs | Diagnostic test | Cannabis Smoker |
| Six Minute Walk Test (6MWT)Also: 6MWTParticipants >35 years of age will perform the six minute walk test as a measure of exercise capacity | Diagnostic test | Cannabis Smoker |
| Cardiopulmonary exercise testing (CPET)Also: CPETParticipants <35 will perform cardiopulmonary exercise testing as a measure of exercise capacity | Diagnostic test | Cannabis Smoker |
| Sputum analysisParticipants will provide a sputum sample that will be analysed for eosinophils | Diagnostic test | Cannabis Smoker |
| Blood analysisParticipants will have their blood drawn and analysed for eosinophil count. | Diagnostic test | Cannabis Smoker |
Primary outcome
Changes in airways over time
Time frame: 3 years
Measured using Xenon-129 (129-Xe) MRI
Changes in parenchyma over time
Time frame: 3 years
Measured using Xenon-129 (129-Xe) MRI
Differences in lung ventilation in cannabis smokers compared to never-smokers and tobacco smokers
Time frame: 3 years
Measured using 129-Xe MRI
Differences in perfusion in cannabis smokers compared to never-smokers and tobacco smokers
Time frame: 3 years
Measured using 129-Xe MRI
Differences in parenchyma integrity in cannabis smokers compared to never-smokers and tobacco smokers
Time frame: 3 years
Measured using 129-Xe MRI
Differences in airways between cannabis-only smokers and cannabis and tobacco smokers
Time frame: 3 years
Measured using 129-Xe MRI
Differences in parenchyma between cannabis-only smokers and cannabis and tobacco smokers
Time frame: 3 years
Measured using 129-Xe MRI
Dose-response of cannabis use to changes in airways over time
Time frame: 3 years
Measured using 129-Xe MRI
Dose-response of cannabis use to changes in parenchyma over time
Time frame: 3 years
Measured using 129-Xe MRI
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Aug 2025.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Grace E Parraga, PhD principal investigator
Robarts Research Institute, The University of Western Ontario
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Cannabis Use and Cannabis Smoking, run by Western University, Canada at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 15 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Grace E Parraga, PhD (519-931-5265, gparraga@uwo.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Changes in airways over time (time frame: 3 years). The study lists 9 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Aug 2025.