Pulmonary EmbolismPASEPNCT03579849
Pulmonary Perfusion by Iodine Subtraction Mapping CT Angiography in Acute Pulmonary Embolism
A study testing Pulmonary tomoscintigraphy in people with Pulmonary Embolism, run by University Hospital, Brest at 1 site in France.
Trial summary
Pulmonary embolism (PE) is a diagnostic and therapeutic challenge. The risk of death of untreated PE is approximately 25%. On the other hand, anticoagulant treatment is associated with a haemorrhagic risk (2% of major haemorrhagic accidents per year, of which 10% are fatal). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Pulmonary Embolism
- What is being tested?
- Pulmonary tomoscintigraphy
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteFrance
- Study dates
- 25 Jun 2018to 25 Apr 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- All patients who have been diagnosed with acute pulmonary embolism on the Aquilion One Genesis scan (Toshiba, Medical System, Tokyo, Japan) at the Brest University Hospital, and who have had a mapping of the iodine derived from the subtraction images.
Who cannot join
- Tomoscintigraphy not feasible within 24 hours.
- Massive pulmonary embolism or with signs of gravity
- Pregnant or lactating women
- Minor patient
- Protected adults
- Incapacity / refusal to give consent
- Hypersensitivity to pertechnetate (99m Tc)
- Hypersensitivity to human albumin
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Pulmonary Perfusion by Iodine Subtraction Mapping CT Angiography in Acute Pulmonary Embolism: a Diagnostic Accuracy Study Versus Pulmonary Perfusion SPECT.
- Pulmonary embolism (PE) is a diagnostic and therapeutic challenge. The risk of death of untreated PE is approximately 25%. On the other hand, anticoagulant treatment is associated with a haemorrhagic risk (2% of major haemorrhagic accidents per year, of which 10% are fatal). A diagnostic accuracy is therefore necessary.
- Two approaches are available to diagnose PE:
- A functional approach, represented by pulmonary ventilation / perfusion scintigraphy (V / P), which looks for the functional consequences of PE. The main disadvantage of this approach is that there is a high rate of non-diagnostic examinations. On the other hand, it allows a mapping of pulmonary perfusion at the microcapillary scale, and thus allows the quantification of the vascular obstruction index, which would be an independent risk factor of PE recurrence.
- A morphological approach, represented by CT pulmonary angiography (CTPA), which allows the visualisation of the clot itself. This approach is currently the most used but has some limitations, including a risk of over-diagnosis of pulmonary embolism and the inability to reliably quantify the index of vascular obstruction.
Read more
Lung subtraction iodine mapping CT is a new technique allowing, during the realization of a CTPA, without additional irradiation, to provide a mapping of the iodine. This mapping of iodine could potentially be used to evaluate pulmonary perfusion.
It would then be possible to obtain, during a single examination, in addition to the anatomical information of the thoracic angioscan, information on the pulmonary perfusion and thus to assess the functional consequences of PE.
No study to date has evaluated the performance of the pulmonary subtraction CT for the evaluation of pulmonary perfusion in the context of acute pulmonary embolism suspicion.
- Conditions
- Pulmonary Embolism
- Being tested
- Pulmonary tomoscintigraphy
- Medical subject headings
- Pulmonary Embolism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Pulmonary tomoscintigraphyDiagnostic test
The included patients will benefit from pulmonary tomoscintigraphy within 24 hours after the diagnosis of pulmonary embolism. Each tomoscintigraphy will be interpreted blindly by 3 nuclear physicians. Each of the 20 lung segments will be interpreted as normoperfused or hypoperfused.
| Study group | Role | What they receive |
|---|---|---|
| Perfusion SPECT | Experimental | Included patients with a diagnosis of acute PE on CTPA and who had a subtraction iodine mapping CT will undergo a SPECT/CT within 24 hours.
Each lung subtraction iodine mapping CT will be interpreted blindly by 3 radiologists. Each of the 20 lung segments will be interpreted as normoperfused or hypoperfused.
Each perfusion SPECT will be interpreted blindly by 3 nuclear medicine physicians. Each of the 20 lung segments will be interpreted as normoperfused or hypoperfused. Receives: Diagnostic Test: Pulmonary tomoscintigraphy |
What is being measured
The primary outcome is the main question the study is designed to answer.
The sensitivity of iodine mapping by subtraction technique.
The sensitivity of iodine mapping by subtraction technique for the detection of perfusion defects in pulmonary embolism is evaluated with using pulmonary perfusion tomoscintigraphy as a reference standard .
Measured: 24 hours
Secondary outcomes (5)
The specificity of iodine mapping by subtraction technique
The specificity of iodine mapping by subtraction technique for the detection of perfusional defects in acute pulmonary embolism is determinated with using pulmonary perfusion tomoscintigraphy as reference standard.
Measured: 24 hours
Pulmonary vascular obstruction index
Thé correlation between the pulmonary vascular obstruction index measured by iodine mapping by subtraction technique and that obtained by perfusion tomoscintigraphy is evaluating
Measured: 24 hours
Concordance CTPA - iodine substraction
The concordance between the morphological abnormalities visualized at the thoracic angioscanner (visualization of an endoluminal defect within the pulmonary arterial network) is evaluated.
Measured: 24 hours
Concordance CTPA - SPECT
The concordance between the morphological abnormalities on CTPA (visualization of an endoluminal defect within the pulmonary arterial network) is evaluated.
Measured: 24 hours
Interobserver reproductibility
The interobserver reproducibility of subtraction technique versus pulmonary tomoscintigraphy in reported as normal or abnormal lung perfusion at a segmental level.
Measured: 24 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jul 2018
- Study start25 Jun 2018
- Primary completion24 Apr 2019
- Study completion25 Apr 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Pulmonary EmbolismStudies of the same condition, open and under way.
- More trials run by University Hospital, BrestThe 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Brest
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03579849
- Sponsor's protocol ID
- 29BRC18.0083 (PASEP)
- Acronym
- PASEP
- Status last verified
- Apr 2019
- First submitted
- 11 Jun 2018
- Last updated
- 3 Dec 2025
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Dissaux B, Le Floch PY, Robin P, Bourhis D, Couturaud F, Salaun PY, Nonent M, Le Roux PY. Pulmonary perfusion by iodine subtraction maps CT angiography in acute pulmonary embolism: comparison with pulmonary perfusion SPECT (PASEP trial). Eur Radiol. 2020 Sep;30(9):4857-4864. doi: 10.1007/s00330-020-06836-3. Epub 2020 Apr 11.
PubMed 32279113
Study at a glance
From the registry record, last updated by the sponsor on 3 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pulmonary Perfusion by Iodine Subtraction Mapping CT Angiography in Acute Pulmonary Embolism: a Diagnostic Accuracy Study Versus Pulmonary Perfusion SPECT.
- ClinicalTrials.gov ID
- NCT03579849
- Acronym / sponsor ID
- PASEP / 29BRC18.0083 (PASEP)
- Conditions
- Pulmonary Embolism
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- University Hospital, BrestUniversity, hospital or other
- Study start
- 25 Jun 2018 (actual)
- Primary completion
- 24 Apr 2019 (actual)
- Study completion
- 25 Apr 2019 (actual)
- First posted
- 9 Jul 2018 (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.
- Pulmonary embolism (PE) is a diagnostic and therapeutic challenge. The risk of death of untreated PE is approximately 25%. On the other hand, anticoagulant treatment is associated with a haemorrhagic risk (2% of major haemorrhagic accidents per year, of which 10% are fatal). A diagnostic accuracy is therefore necessary.
- Two approaches are available to diagnose PE:
- A functional approach, represented by pulmonary ventilation / perfusion scintigraphy (V / P), which looks for the functional consequences of PE. The main disadvantage of this approach is that there is a high rate of non-diagnostic examinations. On the other hand, it allows a mapping of pulmonary perfusion at the microcapillary scale, and thus allows the quantification of the vascular obstruction index, which would be an independent risk factor of PE recurrence.
- A morphological approach, represented by CT pulmonary angiography (CTPA), which allows the visualisation of the clot itself. This approach is currently the most used but has some limitations, including a risk of over-diagnosis of pulmonary embolism and the inability to reliably quantify the index of vascular obstruction.
Lung subtraction iodine mapping CT is a new technique allowing, during the realization of a CTPA, without additional irradiation, to provide a mapping of the iodine. This mapping of iodine could potentially be used to evaluate pulmonary perfusion.
It would then be possible to obtain, during a single examination, in addition to the anatomical information of the thoracic angioscan, information on the pulmonary perfusion and thus to assess the functional consequences of PE.
No study to date has evaluated the performance of the pulmonary subtraction CT for the evaluation of pulmonary perfusion in the context of acute pulmonary embolism suspicion.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Perfusion SPECT | Experimental | Diagnostic Test: Pulmonary tomoscintigraphyIncluded patients with a diagnosis of acute PE on CTPA and who had a subtraction iodine mapping CT will undergo a SPECT/CT within 24 hours. Each lung subtraction iodine mapping CT will be interpreted blindly by 3 radiologists. Each of the 20 lung segments will be interpreted as normoperfused or hypoperfused. Each perfusion SPECT will be interpreted blindly by 3 nuclear medicine physicians. Each of the 20 lung segments will be interpreted as normoperfused or hypoperfused. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- All patients who have been diagnosed with acute pulmonary embolism on the Aquilion One Genesis scan (Toshiba, Medical System, Tokyo, Japan) at the Brest University Hospital, and who have had a mapping of the iodine derived from the subtraction images.
Key exclusion criteria (8 listed)
- Tomoscintigraphy not feasible within 24 hours.
- Massive pulmonary embolism or with signs of gravity
- Pregnant or lactating women
- Minor patient
- Protected adults
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 |
|---|---|---|
| Pulmonary tomoscintigraphyThe included patients will benefit from pulmonary tomoscintigraphy within 24 hours after the diagnosis of pulmonary embolism. Each tomoscintigraphy will be interpreted blindly by 3 nuclear physicians. Each of the 20 lung segments will be interpreted as normoperfused or hypoperfused. | Diagnostic test | Perfusion SPECT |
Primary outcome
The sensitivity of iodine mapping by subtraction technique.
Time frame: 24 hours
The sensitivity of iodine mapping by subtraction technique for the detection of perfusion defects in pulmonary embolism is evaluated with using pulmonary perfusion tomoscintigraphy as a reference standard .
5 secondary outcomes
The specificity of iodine mapping by subtraction technique
Time frame: 24 hours
Pulmonary vascular obstruction index
Time frame: 24 hours
Concordance CTPA - iodine substraction
Time frame: 24 hours
Concordance CTPA - SPECT
Time frame: 24 hours
Interobserver reproductibility
Time frame: 24 hours
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Dec 2025.
- Results publication: PubMed 32279113Dissaux B, Le Floch PY, Robin P, Bourhis D, Couturaud F, Salaun PY, Nonent M, Le Roux PY. Pulmonary perfusion by iodine subtraction maps CT angiography in acute pulmonary embolism: comparison with pulmonary perfusion SPECT (PASEP trial). Eur Radiol. 2020 Sep;30(9):4857-4864. doi: 10.1007/s00330-020-06836-3. Epub 2020 Apr 11.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Pulmonary tomoscintigraphy in people with Pulmonary Embolism, run by University Hospital, Brest at 1 site in France.
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 1 inclusion and 8 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: finished, as of the sponsor's last update on 3 Dec 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 France. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The sensitivity of iodine mapping by subtraction technique. (time frame: 24 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03579849, which also lists 1 linked publication.
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 3 Dec 2025.