Iodine mapping and functional limitation in CTED
Research type
Research Study
Full title
Iodine mapping in the diagnosis and assessment of functional limitation in patients with chronic thromboembolic disease.
IRAS ID
264298
Contact name
Colin Church
Contact email
Sponsor organisation
NHS Greater Glasgow and Clyde
Duration of Study in the UK
1 years, 5 months, 0 days
Research summary
We plan to investigate patients who have had pulmonary embolus (blood clot in the lung), who remain symptomatic despite 3months of anticoagulation(treatment with blood thinning agent). A large proportion of patients will have scarring following a blood clot. The importance of this is unclear. 2-4% of patients will develop enough scarring to develop high blood pressure within the lungs (chronic thromboembolic pulmonary hypertension) causing physical restriction, for which there is effective treatment, in the form of surgery, called a pulmonary endaterectomy. However, there is a group of patients that have chronic scarring, that do not develop pulmonary hypertension, but still have limitation.
Patients who have had pulmonary embolus are routinely followed up in an outpatient clinic after at least 3 months of treatment. If they have on going symptoms, they undergo investigations, namely ventilation/perfusion scan, CT scan of chest, ultrasound assessment of the heart (echocardiogram) and blood tests. They also undergo cardiopulmonary bike exercise testing (CPET), which helps actively assess the reason why they are breathless, i.e is it their heart or lungs limiting exercise.
A new generation of CT Scanner is now available, which uses a subtraction method with sophisticated software techniques, allowing visualisation of organ contrast perfusion(iodine mapping), including the lungs. The iodine map is a surrogate for blood flow (perfusion) within the lung and allows visualisation of the areas of lung with limited blood supply because of blood clots. This is performed with modification to a standard CT scan using a low dose initial scan without contrast, given the dose saving features of the modern research CT scanner does not incur any additional radiation exposure than would be expected with standard of care CT scans within NHS GGC. We aim to examine for a correlation between the iodine map and exercise limitation seen on CPET and VQ scan .
REC name
West of Scotland REC 1
REC reference
20/WS/0064
Date of REC Opinion
16 Apr 2020
REC opinion
Further Information Favourable Opinion