An interventional study of [18F]FDG Long-Axial Field of View (LAFOV)-PET/CT and CT Angiogram in Large Vessel Vasculitis, Takayasu Arteritis and Giant Cell Arteritis (GCA), sponsored by Imperial College London. Not yet recruiting at 3 sites in United Kingdom. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Imperial College London · Not applicable, Interventional, and Basic science
Large vessel vasculitis (LVV) is an autoimmune inflammatory disorder affecting the major arteries of the body. The diagnosis and monitoring this condition can be challenging, as patients often present with symptoms that are unclear, and the diagnostic criteria currently used are varied. Accurate diagnosis is essential because it helps to tailor the treatment to each patient. Some treatments, such as steroids and immunosuppressive medications, can have significant side effects, so they need to be used carefully and only when truly needed.
An [18F]FDG Positron Emission Tomography/Computed Tomography (PET/CT) involves the injection of a small amount of radiolabelled sugar, which assesses glucose metabolism within the body. [18F]FDG PET/CT is already used by the NHS to detect inflammation within the vessel walls and diagnose LVV. Current diagnostic criteria for LVV largely rely on visual assessment by a radiologist. This approach therefore has limitations and may not fully capture changes in the levels of inflammation over time.
A new generation of scanners, known as Long Axial Field-of-View (LAFOV)-PET/CT or Total Body PET, are currently transforming what is possible in the field of medical imaging. These LAFOV-PET/CT scanners have new digital detectors that are more sensitive, produce sharper images, and can scan the entire body rapidly. This offers several potential advantages for patients with LVV, including the clearer detection of vessel wall inflammation, the ability to administer lower doses of the radiolabelled sugar ([18F]FDG), and the ability to take repeated pictures over time to measure subtle changes in blood flow and inflammation. Patients receiving a routine NHS [18F]FDG PET/CT scan for LVV are typically scanned 60 minutes after injection of the radiotracer using a standard PET/CT. Another benefit of LAFOV-PET/CT scanners is their ability to assess the amount of the radiolabelled sugar taken up by the whole body almost as soon as it is injected which could give important additional information.
As part of the LAVA-FLOW study we are planning to combine LAFOV-PET/CT with a CT Angiogram (CTA) in patients with LVV. A CTA is a scan that shows doctors what your blood vessels look like. It involves the injection of a dye into a vein that makes your blood vessels visible, highlighting vessel wall inflammation and vessel wall narrowing. This combination of LAFOV-PET/CT and CTA therefore has the potential to give a much more detailed picture of LVV than is achievable using current methods.
The LAVA-FLOW study therefore aims to develop a standardised protocol to be used in different hospital centres across the UK for the imaging of LVV using LAFOV-PET/CT. We also hope that the results of this particular study could lead to further larger studies with the potential to update the diagnostic criteria and improve the monitoring of this condition.
Systemic vasculitidies are autoimmune diseases which cause inflammation of blood vessels and are categorised according to the size of blood vessels they predominantly involve. The main forms of LVV are giant cell arteritis (GCA) and Takayasu arteritis (TA).
Various imaging modalities are available for the diagnosis of large vessel vasculitis (LVV): ultrasound, magnetic resonance angiography (MRA), computed tomography angiography (CTA) and [18F]fluorodeoxyglucose ([18F]FDG) PET/CT.
Whilst [18F]FDG PET/CT is established in the diagnostic work up of LVV, the relatively low spatial resolution, radiation exposure, and long imaging times have limited its use especially for assessing smaller calibre vessels and coronary arteries.
Digital long-axial field of view (LAFOV)-PET/CT systems are expected to significantly improve the diagnosis and management of LVV, as their increased sensitivity allows for improved detection of the involvement of smaller calibre vessels and low-grade inflammation, even at shorter scan times and/or reduced tracer doses.
LAFOV-PET/CT has the potential to perform dynamic whole-body imaging from the time of radiotracer injection for detailed analysis of [18F]FDG uptake. Additionally, there is the opportunity to acquire LAFOV-PET/CT images and combine this approach with CT angiogram imaging of the heart and all large vessels within one sitting. At present, determining the involvement of small vessels currently relies on the treating physician requesting a CT angiogram (CTA) in addition to other imaging investigations at diagnosis, which is not currently common practice. A combined protocol of [18F]FDG LAFOV-PET/CT and CTA performed that could be performed at diagnosis and during follow-up may allow the burden of coronary artery disease in this cohort to be fully established and to better define its natural history on treatment. For follow-up response cases, particularly in TA, the potential for using lower radiation does with LAFOV-PET/CT is important to further develop the use of PET/CT in these cohort for surveillance monitoring.
The current European Association of Nuclear Medicine (EANM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) guidelines for assessment of LVV on [18F]FDG PET/CT recommend visual interpretation of static images using a 4-point visual scale. Although visual analysis of static [18F]FDG PET/CT data is currently clinically recommended for LVV cases, this has limitations. The improved spatial resolution of LAFOV-PET/CT could lead to higher vessel identification through the use of semi-quantitative analysis methods.
The improved spatial resolution of LAFOV-PET/CT could lead to higher vessel identification and the potential misdiagnosis of LVV in normal vessels compared to standard PET/CT. We will therefore need to consider the use of different thresholds when using LAFOV-PET/CT.
In addition to collecting data from patients diagnosed with LVV, data from healthy volunteers (HV) will help us to establish normal background vessel activity on LAFOV-PET/CT. The HV cohort shall have MR angiography (MRA) instead of CTA to keep radiation doses as low as possible.
This study will establish a protocol for LAFOV-PET/CT imaging and provide pilot data for a larger study, which may lead to changing the current visual reporting criteria for LVV by establishing new reference ranges for disease activity. LAVA-FLOW aims to establish an [18F]FDG LAFOV-PET/CT protocol utilising both dynamic and static imaging in combination with angiography.
78 studies on the registry are indexed under Takayasu Arteritis; 32 are open to participants now.
This study's planned enrollment of 18 is below the median of 50 across 37 interventional studies indexed under Takayasu Arteritis.
Browse Takayasu Arteritis studies →Imperial College London is the lead sponsor of 843 studies on the registry; 180 are open to participants now.
Of its 9 completed or terminated interventional studies of FDA-regulated products, 6 (67%) have results posted.
Counted across the registry records on this site, refreshed daily.
The criteria were revised on the registry on Oct 16, 2026. See what changed
Inclusion Criteria LVV Patients:
Exclusion Criteria LVV Patients:
Inclusion Criteria Healthy Volunteers:
Exclusion Criteria Healthy Volunteers:
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.
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
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.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
ECOG performance status
A scale of how much an illness limits everyday activity. For people being assessed to join a study, scores run from 0 (fully active) to 4; lower is more active.
Studies most often ask for 0–1 or 0–2. Your doctor gives the score; the WHO scale uses the same steps. The full scale also has 5, which records death.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Diagnostic Test: [18F]FDG Long-Axial Field of View (LAFOV)-PET/CT · Diagnostic Test: CT Angiogram
Diagnostic Test: [18F]FDG Long-Axial Field of View (LAFOV)-PET/CT · Diagnostic Test: MR Angiogram
All participants will undergo an initial standard dose attenuation correction CT (ACCT) scan. \[18F\]FDG will be administered with a target injected dose of 1.5MBq/kg at 0 minutes in a single IV bolus. The participants will undergo a dynamic LAFOV-PET/CT scan between 0-70 minutes. The final 10-minutes of the dynamic LAFOV-PET/CT scan (60-70 minutes post-injection of \[18F\]FDG will be cardiac-gated (ECG leads will have been applied to the participant prior to their ACCT). A further ACCT (standard dose ACCT for LVV patients \& low dose ACCT for healthy volunteers) followed by a delayed static LAFOV-PET/CT will subsequently be performed at +120 minutes post-injection for up to 10 minutes.
LVV patients will undergo a CT angiogram. This will take place immediately after their \[18F\]FDG LAFOV-PET/CT.
Healthy Volunteers will have an MR angiogram at Imperial College Healthcare NHS Trust. This scan visit will be performed on a separate date following the performance of their LAFOV-PET/CT.
To investigate [18F]FDG localisation in LVV patients and HVs (controls) on LAFOV-PET/CT.
SUVmax of all vascular segments in the LVV patient cohort versus the HV cohort (60-70 min p.i. data).
Time frame: [18F]FDG LAFOV-PET/CT Scan Visit - 60-70 minutes post-injection of [18F]FDG
To compare visual, semi-quantitative and quantitative scoring systems in LVV and HV, including smaller calibre vessels using LAFOV-PET/CT.
Summary comparison of visual (PETVAS scoring), semi-quantitative (SUVmax, SUVmean \& tissue to background ratio (TBR) and SUV/TBR) and quantitative (Ki Patlak analysis) scoring systems at 60-70 min p.i.
Time frame: [18F]FDG LAFOV-PET/CT Scan Visit - 60-70 minutes post-injection of [18F]FDG
To investigate how simulated lower dose acquisitions affect vascular activity and scan quality on LAFOV-PET/CT.
Visual scoring (PETVAS scoring - most diseased and summed vascular segments), and semi-quantitative scoring (SUVmax and TBR) on image data (at 60-70 min p.i.) reconstructed using shorter acquisition times (1, 2, 4, 6, 8 and 10 min).
Time frame: [18F]FDG LAFOV-PET/CT Scan Visit - 60-70 minutes post-injection of [18F]FDG
To assess the impact of using the CT angiogram (CTA) for attenuation correction in LVV patients on LAFOV-PET/CT.
Summary comparison of visual (PETVAS scoring) and semi-quantitative (SUVmax, SUVmean and TBR) using CTA or attenuation correction CT (ACCT) for the purpose of attenuation correction of the 120-130 min p.i. data (120-130 min static) and 60-70 min p.i. data (60-70 min static).
Time frame: [18F]FDG LAFOV-PET/CT Scan Visit - 60-70 minutes versus 120-130 minutes post-injection of [18F]FDG
To investigate the impact of delayed imaging at 120-minutes post-injection on vascular activity on LAFOV-PET/CT.
Summary comparison of visual (PETVAS scoring), semi-quantitative (SUVmax, SUVmean , TBR and SUV/TBR) and quantitative (Ki Patlak analysis) scoring systems at multiple acquisition time points (60-70 min compared to 120-130 min p.i.).
Time frame: [18F]FDG LAFOV-PET/CT Scan Visit - 60-70 minutes versus 120-130 minutes post-injection of [18F]FDG
To establish normal background [18F]FDG uptake in HV controls on LAFOV-PET/CT.
Summary statistics including confidence intervals of visual (PETVAS scoring) and semi-quantitative (SUVmax, SUVmean , TBR and SUV/TBR) scoring at 60-70 and 120-130 min p.i.
Time frame: [18F]FDG LAFOV-PET/CT Scan Visit - 60-70 minutes versus 120-130 minutes post-injection of [18F]FDG
Plan to share: Undecided
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