Learning objectives
Illustrate the advantages of utilising18F-FDG PETinthe diagnosis oflarge vessel vasculitis (LVV).
Demonstrate through our patient series how18F-FDG PET may be a useful non-invasive imaging modality in the investigation of patients with suspected LVV.
Outline the expected PET findings in these patients.
Background
LVV is a term used to describe a range of idiopathic chronic primary vasculitides characterised by granulomatous inflammation affecting the aorta and its major branches.
The major variants are giant cell arteritis (GCA) and Takayasu arteritis (TA).
GCA usually affects persons over the age of 50,
with a higher incidence reported in Northern European women at a ratio of 2.5:1.[1].
TA is a rare disease usually found in young females.
It is being increasingly recognised in Europe with reported incidence estimates varying from 0.4 to...
Findings and procedure details
In LVV,
ongoing inflammation leads to locally increased metabolic demands resulting in an increased cellular uptake of a radiolabelled glucose analogue (18F-FDG).
This is reflected by increased radiotracer uptake in the walls of affected vessels.
The affected large vessels include:
· Aorta and its main branches,
especially within the thorax
· Internal and external carotid arteries and their branches
GCA primarily affects extracranial large vessels with or without involvement of the cranial vessels.
TA predominantly effects the aorta and its major branches and pulmonary arteries....
Conclusion
18F-FDG PET should be considered as a non-invasive imaging modality in patients presenting with a combination of non-specific systemic symptoms,
elevated inflammatory markers and unremarkable findings on conventional cross-sectional imaging with a clinical suspicion of LVV.
Studies have indicated that this modality shows an overall good sensitivity and specificity in the diagnosis of LVV,
expediting diagnosis and assessing disease extent prior to the development of complications.
Further studies using standardised image acquisition and interpretation are required to consolidate these findings and to establish the role...
References
Watts R,
Epidemiology of giant cell arteritis: a critical review,Rheumatology,
Volume 53,
Issue suppl_2,
1 July 2014,
Pages i1–i2.
Onen F,
Akkoc N.
Epidemiology of Takayasu arteritis.
Presse Med.
2017 Jul - Aug;46(7-8 Pt 2) e197-e203.
doi: 10.1016/j.lpm.2017.05.034.
PMID: 28756072.
Hunder G G,
Bloch D A,
Michel B A,
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