aClinic of Internal Medicine, Ente Ospedaliero Cantonale, Bellinzona, Switzerland; bClinic of Nuclear Medicine and PET/CT Centre, Ente Ospedaliero Cantonale, Bellinzona, Switzerland; cHealth Technology Assessment Unit, Ente Ospedaliero Cantonale, Bellinzona, Switzerland; dDepartment of Nuclear Medicine and Molecular Imaging, Lausanne University Hospital, Lausanne, Switzerland
18F-FDG PET/CTA is a useful imaging method in the initial diagnosis of LVV.
A 80-year-old male patient was admitted to our hospital with fever and increased serum inflammatory markers (erythrocyte sedimentation rate, C-reactive protein and leucocyte count). The patient underwent fluorine-18 fluorodeoxyglucose positron emission tomography / computed tomography angiography (18F-FDG PET/CTA) for suspected large vessel vasculitis (LVV). The patient was instructed to fast for at least 6 h prior to radiopharmaceutical administration.
CTA was normal whereas 18F-FDG PET showed areas of increased glucose metabolism in the cervical region, corresponding to both vertebral arteries on hybrid PET/CTA images (fig. 1). Therefore a diagnosis of LVV limited to the vertebral arteries was hypothesised.
Figure 1
Three-dimensional reconstruction of CTA (A), summary 18F-FDG PET image (B) and hybrid PET/CTA images in axial (C), coronal (D) and sagittal (E) projection. CTA was normal whereas 18F-FDG PET showed areas of increased uptake corresponding to the vertebral arteries (arrows), thus demonstrating vasculitis limited to these arteries.
Based on these findings, the patient received corticosteroid therapy with normalisation of symptoms and laboratory data.
18F-FDG PET/CTA is a useful imaging method in the initial diagnosis of LVV and in the assessment of activity and extent of disease [1–3]. This hybrid imaging method may even detect LVV limited to specific arteries. Atherosclerotic vascular uptake may be a source of false positivity in LVV evaluation with 18F-FDG PET, despite a classical patchy uptake pattern; vascular inflammation in LVV classically appears as a smooth linear pattern on 18F-FDG PET [2]. CTA detecting structural changes in large vessels may also be helpful to differentiate LVV and atherosclerosis [2].
Correspondence
Giorgio Treglia, MD MSc(HTA), Clinic of Nuclear Medicine and PET/CT Centre, Ente Ospedaliero Cantonale, Via Ospedale 12, CH-6500 Bellinzona, giorgio.treglia[at]eoc.ch
References
1Treglia G, Mattoli MV, Leccisotti L, Ferraccioli G, Giordano A. Usefulness of whole-body fluorine-18-fluorodeoxyglucose positron emission tomography in patients with large-vessel vasculitis: a systematic review. Clin Rheumatol. 2011;30(10):1265–75. doi:. http://dx.doi.org/10.1007/s10067-011-1828-9PubMed
2Slart RHJA; Writing group; Reviewer group; Members of EANM Cardiovascular; Members of EANM Infection & Inflammation; Members of Committees, SNMMI Cardiovascular; Members of Council, PET Interest Group; Members of ASNC; EANM Committee Coordinator. FDG-PET/CT(A) imaging in large vessel vasculitis and polymyalgia rheumatica: joint procedural recommendation of the EANM, SNMMI, and the PET Interest Group (PIG), and endorsed by the ASNC. Eur J Nucl Med Mol Imaging. 2018;45(7):1250–69. doi:. http://dx.doi.org/10.1007/s00259-018-3973-8PubMed
3Mattoli MV, Treglia G, Leccisotti L, Giordano A. The role of 18F-FDG PET/CT in the management of large-vessel vasculitis: applications and limitations in clinical practice. Ital J Med. 2011;5(3):249–54. doi:. http://dx.doi.org/10.1016/j.itjm.2011.03.012
