RT Journal Article SR Electronic T1 Lesson of the month 1: Large vessel vasculitis – a diagnostic challenge and the role of 18-fluorodeoxyglucose positron emission tomography JF Clinical Medicine JO Clin Med FD Royal College of Physicians SP 369 OP 370 DO 10.7861/clinmedicine.17-4-369 VO 17 IS 4 A1 Andrew Allard A1 Ramesh Mootoo YR 2017 UL http://www.rcpjournals.org/content/17/4/369.abstract AB Large vessel vasculitis can pose a significant diagnostic challenge. It may be insidious in onset with the only presenting symptoms consisting of constitutional compromise. It may mimic other pathologies and the only serological abnormalities may be abnormal inflammatory markers. Conventional imaging modalities may not be diagnostic. We present a case of large vessel vasculitis that proved a significant diagnostic challenge with diagnosis established on 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) computerised tomography (CT) imaging. This is one of five cases of large vessel vasculitis that were diagnosed in the rheumatology department at our trust over a 12-month period with diagnosis established with the use of 18F-FDG PET CT. We discuss the advantages of 18F-FDG PET CT over more conventional imaging modalities in diagnosing large vessel vasculitis.