The Role of¹⁸F-FDG PET/CT in Large-Vessel Vasculitis: Appropriateness of Current Classification Criteria?

Abstract

Patients with clinical suspicion of large-vessel vasculitis (LVV) may present with nonspecific signs and symptoms and increased inflammatory parameters and may remain without diagnosis after routine diagnostic procedures. Both the nonspecificity of the radiopharmaceutical 18F-FDG and the synergy of integrating functional and anatomical images with PET/CT offer substantial benefit in the diagnostic work-up of patients with clinical suspicion for LVV. A negative temporal artery biopsy, an ultrasonography without an arterial halo, or a MRI without aortic wall thickening or oedema do not exclude the presence of LVV and should therefore not exclude the use of 18F-FDG PET/CT when LVV is clinically suspected. This overview further discusses the notion that there is substantial underdiagnosis of LVV. Late diagnosis of LVV may lead to surgery or angioplasty in occlusive forms and is often accompanied by serious aortic complications and a fatal outcome. In contrast to the American College of Rheumatology 1990 criteria for vasculitis, based on late LVV effects like arterial stenosis and/or occlusion, 18F-FDG PET/CT sheds new light on the classification of giant cell arteritis (GCA) and Takayasu arteritis (TA). The combination of these observations makes the role of 18F-FDG PET/CT in the assessment of patients suspected for having LVV promising.

The prognostic value of baseline 18F-FDG PET/CT in steroid-naïve large-vessel vasculitis: introduction of volume-based parameters

“…Since those reports, the feasibility and usefulness of PET and PET/CT in this field have been broadly analysed [3,17]. The possible role of FDG scans in the early diagnosis of LVV has been particularly stressed, since the clinical diagnostic process can be long and Fig.…”

“…Third, the diagnosis of LVV (17 of 46 patients) was based on clinical, laboratory and radiological imaging findings in almost all cases: histological confirmation by means of artery biopsy was obtained in just two subjects, due to its invasivity and high falsenegative rate. In this setting, anyway, many previously reported papers have already debated the current lack of a noninvasive and reliable gold standard for the diagnosis of LVV [3].…”

“…TA predominantly affects the aorta and its major branches and usually occurs in younger patients (before the age of 50 years), while GCA, similarly affecting the aorta and/or its major branches, shows a predilection for the branches of the carotid and vertebral arteries and occurs in older patients, often associated with polymyalgia rheumatica; anyway, given that histopathological features of TA and GCA are indistinguishable, it is still not clear if they are just different sides of the same disease [3].…”

Roles of facilitative glucose transporter GLUT1 in [18F]FDG positron emission tomography (PET) imaging of human diseases

“…The non-specific nature of [ which can present with non-specific signs and symptoms [297][298][299][300]. A common form of vasculitis is giant cell arteritis, which shows a close clinical association with the musculoskeletal inflammatory disorder polymyalgia rheumatica [301,302] [307,308].…”

Role of PET/CT in the diagnosis of large vessel vasculitis in a patient with systemic inflammatory response syndrome

“…This case illustrates the central role of 18F-FDG PET/CT findings in early diagnosis of LVV in a patient with unexplained systemic disease. PET/CT imaging reveals increased metabolic activity when morphological changes (like wall thickening, arterial stenosis, or dilatation) and overt vascular symptoms (such as pulselessness, bruits, blood pressure difference) are absent (3). Therefore, when diagnosed in an early stage, most patients would not meet the existing 1990 American College of Rheumatology classification criteria for either GCA or TAK, as these criteria are appropriate for advanced cases.…”