Internal medicine

Radiology

Pathology

Retrospective cohort study

Disease

Nuclear medicine

Gold standard (test)

Ultrasound

Positron emission tomography

Vasculitis

Giant cell arteritis

Aortitis

Aorta

Medicine

Modern Rheumatology

ABSTRACT Objective To assess the accuracy of ultrasound (US) versus fluorodeoxyglucose—positron emission tomography/computed tomography (FDG-PET/CT) to identify extracranial involvement in large vessel vasculitis (LVV). Methods A retrospective observational study of patients with suspected LVV. All patients underwent US exam within 24 h per protocol. FDG-PET/CT was performed according to clinician criteria. The gold standard for LVV diagnosis was clinical confirmation after 6 months. Results Of the 113 patients included (74.3% female, mean age 74 years), 37 (32.7%) were diagnosed with LVV after 6 months. The sensitivity and specificity of US were 86.5% and 96.1%, respectively. Only 12 (42.9%) of 28 patients undergoing a FDG-PET/CT per clinician criteria showed positive findings. The sensitivity and specificity of FDG-PET/CT for LVV were 61.1% and 90%, respectively. Taking FDG-PET/CT as the reference, US showed extracranial inflammation in 10/12 (83.3%) and detected 2 (12.5%) additional cases of extracranial involvement with negative FDG-PET/CT. Conversely, FDG-PET/CT was positive in two patients with negative US (one isolated aortitis and one aortoiliac involvement). Conclusions US and FDG-PET/CT are both valid tools to detect extracranial involvement. The presence of US extracranial artery inflammation is consistent with FDG-PET/CT examination, although a negative US scan does not rule out extracranial involvement.

The role of ultrasound and FDG-PET/CT to detect extracranial artery involvement in patients with suspected large vessel vasculitis