Differentiation of lower limb vasculitis from physiological uptake on FDG PET/CT imaging

• Published in: Annals of nuclear medicine Vol. 37; no. 1; pp. 26 - 33
• Main Authors: Weng, Shijia, Li, Yuan, Wang, Qian, Zhao, Yunyun, Zhou, Yunshan
• Format: Journal Article
• Language: English
• Published: Singapore Springer Nature Singapore 2023; Springer Nature B.V
• Subjects: Body weight; Computed tomography; Diagnosis; Effectiveness; Fluorine isotopes; Fluorodeoxyglucose F18; Glucose; Humans; Imaging; Limbs; Medical imaging; Medicine; Medicine & Public Health; Nuclear Medicine; Original Article; Pattern analysis; Physiology; Positron emission; Positron emission tomography; Positron Emission Tomography Computed Tomography - methods; Radiology; Radiopharmaceuticals; Retrospective Studies; Systemic vasculitis; Vasculitis - diagnostic imaging; Physiological FDG uptake; 2-deoxy-2-; Systemic vasculitis; F]fluoro-D-glucose; Positron emission tomography/computed tomography; 2-deoxy-2-[18F]fluoro-D-glucose
• ISSN: 0914-7187; 1864-6433
• DOI: 10.1007/s12149-022-01800-1

Purposes
To analyze the difference of 2-deoxy-2-[
18
F]fluoro-D-glucose (
18
F-FDG) uptake between vasculitis and non-vasculitic patients in PET/CT imaging and the factors related to vascular uptake in non-vasculitic patients. To investigate the feasibility of identifying vasculitis of the lower limb and physiological uptake with delayed imaging.
Procedures
Among 244 patients who underwent PET/CT examination, imaging features of patients with or without vasculitis were retrospectively analyzed. The factors related to FDG uptake in the lower limb vessels of non-vasculitic patients were analyzed. Another 44 patients with suspected systemic vasculitis in PET/CT were prospectively studied to analyze the efficacy of delayed imaging on differentiating vascular uptake in lower limbs.
Results
In PET/CT imaging of patients with vasculitis, involvement of trunk vessels showed segmental or diffuse FDG distribution. Lower limb vascular involvement showed reticular uptake accompanied by nodular or patchy changes. In non-vasculitic patients, vascular uptake mainly showed linear uptake in lower limb vessels and there was no significant difference in uptake degree compared with vasculitis patients. Body weight and interval time were the independent influence factors of vascular uptake in lower limbs of non-vasculitic patients. In delayed imaging, lower limb vasculitis all showed reticular uptake and physiological uptake all showed a linear pattern. ROC analysis showed the change rate of SUV
max
(≥ 20%) between early and delayed imaging could delineate physiological vascular uptake with a sensitivity of 100% and specificity of 81.0%.
Conclusions
When PET/CT is used for the diagnosis and classification of vasculitis, the physiological uptake of lower limb vessels may mislead the diagnosis. PET/CT imaging features or delayed imaging improved diagnostic efficacy.