Abstract 15229: High Standardized Uptake Value of 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography was correlated with Disease Activity in Patients with Takayasu Arteritis
Introduction: The clinical value of 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography (FDG-PET/CT) in diagnosis of Takayasu Arteritis (T.A) has not been decided. Clinical evaluation of disease activity with CRP is confusing to the value in a majority of patients under steroid treatment often shows low level in recurrence of T.A. Based on that, we hypothesized max standardized uptake value (SUV) of FDG-PET/CT as an imaging tool that can indicate disease activity.
Methods: Twenty seven consecutive patients with T.A and 14 control patients, matched for age and sex, underwent FDG-PET/CT. Experienced radiologists assessed the focal accumulation of FDG-PET/CT as T.A and measured max SUV in the arterial wall of all patients. Disease activity was defined according to the NIH criteria for T.A. Additionally, we measured blood Pentraxin-3(PTX-3) to investigate whether SUV of FDG-PET/CT is reflected by inflammatory arterial lesions.
Results: Among 27 patients with T.A, 14 were diagnosed as active phase according to NIH criteria. The max SUV of 18F-FDG accumulation in the active patients was statistically greater than in the inactive patients and the control (max SUV; 2.9±0.2 v.s 2.0±0.1 and 1.8±0.1, p=0.001). Six of 13 inactive patients showed elevated CRP(>0.3mg/dl), and FDG-PET/CT was negative in these six patients. Given the cut off value of SUV as 2.1, the sensitivity for determining active phase was 100% and the specificity was 85%, otherwise, the CRP cut off over 0.5mg/dl was 100% sensitivity and 69% specificity. Area under the curve (AUC) of the SUV was 92%, otherwise, AUC of the CRP was 86%. Divided into two groups according to the level of PTX-3, the SUV in the high PTX-3 (7.3±0.8ng/ml) patients was statistically higher than in the low PTX-3 (3.9±0.2ng/ml)patients (SUV: 2.9±0.2 v.s 2.3±0.2, p<0.05).
Conclusion: Max SUV of FDG-PET/CT was useful in diagnosing disease activity of T.A, because max SUV was increased when PTX-3 derived from inflammatory arterial lesions was elevated.
- © 2010 by American Heart Association, Inc.