Varying correlation between 18F-fluorodeoxyglucose positron emission tomography and dynamic contrast-enhanced MRI in carotid atherosclerosis: implications for plaque inflammation.
OBJECTIVE
(18)F-fluorodeoxyglucose positron emission tomography and dynamic contrast-enhanced MRI have been proposed to quantitatively assess plaque inflammation by probing macrophages and neovessels, respectively. We examined their correlation to study the in vivo relationship between macrophage and neovessel activities in atherogenesis.


METHODS
Forty-one patients (34 men; aged 65±12 years) with a total of 68 carotid plaques (thickness ≥2 mm on ultrasound; 20 symptomatic) were assessed by both (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and dynamic contrast-enhanced MRI within 2 weeks, measured as target-to-background ratio and transfer constant (K(trans)), respectively.


RESULTS
Overall, the correlation between target-to-background ratio and K(trans) was weak and marginal (r=0.22; P=0.068). They were correlated in the symptomatic plaques (r=0.59; P=0.006) but not in the asymptomatic plaques (r=0.07; P=0.625; P=0.033 for difference in r). Neither target-to-background ratio nor K(trans) was significantly higher in the symptomatic plaques, but both showed an inverse relationship with time since last neurological event (r=-0.94 and -0.69 for target-to-background ratio and K(trans), respectively).


CONCLUSIONS
The correlation between (18)F-fluorodeoxyglucose positron emission tomography and dynamic contrast-enhanced MRI measurements varied with clinical conditions, pointing to a complex interplay between macrophages and neovessels under different pathophysiological conditions. The moderate correlation shown only in symptomatic plaques indicates the presence of acute plaque inflammation with increased metabolic activity and cytokine production by inflammatory cells.
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Juan
J
Wang
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.). liuhbcad301@163.com.
Hongbin
H
Liu
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Jie
J
Sun
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Hao
H
Xue
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Leixing
L
Xie
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Shengyuan
S
Yu
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Changzai
C
Liang
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Xu
X
Han
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Zhiwei
Z
Guan
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Liqun
L
Wei
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Chun
C
Yuan
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Xihai
X
Zhao
From the Departments of Cardiology (J.W., H.L., H.X., L.X., C.L.), Neurology (S.Y.), and Radiology (X.H., Z.G., L.W.), People's Liberation Army General Hospital, Beijing, China; Department of Radiology, University of Washington, Seattle (J.S., C.Y.); and Center for Biomedical Imaging Research, Department of Biomedical Engineering, Tsinghua University School of Medicine, Beijing, China (C.Y., X.Z., H.C.).
Huijun
H
Chen
D000368:Aged; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging / Q000503:physiopathology; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D049268:Positron-Emission Tomography; D011859:Radiography; D019275:Radiopharmaceuticals / Q000008:administration & dosage*
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
atherosclerosis; carotid arteries; magnetic resonance imaging; positron emission tomography