High resolution FDG-microPET of carotid atherosclerosis: plaque components underlying enhanced FDG uptake.
This study sought to discover which atherosclerotic plaque components co-localize with enhanced [(18)F]-fluorodeoxyglucose (FDG) uptake in carotid positron emission tomography (PET) images. Although in vivo PET currently lacks the resolution, high-resolution ex vivo FDG-microPET with histology validation of excised carotid plaque might accomplish this goal. Thirteen patients were injected with FDG before carotid endarterectomy. After excision, the plaque specimens were scanned by microPET and magnetic resonance imaging, and then serially sectioned for histological analysis. Two analyses were performed using generalized linear mixed models: (1) a PET-driven analysis which sampled high and low FDG uptake areas from PET images to identify their components in matched histology specimens; and (2) a histology-driven analysis where specific plaque components were selected and matched to corresponding PET images. In the PET-driven analysis, regions of high FDG uptake were more likely to contain inflammatory cells (p < 0.001) and neovasculature (p = 0.008) than regions of low FDG uptake. In the histology-driven analysis, regions with inflammatory cells (p = 0.001) and regions with loose extracellular matrix (p = 0.001) were associated with enhanced FDG uptake. Furthermore, areas of complex inflammatory cell infiltrate (co-localized macrophages, lymphocytes and foam cells) had the highest FDG uptake among inflammatory subgroups (p < 0.001). In conclusion, in carotid plaque, regions of inflammatory cell infiltrate, particularly complex one, co-localized with enhanced FDG uptake in high-resolution FDG-microPET images. Loose extracellular matrix and areas containing neovasculature also produced FDG signal. This study points to the potential ability of FDG-PET to detect the cellular components of the vulnerable plaque.
Department of Bioengineering, University of Washington, Seattle, WA, USA.
Jin
J
Liu
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
William S
WS
Kerwin
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
James H
JH
Caldwell
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
Marina S
MS
Ferguson
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
Daniel S
DS
Hippe
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
Adam M
AM
Alessio
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
Vanesa
V
Martinez-Malo
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
Kristi
K
Pimentel
Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA.
Robert S
RS
Miyaoka
Department of Surgery, Seattle VA Puget Sound Health Care System, Seattle, WA, USA.|Department of Surgery, University of Washington, Seattle, WA, USA.
Ted R
TR
Kohler
Department of Surgery, University of Washington, Seattle, WA, USA.
Thomas S
TS
Hatsukami
Department of Bioengineering, University of Washington, Seattle, WA, USA. cyuan@u.washington.edu.|Department of Radiology, University of Washington, 850 Republican St, Box 358050, Seattle, WA, 98109, USA. cyuan@u.washington.edu.
Chun
C
Yuan
D000368:Aged; D000369:Aged, 80 and over; D002339:Carotid Arteries / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D016894:Endarterectomy, Carotid; D005260:Female; D005355:Fibrosis; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods; D009389:Neovascularization, Pathologic; D058226:Plaque, Atherosclerotic; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D061205:Vascular Calcification / Q000000981:diagnostic imaging
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
Atherosclerosis; Carotid plaque; FDG; Inflammation; MicroPET; Vulnerable plaque