Monocyte imaging after myocardial infarction with 19F MRI at 3 T: a pilot study in explanted porcine hearts.
OBJECTIVE
Inflammation is a hallmark of cardiac healing after myocardial infarction and it determines subsequent cardiovascular morbidity and mortality. The aim of the present study was to explore whether inflammation imaging with two perfluorocarbon (PFC) nanoemulsions and fluorine magnetic resonance imaging ((19)F MRI) is feasible at 3.0 T with sufficient signal-to-noise ratio (SNR) using explanted hearts, an (19)F surface coil and dedicated MR sequences.


RESULTS
Acute myocardial infarction (AMI) was induced by balloon angioplasty (50 min) of the distal left anterior descending artery in 12 pigs. One day thereafter, PFCs were injected intravenously to label circulating monocytes. Either emulsified perfluoro-15-crown-5 ether or already clinically applied perfluorooctyl bromide (PFOB) was applied. Four days after AMI and immediately after gadolinium administration, hearts were explanted and imaged with a 3.0 T Achieva MRI scanner. (19)F MRI could be acquired with an SNR of >15 using an in-plane resolution of 2 × 2 mm(2) within <20 min for both agents. Combined late gadolinium enhancement (LGE) and (19)F MRI revealed that (19)F signal was inhomogenously distributed across LGE myocardium reflecting patchy macrophage infiltration as confirmed by histology. In whole hearts, we found an apico-basal (19)F gradient within LGE-positive myocardium. The (19)F-positive volume was always smaller than LGE volume. Ex vivo experiments on isolated monocytes revealed that pig and human cells phagocytize PFCs even more avidly than mouse monocytes.


CONCLUSIONS
This pilot study demonstrates that (19)F MRI at 3.0 T with clinically applicable PFOB is feasible, thus highlighting the potential of (19)F MRI to monitor the inflammatory response after AMI.
Department of Cardiology, Pulmonology and Vascular Medicine, Heinrich Heine University, Düsseldorf, Germany Department of Molecular Cardiology, Heinrich Heine University, Universitätsstr. 1, Düsseldorf 40225, Germany.
F
F
Bönner
Department of Cardiology, Pulmonology and Vascular Medicine, Heinrich Heine University, Düsseldorf, Germany.
M W
MW
Merx
Department of Molecular Pathology, Eberhard Karls University, Tübingen, Germany.
K
K
Klingel
Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Düsseldorf, Germany German Center for Diabetes Research, Partner Düsseldorf, Germany.
P
P
Begovatz
Department of Molecular Cardiology, Heinrich Heine University, Universitätsstr. 1, Düsseldorf 40225, Germany Cardiovascular Research Institute Düsseldorf (CARID), Medical Faculty, University Düsseldorf, Germany.
U
U
Flögel
Central Animal Research Facility, Heinrich Heine University, Düsseldorf, Germany.
M
M
Sager
Department of Molecular Cardiology, Heinrich Heine University, Universitätsstr. 1, Düsseldorf 40225, Germany.
S
S
Temme
Department of Cardiology, Pulmonology and Vascular Medicine, Heinrich Heine University, Düsseldorf, Germany Department of Molecular Cardiology, Heinrich Heine University, Universitätsstr. 1, Düsseldorf 40225, Germany.
C
C
Jacoby
Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Düsseldorf, Germany German Center for Diabetes Research, Partner Düsseldorf, Germany.
M
M
Salehi Ravesh
Department of Pharmaceutical Technology, Albert-Ludwigs University, Freiburg, Germany.
C
C
Grapentin
Department of Pharmaceutical Technology, Albert-Ludwigs University, Freiburg, Germany.
R
R
Schubert
Philips Healthcare, Hamburg, Germany.
J
J
Bunke
Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research, Düsseldorf, Germany German Center for Diabetes Research, Partner Düsseldorf, Germany Department of Endocrinology and Diabetology, Heinrich Heine University, Düsseldorf, Germany.
M
M
Roden
Department of Cardiology, Pulmonology and Vascular Medicine, Heinrich Heine University, Düsseldorf, Germany Cardiovascular Research Institute Düsseldorf (CARID), Medical Faculty, University Düsseldorf, Germany.
M
M
Kelm
Department of Molecular Cardiology, Heinrich Heine University, Universitätsstr. 1, Düsseldorf 40225, Germany schrader@uni-duesseldorf.de.
J
J
Schrader
D000818:Animals; D003287:Contrast Media; D043844:Crown Ethers; D066235:Fluorine-19 Magnetic Resonance Imaging; D005466:Fluorocarbons; D005682:Gadolinium; D006842:Hydrocarbons, Brominated; D021621:Imaging, Three-Dimensional; D009000:Monocytes; D009203:Myocardial Infarction / Q000473:pathology*; D053758:Nanoparticles; D010865:Pilot Projects; D059629:Signal-To-Noise Ratio; D013552:Swine
D003287:Contrast Media; D043844:Crown Ethers; D005466:Fluorocarbons; D006842:Hydrocarbons, Brominated; C042148:15-crown-5; D005682:Gadolinium; C003072:perflubron
19F MRI; 3 Tesla; Inflammation; Myocardial infarction; Preclinical