RT Journal Article
SR Electronic
T1 Characterization of Normal and Infarcted Rat Myocardium Using a Combination of Small-Animal PET and Clinical MRI
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 288
OP 294
VO 48
IS 2
A1 Takahiro Higuchi
A1 Stephan G. Nekolla
A1 Antanas Jankaukas
A1 Axel W. Weber
A1 Marc C. Huisman
A1 Sybille Reder
A1 Sibylle I. Ziegler
A1 Markus Schwaiger
A1 Frank M. Bengel
YR 2007
UL http://jnm.snmjournals.org/content/48/2/288.abstract
AB The combination of small-animal PET and MRI data provides quantitative in vivo insights into cardiac pathophysiology, integrating information on biology and morphology. We sought to determine the feasibility of PET and MRI for the quantification of ischemic injury in the rat model. Methods: Fourteen healthy male Wistar rats were studied with 18F-FDG PET and cine MRI. Myocardial viability was determined in a transmural myocardial infarction model in 12 additional rats, using 18F-FDG PET and delayed-enhancement MRI with gadolinium-diethylenetriaminepentaacetic acid. All PET was acquired with a dedicated small-animal PET system. MRI was performed on a 1.5-T clinical tomograph with a dedicated small-animal electrocardiographic triggering device and a small surface coil. Results: In normal rats, 18F-FDG uptake was homogeneous throughout the left ventricle. The lowest mean uptake of the 18F-FDG was found in the apical regions (79% ± 6.0% of maximum) and the highest uptake was in the anterior wall (93% ± 4.3 % of maximum). Myocardial infarct size as determined by histology correlated well with defects of glucose metabolism obtained with 18F-FDG PET (r = 0.89) and also with delayed-enhancement MRI (r = 0.91). Left ventricular ejection fraction in normal rats measured by cine MRI was 57% ± 5.4% and decreased to 38% ± 12.9% (P < 0.001) in the myocardial infarction model. Conclusion: Integrating information from small-animal PET and clinical MRI instrumentation allows for the quantitative assessment of cardiac function and infarct size in the rat model. The MRI measurements of scar can be complemented by metabolic imaging, addressing the extent and severity of ischemic injury and providing endpoints for therapeutic interventions.