RT Journal Article SR Electronic T1 Stable Delineation of the Ischemic Area by the PET Perfusion Tracer 18F-Fluorobenzyl Triphenyl Phosphonium After Transient Coronary Occlusion JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 965 OP 969 DO 10.2967/jnumed.110.085993 VO 52 IS 6 A1 Takahiro Higuchi A1 Kenji Fukushima A1 Christoph Rischpler A1 Takuro Isoda A1 Mehrbod S. Javadi A1 Hayden Ravert A1 Daniel P. Holt A1 Robert F. Dannals A1 Igal Madar A1 Frank M. Bengel YR 2011 UL http://jnm.snmjournals.org/content/52/6/965.abstract AB 18F-fluorobenzyl triphenyl phosphonium (FBnTP) has recently been introduced as a myocardial perfusion PET agent. We used a rat model of transient coronary occlusion to determine the stability of the perfusion defect size over time and the magnitude of redistribution. Methods: Wistar rats (n = 15) underwent thoracotomy and 2-min occlusion of the left coronary artery (LCA), followed by reperfusion. During occlusion, 18F-FBnTP (92.5 MBq) and 201Tl-thallium chloride (0.74 MBq) were injected intravenously. One minute before the animals were sacrificed at 5, 45, and 120 min after reperfusion, the LCA was occluded again and 2% Evans blue was injected intravenously to determine the ischemic territory. The hearts were excised, frozen, and sliced for serial dual-tracer autoradiography and histology. Dynamic in vivo 18F-FBnTP PET was performed on a subgroup of animals (n = 4). Results: 18F-FBnTP showed stable ischemic defects at all time points after tracer injection and reperfusion. The defects matched the blue dye defect (y = 0.97x+1.5, R2 = 0.94, y = blue-dye defect, x = 18F-FBnTP defect). Count density analysis showed no defect fill-in at 45 min but slightly increased activity at 120 min (LCA/remote uptake ratio = 0.19 ± 0.02, 0.19 ± 0.05, and 0.34 ± 0.06 at 5, 45, and 120 min, respectively, P < 0.05). For comparison, 201Tl showed complete redistribution at 120 min (LCA/remote = 0.42 ± 0.04, 0.72 ± 0.03, and 0.97 ± 0.05 at 5, 45, and 120 min, respectively, P < 0.001). Persistence of the 18F-FBnTP defect over time was confirmed by in vivo dynamic small-animal PET. Conclusion: In a transient coronary occlusion model, perfusion defect size using the new PET agent 18F-FBnTP remained stable for at least 45 min and matched the histologically defined ischemic area. This lack of significant redistribution suggests a sufficient time window for future clinical protocols with tracer injection remote from the scanner, such as in a stress testing laboratory or chest pain unit.