HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH RSS TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Related articles in JNM Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Shoup, T. M. Articles by Fischman, A. J. Search for Related Content PubMed PubMed Citation Articles by Shoup, T. M. Articles by Fischman, A. J.

Evaluation of trans-9-¹⁸F-Fluoro-3,4-Methyleneheptadecanoic Acid as a PET Tracer for Myocardial Fatty Acid Imaging

Division of Nuclear Medicine, Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts

This study describes the radiosynthesis and preliminary biologic evaluation of trans-9(RS)-¹⁸F-fluoro-3,4(RS,RS)-methyleneheptadecanoic acid (¹⁸F-FCPHA) as a new potential probe for assessing myocardial fatty acid metabolism by PET. This fatty acid, containing a cyclopropyl moiety in the ß,-position, was designed to enter the myocardium by the same mechanism as natural fatty acids and to undergo partial metabolism before being trapped in the cell. Methods: ¹⁸F-FCPHA and the ß-methyl analog 8(RS)-¹⁸F-fluoro-3(RS)-methylheptadecanoic acid (¹⁸F-FBMHA) were prepared from their corresponding mesylate precursors by nucleophilic substitution. The precursors used for labeling were fully characterized, and the data were consistent with the proposed structures. Biodistribution studies of each tracer were performed with Sprague-Dawley rats at 5 and 60 min after injection. Sequential imaging of a rhesus monkey injected with 222 MBq of ¹⁸F-FCPHA was performed by use of a microPET camera. Results: At 5 and 60 min, heart uptake values measured as mean ± SD percentage injected dose per gram (%ID/g) in rats for ¹⁸F-FCPHA were 1.55 ± 0.72 and 1.43 ± 0.14, respectively. The heart-to-blood ratios at 5 and 60 min, an indication of target definition, were 25.8 and 20.4, respectively. The heart-to-lung ratios at 5 and 60 min were 3.3 and 4.6, respectively. Bone accumulation (%ID/g), an indication of defluorination, was 0.16 ± 0.03 at 5 min and increased to 0.70 ± 0.39 at 60 min. The heart-to-blood ratio obtained with ¹⁸F-FBMHA was 2.6 at 5 min and did not change significantly at 60 min. Imaging of the monkey heart after injection of ¹⁸F-FCPHA showed an initial spike of activity corresponding to blood flow followed by a plateau at 10 min. Conclusion: The cyclopropyl moiety in ¹⁸F-FCPHA does have a significant influence on heart accumulation, as suggested by the high heart-to-blood ratio and the fast blood clearance in rats. These results, along with the remarkable quality of the PET images, indicate the potential of this new class of labeled fatty acids for use in studying heart disease by PET.

Key Words: ¹⁸F fatty acid • PET • myocardial fatty acid imaging

Related articles in JNM:

THIS MONTH IN JNM

JNM 2005 46: 8a-9a. [Full Text]