Initial Human PET Imaging Studies with the Dopamine Transporter Ligand 18F-FECNT

Initial Human PET Imaging Studies with the Dopamine Transporter Ligand ¹⁸F-FECNT

Margaret R. Davis, MD¹^,2, John R. Votaw, PhD¹^,3, J. Douglas Bremner, MD¹^,3^,4, Michael G. Byas-Smith, MD⁵, Tracy L. Faber, PhD¹^,3, Ronald J. Voll, PhD¹^,3, John M. Hoffman, MD⁶, Scott T. Grafton, MD⁷, Clinton D. Kilts, PhD⁴ and Mark M. Goodman, PhD¹^,3^,4

¹ PET Center, Emory University, Atlanta, Georgia
² Department of Neurology, Emory University, Atlanta, Georgia
³ Department of Radiology, Emory University, Atlanta, Georgia
⁴ Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, Georgia
⁵ Department of Anesthesiology, Emory University, Atlanta, Georgia
⁶ Biomedical Imaging Program, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
⁷ Center for Cognitive Neuroscience, Dartmouth College, Hanover, New Hampshire

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FIGURE 1. Chemical structure of ¹⁸F-FECNT.

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FIGURE 2. Arterial plasma time–activity curve from typical healthy subject (subject 4, Table 1) injected with 206 MBq ¹⁸F-FECNT. Total arterial ¹⁸F plasma activity ( ${diamond}$ ) and arterial parent ¹⁸F-FECNT plasma activity ( ${blacksquare}$ ) are shown.

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FIGURE 3. Summed early-phase (0–15 min) (A), middle-phase (16–65 min) (B), and late-phase, or DAT (66–185 min) (C) ¹⁸F-FECNT PET images in typical healthy volunteer (subject 5, Table 1). Images were normalized to maximum average cerebellar uptake, yielding equal scaling. Note that color scale is not linear. Images had to be ${gamma}$ -corrected (with shift of ${gamma}$ -scale to left) so that first 2 images could be seen.

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FIGURE 4. Logarithmic plot of brain tissue time–activity curve in healthy 63.4-kg male subject (subject 2, Table 1) injected with 216 MBq ¹⁸F-FECNT. Brain regions represented are caudate ( ${diamondsuit}$ ), putamen ( ${blacksquare}$ ), thalamus ( ${blacktriangleup}$ ), brain stem (x), occipital cortex (+), and cerebellum (•).

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FIGURE 5. Late-phase (60 min) images of DAT ¹⁸F-FECNT PET scans of H&Y stage 1.5 (A) and stage 4 (B) PD patients. Images were normalized to maximum cerebellar uptake, yielding equal scaling. Note that caudate (

) and anterior putamen (

) are still fairly intact (caudate nuclei more so than anterior putamen) in H&Y stage 1.5 subject, whereas posterior putamen (

) are of nearly equal contrast, or deterioration, in both H&Y 1.5 and H&Y 4 subject. Also, note that color scale is not linear. Images were ${gamma}$ -corrected (with shift of ${gamma}$ -scale to left) so that they could be better seen.

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FIGURE 6. Comparison of tissue-to-cerebellum ratios at 90 min after injection of healthy subjects and PD patients.