Biomedical Applications of Emission Tomography - Correction Techniques in Emission Tomography - page 21

FIGURE 2.3: Dynamic PET imaging of the sympathetic nervous system in
two mice following simultaneous i.v. injection of [ 11 C]mHED. (A) shows PET
images with good uptake of the tracer in the heart (arrows) in both mice 10
min p.i. Mouse 1 was additionally injected with metaraminol 15 min p.i. (B)
shows PET images 30 min after application of metaraminol (40 molkg 1 i.v.)
in mouse 1, where there is virtually no [ 11 C]mHED uptake left in the heart of
mouse 1 while the heart of mouse 2 shows only a slight washout. (C) depicts
time-activity-curves generated from regions-of-interest placed over the heart
and calculated from the PET listmode stream ( mouse 1, mouse 2). Note
the spontaneous slight washout of [ 11 C]mHED from the myocardium in the
untreated mouse 2 but the dramatic loss of the tracer upon injection of the
competitor metaraminol in mouse 1. From the tracer dynamics, measures for
eciency of neuronal re-uptake can be calculated. Modified from [11]
imaging of enhanced green fluorescent protein (EGFP) expressing donor cells.
Infiltration of colon tissue by EGFP-positive donor lymphocytes matched in-
creased FDG uptake in serial PET examinations in GvHD-positive mice. Most
interestingly, in a translational approach, these preclinical data were confirmed
in a cohort of patients with suspected intestinal GvHD, where the intestinal
FDG uptake was highly predictive for clinically relevant GvHD (Figure 2.4).
This study is a prime example for the translational potential of PET but also