Evaluation of the brain uptake properties of [1-11C]labeled hexanoate in anesthetized cats by means of positron emission tomography

1996 ◽  
Vol 10 (3) ◽  
pp. 361-366 ◽  
Author(s):  
Yojiro Sakiyama ◽  
Kiichi Ishiwata ◽  
Kenji Ishii ◽  
Keiichi Oda ◽  
Hinako Toyama ◽  
...  
2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Toyohara ◽  
Norihiro Harada ◽  
Takeharu Kakiuchi ◽  
Hiroyuki Ohba ◽  
Masakatsu Kanazawa ◽  
...  

Abstract Introduction Increases in fasting plasma glucose (PG) levels lead to a decrease in 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) uptake in the normal brain, especially in the precuneus, resulting in an Alzheimer’s disease (AD)-like uptake pattern. Therefore, patients with higher PG levels, such as those with diabetes, can be erroneously diagnosed with AD when positron emission tomography (PET) imaging is done using [18F]FDG, due to reduced uptake of [18F]FDG in the precuneus. To help avoid an erroneous diagnosis of AD due to differences in glucose metabolism, evaluating cerebral blood flow (CBF) in the brain is useful. However, current techniques such as single photon emission computed tomography (SPECT) and [15O]H2O PET have limitations regarding early diagnosis of AD because the images they produce are of low resolution. Here, we developed a novel CBF PET tracer that may be more useful than [18F]FDG for diagnosis of AD. Methods We synthesized and evaluated N-isopropyl-p-[11C]methylamphetamine ([11C]4) as a carbon-11-labeled analogue of the standard CBF SPECT tracer N-isopropyl-p-[123I]iodoamphetamine. Fundamental biological evaluations such as biodistribution, peripheral metabolism in mice, and brain kinetics of [11C]4 in non-human primates with PET with successive measurement of [15O]H2O were performed. Results [11C]4 was synthesized by methylation of the corresponding tributyltin precursor (2) with [11C]MeI in a palladium-promoted Stille cross-coupling reaction. The brain uptake of [11C]4 in mice peaked at 5–15 min after injection and then promptly decreased. Most radioactivity in the brain was detected in the unchanged form, although in the periphery, [11C]4 was rapidly metabolized to hydrophilic components. Acetazolamide (AZM) treatment significantly increased the brain uptake of [11C]4 without affecting the blood levels of radioactivity in mice. Preliminary kinetics analysis showed that the K1 of [11C]4 reflected regional CBF in a vehicle-treated monkey, but that the K1 did not reflect CBF in higher flow regions after AZM loading. Conclusion [11C]4 is a potential novel CBF PET tracer. Further validation studies are needed before [11C]4 can be used in humans.


2011 ◽  
Vol 31 (12) ◽  
pp. 2334-2342 ◽  
Author(s):  
Patrick J Riss ◽  
Young T Hong ◽  
David Williamson ◽  
Daniele Caprioli ◽  
Sergey Sitnikov ◽  
...  

The 5-hydroxytryptamine type 2a (5-HT2A) selective radiotracer [18F]altanserin has been subjected to a quantitative micro-positron emission tomography study in Lister Hooded rats. Metabolite-corrected plasma input modeling was compared with reference tissue modeling using the cerebellum as reference tissue. [18F]altanserin showed sufficient brain uptake in a distribution pattern consistent with the known distribution of 5-HT2A receptors. Full binding saturation and displacement was documented, and no significant uptake of radioactive metabolites was detected in the brain. Blood input as well as reference tissue models were equally appropriate to describe the radiotracer kinetics. [18F]altanserin is suitable for quantification of 5-HT2A receptor availability in rats.


2017 ◽  
Vol 37 (10) ◽  
pp. 3401-3408 ◽  
Author(s):  
Shi Shu ◽  
Li Zhang ◽  
Yi Cheng Zhu ◽  
Fang Li ◽  
Li Ying Cui ◽  
...  

Angiogenesis is a critical compensation route, which has been demonstrated in the brain following ischemic stroke; however, few studies have investigated angiogenesis in chronic intracranial atherosclerosis disease (ICAD). We used 68Ga-NOTA-PRGD2 positron emission tomography/computed tomography based imaging to detect angiogenesis in chronic ICAD and to explore the factors that may have affected it. A total of 21 participants with unilateral severe chronic ICAD were included in the study. Of the 21 participants, 19 were men; the mean (SD) age was 52 (15) years. In 18 participants, we observed elevated 68Ga-NOTA-PRGD2 uptake in the peri-infarct, subcortical, and periventricular regions of the lesioned side, with a higher 68Ga-NOTA-PRGD2 SUVmax compared to that in the contralateral hemisphere (0.15 vs. 0.06, p=0.001). The 18F-FDG PET SUVmax was significantly lower on the lesioned side (11.28 vs. 13.92, p=0.001). Subgroup analyses revealed that the recent group (<6 months) had a higher lesion-to-contralateral region ratio SUVmax than the remote group (>6 months) (6.73 vs. 2.36, p<0.05). Our results provide molecular imaging evidence of angiogenesis in patients with severe chronic ICAD. Furthermore, the extent of angiogenesis in chronic ICAD may be affected by the post-qualified event time interval, and not by infarction itself or the severity of the arterial lesion.


Author(s):  
Saugat Bhattacharyya ◽  
Anwesha Khasnobish ◽  
Poulami Ghosh ◽  
Ankita Mazumder ◽  
D. N. Tibarewala

Evolution has endowed human race with the most adroit brain, and to harness its potential to the fullest the concept of brain computer interface (BCI) has emerged. One of the most crucial components of BCI is the technique of brain imaging. The first approach in the field of brain imaging was to measure the electrical and magnetic activity of the brain, the techniques being known as Electroencephalography and Magnetoencephalography. Striving for furtherance, researchers came up with another alternative known as Magnetic Resonance Imaging. But it being confined to only structural imaging, the functional aspects of brain were mapped using functional magnetic resonance imaging. A similar but comparatively newer neuroimaging modality is Functional Near Infrared Spectroscopy. Transcranial Magnetic Stimulation neuro-physiological technique is based on the principle of electromagnetic induction. Based on nuclear medicine the brain imaging technologies that are widely explored in the world of BCI are Positron Emission Tomography and Single Positron Emission Tomography.


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