Tomography positron emission

Distribution in vivo could be studied by positron emission tomography (PET). Positron emission tomography is a sensitive and specific functional non invasive 3-D imaging method that permits rapidly and directly measurement of the total radioactivity from a drug labelled with a positron-emitting radionuclide (Gupta). 

The optimal isotopes should be selected depending of the pharmacokinetic of the drug and their half-life values (20.4, 2.03,10 and 109.8 min for nC, 150, 13N and 1SF, respectively). 

Quantitative values on the drugs/tracers radioactivity concentration-time profile in different organs or sub-regions of organs are determined. 

PET has a number of advantages. The entire time course of the distribution can be determined quantitatively in a living animal or human with a temporal resolution of seconds to minutes. Each subject can be used as its own 

New materials with higher sensitivity or resolution have been designed A 3-dimensional PET scanner using gadolinium oxyorthosilicate (GSO) crystals (Surti). 

The PET signal from F-crosslinked dextran coating (CLIO) is significantly higher from murine aortic aneurysms than it is from normal aortas, due to F-CLIO targeting monocytes and macrophages within the aneurysm [137]. Conjugates of nanoparticles 

Nanoparticles may also be labelled with or to generate PET images. Garcia and co-workers, for example, used to label nanodiamonds, a kind of carbon nanoparticle, and studied the biodistribution of such nanocarriers using PET in vivo. Nanodiamonds are mainly retained in the lungs, as a result of size exclusion, and are absorbed into the endothelial system organs by phagocytosis in the rodent model used [141]. 

---

K. F. Hubner, J. CoUmann, E. Buonocore, and G. W. Kabalka, Clinical Positron Emission Tomography, Mosby Year Book, St. Louis, Mo., 1991. 

Applications in agrochemicals [42, 43], pharmaceuticals [44,45], and positron emission tomography (PET) [46, 47, 48 49] have resulted in the resuscitation of the Wallach reaction The Wallach technique provides high-specific-activity F-radiolabeled aromatic fluoride for PET studies, in contrast to the low-specific-ac-tivity product by the Balz-Schiemann route... 

Positron emission tomography (PET), 516 Post-transition metal Lower members of periodic groups 13,14, and 15, such as PbandBi, 31,38-39... 

An additional benefit of COMT inhibitors can be found in positron emission tomography (PET) studies. In PET, using 6-[18F]-fluoro-L-dopa (6-FD) to visualize the brain dopamine metabolism, the peripheral formation of 3-0-methyl-6-[18F]-fluoro-L-dopa (3-OMFD) by COMT is harmful. 3-OMFD contaminates the brain radioactivity analysed since it is easily transported like 3-OMD to the... 

Brain imaging technique that allows visualization of the brain, in order to understand which brain regions are involved in specific functions. Its functioning is based on the measurement of the regional cerebral blood flow which increases when a specific brain region is activated. Its use is similar to that of positron emission tomography (PET). 

Positron emission tomography (PET) is an imaging technique that relies on the emission of positrons from radionucleotides tagged to an injectable compound of interest. Each positron emitted by the radioisotope collides with an electron to emit two photons at 180° from each other. The photons are detected and the data processed so that the source of the photons can be identified and an image generated showing the anatomical localization of the compound of interest. 

Poor Metabolizer Phenotype Population Pharmacokinetics Positron Emission Tomography Post-translational Modification Potassium Channels Potassium Competitive Acid Blockers PP... 

Positron emission tomography (PET) makes use of a short-lived positron emitter such as fluorine-18 to image human tissue with a degree of detail not possible with x-rays. It has been used extensively to study brain function (see illustration) and in medical diagnosis. For example, when the hormone estrogen is labelled with fluorine-18 and injected into a cancer patient, the fluorine-bearing compound is preferentially absorbed by the tumor. The positrons given off by the fluorine atoms are quickly annihilated when they meet... 

In 2003 LJngstrOm and Samuelsson described the synthesis of a radiopharmaceutical for PET (positron emission tomography) using a microwave-assisted Stille reaction [25]. l-(2 -Deoxy-2 -fluoro- 6-D-arabinofuranosyl)-... 

In their search for new hgands with a very high binding affinity for the nicotinic acetylchohne receptor (nAChR), potentially useful in positron emission tomography (PET) when radiolabeled with [ F], Horti et al. described the synthesis of BOC-protected 5-(azetidin-2-ylmethoxy)-2-chloro-6 -fluoro-3,3 -bipyridine via a sequential classical heating and microwave irradiation of (2-fluoro-5-pyridinyl)(trimethyl)stannane with f-butyl 2- [(6-chloro-5-... 

Wong DF, Maini A, Rousset OG, et al Positron emission tomography—a tool for identifying the effects of alcohol dependence on the brain. Alcohol Res Health 27 161-173,2003... 

Positron emission tomography studies using "C-toluene in nonhuman primates and mice showed a rapid uptake of radioactivity into striatal and frontal brain regions (Gerasimov et al. 2002). Maximal uptake of the radiotracer by these structures occurred 1 minutes after intravenous administration. Subsequently, clearance of the radiotracer from the striatal and frontal areas occurred rapidly, with a clearance half-life from peak uptake of 10—20 minutes. Radiotracer clearance from white matter appears to be slower... 

Considerable interest has been focused on the efficient and rapid synthesis of 2-deoxy-2-[ F]fluoro-D-gIucose, a popular imaging agent for positron-emission tomography (see Section III, 1). However, introduction of a fluorine atom at C-2 by nucleophilic displacement is generally not easy on account of the weak nucleophilic character of the fluoride ion. One possible... 

T. Greitz. D. H. Ingvar. and L. Widen (Eds.), The Metabolism of the Human Brain Studied with Positron Emission Tomography, Raven Press, New York, 1985. 

---