Scintigraphic imaging

Scintigraphic imaging is a noninvasive imaging technique commonly applied in nuclear medicine. Radiolabeled compounds (called radiopharmaceuticals or radiotracers) are administered intravenously to patients for diagnostic or, in certain cases, therapeutic purposes. The in vivo distribution can provide important physiological information about tissue function. 

Photons with detectable energy differences that are emitted by various radionuclides can be quantified simultaneously, but independently from each other. This allows the use of dual-labeling approaches (4). These experiments will reveal information regarding both the liposomal carrier—labeled with one radionuclide—and the encapsulated compound—labeled with a different radionuclide—after a single injection in the same animal. However, 

The commonly used isotopes for scintigraphic imaging— Ga, Tc, in and iodine-123 ( I)—are all widely available (Table 1). However, generally Tc is preferred over the other isotopes, due to its optimal 

Afterloading Methods Using Aqueous Space Trapping 

There are two major ways in which liposomes have been radiolabeled by stably trapping the radionuclide in the liposome interior (i) use of second molecule encapsulated in liposome and (ii) chemical gradient with pH or ammonium sulfate. In the first method, a radionuclide is incubated with a lipophilic chelator and then mixed with an aliquot of liposomes encapsulating a second molecule. Once the lipophilic chelator carries the radionuclide across the lipid bilayer, the second molecule interacts with the radionuclide-chelator causing the radionuclide to become trapped within the interior of the liposome. This interaction may be due to the second molecule having a higher affinity for the radionuclide than the original lipophilic chelator. An 

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Figure 3 Representative scintigraphic images taken from a single volunteer following dosing with new paracetamol tablets containing sodium bicarbonate (A) and conventional tablets (B) in the fasted state.

Figure 4 Gamma scintigraphic images of small intestinal transit of capsules showing periods of stasis during a 30 sec acquisition. M = exterior marker.

Goins BA, Phillips WT. The use of scintigraphic imaging as a tool in the development of liposome formulations. Prog Lipid Res 2001 40 95. 

Figure 3 Planar scintigraphic images acquired at various times of a normal rat intravenously injected with Tc-Doxil (17MBq) Tc, 2 mg doxorubicin, and 16 mg total lipid labeled using Tc-iV,iV-bis(2-mercaptoethyl)-Af, Af diethyl-ethylenediamine method. Abbreviations-. H, heart L, liver K, kidney B, bowel.

Laverman P, Boerman OC, Storm G. Radiolabeling of liposomes for scintigraphic imaging. Methods Enzymol 2003 373 234—248. 

Radiolabelling of Pharmaceutical Aerosols and Gamma Scintigraphic Imaging for Lung Deposition... 

Hak-Kim Chan, Ph.D. Senior Lecturer, Faeulty of Pharmacy, University of Sydney, New South Wales, Sydney, Australia Radiolabelling of Pharmaceutical Aerosols and Gamma Scintigraphic Imaging for Lung Deposition... 

Perchlorate, given orally as the sodium salt, inhibits the iodide pump. Adverse reactions include aplastic anemia. Compared with thioamides, its therapeutic importance is low but it is used as an adjunct in scintigraphic imaging of bone by means of technetate when accumulation in the thyroid gland has to be blocked. 

E = 137keV). The accompanying emission of 7-radiation can be used for scintigraphic imaging but also makes patient isolation necessary. The different half-lifes and /3 -energies allow individual therapeutic demands such as the pharmacokinetics of the tracer molecule, the linear energy transfer of the nuclides or the biodistribution and clearance of the radiolabeled drug to be met. The principles of the application of radioactive materials for therapy are summarized in an excellent review. ... 

M. Schafers, B. Riemann, K. Kopka, H.J. Breyholz, S. Wagner, K.P. Schafers, M.P. Law, O. Schober, B. Levkau, Scintigraphic imaging of matrix metalloproteinase activity in the arterial wall in vivo. Circulation 109 (2004) 2554-2559. 

B.G. Siim, W.T. Laux, M.D. Rutland, B.N. Palmer, W.R. Wilson, Scintigraphic imaging of the hypoxia marker (99m)technetium-labeled 2,2 -(1,4-diaminobutane)bis (2-methyl-3-butanone) dioxime (99mTc-labeled HL-91 prognox) Noninvasive detection of tumor response to the antivascular agent 5,6-dimethylxanthenone-4-acetic acid. Cancer Res. 60(16) (2000) 4582-4588. 

U. Haberkorn, W. Mier, M. Eisenhut, Scintigraphic imaging of gene expression and gene transfer, Curr. Med. Chem. 12 (2005) 779-794. 

The only radionuclidic impurity detected in the 1-122 is less than 0.1% radioxenons and other radioiodines, which neither interfere with scintigraphic imaging nor result in a high radiation exposure to the patient. Further improvement of the radioiodine contamination could be attained with an iodine trap between the storage reservoir and the growth chamber. The milking efficiency is about 40%. We consider this generator assembly to be a preliminary version that can be refined considerably. Further details may be obtained from Richards and Ku (8). 

Fe(Hedta), Na2Fe(edta) Zn2+, Mn2+, Mg2 edta complexes see Chapter 62.1) (iv) removal of poisoning or radioactive metal ions from the body (Cd2+ NaCa(edta) Pb2+ Na3Ca(dtpa) see Chapter 62.2). Complexones have been used in the form of " Tc complexes to obtain scintigraphic imaging of human organs in diagnostic nuclear medicine (see Chapter 65). 

Early scintigraphic imaging during sublingual retention of the radioallergen clearly showed no change in the radioactive content of the mouth before... 

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