Gadolinium-based contrast agents (GBcAs) are frequently used in patients undergoing magnetic resonance imaging. in GBcAs gadolinium (Gd) is present in a bound chelated form. Gadolinium is a rareearth element, which is normally not present in human body. though the blood elimination half-life of contrast agents is about 90 minutes, recent studies demonstrated that some tissues retain gadolinium, which might further pose a health threat due to toxic effects of free gadolinium. It is known that the bone tissue can serve as a gadolinium depot, but so far only bulk measurements were performed. Here we present a summary of experiments in which for the first time we mapped gadolinium in bone biopsy from a male patient with idiopathic osteoporosis (without indication of renal impairment), who received MRI 8 months prior to biopsy. In our studies performed by means of synchrotron radiation induced micro-and submicro-X-ray fluorescence spectroscopy (SR-XRF), gadolinium was detected in human cortical bone tissue. The distribution of gadolinium displays a specific accumulation pattern. Correlation of elemental maps obtained at AnKA synchrotron with qBei images (quantitative backscattered electron imaging) allowed assignment of Gd structures to the histological bone structures. follow-up beamtimes at eSRf and Diamond Light Source using submicro-SR-XRf allowed resolving thin Gd structures in cortical bone, as well as correlating them with calcium and zinc. The method of contrast-enhanced MRI (CE-MRI) dates to 1988, when the first gadolinium (Gd)-based contrast agent (GBCA), gadopentetate dimeglumine (Magnevist, Bayer), was approved for clinical use. CE-MRI is a useful imaging tool nowadays, with approximately 30 million procedures done each year worldwide, and more than 300 million procedures already performed to date 1. Estimates show that the GBCAs are administered in 25-35% of all MRI examinations 1,2. According to the data available, most of the administered dose of GBCAs (regardless of an agent used), should be cleared in less than 2 and >95% by 24 hours 3. Recent findings, however, demonstrate that the GBCAs are not fully excreted and the accumulation of Gd in, e.g. neuronal tissues and organs such as brain takes place 4. The GBCAs are considered to be rather safe, yet there is a number of papers reporting nephrotoxic, hematotoxic, hepatotoxic and neurotoxic effects observed in animals and humans 5. One of the most serious adverse reactions associated with the use of GBCAs is nephrogenic systemic fibrosis (NSF), which had been observed in patients with renal insufficiency 6. NSF is a rare, but serious disease characterized by widespread tissue hardening (primarily skin is affected) with fibrotic nodules and plaques. First described in 1997, it was finally linked to the use of GBCAs in patients with kidney dysfunction in 2006 6,7. The pathophysiological mechanism involved

Determining the local distribution of major, minor and trace elements in biological tissues provides fundamental information on the chemical composition and often allows conclusions on the underlying biochemical mechanisms. Within...

The radiochemical effects of thermal neutron capture in tris(2,2,6,6-tetramethyl-3,5-heptandionato)chromium(III) (Cr(tmhd)3) were investigated. A method was devised to quantify the amount of the induced 51Cr activity recoverable in the original chemical form and to confirm that it is indeed Cr(tmhd)3. The method is based on a combination of chemical separation (column chromatography and recrystallization) and analytical (radio-TLC, HPLC, and gamma spectrometry) techniques. Cr(tmhd)3 samples were irradiated and purified in two steps after irradiation. We found that two of the (three) purification pathways yielded good agreement among final 51Cr activity concentrations. The corresponding samples appeared to be of exceptional radiochemical purity.