Search results for "radionuclide"
showing 10 items of 196 documents
Post-Processing via Cation Exchange Cartridges: Versatile Options
2012
New 68Ge/68Ga radionuclide generators provide the positron emitter 68Ga (T½ = 67.7 min) as an easily available and relatively inexpensive source of a PET nuclide for labeling of interesting targeting vectors. However, currently available “ionic” 68Ge/68Ga radionuclide generators are not necessarily optimized for the routine synthesis of 68Ga-labeled radiopharmaceuticals in a clinical environment. Post-processing of 68Ge/68Ga generators using cation exchange resins provides chemically and radiochemically pure 68Ga with 97±2% within less than 4 min, with 68Ge almost completely removed, and ready for online labeling. This simple, fast, and efficient technology can be extended for new applicati…
The prognostic value of sentinel lymph node micrometastases in patients with invasive breast carcinoma
2016
The prognostic value of sentinel lymph node micrometastases in invasive breast cancer patients is still widely debated. Even if, in the absence of unequivocal guidelines, the axillary lynphadenectomy is not still performed in the routine clinical care of these patients.We have retrospectively analyzed 746 patients with operable invasive breast cancer and clinically negative axillary lymph nodes. These patients underwent conservative surgery or total mastectomy with sentinel lymph node biopsy. Patients with micrometastases in the sentinel lymph node treated with axillary dissection has been checked and the involvement of the remaining lymph nodes analyzed. Patients with micrometastases in th…
Theragnostic Use of Radiolabelled Dota-Peptides in Meningioma: From Clinical Demand to Future Applications.
2019
Meningiomas account for approximately 30% of all new diagnoses of intracranial masses. The 2016 World Health Organization’s (WHO) classification currently represents the clinical standard for meningioma’s grading and prognostic stratification. However, watchful waiting is frequently the chosen treatment option, although this means the absence of a certain histological diagnosis. Consequently, MRI (or less frequently CT) brain imaging currently represents the unique available tool to define diagnosis, grading, and treatment planning in many cases. Nonetheless, these neuroimaging modalities show some limitations, particularly in the evaluation of skull base lesions. The emerging evidence supp…
Unusual case of continuous urinary dribbling in a young female due to unknown complex urogenital malformation: magnetic resonance features
2020
Congenital anomalies of kidney and urinary tract (CAKUT) occur in up to 3.2% of infants, and in almost one third of cases they are associated to genital aberrations. DMSA renal scintigraphy is considered the gold standard in CAKUT patients, to assess renal function, depict and locate ectopic kidney and to guide eventual surgical management. Recent cases have shown the noticeable limit of scintigraphy in detecting poorly functional renal moieties and associated genital anomalies; thus leading to a substantial delay in therapy, and, in females, to severe uro-gynecological complications. We herein describe a case of a young girl with unusual urinary dribbling, where DSMA scintigraphy was not d…
Total synthesis and evaluation of [18F]MHMZ.
2007
Radiochemical labeling of MDL 105725 using the secondary labeling precursor 2-[(18)F]fluoroethyltosylate ([(18)F]FETos) was carried out in yields of approximately 90% synthesizing [(18)F]MHMZ in a specific activity of approximately 50MBq/nmol with a starting activity of approximately 3GBq. Overall radiochemical yield including [(18)F]FETos synthon synthesis, [(18)F]fluoroalkylation and preparing the injectable [(18)F]MHMZ solution was 42% within a synthesis time of approximately 100 min. The novel compound showed excellent specific binding to the 5-HT(2A) receptor (K(i)=9.0 nM) in vitro and promising in vivo characteristics.
Abdominal scintigraphy for diagnosis of intestinal bleeding
1978
Abdominal scintigraphy with99mTc-pertechnetate, using a gamma-camera linked to a data processor, was done in 8 patients with acute massive intestinal hemorrhage and in 34 patients with chronic recurrent intestinal hemorrhage. Endoscopy and x-ray studies had failed in all patients to reveal a bleeding source. All but 3 patients underwent exploratory laparotomy, confirming the abnormal findings of scintigraphy. In all acutely bleeding patients, scintigraphy was positive. The bleeding was proven by laparotomy to be due to Meckel's diverticulum with gastric mucosa in 5, jejunal neurinoma in 1, and sigmoid colon carcinoma in 1 patient. Scintigraphy was positive in only 3 chronically bleeding pat…
Emission tomography with a large-hole collimator (CACAO): a possible new way to improve radionuclide imaging.
2002
This work aims to improve the quality of scintigraphy. It evaluates the use of a large-hole collimator, the Computer Aided Collimation Gamma Camera Project (CACAO), in SPECT. Acquisition data from the same object were simulated for CACAO and for a conventional collimator. Better signal-to-noise ratios were found for CACAO images, whatever the number of emitted photons. This work demonstrates that high-resolution images may be obtained with large-hole collimators. The combination of CACAO and pixilated detectors may further improve radionuclide imaging.
Trace elements in native and transplanted Fontinalis antipyretica and Platyhypnidium riparioides from rivers polluted by uranium mining.
2017
The past uranium/polymetallic mining activities in the Sudety (SW Poland) left abandoned mines, pits, and dumps of waste rocks with trace elements and radionuclides which may erode or leach out and create a potential risk for the aquatic ecosystem, among others. In the present work four rivers affected by effluents from such mines were selected to evaluate the application of aquatic mosses for the bioindication of 56 elements. Naturally growing F. antipyretica and P. riparioides were compared with transplanted samples of the same species. The results demonstrate serious pollution of the examined rivers, especially with As, Ba, Fe, Mn, Pb, Ti, U and Zn, reaching extremely high concentrations…
Laser spectroscopy of radioactive lead and thallium isotopes
1990
By collincar fast beam laser spectroscopy hyperfine structure and isotope shift have been measured of neutron deficient radioactive isotopes of lead (190Pb,191Pb,192Pb,193Pb,194Pb,195Pb,196Pb,197Pb) and thallium (188Tl190Tl,191Tl,192Tl,194Tl,196Tl). Therefrom nuclear magnetic dipole moments, electric quadrupole moments, changes of the mean square charge radii and deformation parameters are deduced and compared with predictions from theory.
Intrinsic backgrounds from Rn and Kr in the XENON100 experiment
2018
In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon ([InlineMediaObject not available: see fulltext.]), thoron ([InlineMediaObject not available: see fulltext.]) and krypton ([InlineMediaObject not available: see fulltext.]). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ∼4years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentr…