abstractbackground: an electron beam generated x-ray spectrum consists of characteristic x-ray and continuous bermsstrahlung. the aim of this research is calculating and comparing x-ray spectra for different target filter of mammograms. materials and methods: monte carlo is a very powerful tool to simulate a series of different target-filter assembly in order to calculate the x-ray spectra. mcn...

Myocardial perfusion SPECT imaging with Tc99m-sestamibi is the most accurate non-invasive means of detecting coronary artery disease and assessing the severity of perfusion abnormalities in the patients with coronary stenosis. Though simple and straight forward the results produced by the technique is very much affected by the details being used. One of the main problems with the test, wh...

Background: In CT systems, the machine utilizes a bowtie filter to shape the X-ray beam and remove lower energy photons. The shape of this bowtie filter is complicated and its geometry is often not available in detail. These renders the CT dose index (CTDI) to have different values in measurement versus Monte Carlo simulation studies and other analytical calculations especially in dosimetry of ...

We used dried blood spots successfully as alternative specimens for quantifyingconcentrationsof theophyllinein the circulation by a modified fluorescence polarization immunoassay (FPIA) with the Abbott TDx instrument. The method described is simple, rapid, and acceptably precise. More importantly, it can provide results comparable with those of the conventional serum assay. Results for 64 pairs...

The majority of methods for determining high-density lipoprotein (HDL) cholesterol failed the 1991 College of American Pathologists (CAP) linearity survey (sets LN2-A, B, C). We hypothesized that they failed because of the survey material matrix. We evaluated linearity with dextran sulfate or phosphotungstate as the precipitating reagents for several methods: Ektachem; TDx; Sigma; Dimension; Co...

We developed automated homogeneous immunoassays, based on immunolysis of liposomes, for measuring phenytoin, phenobarbital, and carbamazepine from serum. Liposome lysis was detected spectrophotometrically from entrapped glucose-6-phosphate dehydrogenase activity. The procedure was fully automated on a routine automated clinical analyzer. Within-run, between-run, dilution, and recovery tests sho...

An enzyme-labeled immunometric assay has been developed for measuring digoxin concentrations in serum or plasma. Unitized, compartmentalized reagents are used with an automated sample-processing instrument. The enzyme activity of the processed sample, which is directly proportional to the digoxin concentration, is measured by using a reagent strip and the Ames Seralyzer reflectance photometer. ...

Determination of digoxin by fluorescence polarization immunoassay (FPIA) with the Abbott "TDx" is significantly influenced by the concentration of total serum protein. Each 10 g/L increase in serum protein results in an 8% decrease in measured digoxin. Studies with [3H]digoxin confirmed that digoxin binds to the protein pellet during the trichloroacetic acid precipitation step before the immuno...