This paper presents the establishment of a quality control program and correction factors for the geometry of the vials used for distribution of radiopharmaceutical and activimeters calibration. The radiopharmaceutical produced by IPEN 67Ga, 131I, 201Tl and 99mTc had been tested using two different vials. Results show a maximum variation of 22% for 201Tl, and the minimum variation was 2.98% for...

In a recent paper, Tang and Mayersohn [(2005) Drug Metab Dispos 33:1294-1296] mathematically described the functionality of the correction factors (CFs), maximum life-span potential (MLP), and brain weight (BrW) used in allometric scaling for the prediction of human drug clearance. They found that there is an intrinsic defect in using correction factors because different combinations of species...

PURPOSE Analyze the characteristics of TLD LiF-100 powder between multiple LiF crystal batches. METHODS The RPC used TLD LiF-100 encapsulated powder to verify the output for photon and electron beams for 4 to 23 MV X-ray beams and 6 to 23 MeV electron beams, respectively, from the past 15 years. During that time period, the RPC commissioned more than 15 batches of TLD powder. Commissioning of...

Determination of lanthanides by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) using modified mathematical correction method has been studied. Normally, the ICP-MS analysis of middle and heavier lanthanides becomes difficult by severe spectroscopic overlap of M , MO or MOH ions from lighter lanthanides and Ba. A q q q correction method based on a single element oxide yield measurement, i...

The conversion of absorbed dose-to-graphite in a graphite phantom to absorbed dose-to-water in a water phantom is performed by water to graphite stopping power ratios. If, however, the charged particle fluence is not equal at equivalent depths in graphite and water, a fluence correction factor, kfl, is required as well. This is particularly relevant to the derivation of absorbed dose-to-water, ...

A number of treatment-planning systems still use conventional correction methods for body inhomogeneities. Most of these methods (power law method, tissue-air ratio (TAR), etc.) consider only on-axis points, rectangular fields, and inhomogeneous slabs covering the whole irradiating field. A new method is proposed that overcomes the above limitations. The new method uses the principle of the Cla...

SUMMARY Background gradients induced by magnetic susceptibility variations near air-filled cavities in the brain cause signal-intensity loss in gradient-echo images and shorten T2* considerably. With a correction method in which the exponential decay is restored with section-profile-dependent correction factors, parts of the signal intensity can be recovered. While uncorrected T2* values drop b...