Routine Quality Control Program Research Articles

Quality control program of X-ray mammography

To maintain high quality in mammography, a routine quality control program is necessary to detect drifting or degradation of system performance overtime and it is becoming more important especially when the machine is used for population screening, a large number of asymptomatic women will receive a large amount of dose. Therefore, the importance of optimization of image quality and minimization of radiation dose is essential to accomplish the goals of mammography screening, and this require to have and make sure that the Mammography X-ray machine working properly and stable. Due to advances in technology, the regulation and testing of digital mammography systems has become complicated. Not only does each mammographic X-ray unit model have its own test protocol, peripheral equipment must also be tested according to manufacturer specifications. And this program must be followed in detail by both physicists testing the device and other clinical users performing routine QC functions on a daily basis. In this lecture the Mammography QC testing program will be discussed and recent advances in the automation of QC measurements by some manufacturers will be highlighted.

Determination of the tube voltage from clinic mammo-graphic system using two types of detectors

The use of X rays for diagnostic radiology is very common and important to Medicine, including mammographic diagnosis focusing decreasing of the doses applied to the patients and preserving high quality of the diagnostic image. A quality control program of the irradiation systems it is necessary to control periodically the performance of the X-ray systems applied in that diagnosis in order to obtain the best results in that diagnosis. The verification of the beam characteristics is made by using standard dosimetric procedures which include the determination of the kilovoltage and the kerma rates for the different radiation qualities applied in the diagnosis. The Instruments Calibration Laboratory (LCI) of IPEN perform calibration in dosemeters used in radiation dosimetry (in diagnostic radiology) for many years and are improving their methodology to attend the actual demand of that equipments used in quality control of that X-radiation systems. The objective of that paper were the measurements of kVp and air kerma produced for one mammographic system of LCI, Model VMI – Graphmammo AF (Philips) using two different measurements systems from PTW (Diavolt) and Radcal (kVp meter) that procedure is just to determine the stability of that system that is used to perform diagnosis in mammography level. The results obtained with the two systems utilized shows good agreement. That measurement can be applied at a routine quality control program of that X-ray system.

Mapping of the radiation field of a mammography equipment using molybdenum and rhodium filters

The use of X rays for diagnostic radiology is very common and important to Medicine, including mammographic diagnosis focusing decreasing of the doses applied to the patients and preserving high quality of the diagnostic image. A quality control program of the irradiation systems it is very necessary. The Instruments Calibration Laboratory (LCI) of IPEN perform calibration in dosemeters used in radiation dosimetry (in diagnostic radiology) for many years. The objective of that paper is determining the point of greatest intensity of the beam issued by the mammograph equipment. Exposures were made with filters Rhodium and Molybdenum. That mapping is important before applied a routine quality control program of the mammograph equipment and the calibration of instruments in the diagnosis.

Evaluation of the depth-ratio and backscattering-factor methods in quality control measurements of electron beam energies

Sensitivities of two different methods for evaluating electron beam energy have been investigated. One of them uses the ratio of ionization at two depths corresponding to two different points on the depth curve of ionization. The other one uses the magnitude of backscattering by lead as a measure of the electron beam energy. The depth-ratio method was found to be sensitive and practical for a routine quality control program. The sensitivity of the backscattering effect was found to be insufficient for electron energies higher than 12 MeV.

Quality control phantom for digital chest radiography.

To develop and test a chest phantom for routine quality control testing of digital radiography systems. The phantom was constructed from sheets of copper, aluminum, and acrylic, which were cut and arranged to yield a radiographic projection resembling that of a human thorax. Regional test objects allowed quantitative assessment of optical density, contrast detail, and spatial resolution. Validation tests were performed to assess image stability in a stable imaging environment and sensitivity to changes in image quality when they occur. The phantom yielded consistent pseudoclinical images when used in a routine quality control program and facilitated detection of simulated problems that were induced in imaging system performance. The chest phantom enables quantitative, full-system testing of digital radiography system as they are used clinically for chest radiography.

Rapid Miniaturized Chromatographic Quality Control Procedures for Iodinated Radiopharmaceuticals

A rapid, miniaturized chromatographic system was developed to determine the labeling efficiency of iodinated radio-pharmaceuticals including I-131 orthoiodohippurate, I-131 rose bengal, I-125 RISA, and I-131 19-iodocholesterol. The system consists of three specific chromatography strips (Whatman 31ET paper chromatography, silica gel and silicic acid instant thin-layer chromatography) and three solvents (chloroform:glacial acetic acid in a 1.00:0.05 v/v mixture, absolute methanol, and 0.9% sodium chloride). The strips are color-coded, miniaturized, and appropriately labeled. The chromatographic quality control procedures are easy to use, rapid, and can be incorporated easily in a routine quality control program.