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David A Schauer

Publications and source records attributed to David A Schauer.

5 recordsLinked to original sources
PubMed2006

Applicability of ACR breast dosimetry methodology to a digital mammography system.

Determination of mean glandular dose (MGD) to breast tissue is an essential aspect of mammography equipment evaluations and exposure controls. The American College of Radiology (ACR) Quality Control Manual outlines the procedure for MGD determination in screen-film mammography based upon conversions of entrance skin exposures (ESEs) measured with an ionization chamber (IC). The development of digital mammography has increased with the demand for improved object resolution and tissue contrast. This change in image receptor from screen-film to a solid-state detector has led to questions about the applicability of the ACR MGD methodology to digital mammography. This research has validated the applicability of the ACR MGD methodology to digital mammography in the GE digital mammography system Senographe 2000D. MGD was determined using light output measurements from thermoluminescent dosimeters (MGDTL), exposure measurements from an IC (MGD(IC)) and conversion factors from the ACR Mammography Quality Control Manual. MGD(TL) and MGD(IC) data indicate that there is a statistically significant difference between the two measurements with the Senographe 2000D. However, the applicability of the ACR's methodology was validated by calculating MGD at various depths in a 50/50 breast phantom. Additionally, the results of backscatter measurements from the image receptors of both mammography modalities indicate there is a difference (all P values < 0.001) in the radiation backscattered from each image receptor.

Algorithms↗
PubMed2006

Analysis of current assessments and perspectives of ESR tooth dosimetry for radiation dose reconstruction of the population residing near the Semipalatinsk nuclear test site.

Between 1949 and 1989 the Semipalatinsk nuclear test site (SNTS), an area of 19,000 square km in northeastern Kazakhstan, was the location of over 400 nuclear test explosions with a total explosive energy of 6.6 Mt TNT (trinitrotoluene or trotyl) equivalent. It is estimated that the bulk of the radiation exposure to the population resulted from three tests, conducted in 1949, 1951, and 1953 although estimations of radiation doses received by the local population have varied significantly. Analysis of the published ESR dose reconstruction results for residents of the villages near the SNTS show that they do not correlate well with other methods of dose assessment (e.g. model dose calculation and thermo luminescence dosimetry (TLD) in bricks). The most significant difference in dose estimations was found for the population of Dolon, which was exposed as result of the first Soviet nuclear test in 1949. Published results of ESR measurements in tooth enamel are considerably lower than other dose estimations. Detailed analysis of these results is provided and a possible explanation for this discrepancy and ways to eliminate it are suggested.

Adult↗
PubMed2002

Imaging body armor.

This study examined the feasibility of performing radiographic studies on patients wearing standard-issue body armor. The Kevlar helmet, fragmentation vest, demining suit sleeve, and armor plate were studied with plain film and computed tomography in a simulated casualty situation. We found that the military helmet contains metal screws and metal clips in the headband, but diagnostic computed tomographic images can be obtained. Kevlar, the principal component of soft armor, has favorable photon attenuation characteristics. Plate armor of composite material also did not limit radiographic studies. Therefore, when medically advantageous, patients can be examined radiographically while wearing standard military body armor. Civilian emergency rooms should be aware of these observations because law enforcement officers wear similar protective armor.

Extremities↗