[en] This report constitutes the third phase of the review of reports prepared by Sandia for the USNRC; the first two phases were reported in Volumes 1 and 2 of NUREG/CR-1672. The reviewers generally agree that the compartment model used in Volume 1 to describe environmental transport is capable of accurately calculating the phenomena if suitable data is available. The sensitivity analysis of the environmental transport model as presented in Volume 2, was judged to be inferior to Volume 1. The reasons for selecting certain input variables for the sensitivity analysis are not clear. The input data and associated uncertainty ranges appear not to have been selected from real geophysical sources. The significance of results is not clear. Tabular and graphical results are not discussed. In Volume 3, the compartment model is used to derive the asymptotic values of Cm²⁴⁵ concentration in sub-zones of ground water, soil, surface water and sediment. Methodology is not discussed; nor how the study can be used in an overall risk assessment of a waste repository

No abstract available

[en] The calculations were performed for a standing and a prone man at four different orientations to the burst and at two different ranges. The detailed nature of the calculations allowed the determination of the transmitted neutrons, the transmitted gamma-rays and the gamma-rays produced by neutron interactions in the human body. The corresponding transmission factors do not vary too much with orientation or range, but are very different for the head and the intestine. For instance only 13% of the free field neutron dose reach the GI tract, but 43% reach the midhead position. Most of the dose at the GI tract consists of gamma-rays even at high n/γ free field dose ratios. The calculations permit an easy computation of any critical organ dose, if neutron and gamma doses were recorded by a dosimeter. (orig./DG)

No abstract available

[en] Purpose. For accurate resection of nonpalpable malignant breast lesions with a tumor-free resection rim, an exact and stable wire localization is essential. We tested the resistance towards traction force of different localization devices used in our clinic for breast lesions in two types of tissue. Materials and Methods. Eight different commercially available hook-wire devices were examined for resistance towards traction force using an analogue spring scale. Results. Most systems showed a high level of movement already under small traction force. Retractable systems with round hooks such as the Bard DuaLok , the Fil d ’ Ariane, and the RPLN Breast Localization Device withstood less traction force than the other systems. However, the Bard DuaLok system was very resistant towards a small traction force of 50 g when compared to the other systems. The Ultra wire Breast Localization Device withstood the most traction force in softer tissue and Kopans Breast Lesion Localization Needle withstood the most force in harder tissue. Conclusion. The Ultra wire Breast Localization Device and Kopans Breast Lesion Localization Needle withstood the most traction force. In general retractable systems withstand less traction force than non retractable systems

[en] To assess how ASIR (adaptive statistical iterative reconstruction) contributes to dose reduction and affects image quality of non-contrast cranial computed tomography (cCT). Non-contrast emergency CT scans of the head acquired in 177 patients were evaluated. The scans were acquired and processed using four different protocols: Group A (control): 120 kV, FBP (filtered back projection) n=71; group B1: 120 kV, scan and reconstruction performed with 20 % ASIR (blending of 20 % ASIR and 80 % FBP), n=86; group B2: raw data from group B1 reconstructed using a blending of 40 % ASIR and 60 % FBP, n=74; group C1: 120 kV, scan and reconstruction performed with 30 % ASIR, n=20; group C2: raw data from group C1 reconstructed using a blending of 50 % ASIR and 50 % FBP, n=20. The effective dose was calculated. Image quality was assessed quantitatively and qualitatively. Compared to group A, groups B1/2 and C1/2 showed a significantly reduced effective dose of 40.4 % and 73.3 % (p < 0.0001), respectively. Group B1 and group C1/2 also showed significantly reduced quantitative and qualitative image quality parameters. In group B2, quantitative measures were comparable to group A, and qualitative scores were lower compared to group A but higher compared to group B1. Diagnostic confidence grading showed groups B1/2 to be adequate for everyday clinical practice. Group C2 was considered acceptable for follow-up imaging of severe acute events such as bleeding or subacute stroke. Conclusion: Use of ASIR makes it possible to reduce radiation significantly while maintaining adequate image quality in non-contrast head CT, which may be particularly useful for younger patients in an emergency setting and in follow-up.

[en] Highlights: • Iterative reconstruction (IR) in staging CT provides equal objective image quality compared to filtered back projection (FBP). • IR delivers excellent subjective quality and reduces effective dose compared to FBP. • In patients with neuroendocrine tumor (NET) or may other hypervascular abdominal tumors IR can be used without scarifying diagnostic confidence. - Abstract: Objective: To investigate whether dose reduction via adaptive statistical iterative reconstruction (ASIR) affects image quality and diagnostic accuracy in neuroendocrine tumor (NET) staging. Methods: A total of 28 NET patients were enrolled in the study. Inclusion criteria were histologically proven NET and visible tumor in abdominal computed tomography (CT). In an intraindividual study design, the patients underwent a baseline CT (filtered back projection, FBP) and follow-up CT (ASIR 40%) using matched scan parameters. Image quality was assessed subjectively using a 5-grade scoring system and objectively by determining signal-to-noise ratio (SNR) and contrast-to-noise ratios (CNRs). Applied volume computed tomography dose index (CTDI_v_o_l) of each scan was taken from the dose report. Results: ASIR 40% significantly reduced CTDI_v_o_l (10.17 ± 3.06 mGy [FBP], 6.34 ± 2.25 mGy [ASIR] (p < 0.001) by 37.6% and significantly increased CNRs (complete tumor-to-liver, 2.76 ± 1.87 [FBP], 3.2 ± 2.32 [ASIR]) (p < 0.05) (complete tumor-to-muscle, 2.74 ± 2.67 [FBP], 4.31 ± 4.61 [ASIR]) (p < 0.05) compared to FBP. Subjective scoring revealed no significant changes for diagnostic confidence (5.0 ± 0 [FBP], 5.0 ± 0 [ASIR]), visibility of suspicious lesion (4.8 ± 0.5 [FBP], 4.8 ± 0.5 [ASIR]) and artifacts (5.0 ± 0 [FBP], 5.0 ± 0 [ASIR]). ASIR 40% significantly decreased scores for noise (4.3 ± 0.6 [FBP], 4.0 ± 0.8 [ASIR]) (p < 0.05), contrast (4.4 ± 0.6 [FBP], 4.1 ± 0.8 [ASIR]) (p < 0.001) and visibility of small structures (4.5 ± 0.7 [FBP], 4.3 ± 0.8 [ASIR]) (p < 0.001). Conclusion: In clinical practice ASIR can be used to reduce radiation dose without sacrificing image quality and diagnostic confidence in staging CT of NET patients. This may be beneficial for patients with frequent follow-up and significant cumulative radiation exposure