Narrow Results

PIXE technique was applied to measurement of trace elements in total diet samples collected in Japan for estimation of their daily dietary intake. Results of PIXE analysis were compared with INAA Concentration of Cl, K, Mn and Zn by PIXE analysis well agreed with the results from NAA, while Ca, Fe and Cu showed different results between these two techniques. Preliminary data of elemental concentrations in Mate-cha, a kind of tea popular in South America, determined by ICP-AES indicated a little higher concentration of Cu than that by PIXE and much lower value than that by INAA For Zn. concentrations by PIXE and ICP well agreed to each other, while INAA gave much lower value. Japanese internal radiation doses by ¹³⁷Cs and ⁹⁰Sr were estimated to be 2.30µSv/year and 1.27µSv/year respectively as the effective dose equivalents using the daily intake data obtained for K and Ca.

Herein, the X-ray phase analysis (XPA) and differential-thermal analysis (DTA) of the CuTlSe₂ compound obtained by the Bridgman–Stockbarger method have been investigated. As a result of the study, the values of energy absorption and mass losses of CuTlSe₂ single crystal have been estimated depending on the temperature given their change mechanisms. The surface morphology of single crystals of the ternary coppercopounds (Cu-Tl-X ($x=\mathrm{\text{Se}}$)) in the initial state, annealing and after exposure to gamma-radiation is studied by atomic force microscopy. It is shown that the surface relief undergoes modification in the absorbed dose region of $D\gamma \le$ 500krad.

The twist CT has been advocated as a useful diagnostic tool for determining lumbar segment instability. According to this test, facet joints showing wide separation on lumbar spine rotation are believed to be pathological. However, no reports have presented the reliability of measuring facet joint separation from clinical twist CT films, nor tested for an association between tendency to separate and anatomical joint orientation.

Forty-five patients, referred for mechanical low back pain, were scanned first in neutral, then right and left trunk twisted positions. Images were video-digitized onto computer for quantitative measurement of facet joint morphology. The induced facet joint separation was contrasted with the neutral scan joint approximation and any difference was expressed in millimeters.

The coefficient of variability (c.v.) of defining right and left transverse plane facet joint orien-tation, and of joint separation, from repeated assessment in ten images was acceptable (c.v. = 2% and 3.5%, respectively). The average joint angle increased from L2–3 to L5–S1 and the mean facet joint separation of 2.6 mm was greatest at the L4–5 level. Forty-three percent of all segments showed little additional separation (<0.2 mm) when in a rotated posture. In the remainder, a slight relationship existed between facet geometry and separation; joints with wider angles were associated with greater separation than those with a more sagittal configuration (r=0.36, p<0.01).

No conclusive trend was recorded in this patient series for facet joints to separate when the subject adopted an end-range rotated posture. A mild association between physiological separation of facet joints and their morphological angle was determined. This trend alone should not afford confidence in attributing such separation as having pathological significance.

Coronary CT angiography (CCTA) is a widely used less-invasive imaging modality for diagnostic assessment of coronary artery disease with high diagnostic value. Technical developments have rapidly evolved in recent years to overcome limitations of conventional CCTA, in particular further lowering radiation dose and improving diagnostic performance. This chapter focuses on the recent and novel imaging techniques that are used in CCTA. It is clinically important to understand these techniques for enhancing the diagnostic performance of CCTA while minimizing radiation exposure to patients.