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- Thunberg, S., et al.
(författare)
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Dose reduction in mammography with photon counting imaging
- 2004
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. ; , s. 457-465
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Konferensbidrag (refereegranskat)abstract
- The purpose of this study was to investigate if the glandular dose to the breast in mammography can significantly be reduced without compromising image quality, when using photon counting technology, in a multi-slit scanning photon counting detector, compared to a conventional film mammography system and commercial available digital mammography systems with TFT-array detectors. A CDMAM phantom study, with two different thicknesses of additional PMMA absorber, 4 cm and 7 cm respectively, has shown that multi-slit scanning photon counting detector technology can reduce the dose, without reducing the image quality. This comparison was made to two commercial available digital mammography systems Senographe 2000D (from GEMS) and Selenia (from Lorad). The results show that dose can be reduced with 63% to 77%, depending on object thickness, when using XCT for mammography. This dose reduction has also been verified clinically through a small pilot study with patients and specimen, where the comparison was made between XCT and film.
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| 2. |
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| 3. |
- Morin, Maxim, et al.
(författare)
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Skin hydration dynamics investigated by electrical impedance techniques in vivo and in vitro
- 2020
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Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1, s. 17218-
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Tidskriftsartikel (refereegranskat)abstract
- Skin is easily accessible for transdermal drug delivery and also attractive for biomarker sampling. These applications are strongly influenced by hydration where elevated hydration generally leads to increased skin permeability. Thus, favorable transdermal delivery and extraction conditions can be easily obtained by exploiting elevated skin hydration. Here, we provide a detailed in vivo and in vitro investigation of the skin hydration dynamics using three techniques based on electrical impedance spectroscopy. Good correlation between in vivo and in vitro results is demonstrated, which implies that simple but realistic in vitro models can be used for further studies related to skin hydration (e.g., cosmetic testing). Importantly, the results show that hydration proceeds in two stages. Firstly, hydration between 5 and 10 min results in a drastic skin impedance change, which is interpreted as filling of superficial voids in skin with conducting electrolyte solution. Secondly, a subtle impedance change is observed over time, which is interpreted as leveling of the water gradient across skin leading to structural relaxation/changes of the macromolecular skin barrier components. With respect to transdermal drug delivery and extraction of biomarkers; 1 h of hydration is suggested to result in beneficial and stable conditions in terms of high skin permeability and extraction efficiency.
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| 4. |
- Svedenhag, Jan, et al.
(författare)
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Individual reference values for 2D echocardiographic measurements. The Stockholm - Umeå Study
- 2015
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Ingår i: Clinical Physiology and Functional Imaging. - : Wiley. - 1475-0961 .- 1475-097X. ; 35:4, s. 275-282
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Improved reference values for 2D echocardiographic measurements are required, even when more recent echocardiographic technology is employed. In addition, it may be preferable to individualize reference values from age, gender and body characteristics of any subject. Design: A material of 180 healthy subjects was collected and investigated, aiming for an even distribution of sex and age (from 20 to 80years of age; the Stockholm material). For atrial areas, material from another 216 healthy subjects with similar sex and age distribution was added (the Umea material). The 2D measures determined were the left and right ventricular diameters in diastole, the left ventricular diameter in systole, the thickness of septum and posterior wall, the diameters of the aortic root (sinotubular junction) and the left atrium (all in parasternal view), together with the left and right ventricular diameters in diastole and left and right atrial areas in end-systole (apical four-chamber view). The width of the inferior vena cava (from subcostal view) was also determined. Results: Confidence intervals for females and males are presented for each of these measures. Multiple linear regression analyses with age, sex and measures of body characteristics as predictors were also performed, and for eight of the 12 measurements, such equations are presented. Conclusions: It is possible to obtain more highly individualized reference values for these cardiac dimensions, which may clinically be a better way of distinguishing pathological states from normal states.
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