Search for dissertations about: "dose dependency"
Showing result 1 - 5 of 24 swedish dissertations containing the words dose dependency.
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1. Biomarkers of ionising radiation relevant to carcinogenesis : Dose, dose rate and LET dependency of the responses
Abstract : A better understanding of the relationship between ionising radiation (IR) dose, dose rate and radiation quality, and the risk of stochastic effects would improve risk extrapolation from atomic bomb survivors’ data. Owing to insufficient statistical power of epidemiological studies to detect excess incidence of cancer following low doses of IR delivered at low dose rates (LDLDR), as typically encountered in most common human exposure scenarios, radiobiological experiments are fundamental to describe the biological effectiveness of LDLDR and to define the underlying molecular mechanisms. READ MORE
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2. Angiotensin converting enzyme inhibition and aspirin in congestive heart failure
Abstract : Angiotensin-converting enzyme (ACE) inhibitors act by decreasing production of angiotensin II and by potentiating the effects of bradykinin by inhibition of its breakdown. Bradykinin exerts part of its effects via vasodilating prostaglandins. Since the cyclooxygenase (COX)-inhibitors, e.g. READ MORE
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3. ESR dosimetry in the radiation therapy dose range : development of dosimetry systems and sensitive dosimeter materials
Abstract : ESR dosimetry with L-α-alanine as a dosimeter material is a well known and frequently used method for measuring high absorbed doses, for example at sterilisation and food irradiation. The increased sensitivity of modem spectrometers and an increased knowledge of the radiochemical properties of alanine have lowered the detection limit of ESR/alanine dosimetry to the dose range relevant for radiation therapy. READ MORE
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4. Detection of pulmonary nodules in chest tomosynthesis: Comparison with chest radiography, evaluation of learning effects and investigation of radiation dose level dependency
Abstract : Chest tomosynthesis is a relatively recently introduced technique in healthcare, which produces section images of the chest at a lower radiation dose than computed tomography (CT) and with better depth resolution than conventional chest radiography. The primary aims of the studies described in this dissertation were to compare chest tomosynthesis with conventional radiography, to evaluate the effects of clinical experience and learning with feedback on the performance of observers analyzing tomosynthesis images, and to investigate the effect of radiation dose level in tomosynthesis, in the detection of pulmonary nodules. READ MORE
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5. The dependency of image quality on acquisition protocol and image processing in chest tomosynthesis
Abstract : The digital tomosynthesis (DTS) technique is a next generation of the old tomography technique, the use of which has been extended during the past decade. The interest in this technique has increased more and more in Radiology due to its ability to provide threedimensional images by acquiring a number of projection radiographs at lower radiation dose and potentially lower cost than CT in certain clinical situations. READ MORE
