Sökning: "Diagnostic radiology"
Visar resultat 31 - 35 av 147 avhandlingar innehållade orden Diagnostic radiology.
31. Radiation dose and image quality in diagnostic radiology : optimization of the dose - image quality relationship with clinical experience from scoliosis radiography, coronary intervention and a flat-panel digital detector
Sammanfattning : Det är känt att röntgenstrålning kan orsaka cancersjukdomar, hudskador och andra sidoeffekter. Därför är det viktigt och även föreskrivet i lag att strålexpaneringen inom diagnostisk radiologi skall sänkas så långt som möjligt. Detta kallas på engelska ALARA-principen (As Low As Reasonably Achievable). LÄS MER
32. Non-invasive diagnostic methods of intracranial arteries
Sammanfattning : Aims of this thesis were to compare the agreement of different magnetic resonance angiography(MRA) techniques and digital subtraction angiography (DSA) in follow-up of intracranial aneurysms treated with coils in order to select the best MRA method, to evaluate the impact of increased iodine concentration in contrast medium and decreased tube voltage on arterial attenuation and image quality in computed tomography angiography (CTA) of intracranial arteries, and finally to evaluate the diagnostic accuracy of CTA in non-traumatic subarachnoid haemorrhage (SAH) compared to DSA and to assess the arterial attenuation (HU) as an image quality factor in this aspect. Follow-up DSA and time-of-flight (TOF) MRA at 1. LÄS MER
33. Standardized ultrasonography with cine-loop documentation : diagnostic variability in liver and kidney examinations
Sammanfattning : Background: Ultrasound examination of the abdomen is often a first choice at radiology departments due to the lack of ionizing radiation. For diagnostic accuracy and economic benefits there has been a need for new routines in this area that incorporate the benefits of an radiographer or sonographer performing a multitude of ultrasound examinations following strictly standardized examination protocols and documentation forms made by cine-loops that will give the radiologist access to all relevant information needed for an accurate postexamination diagnosis. LÄS MER
34. Effective use of X rays in diagnostic radiology : Guidance for the optimisation of image quality and absorbed dose in the patient by use of a Monte Carlo computational model of the imaging chain
Sammanfattning : The primary objective of this thesis is to give guidance for the reduction of absorbed dose in the patient and the improvement of image quality by the optimisation of the various parameters which control the performance of the radiological imaging system. The optimisation means that image quality (contrast in screen-film imaging and signal-to-noise ratio in digital imaging) is kept constant and combinations of operating parameters which yields the lowest mean absorbed dose in the patient is determined. LÄS MER
35. Calibration of Ionization Chambers for Measuring Air Kerma Integrated over Beam Area in Diagnostic Radiology
Sammanfattning : The air kerma area product PKA is an important quantity used by hospital physicists in quality assurance and optimization processes in diagnostic radiology and is recommended by national authorities for setting of diagnostic reference levels. PKA can be measured using a transmission ionization chamber (kerma area product (KAP) meter) mounted on the collimator housing. LÄS MER
