purpose : the aim of this study was to investigate the effect of misalignment (tilt & decentration) of iols in cataract surgery using liu-brennan optical eye model in a simulation. methods : a phantom with the real eye parameters –liu-brennan model– and tecnis z9000 iol were used for simulation. results : results showed that with 0.4 mm decentration and more the modulation transfer function (mt...

conclusion scout views may be useful in determining dose and image quality in ct scanning; however, it is necessary to first determine the most appropriate scout view for ct scans. background while using the automatic exposure control technique in computed tomography (ct), the scout view determines the radiation dose for the ct scan by taking anatomical morphology into consideration. objectives...

Purpose: Children are sometimes examined with Computed Tomography protocols designed for adults, leading to radiation doses higher than necessary. Lack of optimisation could lead image quality what is needed diagnostic purposes associated high patients. Optimising the paediatric head trauma CT imaging will reduce dose. Objective: The study aimed optimise dose and assess a set by evaluating nois...

BACKGROUND In integrated PET/MR hybrid imaging the evaluation of PET performance characteristics according to the NEMA standard NU 2-2007 is challenging because of incomplete MR-based attenuation correction (AC) for phantom imaging. In this study, a strategy for CT-based AC of the NEMA image quality (IQ) phantom is assessed. The method is systematically evaluated in NEMA IQ phantom measurements...

OBJECTIVE To assess effects of off-centering, automatic exposure control, and padding on attenuation values, noise, and radiation dose when using in-plane bismuth-based shields for CT scanning. MATERIALS AND METHODS A 30 cm anthropomorphic chest phantom was scanned on a 64-multidetector CT, with the center of the phantom aligned to the gantry isocenter. Scanning was repeated after placing a b...

Image quality is a key issue in radiology, particularly in a clinical setting where it is important to achieve accurate diagnoses while minimizing radiation dose. Some computed tomography (CT) manufacturers have introduced algorithms that claim significant dose reduction. In this study, we assessed CT image quality produced by two reconstruction algorithms provided with GE Healthcare's Discover...

PURPOSE As cone-beam CT (CBCT) systems dedicated to various imaging specialties proliferate, technical assessment grounded in imaging physics is important to ensuring that image quality and radiation dose are quantified, understood, and justified. This paper involves technical assessment of a new CBCT scanner (CS 9300, Carestream Health, Rochester, NY) dedicated to imaging of the ear and sinuse...

IntroductionThe utility of evaluating a sagittal view CT the spine is well-known. In many clinical cases, includes noise generated from surrounding objects and may degrade image quality. Iterative reconstruction (IR) techniques are useful for reduction; however, they can reduce spatial resolution. The aim this study was to evaluate effectiveness adaptive statistical iterative (ASiR) generating ...

Purpose. – The aim of the present study was to quantitatively assess the performance of a block matching-based automatic registration algorithm integrated within the commercial treatment planning system designated ISOgrayTM from Dosisoft. The accuracy of the process was evaluated by a phantom study on computed tomography (CT), magnetic resonance (MR) and positron emission tomography (PET) image...

Electronic portal imaging device (EPID) plays an important role in radiation therapy portal imaging, geometric and dosimetric verification. Consistent image quality and stable radiation response is necessary for proper utilization that requires routine quality assurance (QA). A commercial 'EPID QC' phantom weighing 3.8 kg with a dimension of 25 × 25 × 4.8 cm³ is used for EPID QA. This device ha...