PURPOSE To retrospectively quantify the effect of systematic use of tube current modulation for neuroradiology computed tomographic (CT) protocols on patient dose and image quality. MATERIALS AND METHODS This HIPAA-compliant study had institutional review board approval, with waiver of informed consent. The authors evaluated the effect of dose modulation on four types of neuroradiologic CT st...

Low-dose CT (computed tomography) sinogram data have been shown to be signal-dependent with an analytical relationship between the sample mean and sample variance. Spatially-invariant low-pass linear filters, such as the Butterworth and Hanning filters, could not adequately handle the data noise and statistics-based nonlinear filters may be an alternative choice, in addition to other choices of...

results the study consisted of 40 patients (all men, with mean age of 33.38 ± 7.4 years). ct evaluation with standard dose were positive in 22 patients (55%). only 1 (2.5%) ct scan assigned as unacceptable by each radiologist in low-dose group. noise average of low-dose protocol, was approximately 7 times greater than standard dose group, while dlp and ed are 9.7 times smaller. in comparison wi...

--Projection data acquired for image reconstruction of low-dose computed tomography (CT) are degraded by many factors. These factors complicate noise analysis on the projection data and render a very challenging task for noise reduction. In this study, we first investigate the noise property of the projection data by analyzing a repeatedly acquired experimental phantom data set, in which the ph...

abstractbackground: polymer gels are an emerging new class of dosimeters which are being applied to the challenges of modern radiotherapy modalities. research on gel dosimetry involves several scientific domains, one of which is the imaging techniques with which dose data is extracted from the dosimeters. in the current work, we present our preliminary results of investigating capability of x-r...

 ABSTRACTBackground: Although Electronic Portal imaging Devices (EPIDs) have originally developed for positioning verification, they can also be used for dosimetric purposes. In the current work, the dose response of minimum detectable thickness of a Scanning Liquid filled Ion Chamber EPID, SLIC-EPID, and the variation of transmitted dose with the shift of inhomogeneity inside of phantom was al...

PURPOSE Stereotactic body radiation therapy (SBRT) is a potent treatment for early stage primary and limited metastatic disease. Accurate tumor localization is essential to administer SBRT safely and effectively. Tomotherapy combines helical IMRT with onboard megavoltage CT (MVCT) imaging and is well suited for SBRT; however, MVCT results in reduced soft tissue contrast and increased image nois...

The purpose of this study was to evaluate performance of the third generation of model-based iterative reconstruction (MBIR) system, Veo 3.0, based on noise power spectrum (NPS) analysis with various clinical presets over a wide range of clinically applicable dose levels. A CatPhan 600 surrounded by an oval, fat-equivalent ring to mimic patient size/shape was scanned 10 times at each of six dos...

background : the recognition of road traffic noise as one of the main sources of environmental pollution has led to develop models that enable to predict noise level from fundamental variables. traffic noise prediction models are required as aids for designing roads and highways. in addition, sometimes are used in the assessment of existing or envisaged changes in traffic noise conditions. in t...