two main forms of copd (chronic obstructive pulmonary disease) refer to a group of lung diseases that block airflow and cause a huge degree of human suffering. a new method for identifying and estimating the severity of copd from three-dimensional (3-d) pulmonary x-ray ct images would be helpful for evaluation of treatment effects and early diagnosing is presented in this paper. this method has...

Themathematical principles of computed tomography (CT) were first investigated by J. Radon [28] as early as 1917 and were later extended to complex fields by Kirillov [22]. The first application of tomography was, surprisingly, in radio astronomy [2], and today, it finds usage in diverse fields such as medical imaging, seismology, and underwater acoustic imaging. In medical imaging, CT has had ...

Casting is an economical way to manufacture parts. On average, complex aerospace castings incur about one-fourth the cost of forgings. However, castings can not be used as primary structure in aircraft because of poor control over design allowables for the material strength and ductility. They can be used as secondary structure, but must include significant safety factors usually between 3 and ...

An X-ray diffraction computed tomography data-collection strategy that allows, post experiment, a choice between temporal and spatial resolution is reported. This strategy enables time-resolved studies on comparatively short timescales, or alternatively allows for improved spatial resolution if the system under study, or components within it, appear to be unchanging. The application of the meth...

Radiation dose in x-ray computed tomography (CT) has become a topic of high interest due to the increasing numbers of CT examinations performed worldwide. This review aims to present an overview of current concepts for both scanner output metrics and for patient dosimetry and will comment on their strengths and weaknesses. Controversial issues such as the appropriateness of the CT dose index (C...