INTRODUCTION Although flat-panel based X-ray imaging has been well tested in diagnostic radiology, its use as an image-guided-radiotherapy (IGRT) system in a treatment room is new and requires systematic assessment. MATERIALS AND METHODS BrainLab Novalis IGRT system was used for this study. It consists of two floor mounted kV X-ray tubes projecting obliquely into two flat-panel detectors moun...

Flat-Panel Computed Tomography (CT) has found its commonly used applications in the healthcare field by providing an approach of examining 3D structural information of a human’s body. The popular CT reconstruction algorithms are based on a filtered backprojection (FBP) scheme, which would face challenges when imaging the knee. This is because in some views, the X-rays are highly attenuated when...

With the introduction of 2D flat-panel X-ray detectors, 3D image reconstruction using helical cone-beam tomography is fast replacing the conventional 2D reconstruction techniques. In 3D image reconstruction, the source orbit or scanning geometry should satisfy the data sufficiency or completeness condition for exact reconstruction. The helical scan geometry satisfies this condition and hence ca...

Conebeam x-ray CT (CBCT) is a developing imaging technique designed to provide relatively low-dose high-spatial-resolution visualization of high-contrast structures in the head and neck and other anatomic areas. This first installment in a 2-part review will address the physical principles underlying CBCT imaging as it is used in dedicated head and neck scanners. Concepts related to CBCT acquis...

Real-time tumor tracking in external radiotherapy can be achieved by diagnostic (kV) X-ray imaging with a dynamic flat-panel detector (FPD). It is important to keep the patient dose as low as possible while maintaining tracking accuracy. A simulation approach would be helpful to optimize the imaging conditions. This study was performed to develop a computer simulation platform based on a noise ...

Current consumer-level priced and state-of-the-art scanrate converters enable a spatio-temporal decoupling of the received video and the displayed video. This paper presents the results of a subjective assessment indicating the preferred CRT-display format.

Introduction: Electronic portal imaging devices (EPIDs) provide two- and three-dimensional planar and volumetric cone beam images to improve the accuracy of radiation treatment delivery. Periodic quality assurance (QA) of EPIDs is essential for dosimetric verification in radiotherapy. In this study, a QA program was implemented to evaluate the function of the EPID to be confident in applying co...

introduction individual x-ray diffraction patterns of biological tissues are obtained via interference of coherent scattering with their electrons. many scientists have distinguished normal and cancerous breast tissue, bone density, and urinary stone types using the x-ray diffraction patterns resulting from coherent scattering. the goal of this study was to introduce an optimized method for obt...