PURPOSE The development of flat panel detector technology has resulted in renewed interest in the possibility of generating CT-like images from rotational angiographic acquisitions. At least two commercial products now use cone beam reconstruction software in conjunction with flat panel detectors to produce such images. The purpose of the work presented here is to report on image quality obtain...

Introduction: The performance of computed tomography is routinely checked using phantoms, which are known as important diagnostic imaging tools. Depending upon the aim of the study, different phantoms are designed, while trying to satisfy certain levels of diversities in their application. Material and Methods: The present study describes the...

We evaluated the accuracy of coronary artery calcium (CAC) scoring on a dual-source photon-counting detector CT (PCD-CT). An anthropomorphic chest phantom underwent ECG-gated sequential scanning PCD-CT at 120 kV with four radiation dose levels (CTDIvol, 2.0–8.6 mGy). Polychromatic images (T3D) and virtual monoenergetic (VMI), from 60 to 75 keV without quantum iterative reconstruction (no QIR) Q...

ID: 8312 Title: The use of dual-energy CT images for Monte Carlo treatment planning: material extraction and metal artifact reduction Purpose: To investigate the feasibility of dual-energy CT-based material extraction (DECT) for Monte Carlo (MC) dose calculations, to evaluate metal streaking artifact reduction using DECT and to propose a novel scanning technique for motion artifacts reduction. ...

A straightforward method is presented to estimate peak skin doses (PSDs) delivered by computed tomography (CT) scanners. The measured PSD values are related to the well-known volume CT dose index (CTDI(vol)), displayed on the console of CT scanners. PSD measurement estimates were obtained, in four CT units, by placing radiochromic film on the surface of a CTDI head phantom. Six different X-ray ...

In order to provide precision and objective image quality measures (IQMs) for the low dose CT (Computed Tomography) images, various general IQMs need to be validated and analyzed. The IQM based on Markov Random Field (MRF) has not been check and validated by a comprehensive distorted database. First choose a standard distorted image database of LIVE (Laboratory for Image & Video Engineering) to...

The ACR CT accreditation program, begun in 2002, requires the submission of approximately 20 images, several completed data sheets and printouts of three Excel worksheets. The procedure manual is very detailed, yet participants unfamiliar with the program or having minimal CT experience have needed to redo aspects of their submission, or in some cases do not receive accreditation, due to mistak...

Computed Tomography (CT) images often suffer from artifacts caused by misaligned scanner geometry of CT system. Calibration and correction must be done before image reconstruction. A method for calibration of misaligned scanner geometry in cone-beam CT with single-circle orbit is proposed. In this method, a four-point phantom is used to estimate a set of parameters that describe the geometry of...

We propose a method to compensate for six degree-of-freedom rigid motion in helical CT of the head. The method is demonstrated in simulations and in helical scans performed on a 16-slice CT scanner. Scans of a Hoffman brain phantom were acquired while an optical motion tracking system recorded the motion of the bed and the phantom. Motion correction was performed by restoring projection consist...

Quality control (QC) of CT scanners is important to evaluate image quality and radiation dose. Different QC phantoms for testing image quality parameters on CT are commercially available, and Catphan phantoms are widely used for this purpose. More data from measured image quality parameters on CT are necessary to assess test methods, tolerance levels, and test frequencies. The aim of this study...