Computed tomography (CT) scanners

2017 ◽  
Keyword(s):  
Computed Tomography ◽  
Ct Scanners

Multidetector-row Computed Tomography in the Assessment of Coronary Artery Disease – New Techniques and Insights

2010 ◽  
Vol 6 (2) ◽  
pp. 43 ◽  
Author(s):  
Andreas H Mahnken ◽  
Keyword(s):  
Computed Tomography ◽  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Data Acquisition ◽  
Temporal Resolution ◽  
High Temporal Resolution ◽  
Multidetector Row ◽  
Ct Scanners ◽  
Artery Disease ◽  
Cardiac Mdct

Over the last decade, cardiac computed tomography (CT) technology has experienced revolutionary changes and gained broad clinical acceptance in the work-up of patients suffering from coronary artery disease (CAD). Since cardiac multidetector-row CT (MDCT) was introduced in 1998, acquisition time, number of detector rows and spatial and temporal resolution have improved tremendously. Current developments in cardiac CT are focusing on low-dose cardiac scanning at ultra-high temporal resolution. Technically, there are two major approaches to achieving these goals: rapid data acquisition using dual-source CT scanners with high temporal resolution or volumetric data acquisition with 256/320-slice CT scanners. While each approach has specific advantages and disadvantages, both technologies foster the extension of cardiac MDCT beyond morphological imaging towards the functional assessment of CAD. This article examines current trends in the development of cardiac MDCT.

scholarly journals Geographical and Temporal Distribution of Radiologists, Computed Tomography and Magnetic Resonance Scanners in Croatia

2021 ◽  
Vol 58 ◽  
pp. 004695802110602
Author(s):  
Zrinka Biloglav ◽  
Petar Medaković ◽  
Dina Vrkić ◽  
Boris Brkljačić ◽  
Ivan Padjen ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Health Care ◽  
Magnetic Resonance ◽  
Supply And Demand ◽  
Temporal Distribution ◽  
Similar Distribution ◽  
The Public ◽  
System A ◽  
Private And Public ◽  
Ct Scanners

The aim of the study was to analyse the temporal and geographic distribution of radiologists, computed tomography and magnetic resonance scanners in Croatia. In this observational study we estimated radiologists’ number per 100,000 population for 1997, 2006, and 2017 and compared private and public CT and MR scanners between 2011 and 2018. We analyzed the availability of radiologists and scanners, and the relationship between the radiological workforce and economic strength among counties. The workforce increased significantly from 1997 to 2017 and was associated with economic strength categories in 2017. In 2018, there were more CT scanners in the public sector, while MR scanners were distributed evenly. In 2011, there was similar distribution of CT and MR between sectors, while in 2018 there were significantly more public CT scanners. Counties with a medical school had significantly more radiologists and MR scanners. The high-to-low ratios per CT and MR were 11 and 8.2, suggesting inequality of health care. Croatia significantly increased its radiological workforce; however, cross-county inequality remained. Counties with higher economic strength and medical schools have better availability of radiologists and equipment. To ensure the sustainable activity of the health care system, a precise estimate of supply and demand of radiology services is needed.

scholarly journals Determining The Benefits Of Proactive Digital Service For Computed Tomography (Ct) Scanners

2014 ◽  
Vol 17 (3) ◽  
pp. A162
Author(s):  
P.O. Bonnet ◽  
A. Roy ◽  
J.M. Peyronnet
Keyword(s):  
Computed Tomography ◽  
Digital Service ◽  
Ct Scanners

Radiation dose and image quality of computed tomography of the supra-aortic arteries: A comparison between single-source and dual-source CT Scanners

2018 ◽  
Vol 45 (2) ◽  
pp. 136-141 ◽  
Author(s):  
Luca Saba ◽  
Michele di Martino ◽  
Paolo Siotto ◽  
Michele Anzidei ◽  
Giovanni Maria Argiolas ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Radiation Dose ◽  
Dual Source Ct ◽  
Single Source ◽  
Dual Source ◽  
Ct Scanners

The Diffusion of Magnetic Resonance Imagers in the United States and Worldwide

1985 ◽  
Vol 1 (3) ◽  
pp. 499-514 ◽  
Author(s):  
Earl P. Steinberg ◽  
Jane E. Sisk ◽  
Katherine E. Locke
Keyword(s):  
United States ◽  
Computed Tomography ◽  
Magnetic Resonance ◽  
Mr Imaging ◽  
Medical Profession ◽  
The United States ◽  
Diagnostic Modality ◽  
X Ray ◽  
X Ray Computed ◽  
Ct Scanners

Magnetic resonance (MR) imaging is an exciting new diagnostic modality that has created tremendous interest in the medical profession. Although not unparalleled, the excitement engendered by MR imaging conjures up memories of the “CAT fever” induced by introduction of X-ray computed tomography (CT) scanners in 1973 (19).

scholarly journals A New Statistical Reconstruction Method for the Computed Tomography Using an X-Ray Tube with Flying Focal Spot

2021 ◽  
Vol 11 (4) ◽  
pp. 271-286
Author(s):  
Robert Cierniak ◽  
Piotr Pluta ◽  
Marek Waligóra ◽  
Zdzisław Szymański ◽  
Konrad Grzanek ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Focal Spot ◽  
Reconstruction Method ◽  
Reconstruction Procedure ◽  
X Ray ◽  
Statistical Reconstruction ◽  
Reconstruction Methods ◽  
Ct Scanners ◽  
The Impact

Abstract This paper presents a new image reconstruction method for spiral cone- beam tomography scanners in which an X-ray tube with a flying focal spot is used. The method is based on principles related to the statistical model-based iterative reconstruction (MBIR) methodology. The proposed approach is a continuous-to-continuous data model approach, and the forward model is formulated as a shift-invariant system. This allows for avoiding a nutating reconstruction-based approach, e.g. the advanced single slice rebinning methodology (ASSR) that is usually applied in computed tomography (CT) scanners with X-ray tubes with a flying focal spot. In turn, the proposed approach allows for significantly accelerating the reconstruction processing and, generally, for greatly simplifying the entire reconstruction procedure. Additionally, it improves the quality of the reconstructed images in comparison to the traditional algorithms, as confirmed by extensive simulations. It is worth noting that the main purpose of introducing statistical reconstruction methods to medical CT scanners is the reduction of the impact of measurement noise on the quality of tomography images and, consequently, the dose reduction of X-ray radiation absorbed by a patient. A series of computer simulations followed by doctor’s assessments have been performed, which indicate how great a reduction of the absorbed dose can be achieved using the reconstruction approach presented here.

scholarly journals Assessing the Status of Quality Control Parameters of Four Computed Tomography Scanners in Ibadan

2021 ◽  
Vol 3 (4) ◽  
pp. 80-83
Author(s):  
Osayaba Peace Egharevba ◽  
Christian Chukwuemeka Nzotta ◽  
Emmanuel Oyeyemi Oyekunle ◽  
Mohammed Anas
Keyword(s):  
Computed Tomography ◽  
Quality Control ◽  
Clinical Environment ◽  
Ct Number ◽  
Cross Sectional ◽  
Tomography Scanners ◽  
Depth Analysis ◽  
The Mean ◽  
Ct Scanners ◽  
Equipment Lifetime

Background: Quality control (QC) of computed tomography (CT) scanners is important to evaluate succinctly quality image and radiation dose obtainable in a clinical environment. The aim of this study was to evaluate the quality of images generated by CT scanners used at some diagnostic facilities in Ibadan, Nigeria. Materials and Methods: A cross sectional design was employed in this study, four centers were studied, one government hospital and three private hospitals. The head CT phantom was used to verify the accomplishment of the CT scanners performance to the international quality requirements. Regions of interest were selected at the center of the image and at the periphery to obtain results for the CT number for water test, uniformity test, noise, and artifact test. Results: The mean CT number for water across the centers ranged from –0.12 HU to –2.2 HU which were within ±3 HU recommended by the equipment manufacturer. Values of standard deviation of the mean CT number ranged from 2.41 to 5.77 HU which to a little extent exceeded the set ±5 HU tolerance range. Similarly, the presence of streak artifact was observed in the images obtained at one center. Conclusion: Two out of the four computed tomography scanners assessed passed the four tests performed. Noise and artifact were the problem observed at centers B and C respectively. There was however no likelihood of periodic performance of these basic quality control tests at two of the centers in this study. Adequate records of quality control data should be kept regularly to allow in-depth analysis of failure rates of different tests, changes occurring during equipment lifetime and comparisons among CT scanners.

Sign in / Sign up

Export Citation Format

Share Document