:: ukrc 2007

This year's UK Radiological Congress (UKRC2007) was held this June in Manchester, at the conference centre formerly known as GMEX/MICC: Read more about the conference, & you can also access the 'Best 20' of the e-posters.

ImPACT were invited by the committee to deliver the CT Teaching course, on the third day of the congress. Thanks to those who came along to this teaching session; we trust you found it useful. Judging from the questions you asked, you were very interested in what was said. For those who want to review the presentations, our slides are available below.

ImPACT also attended the rest of the congress and the exhibition: we heard some interesting presentations, and met many of you in and around the exhibition. It was fun to make new friends, to hear about how you have used some of the material we have produced over the years, and thank you all for your kind comments and the very interesting conversations that we had.

ImPACT Presentations

The abstract for the invited talks are below, and you can access the presentations as either on-line slide shows - which work best with Internet Explorer- or as PDF versions; which are smaller and quicker to download, and should work for everyone.

Physics and technology of mult-slice CT
Jim Weston

Learning Objectives: To understand: modern scanner designs; detector configuration options; cone-beam and related issues; approaches to reconstruction; artefacts.

Description: Multi-slice CT (MSCT) introduces new areas of physics that need wider understanding by all users. Key principles behind CT scanning and reconstruction are reviewed and extended to multi-detector systems. Various detector array design options are illustrated and their acquisition modes explained. The issues of wide beam helical scanning are identified and some approaches to dealing with these outlined. Related artefacts are shown and explained. Some widely held misunderstandings are identified, and rectified.

Conclusion: MSCT scanning with 16 slices and more is becoming common. It enables the potential for fast isotropic scanning. This talk explains the principles behind the design of the scanners and issues involved in image reconstruction.

(view slides from this presentation as web show (IE only) or as pdf file )

top of page

Image quality and dose issues in multi-slice CT
Sue Edyvean

Objectives: To review the effect of scan and reconstruction parameters on image quality and patient dose in multi-slice CT scannning, and to understand the trade-offs occurring between these performance parameters. To also explore the effect of perceived image noise on minimum diagnostic requirements.

Description: Image quality and dose are affected by many fundamental scanner design characteristics, such as the x-ray tube, detectors and beam filtration, as well as by scanning and reconstruction parameters such as tube current, kV, beam width and pitch. This talk will explain the effect of many of these parameters on the resultant image quality and dose, with particular reference to multi-slice CT scanners. The trade-off that occurs between image quality and dose will also be explored. Image quality is generally described in terms of image noise, or speckle, and scan plane and z-axis spatial resolution. Image contrast and the effect of kV is also considered as well as noise correlation.

Conclusion: The effect on image quality and dose resulting from different multi-slice scanner characteristics and scanning parameters will have been reviewed. An understanding of the relationship between image quality and dose will have been discussed. In addition to standard performance parameters, image contrast and noise correlation will have been addressed, as well as the subjective effect on perception and the noise requirement for a diagnostic image.

(view slides from this presentationas web show (IE only) or as pdf file )

top of page

Principles & implementation of automatic exposure control systems in CT
Maria Lewis

Note: Title in proceedings:Clinical use of CT automatic exposure control systems

Key learning objectives: To understand: the aims of automatic exposure control (AEC) in CT; the principles underlying the operation of AEC; the differences in approach between various AEC systems.

Description: The aim of CT AEC systems is to maintain the required level of image quality from patient to patient and also throughout a scan. This is achieved by compensating for variations in patient thickness and density by the adjustment of tube current. If used properly AEC should assist in patient dose optimisation. In theory AEC can be applied at three levels. The tube current can be adjusted to compensate for: overall patient size i.e. from one patient to the next; attenuation along the long axis of the patient i.e. between subsequent tube rotations; attenuation from different angular directions i.e. throughout a rotation. In practice all three levels are often used simultaneously. The principles behind the operation of AEC can be divided into three areas: how the attenuation information is obtained; what assumptions are made when adjusting the tube current for the measured attenuation; how the desired image quality is specified.

Conclusions: The aims, theory and principles of operation of CT AEC will be described with reference to existing systems from the four main CT manufacturers.

(view slides from this presentation as web show (IE only) or as pdf file )

top of page