I am Dr. Marc Kachelrieß. I am professor of Medical Imaging at the Institute of Medical Physics, Erlangen, Germany. My work focuses on all aspects of CT. Among these are image reconstruction algorithms for cone-beam CT and for cardiac CT, techniques to improve image quality, to reduce image noise and to reduce patient dose. Further I am involved in the development of micro CT scanners for in-vivo and ex-vivo high resolution scanning.

My lecture is designed to provide you with all basic aspects concerning CT. You will understand how x-rays are produced, how they interact with matter and how they are detected. You will learn that CT is the measurement of a very high number of so-called line integrals. These are needed to perform image reconstruction which is the process that provides you with superb high quality and high resolution CT images.

The lecture also shows how today’s CT scanners are designed. It tells you about fan-beam CT, about cone-beam CT and about multi-slice CT. You will find out that the spiral (or helical) scan trajectory is the most important, today. The presentation introduces basic parameters such as the effective tube current or spiral pitch value and it let’s you understand why multi-slice spiral CT is so important.

Finally, some important dose issues are covered. The relation between image noise and dose is emphasized and you will learn about tube current modulation and automatic exposure control techniques to show that the manufactures take efforts to keep dose as low as reasonably achievable.

Prof. Dr. Marc Kachelrieß

Marc Kachelrieß was born in 1969 in Nürnberg, Germany. In 1989 he started to study physics with a focus on theoretical particle physics. His diploma thesis was entitled “Meson exchange currents in light nuclei”. He received his diploma at the Friedrich-Alexander-University of Erlangen-Nürnberg in 1995.

Then, he started with his dissertation at the Institute of Medical Physics (IMP). He thereby developed reconstruction algorithms to reduce metal artifacts in x-ray computed tomography (CT). In parallel, Marc Kachelrieß introduced a new method that allows to generate motion-free images of the human heart using standard CT data. Thereby the clinical feasibility of retrospective electrocardiogram-correlated image reconstruction from CT data was proven. This method is now in world-wide use in clinical CT scanners. Marc Kachelrieß received his Ph.D. at the IMP in 1998.

Since then, he focuses on cardiac imaging and extended the approaches to future scanner generations. Other fields of his research work are image reconstruction of cone-beam CT data, iterative image reconstruction, image reconstruction algorithms in general. He is involved in developing algorithms for automatic exposure control (AEC) for CT, methods to reduce CT artifacts and patient dose reduction techniques.

In 2002 Marc Kachelrieß completed all post doctoral lecturing qualifications (Habilitation) for Medical Physics and in 2005 he was appointed full professor of Medical Imaging at the Friedrich-Alexander-University Erlangen-Nürnberg, Germany. On the basis of his university teaching position he lectures in medical imaging technology, physics and algorithms.