Special Articles

4.　 Further evolution of CT to achieve faster scan speeds, higher image quality,and lower exposure dose

Akiko Iwasa
CT Systems Division, Toshiba Medical Systems Corporation

Abstract

　　There have been remarkable technological advances in X-ray CT systems in recent years, leading to faster scan speeds and larger numbers of detector rows. Specifically, it was only 8 years from the introduction of 4-row multislice CT to the development of 320-row area detector CT, and a fast rotation speed of approximately 0.3 s has also been achieved. These advances are important steps toward overcoming the“target motion”issue that has limited the usefulness of CT in the examination of pediatric patients, who have both high respiration rates and high heart rates. The attainment of faster scan speeds has also involved the development of technologies for improving image quality. This has expanded the range of available scanning techniques and is expected to provide new clinical value. One example is the combined morphological and hemodynamic evaluation of pediatric patients with congenital heart disease by employing the non-helical scanning technique in area detector CT examinations. In order to perform such examinations, it is necessary to obtain a clear understanding of the technologies enabling faster scan speeds and higher image quality and to become familiar with their features. Also, it is important to understand the recent technological innovations in reducing the exposure dose, which is an important concern in the examination of pediatric patients. This report will discuss these important technologies.

Keywords：Faster scan speed, Higher image quality, Reduced exposure dose,Scanning technique