Radiologie up2date 2017; 17(02): 163-178
DOI: 10.1055/s-0043-105755
Gerätetechniken/Neuentwicklungen/Digitale Radiologie
Georg Thieme Verlag KG Stuttgart · New York

Dosis und Dosisreduktion in der Computertomografie

Dose and dose reduction in computed tomography
Michael Lell
,
Michael Wucherer
,
Marc Kachelrieß

Subject Editor: Prof. Dr. med. Jörg Barkhausen, Lübeck
Further Information

Publication History

Publication Date:
03 August 2017 (online)

Zusammenfassung

Die CT wird in der diagnostischen Radiologie immer häufiger eingesetzt. Neue Untersuchungsindikationen, z. B. die Koronar-CTA, die CT-Kolonografie oder diverse CT-Perfusionsuntersuchungen, sind im klinischen Alltag angekommen. Dies erfordert die im Folgenden vorgestellten Verfahren, um die Strahlenexposition zu reduzieren, ohne die sehr kurze Untersuchungszeit bei hoher (isotroper) Auflösung zu beschneiden.

Abstract

CT is widely used in medical imaging due to high availability, relatively low cost, and excellent diagnostic yield. Newer applications like coronary CTA, CT colonography, and CT perfusion imaging are integrated in clinical pathways. Although there is a high level of consensus that the benefits of CT exceeds the risks of radiation exposure for appropriate indications, concerns have been raised regarding the potential of cancer induction. Keeping dose as low as reasonably achievable remains the most important task. Dose reduction strategies are presented and discussed.

Kernaussagen
  • Die Anzahl der CT-Untersuchungen steigt an, aktuell werden über 60% der medizinischen Strahlenexposition in Deutschland durch die CT verursacht.

  • Bei den Dosisgrößen ist zwischen Energiedosis, Äquivalentdosis und effektiver Dosis zu unterscheiden. Im Dosisprotokoll einer CT-Untersuchung werden der CTDIvol und das Dosislängenprodukt (DLP) angegeben.

  • Die aktuellen Verfahren zur Dosisreduktion beruhen auf unterschiedlichen Prinzipien und können kombiniert werden. Zu ihnen gehören Vorfilter, die Modulation von Röhrenstrom oder Röhrenspannung, EKG-basierte Untersuchungstechniken, dynamische Kollimatoren, Bismut-Schilde, Dual-Energy-CT und iterative Rekonstruktionen.

 
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