RT Journal Article
SR Electronic
T1 Dose Exposure of Patients Undergoing Comprehensive Stroke Imaging by Multidetector-Row CT: Comparison of 320-Detector Row and 64-Detector Row CT Scanners
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 1003
OP 1009
DO 10.3174/ajnr.A1971
VO 31
IS 6
A1 S. Diekmann
A1 E. Siebert
A1 R. Juran
A1 M. Roll
A1 W. Deeg
A1 H.-C. Bauknecht
A1 F. Diekmann
A1 R. Klingebiel
A1 G. Bohner
YR 2010
UL http://www.ajnr.org/content/31/6/1003.abstract
AB BACKGROUND AND PURPOSE: Recently introduced 320-detector row CT enables whole brain perfusion imaging compared to a limited scanning area in 64-detector row CT. Our aim was to evaluate patient radiation exposure in comprehensive stroke imaging by using multidetector row CT consisting of standard CT of the head, CTA of cerebral and cervical vessels, and CTP. MATERIAL AND METHODS: Organ doses were measured by using LiF-TLDs located at several organ sites in an Alderson-Rando phantom. Effective doses were derived from these measurements. Stroke protocols including noncontrast head CT, CTA of cerebral and cervical vessels, and CTP were performed on 320- and 64-detector row scanners. RESULTS: Measured effective doses for the different scanning protocols ranged between 1.61 and 4.56 mSv, resulting in an effective dose for complete stroke imaging of 7.52/7.54 mSv (m/f) for 64-detector row CT and 10.56/10.6 mSv (m/f) for 320-detector row CT. The highest organ doses within the area of the primary beam were measured in the skin (92 mGy) and cerebral hemispheres (69.91 mGy). Use of an eye-protection device resulted in a 54% decrease of the lens dose measured for the combo protocol for whole-brain perfusion with the 320-detector row CT scanner. CONCLUSIONS: Phantom measurements indicate that comprehensive stroke imaging with multidetector row CT may result in effective radiation doses from 7.52 mSv (64-detector row CT) to 10.6 mSv (320-detector row CT). The technique of 320-detector row CT offers additional information on the time course of vascular enhancement and whole-brain perfusion. Physicians should weigh the potential of the new technique against the higher radiation dose that is needed. Critical doses that would cause organ damage were not reached. CCTcerebral CTCTACT angiographyCTDICT Dose IndexCTPCT perfusionICAinternal carotid arteryICRPInternational Commission on Radiological ProtectionLiFlithium-fluoridemAseffeffective milliampere-secondm/fmale/femalePMMApolymethylmethacrylateTLDthermoluminescent dosimeterW (T)weighting factor