title: Radiation dose estimates in dual-source computed tomography coronary angiography.
abstract: The purpose of this study was to quantify radiation dose parameters of dual-source CT coronary angiography. Eighty patients underwent contrast-enhanced, retrospectively ECG-gated dual-source CT coronary angiography with heart rate-adapted ECG pulsing using two algorithms: In 40 patients, the tube current was reduced to 20% (A(min1)) of the normal tube current (A(max)) outside the pulsing window; in 40 patients tube current was reduced to 4% (A(min2)) of A(max). Mean CTDI(vol) in the A(min1) group was 45.1 +/- 3.6 mGy; the mean CTDI(vol) in the A(min2) group was 39.1 +/- 3.2 mGy, with CTDI(vol) in the A(min2) group being significantly reduced when compared to the A(min1) group (P < 0.001). A significant negative correlation was found between CTDI(vol) and heart rate in group A(min1) (r = -0.82, P < 0.001), whereas no correlation was found between CTDI(vol) and heart rate in group A(min2) (r = -0.066). Using the conversion coefficient for the chest, dual-source CT coronary angiography resulted in an estimated mean effective dose of 8.8 mSv in the A(min1) group and 7.8 mSv in the A(min2). Radiation exposure of dual-source CT coronary angiography using an ECG-pulsing protocol reducing the tube current to 20% significantly decreases with increasing heart rates, despite using wider pulsing windows at higher heart rates. When using a protocol with reduced tube current of 4%, the radiation dose is significantly lower, irrespective of the heart rate.
authors.affiliation: Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
authors.forename: Paul
authors.initials: P
authors.lastname: Stolzmann
authors.forename: Hans
authors.initials: H
authors.lastname: Scheffel
authors.forename: Thomas
authors.initials: T
authors.lastname: Schertler
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenfelder
authors.forename: Sebastian
authors.initials: S
authors.lastname: Leschka
authors.forename: Lars
authors.initials: L
authors.lastname: Husmann
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Flohr
authors.forename: Borut
authors.initials: B
authors.lastname: Marincek
authors.forename: Philipp A
authors.initials: PA
authors.lastname: Kaufmann
authors.forename: Hatem
authors.initials: H
authors.lastname: Alkadhi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D017023:Coronary Angiography / Q000379:methods*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000379:methods*