Impact of a Reduced Tube Voltage on CT Angiography and Radiation DoseResults of the PROTECTION I Study
Bernhard Bischoff, MD*,
Franziska Hein, MD*,
Tanja Meyer, MD*,
Martin Hadamitzky, MD*,
Stefan Martinoff, MD ,
Albert Schömig, MD*,
Jörg Hausleiter, MD*,*
* Klinik für Herz- und Kreislauferkrankungen, Deutsches Herzzentrum München, Klinik an der TU München, Munich, Germany
Institut für Radiologie und Nuklearmedizin, Deutsches Herzzentrum München, Klinik an der TU München, Munich, Germany
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Figure 1 Measuring of Image Quality Data in a Proximal Left Main Coronary Artery
Region of interest (circle) in the left main coronary artery example illustrating determination of signal intensity (425 HU) and image noise (28 HU), as performed in every patient in the left main and proximal right coronary artery.
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Figure 2 Diagnostic Image Quality Score Depending on Tube Voltage
Boxplots indicating a comparable image quality score in the 120-kV and 100-kV study groups (p = 0.22). Diagnostic image quality was assessed by an experienced coronary computed tomography angiography investigator with a 4-point score (1: nondiagnostic to 4: excellent image quality).
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Figure 3 Representative Coronary Computed Tomography Angiograms Demonstrating the Image Quality in Both Study Groups
Curved-planar maximum intensity projections of the right coronary artery (A, D), the left descending artery (B, E), and the left circumflex artery (C, F) demonstrating the image quality of the 100-kV (A to C) and the 120-kV protocol (D to F) at identical window levels and hence illustrating the higher attenuation in the 100-kV scan protocol.
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