Impact of a reduced tube voltage on CT angiography and radiation dose: results of the PROTECTION I study.

Bischoff, B; Hein, F; Meyer, T; Hadamitzky, M; Martinoff, S; Schömig, A; Hausleiter, J

doi:10.1016/j.jcmg.2009.02.015

journal article

Dokumenttyp:: Comparative Study; Journal Article; Multicenter Study
Autor(en):: Bischoff, B; Hein, F; Meyer, T; Hadamitzky, M; Martinoff, S; Schömig, A; Hausleiter, J
Titel:: Impact of a reduced tube voltage on CT angiography and radiation dose: results of the PROTECTION I study.
Abstract:: OBJECTIVES: The aim of this study was to determine the impact of a reduced 100-kV tube voltage on image quality and radiation exposure in a pre-defined subgroup analysis of the international, multicenter radiation dose survey PROTECTION I (Prospective Multicenter Study on RadiaTion Dose Estimates Of Cardiac CT AngIOgraphy I) study. BACKGROUND: Cardiac computed tomography angiography (CCTA) has become a frequently used diagnostic tool in clinical practice. Despite continually improving CT technology, there remain concerns regarding the associated radiation exposure. A reduced tube voltage of 100 kV has been proposed as an effective means for dose reduction in nonobese patients. METHODS: The study assessed the relevant radiation dose parameters as well as quantitative and qualitative diagnostic image quality data in a subgroup of 321 patients (100 kV: 82 patients; 120 kV: 239 patients), who were scanned at study sites that applied a 100-kV tube voltage in at least 1 patient. Diagnostic image quality was assessed by an experienced CCTA investigator with a 4-point score (1: nondiagnostic to 4: excellent image quality). Effective radiation dose was estimated from the dose-length-product of each CCTA study. RESULTS: The use of the 100-kV scan protocol was associated with 53% reduction in CCTA median radiation dose estimates, when compared with the conventional 120-kV scan protocol (p < 0.001). Although image noise significantly increased by 26.3% with 100 kV, signal- as well as contrast-to-noise ratios also increased by 7.9% (p = 0.254) and 10.8% (p = 0.027), respectively. Reduction of tube voltage did not impair diagnostic image quality (median diagnostic score: 3.5 [3.25 to 3.75] vs. 3.5 [3.0 to 3.75] for 100 kV vs. 120 kV; p = 0.22). CONCLUSIONS: In this nonrandomized PROTECTION I dose survey, reducing the CCTA tube voltage to 100 kV in nonobese patients is associated with a significant reduction in radiation exposure while maintaining diagnostic image quality. Thus, the 100-kV scan technique should be considered for CCTA dose reduction in adequately selected patients.
Zeitschriftentitel:: JACC Cardiovasc Imaging
Jahr:: 2009
Band / Volume:: 2
Heft / Issue:: 8
Seitenangaben Beitrag:: 940-6
Sprache:: eng
Volltext / DOI:: doi:10.1016/j.jcmg.2009.02.015
PubMed:: http://view.ncbi.nlm.nih.gov/pubmed/19679281
Print-ISSN:: 1936-878X
TUM Einrichtung:: I. Medizinische Klinik und Poliklinik (Kardiologie); Institut für Radiologie
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