Ziel der Arbeit war es, den Einfluss eines Niedrigdosisprotokolls mit verringerter Röhrenspannung auf die Bildqualität und Strahlendosis zu untersuchen. In die Studie wurden 400 nicht übergewichtige Patienten mit Indikation zur CT-Angiographie eingeschlossen, die per Zufallsverfahren in zwei Gruppen eingeteilt wurden. Eine Gruppe wurde mit dem Standartprotokoll mit 120kV untersucht, während die andere Gruppe einer CT-Untersuchung mit 100kV unterzogen wurde. Die Bildqualität wurde anschließend anhand einer 4 Punkte-Skala von zwei unabhängigen Untersuchern bewertet. Die Ergebnisse zeigten, dass in der 100kV-Gruppe eine Reduktion der effektiven Strahlendosis um 31% gelang, während der Bildqualitätsscore in beiden Gruppen gleich blieb. Somit kann die Schlussfolgerung gezogen werden, dass das 100kV-Protokoll für die Untersuchung von nicht-übergewichtigen Patienten geeignet ist.     «

Ziel der Arbeit war es, den Einfluss eines Niedrigdosisprotokolls mit verringerter Röhrenspannung auf die Bildqualität und Strahlendosis zu untersuchen. In die Studie wurden 400 nicht übergewichtige Patienten mit Indikation zur CT-Angiographie eingeschlossen, die per Zufallsverfahren in zwei Gruppen eingeteilt wurden. Eine Gruppe wurde mit dem Standartprotokoll mit 120kV untersucht, während die andere Gruppe einer CT-Untersuchung mit 100kV unterzogen wurde. Die Bildqualität wurde anschließend...     »

Background: Coronary CT Angiography has emerged as a useful diagnostic imaging modality for non-invasive assessment of coronary artery disease in patients with low to intermediate risk profile. But concerns have been raised about radiation exposure during coronary CTA. The use of a 100 kVp tube voltage scan protocol effectively lowers coronary CTA radiation dose. Recent studies have demonstrated an infrequent use of this dose-reduction strategy in daily practice which is most likely explained by a lack of scientific data demonstrating maintained image quality. Objectives: The purpose of this study was to evaluate image quality and radiation dose using a 100 kVp tube voltage scan protocol compared with standard 120 kVp for coronary computed tomography angiography Methods: 400 non-obese patients undergoing clinically indicated coronary CTA for suspected artery disease were enrolled in 8 institutions. 202 patients were randomly assigned to a 100 kV protocol and 198 patients to a 120 kV protocol. The primary end point was to demonstrate non-inferiority in image quality with the 100 kV protocol, which was assessed by a 4-point grading score. Secondary end points included radiation dose and need for additional diagnostic tests during follow-up. Two independent observers assigned a score from 1 to 4 to each coronary artery as follows: score 4 for excellent image quality, score 3 for good image quality despite presence of smaller artifacts, score 2 for sufficient image quality but considerable artefacts and score 1 for non-diagnostic image quality. For the non-inferiority analysis, a margin of -0.2 image quality score points for the difference between both scan protocols was pre-defined. Effective dose was determined based on the dose-length product. Furthermore, the need for subsequent cardiac tests was assessed by a telephone-interview with every patient after 30 days. Results: The 100 kV protocol was associated with a 31% relative reduction in radiation exposure (dose-length product: 868 ± 317 mGy x cm with 120 kV vs. 599 ± 255 mGy x cm with 100 kVp; p = 0.0001). The mean image quality scores in the two groups did not differ (100 kV- Group: 3.30 ±0.67; 120kV-Group 3.28 ± 0.68; p = 0.742).Image quality of the 100 kVp protocol was not inferior, as demonstrated by the 97.5% confidence interval of the difference, which did not cross the pre-defined noninferiority margin of -0.2. At 30-day follow-up, the need for additional diagnostic studies did not differ (13.4% vs. 19.2% for 100 kV vs. 120 kV, respectively; p = 0.114). Conclusions A coronary CTA protocol using 100 kV tube voltage in non-obese patients maintained image quality, but reduced radiation exposure by 31% as compared with the standard 120 kVp protocol. Thus, 100 kVp scan protocols should be considered for nonobese patients to keep radiation exposure as low as reasonably achievable.      «

Background: Coronary CT Angiography has emerged as a useful diagnostic imaging modality for non-invasive assessment of coronary artery disease in patients with low to intermediate risk profile. But concerns have been raised about radiation exposure during coronary CTA. The use of a 100 kVp tube voltage scan protocol effectively lowers coronary CTA radiation dose. Recent studies have demonstrated an infrequent use of this dose-reduction strategy in daily practice which is most likely explained b...     »