کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5726048 | 1609727 | 2017 | 7 صفحه PDF | دانلود رایگان |
- Low tube voltage combined with iterative reconstruction allows for dose reduced protocols.
- 90Â kVp-IR3 and 100Â kVp-IR1 yield similar results as the conventional CAC protocol.
- CAC HU-threshold does not need to be adjusted for 90Â kVp-IR3 or 100Â kVp-IR1.
ObjectivesTo define a dose-reduced coronary calcium CT protocol that provides similar calcium score values as a conventional 120 kVp protocol.MethodsA thorax phantom containing 100 calcifications was scanned with the reference protocol (120 kVp, 90 ref mAs, FBP) and 30 dose-reduced protocols (70-110 kVp, 90 ref mAs, FBP and iterative reconstruction (IR) levels 1-5) with 3rd generation dual-source CT. For protocols that yielded similar detectability and calcium scores as the reference protocol, additional scans were acquired at reduced ref mAs. Kendall's Ïb and independent-samples-median test were used to determine trends and differences in contrast/signal-to-noise ratio (CNR and SNR), dose and calcium scores.ResultsThe detectability and calcium scores decreased at increasing IR levels (Ïb < â 0.825, p < 0.001) and increasing tube voltage (Ïb < â 0.679, p < 0.001). For 90 kVp-IR3 and 100 kVp-IR1, similar detectability and calcium score was found compared to the reference protocol (p > 0.206). For these protocols, lower tube currents did not affect the detectability and Agatston score (p > 0.206), while CNR and SNR were similar/higher compared to the reference protocol (0.008 < p < 0.206). Dose reduction was 60.6% (90 kVp-IR3) and 43.6% (100 kVp-IR1).ConclusionsThe protocol of 90 kVp-IR3 and 100 kVp-IR1 yielded similar calcium detectability, Agatston score and image quality as the reference protocol, with dose reduction up to 60.6%.
Journal: European Journal of Radiology - Volume 93, August 2017, Pages 229-235