Godt Johannes Clemens, Johansen Cathrine K, Martinsen Anne Catrine T, Schulz Anselm, Brøgger Helga M, Jensen Kristin, Stray-Pedersen Arne, Dormagen Johann Baptist
Department of Radiology and Nuclear Medicine, Oslo University Hospital Ullevål, Oslo, Norway.
Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
Acta Radiol Open. 2021 Nov 18;10(10):20584601211055389. doi: 10.1177/20584601211055389. eCollection 2021 Oct.
Radiation-related cancer risk is an object of concern in CT of trauma patients, as these represent a young population. Different radiation reducing methods, including iterative reconstruction (IR), and spilt bolus techniques have been introduced in the recent years in different large scale trauma centers.
To compare image quality in human cadaver exposed to thoracoabdominal computed tomography using IR and standard filtered back-projection (FBP) at different dose levels.
Ten cadavers were scanned at full dose and a dose reduction in CTDIvol of 5 mGy (low dose 1) and 7.5 mGy (low dose 2) on a Siemens Definition Flash 128-slice computed tomography scanner. Low dose images were reconstructed with FBP and Sinogram affirmed iterative reconstruction (SAFIRE) level 2 and 4. Quantitative image quality was analyzed by comparison of contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR). Qualitative image quality was evaluated by use of visual grading regression (VGR) by four radiologists.
Readers preferred SAFIRE reconstructed images over FBP at a dose reduction of 40% (low dose 1) and 56% (low dose 2), with significant difference in overall impression of image quality. CNR and SNR showed significant improvement for images reconstructed with SAFIRE 2 and 4 compared to FBP at both low dose levels.
Iterative image reconstruction, SAFIRE 2 and 4, resulted in equal or improved image quality at a dose reduction of up to 56% compared to full dose FBP and may be used a strong radiation reduction tool in the young trauma population.
辐射相关的癌症风险是创伤患者CT检查中令人关注的问题，因为这些患者群体较为年轻。近年来，不同的大型创伤中心引入了多种辐射减少方法，包括迭代重建（IR）和分剂量团注技术。
比较在不同剂量水平下，使用IR和标准滤波反投影（FBP）对人体尸体进行胸腹计算机断层扫描时的图像质量。
在西门子Definition Flash 128层计算机断层扫描仪上，对10具尸体进行全剂量扫描以及CTDIvol分别降低5 mGy（低剂量1）和7.5 mGy（低剂量2）的扫描。低剂量图像采用FBP以及正弦图确认迭代重建（SAFIRE）2级和4级进行重建。通过比较对比噪声比（CNR）和信噪比（SNR）分析定量图像质量。由四名放射科医生使用视觉分级回归（VGR）评估定性图像质量。
在剂量降低40%（低剂量1）和56%（低剂量2）时，与FBP相比，阅片者更倾向于SAFIRE重建的图像，图像质量的总体印象存在显著差异。在两个低剂量水平下，与FBP相比，SAFIRE 2级和4级重建的图像CNR和SNR均有显著改善。
与全剂量FBP相比，迭代图像重建SAFIRE 2级和4级在剂量降低高达56%时能带来同等或更好的图像质量，可作为年轻创伤患者群体中一种强大的辐射减少工具。
