METHODS: Tubes with different diameters (1-5 mm) were filled with different iodine concentrations and scanned in a water container. Images were reconstructed with 0.4 mm isotropic resolution using a quantitative kernel at all available sharpness levels (Qr36 to Qr76) and using different levels of quantum iterative reconstruction (QIR-2-4). Noise and image sharpness were determined for all reconstructions. Additionally, CT angiograms of 20 patients, reconstructed with a medium (Qr44), sharp (Qr60), and ultrasharp (Qr72) kernel at QIR-2-4, were evaluated by three readers assessing noise, delineation of plaques and vessel walls, and overall quality.
RESULTS: In the phantom study, increased kernel sharpness led to higher image noise (e.g., 16, 38, 77 HU for Qr44, Qr60, Qr72, and QIR-3). Image sharpness increased with increasing kernel sharpness, reaching a plateau at the medium-high level 60. Higher QIR levels decreased image noise (e.g., 51, 38, 25 HU at QIR-2-4 and Qr60) without reducing vessel sharpness. The qualitative in vivo results confirmed these findings: the sharp kernel (Qr60) with the highest QIR yielded the best overall quality.
CONCLUSIONS: The combination of a sharpness level optimized reconstruction kernel (Qr60) and the highest QIR level yield the best image quality for PCD-CT angiography of the lower legs when reconstructed at 0.4-mm resolution.
CONCLUSIONS: Using high-resolution PCD-CT angiography with optimized reconstruction parameters might improve diagnostic accuracy and confidence in peripheral artery disease of the lower legs.
CONCLUSIONS: Effective exploitation of the potential of PCD-CT angiography requires optimized reconstruction parameters. Too soft or too sharp reconstruction kernels reduce image quality. The highest level of quantum iterative reconstruction provides the best image quality.
方法:用不同的碘浓度填充不同直径(1-5mm)的管,并在水容器中扫描。在所有可用的清晰度水平(Qr36至Qr76)下使用定量内核并使用不同水平的量子迭代重建(QIR-2-4)以0.4mm各向同性分辨率重建图像。确定所有重建的噪声和图像清晰度。此外,20例患者的CT血管造影,用介质(QR44)重建,夏普(Qr60),和超声(Qr72)内核在QIR-2-4,由三个读者评估噪声,斑块和血管壁的轮廓,和整体质量。
结果:在幻影研究中,增加的内核清晰度导致更高的图像噪声(例如,Qr44、Qr60、Qr72和QIR-3的16、38、77HU)。图像清晰度随着内核清晰度的增加而增加,达到中高水平60的高原。较高的QIR水平降低了图像噪声(例如,在QIR-2-4和Qr60处的51、38、25HU)没有降低血管锐度。体内定性结果证实了这些发现:具有最高QIR的锋利内核(Qr60)产生了最佳的整体质量。
结论:当在0.4mm分辨率下重建时,锐度级别优化的重建内核(Qr60)和最高QIR级别的组合可产生最佳的下肢PCD-CT血管造影图像质量。
结论:使用具有优化重建参数的高分辨率PCD-CT血管造影可能会提高下肢外周动脉疾病的诊断准确性和置信度。
结论:有效利用PCD-CT血管造影的潜力需要优化重建参数。太软或太尖锐的重建内核降低图像质量。最高水平的量子迭代重建提供最佳图像质量。