Decker Josua A, O'Doherty Jim, Schoepf U Joseph, Todoran Thomas M, Aquino Gilberto J, Brandt Verena, Baruah Dhiraj, Fink Nicola, Zsarnoczay Emese, Flohr Thomas, Schmidt Bernhard, Allmendinger Thomas, Risch Franka, Varga-Szemes Akos, Emrich Tilman
Division of Cardiovascular Imaging, Department of Radiology and Radiological Science, Medical University of South Carolina, 25 Courtenay Drive, Charleston, SC, USA.
Department of Diagnostic and Interventional Radiology, University Hospital Augsburg, Augsburg, Germany.
Eur Radiol. 2023 Apr;33(4):2469-2477. doi: 10.1007/s00330-022-09283-4. Epub 2022 Dec 3.
To assess the impact of scan modes and reconstruction kernels using a novel dual-source photon-counting detector CT (PCD-CT) on lumen visibility and sharpness of different stent sizes.
A phantom containing six balloon-expandable stents (2.5 to 9 mm diameter) in silicone tubing was scanned on a PCD-CT with standard (0.6 mm and 0.4 mm thicknesses) and ultra-high-resolution (0.2 mm thickness) modes. With the use of increasing contrast medium concentrations, densities of 0, 200, 400, and 600 HU were achieved. Standard-resolution scans were reconstructed using increasing sharpness kernels, using both polyenergetic quantitative soft tissue "conventional" ((Qr40(0.6 mm), Qr40(0.4 mm), Qr72(0.2 mm)) and vascular (Bv) virtual monoenergetic reconstructions (Bv44(0.4 mm), Bv60(0.4 mm)) at 70 keV. In-stent lumen visibility, sharpness (max. ΔHU of the stent measured in profile plots), and in-stent noise (standard deviation of HU) were measured.
In-stent lumen visibility was highest for Qr72(0.2 mm) (86.5 ± 2.8% to 88.3 ± 2.6%) and in Bv60(0.4 mm) reconstructions (77.3 ± 2.9 to 82.7 ± 2.5%). Lumen visibility was lowest in the smallest stent (2.5 mm) ranging from 54.1% in Qr40(0.6 mm) to 74.1% in Qr72(0.2 mm) and highest in the largest stent (9 mm) ranging from 93.8% in Qr40c(0.6 mm) to 99.1% in the Qr72(0.2 mm) series. Lumen visibility decreased by 2.1% for every 200-HU increase in lumen attenuation. Max. ΔHU between stents and stent lumen was highest in Qr72(0.2 mm) (ΔHU 892 ± 504 to 1526 ± 517) and Bv60(0.4 mm) series (ΔHU 480 ± 357 to 1030 ± 344). Improvement of lumen visibility and sharpness in UHR and Bv60(0.4 mm) series was strongest in smaller stent sizes.
UHR acquisition mode and sharp reconstruction kernels on a novel PCD-CT system significantly improve in-stent lumen visibility and sharpness-especially for smaller stent sizes.
• In-stent lumen visibility and sharpness of stents significantly improve using sharp reconstruction kernels (Bv60) and ultra-high-resolution mode in photon-counting detector computed tomography. • The observed improvement of stent-lumen visibility was highest in smaller stent sizes.
使用新型双源光子计数探测器CT（PCD-CT）评估扫描模式和重建核对于不同尺寸支架管腔可视性和清晰度的影响。
在一台PCD-CT上，对一个包含置于硅胶管内的六个球囊扩张支架（直径2.5至9毫米）的模体进行扫描，扫描模式包括标准模式（层厚0.6毫米和0.4毫米）和超高分辨率模式（层厚0.2毫米）。通过增加造影剂浓度，实现了0、200、400和600HU的密度值。标准分辨率扫描使用逐渐增大锐度的重建核进行重建，在70keV能量下，采用多能定量软组织“传统”模式（Qr40(0.6毫米)、Qr40(0.4毫米)、Qr72(0.2毫米)）以及血管（Bv）虚拟单能重建模式（Bv44(0.4毫米)、Bv60(0.4毫米)）。测量支架内管腔的可视性、清晰度（在剖面图中测量的支架最大HU差值）以及支架内噪声（HU的标准差）。
Qr72(0.2毫米)（86.5±2.8%至88.3±2.6%）和Bv60(0.4毫米)重建模式（77.3±2.9至82.7±2.5%）下的支架内管腔可视性最高。最小支架（2.5毫米）的管腔可视性最低，在Qr40(0.6毫米)模式下为54.1%，在Qr72(0.2毫米)模式下为74.1%；最大支架（9毫米）的管腔可视性最高，在Qr40c(0.6毫米)模式下为93.8%，在Qr72(0.2毫米)系列中为99.1%。管腔衰减每增加200HU，管腔可视性降低2.1%。支架与支架内管腔之间的最大HU差值在Qr72(0.2毫米)（ΔHU 892±504至1526±517）和Bv60(0.4毫米)系列（ΔHU 480±357至1030±344）中最高。在较小尺寸支架中，超高分辨率模式和Bv60(0.4毫米)系列在管腔可视性和清晰度方面的改善最为明显。
新型PCD-CT系统上的超高分辨率采集模式和锐利的重建核显著提高了支架内管腔的可视性和清晰度，尤其是对于较小尺寸的支架。
• 在光子计数探测器计算机断层扫描中，使用锐利的重建核（Bv60）和超高分辨率模式可显著提高支架内管腔的可视性和清晰度。• 观察到在较小尺寸支架中，支架-管腔可视性的改善最为明显。
