Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091 Zurich, Switzerland.
Acad Radiol. 2010 Nov;17(11):1366-74. doi: 10.1016/j.acra.2010.06.017.
To evaluate the quality of stent lumen delineation using dual-source computed tomography (DSCT) in the standard-pitch mode (SP) as compared to the high-pitch mode (HP) in a phantom study.
Forty different coronary stents placed in plastic tubes filled with contrast agent were imaged with a second generation DSCT system in a SP (pitch 0.23) and HP (pitch 3.4) mode in orientations of 0°, 45°, and 90° relative to the z-axis. Two observers independently measured the in-stent lumen and the attenuation values in the center of the stents. The artificial lumen narrowing (ALN) was calculated using the measured in-stent lumen and the nominal diameter of the plastic tube.
Interobserver correlation was excellent for in-stent lumen (0.86) and attenuation measurements (0.91). There was no significant difference neither for ALN (SP: 54.7-62.8%; HP: 55.8-64.0%) nor attenuation (SP: 356-395 Hounsfield units [HU]; HP: 352-384 HU) between SP and HP mode. For both modes, the orientation of the stent relative to the z-axis significantly affected ALN and attenuation (each P < .001). CT volume dose index was significantly lower using HP mode as compared to SP mode (P < .001).
The HP mode in DSCT provides visualization of the coronary in-stent lumen comparable to that measured in SP mode while reducing applied radiation dose in a stationary phantom model.
通过体模研究评估在标准螺距（SP）模式与高螺距（HP）模式下，双源 CT（DSCT）用于显示支架内腔的质量。
在第二代 DSCT 系统中，将 40 个不同的冠状动脉支架放置在充满对比剂的塑料管中，以 0°、45°和 90°相对于 z 轴的方向进行 SP（螺距 0.23）和 HP（螺距 3.4）模式成像。两位观察者独立测量支架内的内腔和支架中心的衰减值。使用测量的支架内腔和塑料管的标称直径计算人工内腔狭窄（ALN）。
观察者间的支架内腔和衰减测量的相关性均极好（分别为 0.86 和 0.91）。无论是在 ALN（SP：54.7-62.8%；HP：55.8-64.0%）还是在衰减（SP：356-395 亨氏单位[HU]；HP：352-384 HU）方面，SP 和 HP 模式之间均无显著差异。对于两种模式，支架相对于 z 轴的方向均显著影响 ALN 和衰减（均 P <.001）。与 SP 模式相比，HP 模式的 CT 容积剂量指数明显更低（P <.001）。
在固定体模模型中，与 SP 模式相比，DSCT 的 HP 模式可提供冠状动脉支架内腔的可视化效果，同时降低了辐射剂量。
