Department of Neuroradiology, University Medicine Goettingen, Goettingen, Germany.
Invest Radiol. 2013 Feb;48(2):98-103. doi: 10.1097/RLI.0b013e318276db43.
Intra-arterial digital subtraction angiography (IA-DSA), an invasive procedure, is the current reference examination after percutaneous transluminal angioplasty and stenting for the detection of in-stent restenosis (ISR). In this phantom study, we evaluated flat-panel angiographic computed tomography after intravenous contrast agent application (IV-ACT) and multidetector computed tomographic angiography (MDCTA) as potential noninvasive follow-up alternatives after intracranial percutaneous transluminal angioplasty and stenting.
We simulated an intracranial vessel using a silicon tube placed inside a human skull. Three different stent systems were deployed inside the silicon tubes, each with diameters of 3 or 4 mm. Three grades of ISR (25%, 50%, and 75%) were simulated. The IA-DSA and IV-ACT examinations were performed on a flat-panel detector angiography system. The MDCTA images were acquired with a 128-slice computed tomographic scanner. The mean stenosis diameters, measured with each technique, were compared using the Bland-Altman plot. The difference between the known stenosis diameter and the measured stenosis diameter was calculated for each examination.
Stenosis measurements on the IA-DSA images showed no statistically significant differences compared with the known stenosis diameters (P = 0.19). In the 3-mm stent category, when compared with the known stenosis diameter, mean (SD) differences of 0.01 (0.15) mm, 0.03 (0.24) mm and 0.16 (0.5) mm were calculated for the IA-DSA, IV-ACT, and MDCTA stenosis measurements, respectively. As for the 4-mm stents, IA-DSA and IV-ACT were again very accurate, with mean (SD) differences of -0.03 (0.11) mm and 0.07 (0.19) mm, respectively, compared with the known stenosis diameters, whereas MDCTA overestimated ISR, with a mean (SD) difference of 0.49 (0.53) mm. The Bland-Altman plots show a mean (SD) difference of 0.08 (0.2) mm between IA-DSA and IV-ACT (95% confidence interval, 0.05-0.11) and a mean (SD) difference of 0.34 (0.56) mm between IA-DSA and MDCTA measurements (95% confidence interval, 0.25-0.42).
In our phantom study, IA-DSA was the only examination to predict accurately degrees of stenosis compared with the known stenosis diameters. The results of the IV-ACT measurements were comparable with those of IA-DSA. Multidetector computed tomographic angiography was less accurate in the quantification of stenosis, usually overestimating ISR.
血管内数字减影血管造影（IA-DSA）是一种有创性检查，是经皮腔内血管成形术和支架置入术治疗支架内再狭窄（ISR）后的当前参考检查。在这项体模研究中，我们评估了静脉内造影剂应用后的平板血管造影计算机断层扫描（IV-ACT）和多排螺旋 CT 血管造影（MDCTA）作为颅内经皮腔内血管成形术和支架置入术的潜在非侵入性随访替代方法。
我们使用放置在人颅骨内的硅管模拟颅内血管。在硅管内放置了三种不同的支架系统，每个支架的直径为 3 或 4 毫米。模拟了三种程度的 ISR（25%、50%和 75%）。IA-DSA 和 IV-ACT 检查均在平板探测器血管造影系统上进行。MDCTA 图像使用 128 层 CT 扫描仪采集。使用 Bland-Altman 图比较每种技术测量的平均狭窄直径。为每个检查计算了已知狭窄直径和测量狭窄直径之间的差值。
IA-DSA 图像上的狭窄测量值与已知狭窄直径相比无统计学差异（P = 0.19）。在 3 毫米支架类别中，与已知狭窄直径相比，IA-DSA、IV-ACT 和 MDCTA 狭窄测量值的平均（SD）差异分别为 0.01（0.15）mm、0.03（0.24）mm 和 0.16（0.5）mm。对于 4 毫米支架，IA-DSA 和 IV-ACT 再次非常准确，与已知狭窄直径相比，平均（SD）差异分别为-0.03（0.11）mm 和 0.07（0.19）mm，而 MDCTA 高估了 ISR，平均（SD）差异为 0.49（0.53）mm。Bland-Altman 图显示 IA-DSA 和 IV-ACT 之间的平均（SD）差异为 0.08（0.2）mm（95%置信区间，0.05-0.11），IA-DSA 和 MDCTA 测量值之间的平均（SD）差异为 0.34（0.56）mm（95%置信区间，0.25-0.42）。
在我们的体模研究中，IA-DSA 是唯一能够准确预测与已知狭窄直径相比的狭窄程度的检查方法。IV-ACT 测量结果与 IA-DSA 相当。多排螺旋 CT 血管造影在狭窄程度的定量评估中准确性较低，通常高估 ISR。
