Li Xiao-Shi, Geng Ji-Gang, Zhu Yin-Hu, Liu Li-Yao, Qiao Yan-Qiang, Ma Yong-Li, Lu Lu, Song Chang-Rui, Qin Yue, Chen Guo-Ping, Xu Min, Wang Ya-Rong
Department of Radiology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 227 YanTa West Road, Xi'an 710061, China; Department of Radiology, Xi'an Daxing Hospital, No. 353 LaoDong Road, Xi'an 710016, China.
Department of Radiology, Xi'an Daxing Hospital, No. 353 LaoDong Road, Xi'an 710016, China.
Eur J Radiol. 2024 Dec;181:111792. doi: 10.1016/j.ejrad.2024.111792. Epub 2024 Oct 25.
This study aimed to explore the feasibility of reducing contrast medium (CM) volume, improving image quality and diagnostic accuracy using variable helical pitch (VHP) scanning for patients with lower extremity arterial disease (LEAD).
Eighty patients who underwent lower extremity CT angiography (CTA) were prospectively enrolled and randomly assigned to either the VHP group (n = 40) or the conventional group (n = 40). Quantitative parameters and qualitative scores were compared between the two groups. Additionally, out of these patients, 72 arteries from 18 patients had DSA as the reference standard, and the diagnostic accuracy for the degree of vessel stenosis was assessed and compared.
In the VHP group, the contrast volume was significantly lower than in the conventional group (79.55 ± 11.87 mL vs. 89.63 ± 10.03 mL, p < 0.001), showing a reduction of 12.7 %. For all image quality characteristics, scores in VHP group were significantly superior to those in the conventional groups (all p < 0.05). Quantitative analysis revealed that images from the VHP group exhibited superior CT enhancement, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the anterior tibial arteries (ATA) and dorsali pedis arteries (DPA) compared to the conventional group (all p < 0.001). Moreover, segment-based analysis showed the VHP group had significantly higher positive predictive value (PPV) and accuracy than the conventional group (PPV: 100 % vs. 76.19 %, p = 0.01; accuracy: 100 % vs. 84.38 %, p = 0.01, respectively).
The implementation of the VHP protocol led to a 12.7 % decrease in contrast medium dosage compared to the conventional lower extremity CTA scanning protocol. Furthermore, it improved image quality and diagnostic accuracy, particularly for arteries below the knee.
本研究旨在探讨采用可变螺距螺旋扫描（VHP）技术减少下肢动脉疾病（LEAD）患者造影剂（CM）用量、提高图像质量和诊断准确性的可行性。
前瞻性纳入80例行下肢CT血管造影（CTA）的患者，并随机分为VHP组（n = 40）和传统组（n = 40）。比较两组的定量参数和定性评分。此外，在这些患者中，选取18例患者的72条动脉以数字减影血管造影（DSA）作为参考标准，评估并比较血管狭窄程度的诊断准确性。
VHP组的造影剂用量显著低于传统组（79.55 ± 11.87 mL vs. 89.63 ± 10.03 mL，p < 0.001），减少了12.7%。对于所有图像质量特征，VHP组的评分均显著优于传统组（所有p < 0.05）。定量分析显示，与传统组相比，VHP组的图像在胫前动脉（ATA）和足背动脉（DPA）中表现出更好的CT增强、信噪比（SNR）和对比噪声比（CNR）（所有p < 0.001）。此外，基于节段的分析表明，VHP组的阳性预测值（PPV）和准确性显著高于传统组（PPV：100% vs. 76.19%，p = 0.01；准确性：100% vs. 84.38%，p = 0.01）。
与传统的下肢CTA扫描方案相比，VHP方案的实施使造影剂用量减少了12.7%。此外，它还提高了图像质量和诊断准确性，尤其是对膝以下动脉。
