Photon-Counting Detector CT: Clinical Utility of Virtual Monoenergetic Imaging Combined With Tin Prefiltration to Reduce Metal Artifacts in the Postoperative Ankle.

IF 7 1区医学 Q1 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Investigative Radiology Pub Date : 2024-08-01 Epub Date: 2024-01-10 DOI:10.1097/RLI.0000000000001058

Adrian A Marth, Sophia S Goller, Georg W Kajdi, Roy P Marcus, Reto Sutter

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引用次数: 0

Abstract

Objectives: The aim of this study was to compare the effectiveness and clinical utility of virtual monoenergetic image (VMI) reconstructions in computed tomography (CT) scans with and without tin prefiltration on a photon-counting detector (PCD) CT system to reduce metal implant artifacts in the postoperative ankle.

Materials and methods: This retrospective study included patients with internal fixation of the ankle scanned with and without tin prefiltration (Sn) on a PCD CT scanner between March and October 2023. Virtual monoenergetic images between 60 and 190 keV were reconstructed with a 10-keV increment in a bone kernel for both acquisitions (VMI Sn and VMI Std , respectively). Noise measurements assessed artifact reduction in the most prominent near-metal image distortions and were compared between acquisitions modes as well as between polychromatic images and VMIs. Three readers assessed the visibility of osseous healing along with interpretability and artifact extent for 5 reconstruction levels.

Results: A total of 48 patients (21 females, 27 males; mean age, 55.1 ± 19.4 years) were included in this study. Tin-prefiltered acquisitions (n = 30) had a lower artifact level for polychromatic images and VMIs compared with non-tin-prefiltered acquisitions (n = 18; P ≤ 0.043). A significant reduction of metal artifacts was observed for VMI Sn ≥120 keV compared with polychromatic images (hyperdense artifacts: 40.2 HU [interquartile range (IQR) 39.8] vs 14.0 HU [IQR 11.1]; P ≤ 0.01 and hypodense artifacts: 91.2 HU [IQR 82.4] vs 29.7 HU [IQR 39.6]; P ≤ 0.001). For VMI Std , this applied to reconstructions ≥100 keV (hyperdense artifacts: 57.7 HU [IQR 33.4] vs 19.4 HU [IQR 27.6]; P ≤ 0.001 and hypodense artifacts: 106.9 HU [IQR 76.1] vs 57.4 HU [IQR 55.7]; P ≤ 0.021). For visibility of osseous healing, VMI Sn at 120 keV yielded higher ratings compared with polychromatic images ( P ≤ 0.001), whereas image interpretability was rated better ( P = 0.023), and artifact extent was rated lower ( P ≤ 0.001) compared with polychromatic images.

Conclusions: Tin-prefiltered VMI at 120 keV showed a significant reduction in metal artifacts compared with polychromatic images, whereas visibility of osseous healing and image interpretability was improved. Therefore, tin-prefiltration PCD CT with VMI reconstructions may be a helpful complement to postsurgical CT imaging of the ankle in patients with metal implants.

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光子计数探测器 CT：虚拟单能成像结合锡预过滤以减少术后踝关节金属伪影的临床实用性。

研究目的本研究旨在比较在光子计数探测器（PCD）CT 系统上进行和未进行锡预过滤的计算机断层扫描（CT）虚拟单能图像（VMI）重建对减少术后踝关节金属植入物伪影的有效性和临床实用性：这项回顾性研究纳入了 2023 年 3 月至 10 月期间在 PCD CT 扫描仪上扫描过和未扫描过锡预过滤（Sn）的踝关节内固定患者。两次采集（分别为 VMISn 和 VMIStd）均在骨核中以 10 千伏增量重建了 60 至 190 千伏之间的虚拟单能量图像。噪声测量评估了最突出的近金属图像畸变中的伪影减少情况，并对不同采集模式以及多色图像和 VMI 进行了比较。三位读者评估了骨愈合的可见度、可解释性和 5 个重建级别的伪影程度：共有 48 名患者（21 名女性，27 名男性；平均年龄为 55.1 ± 19.4 岁）参与了此次研究。与未经锡预滤的采集结果（n = 18；P ≤ 0.043）相比，锡预滤采集结果（n = 30）的多色影像和 VMI 的伪影水平较低。与多色图像相比，VMISn ≥120 keV 的金属伪影明显减少（高密度伪影：高密度伪影：40.2 HU [四分位数间距 (IQR) 39.8] vs 14.0 HU [IQR 11.1]；P ≤ 0.01，低密度伪影：91.2 HU [IQR 39.8] vs 14.0 HU [IQR 11.1]；P ≤ 0.01：91.2 HU [IQR 82.4] vs 29.7 HU [IQR 39.6]; P ≤ 0.001）。对于 VMIStd，这适用于≥100 keV 的重建（超密度伪影：57.7 HU [IQR 82.4] vs 29.7 HU [IQR 39.6]；P ≤ 0.001）：57.7 HU [IQR 33.4] vs 19.4 HU [IQR 27.6]；P ≤ 0.001，低密度伪影：106.9 HU [IQR 39.6]；P ≤ 0.001：106.9 HU [IQR 76.1] vs 57.4 HU [IQR 55.7]; P ≤ 0.021）。就骨愈合的可见度而言，与多色图像相比，120 keV的VMISn获得的评分更高（P≤0.001），而与多色图像相比，图像的可解释性更好（P = 0.023），伪影程度更低（P≤0.001）：结论：与多色图像相比，120 keV 锡滤波 VMI 可显著减少金属伪影，同时提高骨愈合的可见度和图像的可解释性。因此，锡过滤 PCD CT 与 VMI 重建可作为金属植入物患者踝关节术后 CT 成像的有益补充。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Investigative Radiology 医学-核医学

CiteScore

15.10

自引率

16.40%

发文量

188

审稿时长

4-8 weeks

期刊介绍： Investigative Radiology publishes original, peer-reviewed reports on clinical and laboratory investigations in diagnostic imaging, the diagnostic use of radioactive isotopes, computed tomography, positron emission tomography, magnetic resonance imaging, ultrasound, digital subtraction angiography, and related modalities. Emphasis is on early and timely publication. Primarily research-oriented, the journal also includes a wide variety of features of interest to clinical radiologists.