Aissa Joel, Boos Johannes, Sawicki Lino Morris, Heinzler Niklas, Krzymyk Karl, Sedlmair Martin, Kröpil Patric, Antoch Gerald, Thomas Christoph
1 Department of Diagnostic and Interventional Radiology, University Dusseldorf, Medical Faculty, Dusseldorf, Germany.
2 Department of Computed Tomography, Siemens Healthineers GmH, Cologne, Germany.
Br J Radiol. 2017 Nov;90(1079):20160778. doi: 10.1259/bjr.20160778. Epub 2017 Aug 22.
The purpose of this study was to evaluate the impact of three novel iterative metal artefact (iMAR) algorithms on image quality and artefact degree in chest CT of patients with a variety of thoracic metallic implants.
27 postsurgical patients with thoracic implants who underwent clinical chest CT between March and May 2015 in clinical routine were retrospectively included. Images were retrospectively reconstructed with standard weighted filtered back projection (WFBP) and with three iMAR algorithms (iMAR-Algo1 = Cardiac algorithm, iMAR-Algo2 = Pacemaker algorithm and iMAR-Algo3 = ThoracicCoils algorithm). The subjective and objective image quality was assessed.
Averaged over all artefacts, artefact degree was significantly lower for the iMAR-Algo1 (58.9 ± 48.5 HU), iMAR-Algo2 (52.7 ± 46.8 HU) and the iMAR-Algo3 (51.9 ± 46.1 HU) compared with WFBP (91.6 ± 81.6 HU, p < 0.01 for all). All iMAR reconstructed images showed significantly lower artefacts (p < 0.01) compared with the WFPB while there was no significant difference between the iMAR algorithms, respectively. iMAR-Algo2 and iMAR-Algo3 reconstructions decreased mild and moderate artefacts compared with WFBP and iMAR-Algo1 (p < 0.01).
All three iMAR algorithms led to a significant reduction of metal artefacts and increase in overall image quality compared with WFBP in chest CT of patients with metallic implants in subjective and objective analysis. The iMARAlgo2 and iMARAlgo3 were best for mild artefacts. IMARAlgo1 was superior for severe artefacts. Advances in knowledge: Iterative MAR led to significant artefact reduction and increase image-quality compared with WFBP in CT after implementation of thoracic devices. Adjusting iMAR-algorithms to patients' metallic implants can help to improve image quality in CT.
本研究旨在评估三种新型迭代金属伪影（iMAR）算法对各种胸部金属植入物患者胸部CT图像质量和伪影程度的影响。
回顾性纳入2015年3月至5月在临床常规检查中接受胸部CT检查的27例有胸部植入物的术后患者。图像采用标准加权滤波反投影（WFBP）以及三种iMAR算法（iMAR-Algo1 = 心脏算法，iMAR-Algo2 = 起搏器算法，iMAR-Algo3 = 胸部线圈算法）进行回顾性重建。对主观和客观图像质量进行评估。
在所有伪影方面进行平均后，与WFBP（91.6±81.6 HU，所有p<0.01）相比，iMAR-Algo1（58.9±48.5 HU）、iMAR-Algo2（52.7±46.8 HU）和iMAR-Algo3（51.9±46.1 HU）的伪影程度显著更低。与WFPB相比，所有iMAR重建图像的伪影均显著减少（p<0.01），而iMAR算法之间无显著差异。与WFBP和iMAR-Algo1相比，iMAR-Algo2和iMAR-Algo3重建减少了轻度和中度伪影（p<0.01）。
在主观和客观分析中，与WFBP相比，所有三种iMAR算法在有金属植入物患者的胸部CT中均导致金属伪影显著减少且整体图像质量提高。iMARAlgo2和iMARAlgo3对轻度伪影效果最佳。IMARAlgo1对重度伪影效果更佳。知识进展：与WFBP相比，在实施胸部装置后的CT中，迭代MAR导致伪影显著减少并提高了图像质量。根据患者的金属植入物调整iMAR算法有助于提高CT图像质量。
