Do Thuy Duong, Heim Julia, Skornitzke Stephan, Melzig Claudius, Vollherbst Dominik F, Faerber Michael, Pereira Philippe L, Kauczor Hans-Ulrich, Sommer Christof Matthias
Clinic for Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany.
Department of Neuroradiology, University Hospital Heidelberg, Heidelberg, Germany.
PLoS One. 2021 Apr 26;16(4):e0249921. doi: 10.1371/journal.pone.0249921. eCollection 2021.
To evaluate dual-energy CT (DE) and dedicated metal artifact reduction algorithms (iMAR) during CT-guided biopsy in comparison to single-energy CT (SE).
A trocar was placed in the liver of six pigs. CT acquisitions were performed with SE and dose equivalent DE at four dose levels(1.7-13.5mGy). Iterative reconstructions were performed with and without iMAR. ROIs were placed in four positions e.g. at the trocar tip(TROCAR) and liver parenchyma adjacent to the trocar tip(LIVER-1) by two independent observers for quantitative analysis using CT numbers, noise, SNR and CNR. Qualitative image analysis was performed regarding overall image quality and artifacts generated by iMAR.
There were no significant differences in CT numbers between DE and SE at TROCAR and LIVER-1 irrespective of iMAR. iMAR significantly reduced metal artifacts at LIVER-1 for all exposure settings for DE and SE(p = 0.02-0.04), but not at TROCAR. SNR, CNR and noise were comparable for DE and SE. SNR was best for high dose levels of 6.7/13.5mGy. Mean difference in the Blant-Altman analysis was -8.43 to 0.36. Cohen's kappa for qualitative interreader-agreement was 0.901.
iMAR independently reduced metal artifacts more effectively and efficiently than CT acquisition in DE at any dose setting and its application is feasible during CT-guided liver biopsy.
与单能量CT（SE）相比，评估双能量CT（DE）和专用金属伪影减少算法（iMAR）在CT引导下活检中的应用。
在六头猪的肝脏中放置一根套管针。分别采用SE和剂量等效的DE在四个剂量水平（1.7 - 13.5mGy）下进行CT扫描。在有和没有iMAR的情况下进行迭代重建。由两名独立观察者在四个位置（例如套管针尖端（TROCAR）以及套管针尖端附近的肝实质（LIVER - 1））放置感兴趣区（ROI），以使用CT值、噪声、信噪比（SNR）和对比噪声比（CNR）进行定量分析。对整体图像质量和iMAR产生的伪影进行定性图像分析。
无论有无iMAR，在TROCAR和LIVER - 1处，DE和SE的CT值均无显著差异。对于DE和SE的所有曝光设置，iMAR均显著减少了LIVER - 1处的金属伪影（p = 0.02 - 0.04），但在TROCAR处未减少。DE和SE的SNR、CNR和噪声相当。在6.7/13.5mGy的高剂量水平下，SNR最佳。Bland - Altman分析中的平均差异为 - 8.43至0.36。定性阅片者间一致性的Cohen's kappa为0.901。
在任何剂量设置下，iMAR比DE中的CT采集更有效且高效地独立减少金属伪影，并且其在CT引导下肝活检中的应用是可行的。
