Quantitative evaluation of metal artifact reduction techniques
Quantitative evaluation of metal artifact reduction techniques
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DOI：
10.1002/jmri.20144
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发表时间：
2004-09-01
影响因子：
4.4
通讯作者：
Xiang, QS
中科院分区：
文献类型：
--
作者：
Kolind, SH;MacKay, AL;Xiang, QS
目的：开发一种量化伪影的技术，并使用它来比较几种减少金属伪影的方法的有效性。包括视角倾斜和增加切片选择和图像带宽（BW）。材料和方法：两种金属植入物（不锈钢和钛/铬钴股骨假体）的非金属复制品由蜡制成，并获得浸入水中的每个组件的MR图像。测量每个金属假体和其蜡对应物的图像之间的差异。来自噪声和模糊的贡献被隔离，从而导致金属伪影的测量。根据金属伪影减少能力评估了几种非共振伪影减少技术。结果：将图像带宽从+/-16 kHz增加到+/-64 kHz，伪影平均减少60%，而单独使用视角倾斜（VAT），伪影平均减少63%。金属伪影减少序列（MARS）。结论：与传统的自旋回波脉冲序列相比，单独使用VAT（图像带宽为+/-16 kHz）可以获得最小的总能量，并且信噪比没有降低。MARS导致明显更少的伪影和显着更少的模糊。
Purpose: To develop a technique to quantify artifact, and to use it to compare the effectiveness of several approaches to metal artifact reduction. including view angle tilting and increasing the slice select and image bandwidths (BWs), in terms of metal artifact reduction. noise, and blur.Materials and Methods: Nonmetallic replicas of two metal implants (stainless steel and titanium/chromium-cobalt femoral prostheses) were fabricated from wax, and MR images were obtained of each component immersed in water. The differences between the images of each metal prosthesis and its wax counterpart were measured. The contributions from noise and blur were isolated, resulting in a measure of the metal artifact. Several off-resonance artifact reduction techniques were assessed in terms of metal artifact reduction capability. as well as signal to noise ratio and blur.Results: Increasing the image BW from +/-16 kHz to +/-64 kHz was found to reduce the artifact by an average of 60%, while employing view angle tilting (VAT) alone was found to reduce the artifact by an average of 63%. The metal artifact reduction sequence (MARS). which combines several susceptibility artifact reduction techniques, resulted in the least amount of image distortion, reducing the artifact by an average of 79%.Conclusion: The results indicate that while VAT alone (with an image BW of +/-16 kHz) resulted in the smallest amount of total energy and no reduction in the signal-to-noise ratio compared to a conventional spin-echo pulse sequence. MARS resulted in significantly less artifact and dramatically less blur.