We propose a novel processing method for reducing shading artifacts in quantitative susceptibility mapping (QSM) for prostate imaging. In the conventional method, calculation errors in the boundary regions between water and fat cause shading artifacts that degrade the image quality for QSM. In the proposed method, water and fat regions are separated, and susceptibilities in these two regions are calculated separately and then combined. Susceptibility in the water regions is calculated by using the fat regions as a background susceptibility source to remove shading artifacts. Susceptibility in the fat regions is calculated by using the constraint that shading artifacts in the water regions are suppressed to improve accuracy. In quantitative evaluation of the method with a numerical simulation, calculation errors for the water and fat regions were reduced by 62% and 85%, respectively, compared with the conventional method. In visual evaluation using human prostate imaging, the proposed method also reduced the shading artifacts unlike the conventional method. The proposed method is expected to improve the performance of QSM in diagnosing such diseases as prostate cancer.

中文翻译：

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通过对水和脂肪区域进行单独计算以减少阴影伪影，对前列腺进行定量药敏度测绘。

我们提出了一种新颖的处理方法，用于减少前列腺成像的定量磁化图（QSM）中的阴影伪影。在常规方法中，水和脂肪之间的边界区域中的计算误差导致阴影伪影，从而降低了QSM的图像质量。在提出的方法中，将水和脂肪区域分开，并分别计算这两个区域中的磁化率，然后合并。通过使用脂肪区域作为背景敏感性源来去除阴影伪影，可以计算出水区域中的敏感性。通过使用抑制水区域中的阴影伪影以提高精度的约束条件，可以计算出脂肪区域中的磁化率。在通过数值模拟对该方法进行定量评估时，与常规方法相比，水和脂肪区域的计算误差分别减少了62％和85％。在使用人类前列腺成像的视觉评估中，与常规方法不同，所提出的方法还减少了阴影伪影。预期所提出的方法将改善QSM在诊断诸如前列腺癌等疾病中的性能。