Multiscale bilateral filtering for improving image quality in digital breast tomosynthesis
Multiscale bilateral filtering for improving image quality in digital breast tomosynthesis
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DOI：
10.1118/1.4903283
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发表时间：
2015-01-01
期刊：
影响因子：
3.8
通讯作者：
Samala, Ravi K.
中科院分区：
文献类型：
--
作者：
Lu, Yao;Chan, Heang-Ping;Samala, Ravi K.
目的：由于数字乳腺断层合成摄影（DBT）体积大且有噪声，因此检测DBT中的细微微钙化是一项具有挑战性的任务。在DBT重建中，提高微钙化点的对比噪声比（CNR）是非常重要的。大多数正则化方法依赖于局部梯度，并且由于它们的小梯度，可能将质量的边界不明确或细微的毛刺和细微的微钙化视为噪声。作者开发了一种新的多尺度双边滤波（MSBF）正则化方法的同时代数重建技术（SART），以提高CNR的微钙化，而不影响质量的质量mass.Methods：MSBF利用多尺度结构的DBT图像，以抑制噪声和选择性地增强高频结构。在每次SART迭代结束时，通过拉普拉斯金字塔分解将每个DBT切片分解为若干频带。没有正则化应用于低频带，以便保留质量和结构化背景的细微边缘。双边滤波应用于高频带，以增强微钙化，同时抑制噪声。正则化的DBT图像用于在下一个SART迭代中进行更新。将新的MSBF方法与非凸全p变差（TpV）方法进行了比较，并使用SART进行了噪声正则化。GE GEN 2原型DBT系统用于在+/-30度范围内以3度增量在21个角度采集投影。使用异质乳腺体模和几个具有肿块和微钙化的人类受试者的DBT扫描，比较了无正则化（NR）和两种正则化方法的重建图像质量。的CNR和半高全宽（FWHM）的线轮廓的微钙化和在焦点DBT slices.Results内的毛刺被用作图像质量measurements：MSBF方法减少轮廓伪影和增强CNR的微钙化相比，TpV方法，从而保持结构化背景的图像质量。MSBF方法在三种方法中实现了最高的微钙化CNR。MSBF方法产生的微钙化和肿块毛刺的FWHM与未正则化的FWHM相当，并且上级优于TpV方法。结论：多尺度双边滤波方法正则化的SART增强了微钙化的CNR，并保留了微钙化和毛刺肿块的清晰度。MSBF方法提供了更好的结构化背景图像质量，在增强微钙化同时保留肿块边缘外观方面上级TpV和NR。(c)2015年美国医学物理学家协会。
Purpose: Detection of subtle microcalcifications in digital breast tomosynthesis (DBT) is a challenging task because of the large, noisy DBT volume. It is important to enhance the contrast-to-noise ratio (CNR) of microcalcifications in DBT reconstruction. Most regularization methods depend on local gradient and may treat the ill-defined margins or subtle spiculations of masses and subtle microcalcifications as noise because of their small gradient. The authors developed a new multiscale bilateral filtering (MSBF) regularization method for the simultaneous algebraic reconstruction technique (SART) to improve the CNR of microcalcifications without compromising the quality of masses.Methods: The MSBF exploits a multiscale structure of DBT images to suppress noise and selectively enhance high frequency structures. At the end of each SART iteration, every DBT slice is decomposed into several frequency bands via Laplacian pyramid decomposition. No regularization is applied to the low frequency bands so that subtle edges of masses and structured background are preserved. Bilateral filtering is applied to the high frequency bands to enhance microcalcifications while suppressing noise. The regularized DBT images are used for updating in the next SART iteration. The new MSBF method was compared with the nonconvex total p-variation (TpV) method for noise regularization with SART. A GE GEN2 prototype DBT system was used for acquisition of projections at 21 angles in 3 degrees increments over a +/- 30 degrees range. The reconstruction image quality with no regularization (NR) and that with the two regularization methods were compared using the DBT scans of a heterogeneous breast phantom and several human subjects with masses and microcalcifications. The CNR and the full width at half maximum (FWHM) of the line profiles of microcalcifications and across the spiculations within their in-focus DBT slices were used as image quality measures.Results: The MSBF method reduced contouring artifacts and enhanced the CNR of microcalcifications compared to the TpV method, thus preserving the image quality of the structured background. The MSBF method achieved the highest CNR of microcalcifications among the three methods. The FWHM of the microcalcifications and mass spiculations resulting from the MSBF method was comparable to that without regularization, and superior to that of the TpV method.Conclusions: The SART regularized by the multiscale bilateral filtering method enhanced the CNR of microcalcifications and preserved the sharpness of microcalcifications and spiculated masses. The MSBF method provided better image quality of the structured background and was superior to TpV and NR for enhancing microcalcifications while preserving the appearance of mass margins. (c) 2015 American Association of Physicists in Medicine.