Absolute Reconstructions Using Rotational Electrical Impedance Tomography for Breast Cancer Imaging.
Absolute Reconstructions Using Rotational Electrical Impedance Tomography for Breast Cancer Imaging.
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DOI：
10.1109/tmi.2016.2640944
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发表时间：
2017-04
影响因子：
10.6
通讯作者：
Halter RJ
中科院分区：
文献类型：
--
作者：
Murphy EK;Mahara A;Halter RJ
本文描述并展示了旋转电阻抗断层扫描（rEIT）方法，该方法与传统的电阻抗断层扫描（EIT）相比，可以产生空间精确的绝对重建，提高了图像对比度，并提高了区分紧密间隔夹杂物的能力，这些数据来自圆柱形和胸形储罐。在不改变内部电导率分布的情况下，水箱的旋转被用来产生rEIT数据。从数量上看，与传统EIT相比，rEIT能够区分距离圆柱形罐中心2至3厘米的两个近1.5厘米的内含物，并且能够区分传统EIT无法可靠地做到的两个肿瘤样内含物。数学分析表明，对于圆柱形坦克和胸形坦克，rEIT的稳定奇异向量数量分别比传统的EIT提高了4.2倍和4.7倍，这表明分辨率得到了提高。对测量结果的直接调查表明，最小的旋转角度应该产生不受噪声影响的数据。考虑了两种反演方法（一种是先反演再融合数据（I/DF），另一种是先融合数据再反演（DF/I））和两种网格建模方法。结果发现，与I/DF相比，DF/I产生了更好的结果，旋转网格方法产生了进一步的改进。利用rEIT在实际临床场景中获得改进的绝对重建的能力（乳房形罐实验）是利用rEIT改进以前在医学应用中的EIT结果的重要一步。
A rotational Electrical Impedance Tomography (rEIT) methodology is described and shown to produce spatially accurate absolute reconstructions with improved image contrast and an improved ability to distinguish closely spaced inclusions compared to traditional EIT on data recorded from cylindrical and breast-shaped tanks. Rotations of the tank without altering the interior conductivity distribution are used to produce the rEIT data. Quantitatively, rEIT was able to distinguish two inclusions that were 1.5 cm closer together than traditional EIT could achieve for inclusions placed 2 to 3 cm from the center for the cylindrical tank, and rEIT was able to distinguish two tumor-like inclusions where traditional EIT could not reliably do so.Mathematical analysis showed that rEIT improves the number of stable singular vectors by up to 4.2 and 4.7 times than that of traditional EIT for the cylindrical and breast-shaped tanks, respectively, which is an indication of improved resolution. Direct investigations into measurements revealed minimum rotation angles that should yield data uncorrupted by noise. Two inverse approaches (one that inverts then fuses the data (I/DF) and one that fuses the data then inverts (DF/I)) and two mesh modeling approaches were considered. It was found that DF/I produces far better results compared to I/DF and a rotated-mesh approach produces further improvements. The ability to obtain improved absolute reconstructions using rEIT on a practical clinical scenario (breast-shaped tank experiment) is an important step towards using rEIT to improve previous EIT results in medical applications.