Fraunhofer Institute for Digital Medicine MEVIS, Bremen, Germany.
University of Bremen, Bremen, Germany.
Int J Comput Assist Radiol Surg. 2020 Sep;15(9):1487-1490. doi: 10.1007/s11548-020-02197-w. Epub 2020 Jun 3.
We investigate the feasibility of reconstructing ultrasound images directly from raw channel data using a deep learning network. Starting from the raw data, we present the network the full measurement information, allowing for a more generic reconstruction to form, as compared to common reconstructions constrained by physical models using fixed speed of sound assumptions.
We propose a U-Net-like architecture for the given task. Additional layers with strided convolutions downsample the raw data. Hyperparameter optimization was used to find a suitable learning rate. We train and test our deep learning approach on plane wave ultrasound images with a single insonification angle. The dataset includes phantom as well as in vivo data.
The images produced by our method are visually comparable to ones reconstructed with the conventional delay and sum algorithm. Deviations between prediction and ground truth are likely to be related to speckle noise. For the test set, the mean absolute error is [Formula: see text] for the phantom images and [Formula: see text] for the in vivo data.
The result shows the feasibility of our approach and opens up new research directions regarding information retrieval from raw channel data. As the networks reconstruction performance is limited by the quality of the ground truth images, using other ultrasound reconstruction technique or image types as target data would be of interest.
我们研究了使用深度学习网络直接从原始通道数据重建超声图像的可行性。从原始数据出发,为网络提供完整的测量信息,从而可以进行更通用的重建,与使用固定声速假设的物理模型约束的常见重建相比,这种重建方式更加通用。
我们为给定任务提出了一种类似于 U-Net 的架构。带有跨步卷积的附加层对原始数据进行下采样。使用超参数优化来找到合适的学习率。我们在具有单个照射角的平面波超声图像上训练和测试我们的深度学习方法。该数据集包括体模和体内数据。
我们的方法生成的图像在视觉上可与传统的延迟求和算法重建的图像相媲美。预测值与真实值之间的偏差可能与散斑噪声有关。对于测试集,体模图像的平均绝对误差为[公式:见文本],体内数据的平均绝对误差为[公式:见文本]。
结果表明了我们的方法的可行性,并为从原始通道数据中检索信息开辟了新的研究方向。由于网络的重建性能受到真实图像质量的限制,因此使用其他超声重建技术或图像类型作为目标数据将是很有意义的。