Resonant Medical Inc., Montreal, Canada.
IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Nov;57(11):2460-70. doi: 10.1109/TUFFC.2010.1712.
A new method for 3-D ultrasound volume reconstruction using tracked freehand 3-D ultrasound is proposed. The method is based on solving the forward volume reconstruction problem using direct interpolation of high-resolution ultrasound B-mode image frames. A series of ultrasound B-mode image frames (an image series) is acquired using the freehand scanning technique and position sensing via optical tracking equipment. The proposed algorithm creates additional intermediate image frames by directly interpolating between two or more adjacent image frames of the original image series. The target volume is filled using the original frames in combination with the additionally constructed frames. Compared with conventional volume reconstruction methods, no additional filling of empty voxels or holes within the volume is required, because the whole extent of the volume is defined by the arrangement of the original and the additionally constructed B-mode image frames. The proposed direct frame interpolation (DFI) method was tested on two different data sets acquired while scanning the head and neck region of different patients. The first data set consisted of eight B-mode 2-D frame sets acquired under optimal laboratory conditions. The second data set consisted of 73 image series acquired during a clinical study. Sample volumes were reconstructed for all 81 image series using the proposed DFI method with four different interpolation orders, as well as with the pixel nearest-neighbor method using three different interpolation neighborhoods. In addition, volumes based on a reduced number of image frames were reconstructed for comparison of the different methods' accuracy and robustness in reconstructing image data that lies between the original image frames. The DFI method is based on a forward approach making use of a priori information about the position and shape of the B-mode image frames (e.g., masking information) to optimize the reconstruction procedure and to reduce computation times and memory requirements. The method is straightforward, independent of additional input or parameters, and uses the high-resolution B-mode image frames instead of usually lower-resolution voxel information for interpolation. The DFI method can be considered as a valuable alternative to conventional 3-D ultrasound reconstruction methods based on pixel or voxel nearest-neighbor approaches, offering better quality and competitive reconstruction time.
提出了一种使用跟踪自由式三维超声的 3-D 超声体积重建的新方法。该方法基于使用高分辨率超声 B 模式图像帧的直接内插来解决正向体积重建问题。使用自由扫描技术和光学跟踪设备进行位置感测来获取一系列超声 B 模式图像帧（图像序列）。所提出的算法通过直接在原始图像序列的两个或更多相邻图像帧之间进行内插来创建附加的中间图像帧。通过结合原始帧和附加构建的帧来填充目标体积。与传统的体积重建方法相比，不需要对体积内的空体素或孔进行额外的填充，因为体积的整个范围由原始和附加构建的 B 模式图像帧的布置来定义。所提出的直接帧内插（DFI）方法在扫描不同患者的头颈部区域时获取的两个不同数据集上进行了测试。第一个数据集由在最佳实验室条件下采集的八个 B 模式 2-D 帧集组成。第二个数据集由在临床研究期间采集的 73 个图像序列组成。使用所提出的 DFI 方法，以四种不同的插值顺序以及三种不同的插值邻域使用像素最近邻方法，对所有 81 个图像序列进行了样本体积重建。此外，还为比较不同方法在重建位于原始图像帧之间的图像数据方面的准确性和鲁棒性而重建了基于较少图像帧的体积。DFI 方法基于正向方法，利用 B 模式图像帧的位置和形状的先验信息（例如，掩模信息）来优化重建过程，并减少计算时间和内存需求。该方法简单明了，不依赖于其他输入或参数，并且使用高分辨率 B 模式图像帧而不是通常较低分辨率的体素信息进行内插。DFI 方法可以被视为基于像素或体素最近邻方法的传统 3-D 超声重建方法的有价值替代方法，提供更好的质量和具有竞争力的重建时间。
