3D Numerical Breast Phantoms and Ring-Array USCT measurements (3 rings)

Dataset Summary This is the companion dataset for the manuscript by Fu Li, Umberto Villa, Neb Duric, and Mark A. Anastasio titled \"A forward model incorporating elevation-focused transducer properties for 3D full-waveform inversion in ultrasound computed tomography\". IEEE UFFC, link (2023). The dataset comprises two types of thin-slab 3D numerical breast phantoms (NBPs) and their corresponding ring-array ultrasound computed tomography (USCT) simulated measurement data. Two representative ACR BI-RADS breast composition types are selected: B: Scattered areas of fibroglandular density C: Heterogeneously dense breast Each NBP contains maps of acoustic properties (speed of sound, acoustic attenuation, and density). The corresponding ring-array USCT measurement data were simulated using the elevation-focused transducer described in the accompanying paper. Wave propagation simulations were conducted in lossy heterogeneous media using k-wave. Dataset Structure The dataset is organized into three folders: Dataset folder for phantom type B Dataset folder for phantom type C The imaging_system folder, which contains details about the 3D imaging system, including the excitation source, transducer coordinates, and lens thickness. B:/C: This dataset folder houses three sets of ring-array data, corresponding to acquisitions at three distinct elevation locations. As described in the manuscript, these locations are: ring -1 at z=-1.8mm, ring 0 at z=0mm, and ring 1 at z=1.8mm. The employed NBP and the associated simulated measurement data for each ring are provided. Specifically, the data files include phantom.mat: This .mat file contains three acoustic media: sos: Speed of sound map (m/s) with dimensions [1280,1280,194] (x-,y-,z-direction) and a 0.2 mm pixel size. Data type is float32. aa: Acoustic attenuation map (Np/m/MHz) with dimensions [1280,1280,194] (x-,y-,z-direction) and a 0.2 mm pixel size. Data type is float32. density: Density map (kg/mm³) with dimensions [1280,1280,194] (x-,y-,z-direction) and a 0.2 mm pixel size. Data type is float32. Note: These data are used to generate the corresponding acoustic media for each ring simulation by executing the Matlab script generate_slab.m. See the description of generate_slab.m for more details. data_ring_{i}.h5: Measurement data of the i-th ring (for i = -1, 0, 1) . Measurement is stored with an hdf5 key that matches the transducer index. This is a two-dimensional array of size [1024,4200], where rows denote the receiver index and columns indicate the time sample. The sampling frequency is 25MHz. imaging_system: source300.mat: Time profile of the excitation pulse. Comprises 300 time samples with a sampling frequency of 25MHz. receiver_locations_1024.mat: XY coordinates (in mm) of the location for each receiver transducer in the imaging plane. Data type is float32 with an array size of [2x1024]. emitter_locations_128.mat: XY coordinates (in mm) of the location for each emitter transducer in the imaging plane. Data type is float32 with an array size of [2x128]. lens_thickness.mat: The thickness (in mm) of the lens model with size [1x90]. Each element denotes the thickness of each segment (voxel) of the line aperture, from top to bottom. Additionally, the dataset includes helper MATLAB scripts: read_data.m: A function to aid in loading and visualizing the excitation source, transducer locations, and hdf5 measurement data files. generate_slab.m: A script to extract thin-slab from phantom.mat, the extracted medium is the used as computational domain for each ring-array simulation (for ring -1,0,1). Specifically, acoustic media were extracted from the shared phantom at different elevation locations. Two adjacent slabs are shifted vertically by 1.8 mm. The imaging plane for ring i corresponds to the central z-slice of each computational domain. The positions of each ring-array thin-slab are illustrated in the following figure. This function will generate data files named phantom_ring_{i}.mat, where i=-1, 0, 1. These correspond to the different ring-array simulation grids used to produce the shared three ring-array measurement data. For more details on the NBP generation, please refer to li2021uffc (2021). The anatomical structures of these NBPs were derived using tools from the Virtual Imaging Clinical Trial for Regulatory Evaluation (VICTRE) project.