Full wave 3D inverse scattering: 21st century technology for whole body imaging

Abstract

Quantitative high resolution (QHR) images of speed of sound and attenuation in human breast have been made using full wave inverse scattering in three-dimension (FWIS3D), where only soft tissue is present. The FWIS3D technology and method are reviewed. Recent QHR images in the presence of bone and gas have been obtained with FWIS3D and are shown. Transmission mode quantitative and refraction corrected reflection images of small piglet abdomen, thorax, and head are shown. QHR images of the human knee using the same technology are shown. Human Knee is difficult due to the predominant presence of bone. With low frequency FWIS3D, the meniscus, structure within the Femur-Tibia (F-T) space, ligaments, and the infrapatellar fat pad can be seen. The intra-condyle space in the Femur is visible. It was earlier established that 3D modelling was necessary for breast. It is shown to be even more important for F-T space and whole body imaging. Quantitative estimates of high speed early development bone are made, and imaging through neo-natal skull is performed. Clear correspondence with known structures even in the presence of gas is displayed. This reveals FWIS3D ultrasound tomography as a 21st century whole body imaging modality.

Seismic wavefield imaging of Earth’s interior across scales

“…FWI is computationally and algorithmically demanding, and, although these demands hampered progress for many decades, these restrictions have been largely overcome in the past decade, due to advances in algorithms and computing technology. Today, FWI is widely used in applications including medical imaging [10][11][12][13][14] , nondestructive testing [15][16][17][18][19][20][21][22][23][24] , near-surface characterization [25][26][27][28][29][30] , onshore and offshore exploration seismology [31][32][33][34][35][36][37][38][39] , deep crustal seismic imaging [40][41][42][43][44][45][46][47] , earthquake seismology [48][49][50][51][52][53][54] and ambient-noise seismology 55,56 . A comprehensive ove...…”

“…Applications of seismic FWI can be categorized as controlled-source, earthquake and ambient-noise seismology. In addition to hydrocarbon exploration and deep crustal imaging [40][41][42][43][44][45][46][47] , controlled-source applications can be further subdivided by scale into medical imaging [10][11][12][13][14] , nondestructive testing [15][16][17][18][19][20][21][22][23][24] and near-surface charac terization of the top tens of metres of the Earth [25][26][27][28][29][30] , but these are beyond the scope of this Technical Review. Since 2010, ambient-noise FWI based on seismic interferometry [159][160][161] has emerged 55,56 .…”