DBIM	distorted Born iterative method
GPU	graphic processing unit
3-D	three-dimensional
2-D	two-dimensional
MWT	microwave tomography
MWI	microwave imaging
FDTD	finite difference time domain
EM	electromagnetic
DDA	discrete dipole approximation
GN	Gauss-Newton
FEM	finite element method
CSI	contrast source inversion
VIE	volume integral equation
TSVD	truncated singular value decomposition
FISTA	fast iterative shrinkage/thresholding algorithm
CG	conjugate gradient
FFT	fast Fourier transform
TR	transmitter–receiver
CPML	convolutional perfectly matched layer
RMSE	root mean square error
RE	residual error