| CT | Computed Tomography; |
| SPECT | Single Photon Emission Computed Tomography; |
| PET | Positron Emission Tomography; |
| MRI | Magnetic Resonance Imaging; |
| US | Ultrasound; |
| UST | Ultrasound Tomography; |
| ROI | Region of Interest; |
| ISP | Inverse Scattering Problem; |
| BA | Born Approximation; |
| TSVD | Truncated Singular Value Decomposition. |