Table 1.
Characteristics of breast tomosynthesis systems in clinical use or under development. The specifications for these systems, especially the prototypes, could change in the future.
| System | GE Essential | Hologic Selenia Dimensions | IMS Giotto TOMO | Philips MicroDose | Planmed Nuance Excel DBT | Siemens MAMMOMAT Inspiration |
|---|---|---|---|---|---|---|
| Detector type | Full field—indirect | Full field—direct (a-Se) | Full field—direct (a-Se) | Linear slit scan–spectral photon counting (Si) | Full field—direct (a-Se) | Full field—direct (a-Se) |
| Detector size (cm) | 24 × 30 | 24 × 29 | 24 × 30 | 21 line detectors, each 24 cm long | 24 × 30 | 24 × 30 |
| Detector pixel size (μm) | 100 | 70 (binned 2 × 2)1 | 85 | 50 (perpendicular to motion) | 85 | 85 |
| Detector motion | Static | Rotating | Static | Continuous slit scan | Rotating during exposure2 | Static |
| X-ray tube target | Mo or Rh | W | W | W | W | W |
| X-ray tube filtration | 0.03 mm Mo or 0.025 mm Rh | 0.7 mm Al | 0.05 mm Rh or 0.05 mm Ag | 0.5 mm Al | 0.075 mm Ag or 0.06 mm Rh | 0.05 mm Rh |
| X-ray tube motion | Step-and-shoot | Continuous | Step-and-shoot | Continuous | Continuous | Continuous |
| Angular range (deg) | 25 | 153 | 40 | 11 | 30 | 504 |
| Number of projections | 9 | 15 | 135 | 21 | 15 | 25 |
| Scan time (s) | 7 | 3.7 | 12 | 3–10 | 20 | 254 |
| Source to detector distance (cm) | 66 | 70 | 68 | 66 | 65 | 65.5 |
| Detector to center of rotation distance6 (cm) | 4 | 0 | 2 | −40 | 4.37 | 4.7 |
| Air gap (cm) | 2.2 | 2.5 | 2.2 | 0.4–2.4 | 2.38 | 1.7 |
| Reconstruction method | Iterative | FBP | Iterative with total variation regularization | Iterative | Iterative | FBP |
| Development stage7 | Prototype | Commercial system | Commercial system8 | Prototype | Prototype | Commercial system8 |
| References | 16, 31 | 16 | 32, 33, 34, 35 | 26, 27, 36 | 37 | 16, 38, 39, 40 |
Reconstruction results in an in-plane pixel size of approximately 100 μm.
Detector and compressed breast are rotated with x-ray source, while each projection is being acquired (x-ray tube current is on). Detector and breast are returned to original position at end of each projection.
This system supports an angular range up to 30°, which requires a software change by the manufacturer.
These values for angular range and scan time are for the x-ray tube motion; the x-ray exposures actually cover ∼46° in 20 s.
In the current commercial system outside the U.S., this system can be set to use 50% of the total tube output for the 0° projection and the rest distributed evenly among the other 12 projections.
Positive values are towards the x-ray source.
For systems which perform both mammography and DBT, this information is specific for the DBT mode.
Currently not approved for clinical use in the U.S. by the FDA.