Full breast digital mammography with an amorphous silicon‐based flat panel detector: Physical characteristics of a clinical prototype

Abstract

The physical characteristics of a clinical prototype amorphous silicon-based flat panel imager for full-breast digital mammography have been investigated. The imager employs a thin thallium doped CsI scintillator on an amorphous silicon matrix of detector elements with a pixel pitch of 100 microm. Objective criteria such as modulation transfer function (MTF), noise power spectrum, detective quantum efficiency (DQE), and noise equivalent quanta were employed for this evaluation. The presampling MTF was found to be 0.73, 0.42, and 0.28 at 2, 4, and 5 cycles/mm, respectively. The measured DQE of the current prototype utilizing a 28 kVp, Mo-Mo spectrum beam hardened with 4.5 cm Lucite is approximately 55% at close to zero spatial frequency at an exposure of 32.8 mR, and decreases to approximately 40% at a low exposure of 1.3 mR. Detector element nonuniformity and electronic gain variations were not significant after appropriate calibration and software corrections. The response of the imager was linear and did not exhibit signal saturation under tested exposure conditions.

Contrast Detail Phantom Comparison on a Commercially Available Unit. Digital Breast Tomosynthesis (DBT) versus Full-Field Digital Mammography (FFDM)

“…2,3 Furthermore, from a physical point of view, FFDM has a higher detective quantum efficiency and a greater dynamic range with respect to SFS. [4][5][6][7][8] In FFDM and SFS, benign lesions and background tissue are implicated for undetected breast lesions. 8,9 Tissue background is probably the main factor limiting cancer detection.…”

Automated detection of microcalcification clusters for digital breast tomosynthesis using projection data only: A preliminary study

“…The detector was an amorphous silicon flat-panel detector with a pixel size of 100 m. The characteristics of this detector are described in Ref. 25. No anti-scatter grid was used during DBT projection data acquisition.…”

Noise aliasing and the 3D NEQ of flat-panel cone-beam CT: Effect of 2D/3D apertures and sampling

“…These descriptors have become common for 2D imaging systems, may be determined by experimental measurements 1,2 and by theoretical calculations ͑e.g., cascaded systems analysis͒, [3][4][5] and have been proven useful in system design and optimization. [6][7][8][9][10][11][12][13][14][15][16][17] These metrics can be described similar to 3D imaging, including tomosynthesis and CBCT. [18][19][20][21][22][23][24][25] With a knowledge of the imaging task and an appropriate model observer, these metrics can be extended to a description of task performance as described by ICRU Report No.…”