Optimization of detector operation and imaging geometry for breast tomosynthesis

In breast tomosynthesis there are tradeoffs between resolution, noise and acquisition speed for a given glandular dose. The purpose of the present work is to investigate the dependence of tomosynthesis imaging performance on system configuration, which includes detector operational modes and image acquisition geometry. A prototype Siemens breast tomosynthesis system with maximum angular range of +/- 25 degrees was used in our investigation. The system was equipped with an amorphous selenium (a-Se) full field digital mammography detector with pixel size of 85µm. The detector can be read out with full resolution or 2x1 binning (binning in the tube travel direction), which increases the image readout rate and decreases the degradation effect of electronic noise. The total number of views can be varied from 11 to 49, and filtered back projection (FBP) method was used to reconstruct the tomosynthesis images. We investigated the effects of detector operational modes (binning) and imaging geometry (view angle and number) on temporal performance and spatial resolution of the projection images. The focal spot blur due to continuous tube travel was measured for different acquisition geometry, and its effect on in-plane presampling modulation transfer function (MTF) was compared to that due to pixel binning. A three-dimensional cascaded linear system model was developed for tomosynthesis to predict the 3D MTF, NPS and DQE. The results were compared with experimental measurements, and reasonable agreement was achieved. The understanding of the relationship between the 3D and projection image quality will lead to optimization of the x-ray spectrum, imaging geometry and reconstruction filters for digital breast tomosynthesis.

[1]  Vincent Loustauneau,et al.  Imaging performance of a clinical selenium flat-panel detector for advanced applications in full-field digital mammography , 2003, SPIE Medical Imaging.

[2]  Joseph Y. Lo,et al.  Digital breast tomosynthesis using an amorphous selenium flat panel detector , 2005, SPIE Medical Imaging.

[3]  Ian Shaw,et al.  Design and performance of the prototype full field breast tomosynthesis system with selenium based flat panel detector , 2005, SPIE Medical Imaging.

[4]  Wei Zhao,et al.  Temporal performance of amorphous selenium mammography detectors. , 2005, Medical physics.

[5]  Thomas Mertelmeier,et al.  Optimizing filtered backprojection reconstruction for a breast tomosynthesis prototype device , 2006, SPIE Medical Imaging.

[6]  Bo Zhao,et al.  Characterization of a direct full-field flat-panel digital mammography detector , 2003, SPIE Medical Imaging.

[7]  Gopal B. Avinash,et al.  Characterization of point spread function in linear digital tomosynthesis: a simulation study , 2006, SPIE Medical Imaging.

[8]  Hojjat Adeli,et al.  Medicine and Biology , 2005 .

[9]  D. Jaffray,et al.  A ghost story: spatio-temporal response characteristics of an indirect-detection flat-panel imager. , 1999, Medical physics.

[10]  J A Rowlands,et al.  Digital radiology using active matrix readout of amorphous selenium: theoretical analysis of detective quantum efficiency. , 1997, Medical physics.

[11]  Ann-Katherine Carton,et al.  Initial clinical experience with contrast-enhanced digital breast tomosynthesis. , 2007, Academic radiology.

[12]  K. Hanson,et al.  Detectability in computed tomographic images. , 1979, Medical physics.

[13]  L T Niklason,et al.  Digital breast imaging: tomosynthesis and digital subtraction mammography. , 1998, Breast disease.

[14]  John A. Rowlands,et al.  Investigation of imaging performance of amorphous selenium flat-panel detectors for digital mammography , 2001, SPIE Medical Imaging.

[15]  D. Kopans,et al.  Digital tomosynthesis in breast imaging. , 1997, Radiology.