Geometric calibration of a stationary digital breast tomosynthesis system based on distributed carbon nanotube X-ray source arrays - Fig 5

<p>Comparisons of input values and extracted values of the coordinates of the CNT sources (Zs) (a) and the coordinates of the sources’ projections (<i>v</i>) (b).</p

Profiles of different results shown in Fig 7.

<p>(a) Profile of the reconstructed images with input or extracted geometrical parameters without offset in the 242^th row. (b) Profile of the reconstructed images with or without geometrical calibration with 1-pixel offset in the 275^th row. (c) Profile of the reconstructed images with or without geometrical calibration with 2-pixel offset in the 300^th row. (d) Profile of the reconstructed images with or without geometrical calibration with 5-pixel offset in the 335^th row.</p

Comparisons of the set geometric parameters and the extracted simulation parameters of the coordinates of the sources’ projections on the detector.

<p>(<i>u</i>_set, <i>v</i>_set) and (<i>u</i>_ext, <i>v</i>_ext) represent the set and extracted coordinates, respectively, of the sources’ projections on the detector.</p

Schematic representation of the simulation projection process; the 22 CNT X-ray sources are numbered (1–22) and are sequentially triggered for emission.

<p>Schematic representation of the simulation projection process; the 22 CNT X-ray sources are numbered (1–22) and are sequentially triggered for emission.</p

Schematic representation of the imaging geometry, with two linear arrays of CNT sources arranged opposite the detectors to form the rectangular sDBT system.

<p>Schematic representation of the imaging geometry, with two linear arrays of CNT sources arranged opposite the detectors to form the rectangular sDBT system.</p

Projections of the calibration phantom for all CNT X-ray sources, taking the projections of the 1st, 6th, 11th, 12th, 17th and 22nd source (see Fig 4) as examples.

<p>Projections of the calibration phantom for all CNT X-ray sources, taking the projections of the 1st, 6th, 11th, 12th, 17th and 22nd source (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0188367#pone.0188367.g004" target="_blank">Fig 4</a>) as examples.</p

Schematic of the projection and coordinate system.

<p>Schematic of the projection and coordinate system.</p

Reconstructed images using geometrical parameters with and without calibration.

<p>(a) A reconstructed image with input geometrical parameters without offset. [(b)-(d)] Reconstructed images with different offsets but without calibration. (b) offset = 1 pixel; (c) offset = 2 pixels; (d) offset = 5 pixels. (e) A reconstructed image with extracted geometrical parameters without offset. (f) The reconstructed image in (b) after calibration. (g) The reconstructed image in (c) after calibration. (h) The reconstructed image in (d) after calibration.</p

Comparisons of the set geometric parameters and the extracted simulation parameters.

<p>Comparisons of the set geometric parameters and the extracted simulation parameters.</p

Comparisons of the input geometric parameters and the extracted simulation parameters.

<p>Comparisons of the input geometric parameters and the extracted simulation parameters.</p