We present the implementation of the CT iterative reconstruction strategy developed within the SYRMA-CT project for in vivo phase contrast CT of the uncompressed breast, ongoing at the ELETTRA synchrotron radiation facility (Trieste, Italy). Propagation-based phase-contrast imaging exploited the high spatial coherence of the monoenergetic laminar X-ray beam (3-mm high along the chest-wall-to-nipple direction), as well as the large object-to-detector distance (∼2 m) and the use of a prototype of Pixirad-8 high-resolution photon counting CdTe detector (60-μm pitch, eight detector units arranged in a row). The signal in projection views depends on the X-ray absorption as well as on the phase shift introduced by the breast tissue in the beam path. A phase retrieval algorithm allows recovering the projected 2D phase map of the irradiated tissue layer, which were input to the CT reconstruction; then, the 3D image of the breast was reconstructed via a simultaneous algebraic reconstruction technique (SART) algorithm. The developed iterative reconstruction - coupled with a filtering process for reducing the noise level and ring artifacts by preserving edges sharpness - showed better image quality than conventional filtered backprojection (FBP) reconstruction. A phantom study showed that the iterative reconstruction produced images with a contrast-to-noise-ratio up to 65% and a spatial resolution up to 12% higher than those obtained with FBP. Finally, the developed algorithm removed ring-like artifacts caused by the detector dead space (0.16 mm) across adjacent detector units and by no perfect equalization after flat-field correction, without worsening the image quality.

A framework for iterative reconstruction in phase-contrast computed tomography dedicated to the breast / Sarno, A.; Golosio, B.; Russo, P.; Arfelli, F.; Bellazzini, R.; Brez, A.; Brun, F.; Delogu, P.; Di Lillo, F.; Dreossi, D.; Fedon, C.; Longo, R.; Mettivier, G.; Oliva, P.; Rigon, L.; Spandre, G.; Tromba, G.. - In: IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES. - ISSN 2469-7311. - 2017-:6(2017), pp. 505-510. (Intervento presentato al convegno 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016 tenutosi a fra nel 2016) [10.1109/TRPMS.2017.2749059].

A framework for iterative reconstruction in phase-contrast computed tomography dedicated to the breast

Oliva, P.;
2017-01-01

Abstract

We present the implementation of the CT iterative reconstruction strategy developed within the SYRMA-CT project for in vivo phase contrast CT of the uncompressed breast, ongoing at the ELETTRA synchrotron radiation facility (Trieste, Italy). Propagation-based phase-contrast imaging exploited the high spatial coherence of the monoenergetic laminar X-ray beam (3-mm high along the chest-wall-to-nipple direction), as well as the large object-to-detector distance (∼2 m) and the use of a prototype of Pixirad-8 high-resolution photon counting CdTe detector (60-μm pitch, eight detector units arranged in a row). The signal in projection views depends on the X-ray absorption as well as on the phase shift introduced by the breast tissue in the beam path. A phase retrieval algorithm allows recovering the projected 2D phase map of the irradiated tissue layer, which were input to the CT reconstruction; then, the 3D image of the breast was reconstructed via a simultaneous algebraic reconstruction technique (SART) algorithm. The developed iterative reconstruction - coupled with a filtering process for reducing the noise level and ring artifacts by preserving edges sharpness - showed better image quality than conventional filtered backprojection (FBP) reconstruction. A phantom study showed that the iterative reconstruction produced images with a contrast-to-noise-ratio up to 65% and a spatial resolution up to 12% higher than those obtained with FBP. Finally, the developed algorithm removed ring-like artifacts caused by the detector dead space (0.16 mm) across adjacent detector units and by no perfect equalization after flat-field correction, without worsening the image quality.
2017
9781509016426
A framework for iterative reconstruction in phase-contrast computed tomography dedicated to the breast / Sarno, A.; Golosio, B.; Russo, P.; Arfelli, F.; Bellazzini, R.; Brez, A.; Brun, F.; Delogu, P.; Di Lillo, F.; Dreossi, D.; Fedon, C.; Longo, R.; Mettivier, G.; Oliva, P.; Rigon, L.; Spandre, G.; Tromba, G.. - In: IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES. - ISSN 2469-7311. - 2017-:6(2017), pp. 505-510. (Intervento presentato al convegno 2016 IEEE Nuclear Science Symposium, Medical Imaging Conference and Room-Temperature Semiconductor Detector Workshop, NSS/MIC/RTSD 2016 tenutosi a fra nel 2016) [10.1109/TRPMS.2017.2749059].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11388/202067
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