Print Email Facebook Twitter Simulation of scanner- and patient-specific low-dose CT imaging from existing CT images Title Simulation of scanner- and patient-specific low-dose CT imaging from existing CT images Author Naziroglu, R.E. (TU Delft ImPhys/Quantitative Imaging) van Ravesteijn, V.F. (TU Delft ImPhys/Quantitative Imaging) van Vliet, L.J. (TU Delft ImPhys/Quantitative Imaging) Streekstra, G.J. (Universiteit van Amsterdam) Vos, F.M. (TU Delft ImPhys/Quantitative Imaging; Universiteit van Amsterdam) Date 2017 Abstract Purpose: Simulating low-dose Computed Tomography (CT) facilitates in-silico studies into the required dose for a diagnostic task. Conventionally, low-‐dose CT images are created by adding noise to the projection data. However, in practice the raw data is often simply not available. This paper presents a new method for simulating patient-‐specific, low-dose CT images without the needof the original projection data. Methods: The low-dose CT simulation method included the following: (1) computation of a virtual sinogram from a high dose CT image through aradon transform; (2) simulation of a 'reduced'‐dose sinogram with appropriateamounts of noise; (3) subtraction of the high-‐dose virtual sinogram from thereduced-‐dose sinogram; (4) reconstruction of a noise volume via filtered back-projection; (5) addition of the noise image to the original high-dose image. Therequired scanner-Specific parameters, such as the apodization window, bowtiefilter, the X-ray tube output parameter (reflecting the photon flux) and the detector read-out noise, were retrieved from calibration images of a watercylinder. The low-‐dose simulation method was evaluated by comparing thenoise characteristics in simulated images with experimentally acquireddata.Results:The models used to recover the scanner-specific parameters fitted accurately tothe calibration data, and the values of the parameters were comparable to valuesreported in literature. Finally, the simulated low-dose images accurately reproduced the noise characteristics in experimentally acquired low-dose‐volumes.Conclusion:The developed methods truthfully simulate low-dose CT imaging for a specificscanner and reconstruction using filtered backprojection. The scanner-‐specificparameters can be estimated from calibration data. Subject Filtered back projectionNoise power spectrumBowtie filterRead-out noiseSinogram To reference this document use: http://resolver.tudelft.nl/uuid:b47856e9-b34c-4a39-99a8-cbd5d2210f75 DOI https://doi.org/10.1016/j.ejmp.2017.02.009 Embargo date 2018-03-14 ISSN 1120-1797 Source Physica Medica: an international journal devoted to the applications of physics to medicine and biology, 36, 12-23 Bibliographical note Accepted Author Manuscript Part of collection Institutional Repository Document type journal article Rights © 2017 R.E. Naziroglu, V.F. van Ravesteijn, L.J. van Vliet, G.J. Streekstra, F.M. Vos Files PDF Low_Dose_CT_Physica_Medic ... terial.pdf 5.85 MB Close viewer /islandora/object/uuid:b47856e9-b34c-4a39-99a8-cbd5d2210f75/datastream/OBJ/view