@article{MTMT:33212860,
	title = {Direct dynamic tomographic reconstruction without explicit blood input function},
	url = {https://m2.mtmt.hu/api/publication/33212860},
	author = {Szirmay-Kalos, László and Magdics, Milán and Varnyú, Dóra},
	doi = {10.1016/j.bspc.2022.104313},
	journal-iso = {BIOMED SIGNAL PROCES},
	journal = {BIOMEDICAL SIGNAL PROCESSING AND CONTROL},
	volume = {80},
	unique-id = {33212860},
	issn = {1746-8094},
	abstract = {With dynamic positron emission tomography (PET), we study the metabolic processes by monitoring the uptake of a radioactive tracer. The goal is to reconstruct the time-activity curves (TACs) of the voxels, from which the relevant kinetic parameters can be obtained. These curves are assumed to have the algebraic form of a pre-determined kinetic model. Plausible algebraic forms have a limited number of free parameters and thus can be used even for low-statistic measurements. The kinetic model typically involves the amount of radiotracer in the blood, which should be determined either by direct measurement or by extracting it from the PET data using image-derived or model-based methods. However, the direct measurement of the blood concentration is complicated, and the results of the image-derived and the model-based methods are also not reliable because of the partial volume effect and the unknown fraction of blood in the voxels. Moreover, in direct dynamic tomography, the kinetic model is fit from the very beginning of the reconstruction, thus the blood input function is needed even before the image-derived or model-based approaches can provide it. In this paper, we propose a method that is based on compartmental modeling and the Feng blood input function model defined by a fourth-order exponential equation with a pair of repeated eigenvalues, but does not require the blood input function and the fraction of blood parameters explicitly. Thus, the model can be used in cases when we wish to have the robustness and advantages of compartmental modeling, but no blood input function measurement is available. The test results show that the added error in the TACs of not knowing the blood input is reduced in comparison with the spline-based TAC representation. The method can be applied in reference tissue analysis and in image-derived input function approaches.},
	year = {2023},
	eissn = {1746-8108},
	orcid-numbers = {Szirmay-Kalos, László/0000-0002-8523-2315; Magdics, Milán/0000-0003-4298-1022; Varnyú, Dóra/0000-0002-9220-5868}
}

@{MTMT:33551047,
	title = {CT-based training data generation for DL-based X-ray image processing},
	url = {https://m2.mtmt.hu/api/publication/33551047},
	author = {Magdics, Milán and Tóth, Márton József},
	booktitle = {X. Magyar Számítógépes Grafika és Geometria Konferencia},
	unique-id = {33551047},
	year = {2022},
	pages = {72-79},
	orcid-numbers = {Magdics, Milán/0000-0003-4298-1022}
}

@inproceedings{MTMT:32617907,
	title = {Direct Tomographic Reconstruction without Explicit Blood Input Function},
	url = {https://m2.mtmt.hu/api/publication/32617907},
	author = {Magdics, Milán and Szirmay-Kalos, László and Varnyú, Dóra},
	booktitle = {Proceedings of the Workshop on the Advances in Information Technology 2022},
	unique-id = {32617907},
	year = {2022},
	pages = {91-98},
	orcid-numbers = {Magdics, Milán/0000-0003-4298-1022; Szirmay-Kalos, László/0000-0002-8523-2315; Varnyú, Dóra/0000-0002-9220-5868}
}

@article{MTMT:32182418,
	title = {Adapting Game Engines to Curved Spaces},
	url = {https://m2.mtmt.hu/api/publication/32182418},
	author = {Szirmay-Kalos, László and Magdics, Milán},
	doi = {10.1007/s00371-021-02303-2},
	journal-iso = {VISUAL COMPUT},
	journal = {VISUAL COMPUTER},
	volume = {38},
	unique-id = {32182418},
	issn = {0178-2789},
	year = {2022},
	eissn = {1432-2315},
	pages = {4383-4395},
	orcid-numbers = {Szirmay-Kalos, László/0000-0002-8523-2315; Magdics, Milán/0000-0003-4298-1022}
}

@article{MTMT:31836579,
	title = {Robust Compartmental Model Fitting in Direct Emission Tomography Reconstruction},
	url = {https://m2.mtmt.hu/api/publication/31836579},
	author = {Szirmay-Kalos, László and Kacsó, Ágota Enikő and Magdics, Milán and Tóth, Balázs György},
	doi = {10.1007/s00371-020-02041-x},
	journal-iso = {VISUAL COMPUT},
	journal = {VISUAL COMPUTER},
	volume = {38},
	unique-id = {31836579},
	issn = {0178-2789},
	abstract = {Dynamic tomography reconstructs a time activity curve (TAC) for every voxel assuming that the algebraic form of the function is known a priori. The algebraic form derived from the analysis of compartmental models depends nonlinearly on the nonnegative parameters to be determined. Direct methods apply fitting in every iteration step. Because of the iterative nature of the maximum likelihood–expectation maximization (ML–EM) reconstruction, the fitting result of the previous step can serve as a good starting point in the current step; thus, after the first iteration we have a guess that is not far from the solution, which allows the use of gradient-based local optimization methods. However, finding good initial guesses for the first ML–EM iteration is a critical problem since gradient-based local optimization algorithms do not guarantee convergence to the global optimum if they are started at an inappropriate location. This paper examines the robust solution of the fitting problem both in the initial phase and during the ML–EM iteration. This solution is implemented on GPUs and is built into the 4D reconstruction module of the TeraTomo software.},
	year = {2022},
	eissn = {1432-2315},
	pages = {655-668},
	orcid-numbers = {Szirmay-Kalos, László/0000-0002-8523-2315; Magdics, Milán/0000-0003-4298-1022}
}

@inproceedings{MTMT:32070152,
	title = {Gaming in Elliptic Geometry},
	url = {https://m2.mtmt.hu/api/publication/32070152},
	author = {Szirmay-Kalos, László and Magdics, Milán},
	booktitle = {42nd Annual Conference of the European Association for Computer Graphics: Eurographics 2021: Short Papers},
	doi = {10.2312/egs.20211010},
	unique-id = {32070152},
	year = {2021},
	pages = {5-8},
	orcid-numbers = {Szirmay-Kalos, László/0000-0002-8523-2315; Magdics, Milán/0000-0003-4298-1022}
}

@inproceedings{MTMT:31836817,
	title = {Euclidean to non-Euclidean Transformation of Games},
	url = {https://m2.mtmt.hu/api/publication/31836817},
	author = {Szirmay-Kalos, László and Magdics, Milán},
	booktitle = {Proceedings of the Workshop on the Advances of Information Technology (WAIT) 2021},
	unique-id = {31836817},
	year = {2021},
	pages = {39-46},
	orcid-numbers = {Szirmay-Kalos, László/0000-0002-8523-2315; Magdics, Milán/0000-0003-4298-1022}
}

@inbook{MTMT:32252580,
	title = {Modeling of Depth of Interaction with Inter-crystal Scattering for PET Reconstruction},
	url = {https://m2.mtmt.hu/api/publication/32252580},
	author = {Szirmay-Kalos, László and Varnyú, Dóra and Magdics, Milán and Tóth, Balázs György},
	booktitle = {2020 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC)},
	doi = {10.1109/NSS/MIC42677.2020.9507795},
	unique-id = {32252580},
	year = {2020},
	pages = {1-6},
	orcid-numbers = {Szirmay-Kalos, László/0000-0002-8523-2315; Varnyú, Dóra/0000-0002-9220-5868; Magdics, Milán/0000-0003-4298-1022}
}

@inproceedings{MTMT:31310772,
	title = {Depth of Interaction Modeling for PET},
	url = {https://m2.mtmt.hu/api/publication/31310772},
	author = {Magdics, Milán and Szirmay-Kalos, László and Tóth, Balázs György and Szécsi, László},
	booktitle = {Proceedings of the Workshop on the Advances of Information Technology 2020 : WAIT 2020},
	unique-id = {31310772},
	year = {2020},
	pages = {79-88},
	orcid-numbers = {Magdics, Milán/0000-0003-4298-1022; Szirmay-Kalos, László/0000-0002-8523-2315}
}

@inproceedings{MTMT:31166177,
	title = {Advances in the visualization framework for vehicle intelligence simulations},
	url = {https://m2.mtmt.hu/api/publication/31166177},
	author = {Tóth, Márton József and Kacsó, Ágota Enikő and Magdics, Milán and Salvi, Péter},
	booktitle = {Proceedings of the Workshop on the Advances of Information Technology 2020 : WAIT 2020},
	unique-id = {31166177},
	year = {2020},
	pages = {1-4},
	orcid-numbers = {Magdics, Milán/0000-0003-4298-1022}
}