Dr. rer. nat. Martin Möddel (Hofmann)

Universitätsklinikum Hamburg-Eppendorf (UKE)
Sektion für Biomedizinische Bildgebung
Lottestraße 55
2ter Stock, Raum 212
22529 Hamburg
- Postanschrift -

Technische Universität Hamburg (TUHH)
Institut für Biomedizinische Bildgebung
Gebäude E, Raum 4.044
Am Schwarzenberg-Campus 3
21073 Hamburg

Tel.: 040 / 7410 56309
E-Mail: martin.moeddel(at)tuhh.de
E-Mail: m.hofmann(at)uke.de
ORCID: https://orcid.org/0000-0002-4737-7863

Research Interests

My research on tomographic imaging is primarily focused on magnetic particle imaging. In this context, I am engaged in the study of a number of problems, including:

  • Image reconstruction
    • Multi-contrast imaging
    • Multi-patch imaging
    • Artifact reduction
  • Magnetic field generation and characterisation
  • Receive path calibration

Curriculum Vitae

Martin Möddel is a postdoctoral researcher in the group of Tobias Knopp for experimental Biomedical Imaging at the University Medical Center Hamburg-Eppendorf and the Hamburg University of Technology. He received his PhD in physics from the Universität Siegen in 2014 on the topic of characterizing quantum correlations: the genuine multiparticle negativity as entanglement monotone. Prior to his PhD, he studied physics at the Universität Leipzig between 2005 and 2011, where he received his Diplom On the costratified Hilbert space structure of a lattice gauge model with semi-simple gauge group.

Journal Publications

[191156]
Title: Sparse Kaczmarz for Convergence Speed-up in Multi-Contrast Magnetic Particle Imaging.
Written by: L. Nawwas, M. Möddel, and T. Knopp
in: <em>2024 IEEE International Symposium on Biomedical Imaging (ISBI)</em>. May (2024).
Volume: Number: (1-4),
on pages: 1-4
Chapter:
Editor:
Publisher: IEEE:
Series:
Address:
Edition:
ISBN: 979-8-3503-1333-8
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/ISBI56570.2024.10635342
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings, multi-contrast

Abstract: Magnetic Particle Imaging (MPI) is a tracer-based medical imaging modality with great potential due to its high sensitivity, high spatio-temporal resolution, and capability to quantify the tracer distribution. Image reconstruction in MPI is an ill-posed problem, which regularization methods can address. In MPI, Tikhonov regularization is most commonly used and the corresponding optimization problem is usually solved using the Kaczmarz algorithm. Reconstruction using the Kaczmarz method for single-contrast MPI is very efficient as it produces the desired images fast after a small number of iterations. For multi-contrast MPI, however, the regular Kaczmarz algorithm fails to obtain good-quality images without channel leakage when using a small number of iterations. In this work, we propose a sparsity-promoting regularization term and an associated sparse Kaczmarz method in order to speed up convergence, especially in sparse channels. The proposed method reduces the channel leakage and as a result, speeds up convergence.

[191156]
Title: Sparse Kaczmarz for Convergence Speed-up in Multi-Contrast Magnetic Particle Imaging.
Written by: L. Nawwas, M. Möddel, and T. Knopp
in: <em>2024 IEEE International Symposium on Biomedical Imaging (ISBI)</em>. May (2024).
Volume: Number: (1-4),
on pages: 1-4
Chapter:
Editor:
Publisher: IEEE:
Series:
Address:
Edition:
ISBN: 979-8-3503-1333-8
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/ISBI56570.2024.10635342
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings, multi-contrast

Abstract: Magnetic Particle Imaging (MPI) is a tracer-based medical imaging modality with great potential due to its high sensitivity, high spatio-temporal resolution, and capability to quantify the tracer distribution. Image reconstruction in MPI is an ill-posed problem, which regularization methods can address. In MPI, Tikhonov regularization is most commonly used and the corresponding optimization problem is usually solved using the Kaczmarz algorithm. Reconstruction using the Kaczmarz method for single-contrast MPI is very efficient as it produces the desired images fast after a small number of iterations. For multi-contrast MPI, however, the regular Kaczmarz algorithm fails to obtain good-quality images without channel leakage when using a small number of iterations. In this work, we propose a sparsity-promoting regularization term and an associated sparse Kaczmarz method in order to speed up convergence, especially in sparse channels. The proposed method reduces the channel leakage and as a result, speeds up convergence.

Conference Proceedings

[191156]
Title: Sparse Kaczmarz for Convergence Speed-up in Multi-Contrast Magnetic Particle Imaging.
Written by: L. Nawwas, M. Möddel, and T. Knopp
in: <em>2024 IEEE International Symposium on Biomedical Imaging (ISBI)</em>. May (2024).
Volume: Number: (1-4),
on pages: 1-4
Chapter:
Editor:
Publisher: IEEE:
Series:
Address:
Edition:
ISBN: 979-8-3503-1333-8
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/ISBI56570.2024.10635342
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings, multi-contrast

Abstract: Magnetic Particle Imaging (MPI) is a tracer-based medical imaging modality with great potential due to its high sensitivity, high spatio-temporal resolution, and capability to quantify the tracer distribution. Image reconstruction in MPI is an ill-posed problem, which regularization methods can address. In MPI, Tikhonov regularization is most commonly used and the corresponding optimization problem is usually solved using the Kaczmarz algorithm. Reconstruction using the Kaczmarz method for single-contrast MPI is very efficient as it produces the desired images fast after a small number of iterations. For multi-contrast MPI, however, the regular Kaczmarz algorithm fails to obtain good-quality images without channel leakage when using a small number of iterations. In this work, we propose a sparsity-promoting regularization term and an associated sparse Kaczmarz method in order to speed up convergence, especially in sparse channels. The proposed method reduces the channel leakage and as a result, speeds up convergence.

[191156]
Title: Sparse Kaczmarz for Convergence Speed-up in Multi-Contrast Magnetic Particle Imaging.
Written by: L. Nawwas, M. Möddel, and T. Knopp
in: <em>2024 IEEE International Symposium on Biomedical Imaging (ISBI)</em>. May (2024).
Volume: Number: (1-4),
on pages: 1-4
Chapter:
Editor:
Publisher: IEEE:
Series:
Address:
Edition:
ISBN: 979-8-3503-1333-8
how published:
Organization:
School:
Institution:
Type:
DOI: 10.1109/ISBI56570.2024.10635342
URL:
ARXIVID:
PMID:

[BibTex]

Note: inproceedings, multi-contrast

Abstract: Magnetic Particle Imaging (MPI) is a tracer-based medical imaging modality with great potential due to its high sensitivity, high spatio-temporal resolution, and capability to quantify the tracer distribution. Image reconstruction in MPI is an ill-posed problem, which regularization methods can address. In MPI, Tikhonov regularization is most commonly used and the corresponding optimization problem is usually solved using the Kaczmarz algorithm. Reconstruction using the Kaczmarz method for single-contrast MPI is very efficient as it produces the desired images fast after a small number of iterations. For multi-contrast MPI, however, the regular Kaczmarz algorithm fails to obtain good-quality images without channel leakage when using a small number of iterations. In this work, we propose a sparsity-promoting regularization term and an associated sparse Kaczmarz method in order to speed up convergence, especially in sparse channels. The proposed method reduces the channel leakage and as a result, speeds up convergence.