Lina Nawwas, M.Sc.

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: l.nawwas(at)uke.de
E-Mail: lina.nawwas(at)tuhh.de

Research Interests

  • Magnetic Particle Imaging
  • Image Reconstruction

Curriculum Vitae

Lina Nawwas is a PhD student in the group of Tobias Knopp for experimental Biomedical Imaging at the University Medical Center Hamburg-Eppendorf and the Hamburg University of Technology. In 2016 she earned a Bachelor's degree in Mathematics from An Najah National University in Palestine. From 2016 to 2018 she pursued her Master's degree in Applied Mathematics, majoring Mathematical Modeling for Engineering with MathMods Erasmus Mundus Program in three European universities: University of L’Aquila in Italy, University of Hamburg in Germany, and Gdańsk University of Technology in Poland.

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.

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.