dc.contributor.advisor | Frahm, Jens Prof. Dr. | |
dc.contributor.author | Klosowski, Jakob | |
dc.date.accessioned | 2020-10-28T12:27:45Z | |
dc.date.available | 2020-10-28T12:27:45Z | |
dc.date.issued | 2020-10-28 | |
dc.identifier.uri | http://hdl.handle.net/21.11130/00-1735-0000-0005-14CA-1 | |
dc.identifier.uri | http://dx.doi.org/10.53846/goediss-8258 | |
dc.language.iso | eng | de |
dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
dc.subject.ddc | 610 | de |
dc.title | On the Use of Temporal Information for the Reconstruction of Magnetic Resonance Image Series | de |
dc.type | doctoralThesis | de |
dc.contributor.referee | Frahm, Jens Prof. Dr. | |
dc.date.examination | 2020-02-26 | |
dc.description.abstracteng | Standard clinical magnetic resonance imaging uses data sampled at the Nyquist
rate which limits it to frame rates of 1-4 frames per second. Over the past decade
different methods for the reconstruction of images from sub-Nyquist sampled
data have been proposed, raising frame rates beyond 30 frames per second and
opening the door to real-time cardiac imaging, the study of speech and many
more. Practically all such methods exploit spatio-temporal structure in the data
as prior knowledge to an inverse problem.
This work combines the method of non-linear inversion reconstruction and motion estimation by an optical flow, a model for in-plane motion that is frequently
used in computer vision tasks. The model is quantitatively compared against simpler methods based on temporal finite difference schemes in simulations and real
cardiac data.
Adding an optical flow constraint to the reconstruction’s cost functional is shown
to be advantageous in situations with purely in-plane motion while failure of the
model is observed in the form of artifacts and blur during through-plane motion.
A point that got little attention in related literature. The model’s limits are examined in detail and pointers to possible extensions to overcome them are given. Further, a simple centered finite temporal difference constraint for a batch of frames
is shown to provide better image quality than a previously established scheme
that considers only the backward temporal difference at a single frame.
As in previous works, non-linear inversion reconstruction considers at most a
small batch of frames for every time point. The method does not require availability of the entire image data series at any point during computation. It is thus conceptually capable of providing images in real-time simultaneously with the data
acquisition, a prerequisite for interactive MRI. | de |
dc.contributor.coReferee | Enderlein, Jörg Prof. Dr. | |
dc.contributor.thirdReferee | Grubmüller, Helmut Prof. Dr. | |
dc.subject.eng | Real-time Magnetic Resonance Imaging | de |
dc.subject.eng | Cardiac Imaging | de |
dc.subject.eng | Inverse Problems | de |
dc.subject.eng | Optical Flow | de |
dc.identifier.urn | urn:nbn:de:gbv:7-21.11130/00-1735-0000-0005-14CA-1-2 | |
dc.affiliation.institute | Göttinger Graduiertenschule für Neurowissenschaften, Biophysik und molekulare Biowissenschaften (GGNB) | de |
dc.subject.gokfull | Biologie (PPN619462639) | de |
dc.identifier.ppn | 1737335611 | |