Browsing by Author "Hansen, Christian"

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    2.5D Thermometry Maps for MRI-guided Tumor Ablation
    (Otto-von-Guericke-Universität Magdeburg, 2021) Alpers, Julian; Reimert, Daniel; Rötzer, Maximilian; Gerlach, Thomas; Gutberlet, Marcel; Wacker, Frank; Hensen, Bennet; Hansen, Christian
    Fast and reliable monitoring of volumetric heat distribution during MRI-guided tumor ablation is an urgent clinical need. In this work, we introduce a method for generating 2.5D thermometry maps from uniformly distributed 2D MRI phase images rotated around the applicator’s main axis. The images can be fetched directly from the MR device, reducing the delay between image acquisition and visualization. For reconstruction, we use a weighted interpolation on a cylindric coordinate representation to calculate the heat value of voxels in a region of interest. A pilot study on 13 ex vivo bio protein phantoms with flexible tubes to simulate a heat sink effect was conducted to evaluate our method. After thermal ablation, we compared the measured coagulation zone extracted from the post-treatment MR data set with the output of the 2.5D thermometry map. The results show a mean Dice score of 0.75±0.07, a sensitivity of 0.77±0.03, and a reconstruction time within18.02ms±5.91ms. Future steps should address improving temporal resolution and accuracy, e.g., incorporating advanced bioheat transfer simulations.
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    2D MRI liver slices with navigator frames. A test data set for image based 4D MRI reconstruction
    (Otto-von-Guericke-Universität Magdeburg, 2019) Gulamhussene, Gino; Joeres, Fabian; Rak, Marko; Lübeck, Cindy; Pech, Maciej; Hansen, Christian
    This data contains 2D MRI slices of the abdomens of 13 healthy subjects and corresponding navigator slices as basis to reconstruct 4D MRIs of the breathing motion of the subjects abdomen. Contained is a total of 19 data sets.
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    2D MRI liver slices with navigator frames. A training and test data set for image based 4D MRI reconstruction. (Part II)
    (Otto-von-Guericke-Universität Magdeburg, 2021) Gulamhussene, Gino; Meyer, Anneke; Rak, Marko; Lübeck, Cindy; Omari, Jazan; Pech, Maciej; Hansen, Christian
    This data contains fully anonymized MRI data of the abdomens of 20 healthy subjects as basis to reconstruct 4D MRIs of the breathing motion of the subjects’ abdomen. This data publication uses the same protocol and is a continuation (part 2) of the data publication “2D MRI liver slices with navigator frames. A test data set for image based 4D MRI reconstruction” (https://doi.org/10.24352/UB.OVGU-2019-093)