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dc.contributor.authorAhishakiye, Emmanuel
dc.contributor.authorBastiaan Van Gijzen, Martin
dc.contributor.authorTumwiine, Julius
dc.contributor.authorObungoloch, Johnes
dc.date.accessioned2021-04-02T14:18:30Z
dc.date.available2021-04-02T14:18:30Z
dc.date.issued2020
dc.identifier.citationAhishakiye, E., Van Gijzen, M. B., Tumwiine, J., & Obungoloch, J. (2020). Adaptive-size dictionary learning using information theoretic criteria for image reconstruction from undersampled k-space data in low field magnetic resonance imaging. BMC Medical Imaging, 20(1), 1-12.en_US
dc.identifier.urihttp://ir.must.ac.ug/xmlui/handle/123456789/594
dc.description.abstractBackground: Magnetic resonance imaging (MRI) is a safe non-invasive and nonionizing medical imaging modality that is used to visualize the structure of human anatomy. Conventional (high-field) MRI scanners are very expensive to purchase, operate and maintain, which limit their use in many developing countries. This study is part of a project that aims at addressing these challenges and is carried out by teams from Mbarara University of Science and Technology (MUST) in Uganda, Leiden University Medical Center (LUMC) in the Netherlands, Delft University of Technology (TU Delft) in the Netherlands and Pennsylvania State University (PSU) in the USA. These are working on developing affordable, portable and low-field MRI scanners to diagnose children in developing countries with hydrocephalus. The challenges faced by the teams are that the low-field MRI scanners currently under development are characterized by low Signal-to-Noise Ratio (SNR), and long scan times. Methods: We propose an algorithm called adaptive-size dictionary learning algorithm (AS-DLMRI) that integrates information-theoretic criteria (ITC) and Dictionary learning approaches. The result of the integration is an adaptivesize dictionary that is optimal for any input signal. AS-DLMRI may help to reduce the scan time and improve the SNR of the generated images, thereby improving the image quality. Results: We compared our proposed algorithm AS-DLMRI with adaptive patch-based algorithm known as DLMRI and non-adaptive CSMRI technique known as LDP. DLMRI and LDP have been used as the baseline algorithms in other related studies. The results of AS-DLMRI are consistently slightly better in terms of PSNR, SNR and HFEN than for DLMRI, and are significantly better than for LDP. Moreover, AS-DLMRI is faster than DLMRI. Conclusion: Using a dictionary size that is appropriate to the input data could reduce the computational complexity, and also the construction quality since only dictionary atoms that are relevant to the task are included in the dictionary and are used during the reconstruction. However, AS-DLMRI did not completely remove noise during the experiments with the noisy phantom. Our next step in our research is to integrate our proposed algorithm with an image denoising function.en_US
dc.description.sponsorshipDutch organization NWOWOTRO Granten_US
dc.publisherBMC Medical Imagingen_US
dc.subjectCompressed sensingen_US
dc.subjectDictionary learningen_US
dc.subjectImage reconstructionen_US
dc.subjectInformation-theoretic criteriaen_US
dc.subjectLow-field MRIen_US
dc.titleAdaptive-size dictionary learning using information theoretic criteria for image reconstruction from undersampled k-space data in low field magnetic resonance imagingen_US
dc.typeArticleen_US


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