PhD thesis submitted

My PhD thesis has been submitted on April 6 and graded as excellent (grade 1).

Title of thesis: Concept-Based and Multimodal Methods for Medical Case Retrieval

Abstract:
Medical case retrieval (MCR) is defined as a multimedia retrieval problem, where the document collection consists of medical case descriptions that pertain to particular diseases, patients’ histories, or other entities of biomedical knowledge. Case descriptions are multimedia documents containing textual and visual modalities (images). A query may consist of a textual description of patient’s symptoms and related diagnostic images. This thesis proposes and evaluates methods that aim at improving MCR effectiveness over the baseline of fulltext retrieval. We hypothesize that this objective can be achieved by utilizing controlled vocabularies of biomedical concepts for query expansion and concept-based retrieval. The latter represents case descriptions and queries as vectors of biomedical concepts, which may be generated automatically from textual and/or visual modalities by concept mapping algorithms. We propose a multimodal retrieval framework for MCR by late fusion of text-based retrieval (including query expansion) and concept-based retrieval and show that retrieval effectiveness can be improved by 49% using linear fusion of practical component retrieval systems. The potential of further improvement is experimentally estimated as a 166% increase of effectiveness over fulltext retrieval using query-adaptive fusion of ideal component retrieval systems. Additional contributions of this thesis include the proposal and comparative evaluation of methods for concept mapping, query and document expansion, and automatic classification and separation of compound figures found in case descriptions.

Keywords: multimedia information retrieval / biomedical information retrieval / biomedical concept detection / information fusion / image processing

Bibtex citation:

@PhdThesis{Taschwer2017,
Title                    = {Concept-Based and Multimodal Methods for Medical Case Retrieval},
Author                   = {Taschwer, Mario W.},
School                   = {Alpen-Adria-Universit{\"a}t Klagenfurt},
Year                     = {2017},
Address                  = {Austria},
Month                    = mar,
Url                      = {http://www.itec.aau.at/bib/files/phd-thesis-taschwer.pdf}
}