% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @PHDTHESIS{Schneider:794608, author = {Schneider, Hannah Sophia}, othercontributors = {Schrading, Simone and Najjari, Laila}, title = {{R}adiomics in der {M}amma {MRT}: {K}lassifikation kontrastmittelaufnehmender {L}äsionen nach ihrer {D}ignität mittels zweier klassischer {M}achine {L}earning {A}lgorithmen}, school = {Rheinisch-Westfälische Technische Hochschule Aachen}, type = {Dissertation}, address = {Aachen}, reportid = {RWTH-2020-07774}, pages = {1 Online-Ressource (IV, 66 Seiten) : Illustrationen, Diagramme}, year = {2020}, note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen University; Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2020}, abstract = {In this doctoral thesis, the application of radiomic algorithms in Mamma MRI for classification of contrast-enhancing lesions is depicted. 1294 lesions out of 447 breast MRI examinations were manually segmented and 562 image features were extracted in total. These included shape, statistical and texture features from routinely acquired MRI sequences. Either histopathological analysis or a 2-year follow-up were used as target values, and for comparison with a radiological expert, lesions were grouped into BI-RADS® categories according to their prospective diagnostic reports. Correlation of the extracted features and the corresponding target values was performed by training and validation of two conventional radiomic algorithms - L1-Regularization and Principal Component Analysis. Though classification results were clinically acceptable (sensitivity $72\%$ and $68\%,$ specificity $76\%$ and $75\%,$ AUC 0,81 and 0,78 respectively), those by the radiologist experts were still superior (sensitivity $100\%,$ specificity $86\%,$ AUC 0,98). A second evaluation on a half-size data set resulted in no deterioration of classificator performance, leading to the conclusion, that an increase in sample size would lead to no improvement by means of a learning system. Considering the selected feature (the so-called radiomic signature), especially features describing shape or intratumoral heterogeneity of contrast enhancement were significant for differentiation of benign vs. malignant lesions. Clinical applications of radiomic algorithms as computer-assisted diagnostic systems might improve diagnostic performance of breast MRI, leading to an increased number of examinations and even an implementation in screening programs. Subsequently, an earlier and better detection of conventionally occult tumors would be possible. Moreover, correlation of image features with tumor-specific parameters, i.e. immunohistochemistry or molecular genetics like the proliferation marker Ki-67 or the OnkotypeDX® Score, might make a future use of image biomarkers as complementary biomarker in precision medicine, for an improved planning of biopsies by depiction of intratumoral heterogeneity or even as virtual biopsies possible. In addition, an improved follow-up of neoadjuvant chemotherapy or adjuvant radiotherapy is conceivable. Until radiomic algorithms can be of clinical use, further development is necessary with promising first results of studies using deep or transfer learning algorithms.}, cin = {532010-2}, ddc = {610}, cid = {$I:(DE-82)532010-2_20140620$}, typ = {PUB:(DE-HGF)11}, doi = {10.18154/RWTH-2020-07774}, url = {https://publications.rwth-aachen.de/record/794608}, }