@article{UeceylerHomolaGonzalezetal.2014,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Homola, Gy{\"o}rgy A. and Gonz{\´a}lez, Hans Guerrero and Kramer, Daniela and Wanner, Christoph and Weidemann, Frank and Solymosi, L{\´a}szl{\´o} and Sommer, Claudia},
  title     = {Increased Arterial Diameters in the Posterior Cerebral Circulation in Men with Fabry Disease},
  doi       = {10.1371/journal.pone.0087054},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112614},
  year      = {2014},
  abstract  = {A high load of white matter lesions and enlarged basilar arteries have been shown in selected patients with Fabry disease, a disorder associated with an increased stroke risk. We studied a large cohort of patients with Fabry disease to differentially investigate white matter lesion load and cerebral artery diameters. We retrospectively analyzed cranial magnetic resonance imaging scans of 87 consecutive Fabry patients, 20 patients with ischemic stroke, and 36 controls. We determined the white matter lesion load applying the Fazekas score on fluid-attenuated inversion recovery sequences and measured the diameters of cerebral arteries on 3D-reconstructions of the time-of-flight-MR-angiography scans. Data of different Fabry patient subgroups (males - females; normal - impaired renal function) were compared with data of patients with stroke and controls. A history of stroke or transient ischemic attacks was present in 4/30 males (13\%) and 5/57 (9\%) females with Fabry disease, all in the anterior circulation. Only one man with Fabry disease showed confluent cerebral white matter lesions in the Fazekas score assessment (1\%). Male Fabry patients had a larger basilar artery (p<0.01) and posterior cerebral artery diameter (p<0.05) compared to male controls. This was independent of disease severity as measured by renal function and did not lead to changes in arterial blood flow properties. A basilar artery diameter of >3.2 mm distinguished between men with Fabry disease and controls (sensitivity: 87\%, specificity: 86\%, p<0.001), but not from stroke patients. Enlarged arterial diameters of the posterior circulation are present only in men with Fabry disease independent of disease severity.},
  language  = {en}
}
@article{ZhouDierksKertelsetal.2020,
  author    = {Zhou, Xiang and Dierks, Alexander and Kertels, Olivia and Samnick, Samuel and Kircher, Malte and Buck, Andreas K. and Haertle, Larissa and Knorz, Sebastian and B{\"o}ckle, David and Scheller, Lukas and Messerschmidt, Janin and Barakat, Mohammad and Truger, Marietta and Haferlach, Claudia and Einsele, Hermann and Rasche, Leo and Kort{\"u}m, K. Martin and Lapa, Constantin},
  title     = {The link between cytogenetics/genomics and imaging patterns of relapse and progression in patients with relapsed/refractory multiple myeloma: a pilot study utilizing 18F-FDG PET/CT},
  series = {Cancers},
  volume    = {12},
  journal   = {Cancers},
  number    = {9},
  issn      = {2072-6694},
  doi       = {10.3390/cancers12092399},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211157},
  year      = {2020},
  abstract  = {Utilizing 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT), we performed this pilot study to evaluate the link between cytogenetic/genomic markers and imaging patterns in relapsed/refractory (RR) multiple myeloma (MM). We retrospectively analyzed data of 24 patients with RRMM who were treated at our institution between November 2018 and February 2020. At the last relapse/progression, patients had been treated with a median of three (range 1-10) lines of therapy. Six (25\%) patients showed FDG avid extramedullary disease without adjacency to bone. We observed significantly higher maximum standardized uptake values (SUV\(_{max}\)) in patients harboring del(17p) compared with those without del(17p) (p = 0.025). Moreover, a high SUV\(_{max}\) of >15 indicated significantly shortened progression-free survival (PFS) (p = 0.01) and overall survival (OS) (p = 0.0002). One female patient exhibited biallelic TP53 alteration, i.e., deletion and mutation, in whom an extremely high SUV\(_{max}\) of 37.88 was observed. In summary, this pilot study suggested a link between del(17p)/TP53 alteration and high SUV\(_{max}\) on 18F-FDG PET/CT in RRMM patients. Further investigations are highly warranted at this point.},
  language  = {en}
}
@article{ZhouDierksKertelsetal.2020,
  author    = {Zhou, Xiang and Dierks, Alexander and Kertels, Olivia and Kircher, Malte and Schirbel, Andreas and Samnick, Samuel and Buck, Andreas K. and Knorz, Sebastian and B{\"o}ckle, David and Scheller, Lukas and Messerschmidt, Janin and Barakat, Mohammad and Kort{\"u}m, K. Martin and Rasche, Leo and Einsele, Hermann and Lapa, Constantin},
  title     = {18F-FDG, 11C-Methionine, and 68Ga-Pentixafor PET/CT in patients with smoldering multiple myeloma: imaging pattern and clinical features},
  series = {Cancers},
  volume    = {12},
  journal   = {Cancers},
  number    = {8},
  issn      = {2072-6694},
  doi       = {10.3390/cancers12082333},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211240},
  year      = {2020},
  abstract  = {This study aimed to explore the correlation between imaging patterns and clinical features in patients with smoldering multiple myeloma (SMM) who simultaneously underwent 18F-FDG, 11C-Methionine, and 68Ga-Pentixafor positron emission tomography/computed tomography (PET/CT). We retrieved and analyzed clinical characteristics and PET imaging data of 10 patients with SMM. We found a significant correlation between bone marrow (BM) plasma cell (PC) infiltration and mean standardized uptake values (SUV\(_{mean}\)) of lumbar vertebrae L2-L4 on 11C-Methionine PET/CT scans (r = 0.676, p = 0.031) and 68Ga-Pentixafor PET/CT scans (r = 0.839, p = 0.002). However, there was no significant correlation between BM involvement and SUV\(_{mean}\) of lumbar vertebrae L2-L4 on 18F-FDG PET/CT scans (r = 0.558, p = 0.093). Similarly, mean target-to-background ratios (TBR\(_{mean}\)) of lumbar vertebrae L2-L4 also correlated with bone marrow plasma cell (BMPC) infiltration in 11C-Methionine PET/CT (r = 0.789, p = 0.007) and 68Ga-Pentixafor PET/CT (r = 0.724, p = 0.018) PET/CT. In contrast, we did not observe a significant correlation between BMPC infiltration rate and TBR\(_{mean}\) in 18F-FDG PET/CT (r = 0.355, p = 0.313). Additionally, on 11C-Methionine PET/CT scans, we found a significant correlation between BMPC infiltration and TBR\(_{max}\) of lumbar vertebrae L2-L4 (r = 0.642, p = 0.045). In conclusion, 11C-Methionine and 68Ga-Pentixafor PET/CT demonstrate higher sensitivity than 18F-FDG PET/CT in detecting BM involvement in SMM.},
  language  = {en}
}
@article{ZellerMuellerGutberletetal.2013,
  author    = {Zeller, Mario and M{\"u}ller, Alexander and Gutberlet, Marcel and Nichols, Thomas and Hahn, Dietbert and K{\"o}stler, Herbert and Bartsch, Andreas J.},
  title     = {Boosting BOLD fMRI by K-Space Density Weighted Echo Planar Imaging},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0074501},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97233},
  year      = {2013},
  abstract  = {Functional magnetic resonance imaging (fMRI) has become a powerful and influential method to non-invasively study neuronal brain activity. For this purpose, the blood oxygenation level-dependent (BOLD) effect is most widely used. T2* weighted echo planar imaging (EPI) is BOLD sensitive and the prevailing fMRI acquisition technique. Here, we present an alternative to its standard Cartesian recordings, i.e. k-space density weighted EPI, which is expected to increase the signal-to-noise ratio in fMRI data. Based on in vitro and in vivo pilot measurements, we show that fMRI by k-space density weighted EPI is feasible and that this new acquisition technique in fact boosted spatial and temporal SNR as well as the detection of local fMRI activations. Spatial resolution, spatial response function and echo time were identical for density weighted and conventional Cartesian EPI. The signal-to-noise ratio gain of density weighting can improve activation detection and has the potential to further increase the sensitivity of fMRI investigations.},
  language  = {en}
}
@phdthesis{Zeller2013,
  author    = {Zeller, Mario},
  title     = {Dichtegewichtete Magnetresonanz-Bildgebung mit Multi-Echo-Sequenzen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-84142},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Das Signal-zu-Rausch-Verh{\"a}ltnis (SNR) stellt bei modernen Bildgebungstechniken in der Magnetresonanz-Tomographie heutzutage oftmals die entscheidende Limitation dar. Eine Verbesserung durch Modifikation der Hardware ist kostspielig und f{\"u}hrt meistens zu einer Verst{\"a}rkung anderer Probleme, wie zum Beispiel erh{\"o}hte Energiedeposition ins Gewebe. Im Gegensatz dazu ist Dichtegewichtung eine Methode, die eine SNR-Erh{\"o}hung durch Modifikation der Aufnahmetechnik erm{\"o}glicht. In der MR-Bildgebung erfolgt oftmals eine retrospektive Filterung des aufgenommenen Signalverlaufs, beispielsweise zur Artefaktreduktion. Damit einhergehend findet eine Ver{\"a}nderung der Modulationstransferfunktion (MTF) bzw. ihrer Fouriertransformierten, der r{\"a}umlichen Antwortfunktion (SRF), statt. Optimales SNR wird nach dem Matched Filter-Theorem erzielt, wenn die nachtr{\"a}gliche Filterung dem aufgenommenen Signalverlauf proportional ist. Dies steht dem Ziel der Artefaktreduktion entgegen. Bei Dichtegewichtung steht durch nicht-kartesische Abtastung des k-Raums mit der k-Raum-Dichte ein zus{\"a}tzlicher Freiheitsgrad zur Verf{\"u}gung. Dieser erm{\"o}glicht es, im Falle eines konstanten Signalverlaufs eine gew{\"u}nschte MTF ohne Filterung zu erreichen. Bei ver{\"a}nderlichem Signalverlauf kann ein SNR Matched Filter angewendet werden, dessen negative Einfl{\"u}sse auf die MTF durch Dichtegewichtung kompensiert werden. Somit erm{\"o}glicht Dichtegewichtung eine vorgegebene MTF und gleichzeitig ein optimales SNR. In der vorliegenden Arbeit wurde Dichtegewichtung erstmals bei den schnellen Multi-Echo-Sequenzen Turbo-Spin-Echo und Echoplanar-Bildgebung (EPI) angewendet. Im Gegensatz zu bisherigen Implementierungen muss hier der Signalabfall durch T2- bzw. T2*-Relaxation ber{\"u}cksichtigt werden. Dies f{\"u}hrt dazu, dass eine prospektiv berechnete dichtegewichtete Verteilung nur bei einer Relaxationszeit optimal ist. Bei Geweben mit abweichenden Relaxationszeiten k{\"o}nnen sich wie auch bei den kartesischen Varianten dieser Sequenzen {\"A}nderungen an SRF und SNR ergeben. Bei dichtegewichteter Turbo-Spin-Echo-Bildgebung des Gehirns konnte mit den gew{\"a}hlten Sequenzparametern ein SNR-Vorteil von 43 \% gegen{\"u}ber der kartesischen Variante erzielt werden. Die Akquisition wurde dabei auf die T2-Relaxationszeit von weißer Substanz optimiert. Da die meisten Gewebe im Gehirn eine {\"a}hnliche Relaxationszeit aufweisen, blieb der visuelle Gesamteindruck identisch zur kartesischen Bildgebung. Der SNR-Gewinn konnte in der dichtegewichteten Implementierung zur Messzeithalbierung genutzt werden. Dichtegewichtete EPI weist eine hohe Anf{\"a}lligkeit f{\"u}r geometrische Verzerrungen, welche durch Inhomogenit{\"a}ten des Hauptmagnetfeldes verursacht werden, auf. Die Verzerrungen konnten erfolgreich mit einer Conjugate Phase-Methode korrigiert werden. Dazu muss die r{\"a}umliche Verteilung der Feldinhomogenit{\"a}ten bekannt sein. Dazu ist zus{\"a}tzlich zur eigentlichen EPI-Aufnahme die zeitaufwendige Aufnahme einer sogenannten Fieldmap erforderlich. Im Rahmen dieser Arbeit konnte eine Methode entwickelt werden, welche die zur Erlangung einer Fieldmap notwendige Aufnahmedauer auf wenige Sekunden reduziert. Bei dieser Art der Fieldmap-Aufnahme m{\"u}ssen jedoch durch Atmung hervorgerufene Effekte auf die Bildphase ber{\"u}cksichtigt werden. Die Fieldmap-Genauigkeit kann durch Aufnahme unter Atempause, Mittelung oder retrospektiver Phasenkorrektur erh{\"o}ht werden. F{\"u}r die gew{\"a}hlten EPI-Sequenzparameter wurde mit Dichtegewichtung gegen{\"u}ber der kartesischen Variante ein SNR-Gewinn von 14 \% erzielt. Anhand einer funktionellen MRT (fMRI)-Fingertapping-Studie konnte demonstriert werden, dass die SNR-Steigerung auch zu einer signifikant erh{\"o}hten Aktivierungsdetektion in Teilen der Hirnareale f{\"u}hrt, die bei der Fingerbewegung involviert sind. Die Verwendung von zus{\"a}tzlicher EPI-Phasenkorrektur und iterativer Optimierung der dichtegewichteten k-Raum-Abtastung f{\"u}hrt zu weiteren Verbesserungen der dichtegewichteten Bildgebung mit Multi-Echo-Sequenzen.},
  subject      = {Kernspintomografie},
  language  = {de}
}
@article{ZellerHeidemeierGrigoleitetal.2017,
  author    = {Zeller, Daniel and Heidemeier, Anke and Grigoleit, G{\"o}tz Ulrich and M{\"u}llges, Wolfgang},
  title     = {Case report: subacute tetraplegia in an immunocompromised patient},
  series = {BMC Neurology},
  volume    = {17},
  journal   = {BMC Neurology},
  number    = {31},
  doi       = {10.1186/s12883-017-0814-5},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157576},
  year      = {2017},
  abstract  = {Background: Clinical reasoning in Neurology is based on general associations which help to deduce the site of the lesion. However, even "golden principles" may occasionally be deceptive. Here, we describe the case of subacute flaccid tetraparesis due to motor cortical lesions. To our knowledge, this is the first report to include an impressive illustration of nearly symmetric motor cortical involvement of encephalitis on brain MRI. Case presentation: A 51 year old immunocompromized man developed a high-grade pure motor flaccid tetraparesis over few days. Based on clinical presentation, critical illness polyneuromyopathy was suspected. However, brain MRI revealed symmetrical hyperintensities strictly limited to the subcortical precentral gyrus. An encephalitis, possibly due to CMV infection, turned out to be the most likely cause. Conclusion: While recognition of basic clinical patterns is indispensable in neurological reasoning, awareness of central conditions mimicking peripheral nervous disease may be crucial to detect unsuspected, potentially treatable conditions.},
  language  = {en}
}
@article{WurmbSchlerethKredeletal.2014,
  author    = {Wurmb, Thomas Erik and Schlereth, Stefan and Kredel, Markus and Muellenbach, Ralf M. and Wunder, Christian and Brederlau, J{\"o}rg and Roewer, Norbert and Kenn, Werner and Kunze, Ekkehard},
  title     = {Routine Follow-Up Cranial Computed Tomography for Deeply Sedated, Intubated, and Ventilated Multiple Trauma Patients with Suspected Severe Head Injury},
  series = {BioMed Research International},
  journal   = {BioMed Research International},
  number    = {361949},
  doi       = {10.1155/2014/361949},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-120084},
  year      = {2014},
  abstract  = {Background. Missed or delayed detection of progressive neuronal damage after traumatic brain injury (TBI) may have negative impact on the outcome. We investigated whether routine follow-up CT is beneficial in sedated and mechanically ventilated trauma patients. Methods. The study design is a retrospective chart review. A routine follow-up cCT was performed 6 hours after the admission scan. We defined 2 groups of patients, group I: patients with equal or recurrent pathologies and group II: patients with new findings or progression of known pathologies. Results. A progression of intracranial injury was found in 63 patients (42\%) and 18 patients (12\%) had new findings in cCT 2 (group II). In group II a change in therapy was found in 44 out of 81 patients (54\%). 55 patients with progression or new findings on the second cCT had no clinical signs of neurological deterioration. Of those 24 patients (44\%) had therapeutic consequences due to the results of the follow-up cCT. Conclusion. We found new diagnosis or progression of intracranial pathology in 54\% of the patients. In 54\% of patients with new findings and progression of pathology, therapy was changed due to the results of follow-up cCT. In trauma patients who are sedated and ventilated for different reasons a routine follow-up CT is beneficial.},
  language  = {en}
}
@article{WoźnickiLaquaMessmeretal.2022,
  author    = {Wo{\'{z}}nicki, Piotr and Laqua, Fabian Christopher and Messmer, Katharina and Kunz, Wolfgang Gerhard and Stief, Christian and N{\"o}renberg, Dominik and Schreier, Andrea and W{\´o}jcik, Jan and Ruebenthaler, Johannes and Ingrisch, Michael and Ricke, Jens and Buchner, Alexander and Schulz, Gerald Bastian and Gresser, Eva},
  title     = {Radiomics for the prediction of overall survival in patients with bladder cancer prior to radical cystectomy},
  series = {Cancers},
  volume    = {14},
  journal   = {Cancers},
  number    = {18},
  issn      = {2072-6694},
  doi       = {10.3390/cancers14184449},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288098},
  year      = {2022},
  abstract  = {(1) Background: To evaluate radiomics features as well as a combined model with clinical parameters for predicting overall survival in patients with bladder cancer (BCa). (2) Methods: This retrospective study included 301 BCa patients who received radical cystectomy (RC) and pelvic lymphadenectomy. Radiomics features were extracted from the regions of the primary tumor and pelvic lymph nodes as well as the peritumoral regions in preoperative CT scans. Cross-validation was performed in the training cohort, and a Cox regression model with an elastic net penalty was trained using radiomics features and clinical parameters. The models were evaluated with the time-dependent area under the ROC curve (AUC), Brier score and calibration curves. (3) Results: The median follow-up time was 56 months (95\% CI: 48-74 months). In the follow-up period from 1 to 7 years after RC, radiomics models achieved comparable predictive performance to validated clinical parameters with an integrated AUC of 0.771 (95\% CI: 0.657-0.869) compared to an integrated AUC of 0.761 (95\% CI: 0.617-0.874) for the prediction of overall survival (p = 0.98). A combined clinical and radiomics model stratified patients into high-risk and low-risk groups with significantly different overall survival (p < 0.001). (4) Conclusions: Radiomics features based on preoperative CT scans have prognostic value in predicting overall survival before RC. Therefore, radiomics may guide early clinical decision-making.},
  language  = {en}
}
@article{WoznickiLaquaAlHajetal.2023,
  author    = {Woznicki, Piotr and Laqua, Fabian Christopher and Al-Haj, Adam and Bley, Thorsten and Baeßler, Bettina},
  title     = {Addressing challenges in radiomics research: systematic review and repository of open-access cancer imaging datasets},
  series = {Insights into Imaging},
  volume    = {14},
  journal   = {Insights into Imaging},
  issn      = {1869-4101},
  doi       = {10.1186/s13244-023-01556-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357936},
  year      = {2023},
  abstract  = {Objectives Open-access cancer imaging datasets have become integral for evaluating novel AI approaches in radiology. However, their use in quantitative analysis with radiomics features presents unique challenges, such as incomplete documentation, low visibility, non-uniform data formats, data inhomogeneity, and complex preprocessing. These issues may cause problems with reproducibility and standardization in radiomics studies. Methods We systematically reviewed imaging datasets with public copyright licenses, published up to March 2023 across four large online cancer imaging archives. We included only datasets with tomographic images (CT, MRI, or PET), segmentations, and clinical annotations, specifically identifying those suitable for radiomics research. Reproducible preprocessing and feature extraction were performed for each dataset to enable their easy reuse. Results We discovered 29 datasets with corresponding segmentations and labels in the form of health outcomes, tumor pathology, staging, imaging-based scores, genetic markers, or repeated imaging. We compiled a repository encompassing 10,354 patients and 49,515 scans. Of the 29 datasets, 15 were licensed under Creative Commons licenses, allowing both non-commercial and commercial usage and redistribution, while others featured custom or restricted licenses. Studies spanned from the early 1990s to 2021, with the majority concluding after 2013. Seven different formats were used for the imaging data. Preprocessing and feature extraction were successfully performed for each dataset. Conclusion RadiomicsHub is a comprehensive public repository with radiomics features derived from a systematic review of public cancer imaging datasets. By converting all datasets to a standardized format and ensuring reproducible and traceable processing, RadiomicsHub addresses key reproducibility and standardization challenges in radiomics. Critical relevance statement This study critically addresses the challenges associated with locating, preprocessing, and extracting quantitative features from open-access datasets, to facilitate more robust and reliable evaluations of radiomics models. Key points - Through a systematic review, we identified 29 cancer imaging datasets suitable for radiomics research. - A public repository with collection overview and radiomics features, encompassing 10,354 patients and 49,515 scans, was compiled. - Most datasets can be shared, used, and built upon freely under a Creative Commons license. - All 29 identified datasets have been converted into a common format to enable reproducible radiomics feature extraction.},
  language  = {en}
}
@article{WoznickiLaquaBleyetal.2022,
  author    = {Woznicki, Piotr and Laqua, Fabian and Bley, Thorsten and Baeßler, Bettina},
  title     = {AutoRadiomics: a framework for reproducible radiomics research},
  series = {Frontiers in Radiology},
  volume    = {2},
  journal   = {Frontiers in Radiology},
  issn      = {2673-8740},
  doi       = {10.3389/fradi.2022.919133},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284813},
  year      = {2022},
  abstract  = {Purpose Machine learning based on radiomics features has seen huge success in a variety of clinical applications. However, the need for standardization and reproducibility has been increasingly recognized as a necessary step for future clinical translation. We developed a novel, intuitive open-source framework to facilitate all data analysis steps of a radiomics workflow in an easy and reproducible manner and evaluated it by reproducing classification results in eight available open-source datasets from different clinical entities. Methods The framework performs image preprocessing, feature extraction, feature selection, modeling, and model evaluation, and can automatically choose the optimal parameters for a given task. All analysis steps can be reproduced with a web application, which offers an interactive user interface and does not require programming skills. We evaluated our method in seven different clinical applications using eight public datasets: six datasets from the recently published WORC database, and two prostate MRI datasets—Prostate MRI and Ultrasound With Pathology and Coordinates of Tracked Biopsy (Prostate-UCLA) and PROSTATEx. Results In the analyzed datasets, AutoRadiomics successfully created and optimized models using radiomics features. For WORC datasets, we achieved AUCs ranging from 0.56 for lung melanoma metastases detection to 0.93 for liposarcoma detection and thereby managed to replicate the previously reported results. No significant overfitting between training and test sets was observed. For the prostate cancer detection task, results were better in the PROSTATEx dataset (AUC = 0.73 for prostate and 0.72 for lesion mask) than in the Prostate-UCLA dataset (AUC 0.61 for prostate and 0.65 for lesion mask), with external validation results varying from AUC = 0.51 to AUC = 0.77. Conclusion AutoRadiomics is a robust tool for radiomic studies, which can be used as a comprehensive solution, one of the analysis steps, or an exploratory tool. Its wide applicability was confirmed by the results obtained in the diverse analyzed datasets. The framework, as well as code for this analysis, are publicly available under https://github.com/pwoznicki/AutoRadiomics.},
  language  = {en}
}
@phdthesis{Wirth2012,
  author    = {Wirth, Clemens},
  title     = {Klinische Wertigkeit der funktionellen Magnetresonanzurographie bei Kindern},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-72593},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Die vorliegende retrospektive Arbeit zeigt die Einsatzm{\"o}glichkeiten der funktionellen Magnetresonanzurographie bei Kindern auf. Mit Hilfe der verwendeten Software lassen sich die funktionellen Aspekte der Untersuchung wenig zeitintensiv bearbeiten und die Ergebnisse anschaulich und verst{\"a}ndlich darstellen. Die Beurteilung der funktionellen Ergebnisse erlaubt aus der Zusammenschau von errechneten definierten metrischen Daten der Untersuchung und der Kurvenanalyse eine Aussage zur seitengetrennten Nierenfunktion. Diese korreliert gut mit dem klinischen Ergebnis und der MAG 3 Szintigraphie als Standardverfahren. Als Funktionsparameter zur Unterscheidung zwischen normal funktionierender und dekompensierter obstruierter Nierenuretereinheit dient in erster Linie die renale Transitzeit des Kontrastmittels RTT. Durch Einf{\"u}hrung einer Pseudonativsequenz konnten im Patientenkollektiv Untersuchungen der Auswertung zugef{\"u}hrt werden, die prim{\"a}r nicht auszuwerten waren. Eine Korrelation der errechneten Patlakzahl mit der gesch{\"a}tzten glomul{\"a}ren Filtrationsrate ließ sich in unserem Kollektiv nicht nachweisen. Insgesamt ist das Verfahren im klinischen Alltag weiter zu evaluieren, Prospektive Studien sollten eine eventuelle {\"U}berlegenheit dieser strahlenfreien Methode gegen{\"u}ber der Szintigraphie als zentrale Fragestellung {\"u}berpr{\"u}fen.},
  subject      = {Funktionelle NMR-Tomographie},
  language  = {de}
}
@article{WilliamsMachannKuehleretal.2011,
  author    = {Williams, Tatjana and Machann, Wolfram and K{\"u}hler, Leif and Hamm, Henning and M{\"u}ller-H{\"o}cker, Josef and Zimmer, Michael and Ertl, Georg and Ritter, Oliver and Beer, Meinrad and Sch{\"o}nberger, Jost},
  title     = {Novel desmoplakin mutation: juvenile biventricular cardiomyopathy with left ventricular non-compaction and acantholytic palmoplantar keratoderma},
  series = {Clinical Research in Cardiology},
  volume    = {100},
  journal   = {Clinical Research in Cardiology},
  number    = {12},
  doi       = {10.1007/s00392-011-0345-9},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141198},
  pages     = {1087-1093},
  year      = {2011},
  abstract  = {Two sons of a consanguineous marriage developed biventricular cardiomyopathy. One boy died of severe heart failure at the age of 6 years, the other was transplanted because of severe heart failure at the age of 10 years. In addition, focal palmoplantar keratoderma and woolly hair were apparent in both boys. As similar phenotypes have been described in Naxos disease and Carvajal syndrome, respectively, the genes for plakoglobin (JUP) and desmoplakin (DSP) were screened for mutations using direct genomic sequencing. A novel homozygous 2 bp deletion was identified in an alternatively spliced region of DSP. The deletion 5208_5209delAG led to a frameshift downstream of amino acid 1,736 with a premature truncation of the predominant cardiac isoform DSP-1. This novel homozygous truncating mutation in the isoform-1 specific region of the DSP C-terminus caused Carvajal syndrome comprising severe early-onset heart failure with features of non-compaction cardiomyopathy, woolly hair and an acantholytic form of palmoplantar keratoderma in our patient. Congenital hair abnormality and manifestation of the cutaneous phenotype in toddler age can help to identify children at risk for cardiac death.},
  language  = {en}
}
@phdthesis{Wesemeier2006,
  author    = {Wesemeier, Carmen Gudrun},
  title     = {Eisenpartikelverst{\"a}rkte Magnetresonanztomographie bei der Experimentellen-Autoimmun-Neuritis(EAN)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-24626},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2006},
  abstract  = {In diesem experimentellen Ansatz ist es gelungen, durch Einsatz von eisenhaltigen Kontrastmittel die MRT-Spezifit{\"a}t bei peripheren autoimmunen Nervenentz{\"u}ndungen deutlich zu erh{\"o}hen. Es ist gelungen in vivo den zeitlichen Verlauf der Monozyten/Makropahgeninfiltration bei entz{\"u}ndliche Autoimmunerkrankungen des Peripheren Nervensystems zu demonstrieren.},
  subject      = {Experimentelle allergische Neuritis},
  language  = {de}
}
@phdthesis{Werner2007,
  author    = {Werner, Alexander},
  title     = {Vergleich verschiedener Kontrastmittelkonzentrationen f{\"u}r die Computertomographie des Abdomens},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-24425},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2007},
  abstract  = {Das Ziel der vorliegenden Arbeit war es, die Auswirkungen von drei unter-schiedlichen Jodkonzentrationen eines Kontrastmittels sowohl bei gleicher In-jektionsgeschwindigkeit als auch bei gleicher Jodmenge/Zeiteinheit auf den Dichteanstieg in Leber, Pankreas, Milz und Aorta bei der Mehrzeilendetektor-Spiral-CT zu untersuchen. In die prospektive Studie wurden 120 Patienten im Alter von 70\&\#61617;6 Jahren mit einer bekannten oder vermuteten Leberraumforderung aufgenommen, die sich einer triphasischen Mehrzeilendetektor-Spiral-CT-Untersuchung des Abdomens unterzogen. Als Kontrastmittel wurde das nicht-ionische Iopromid verwendet. Die Patienten wurden in sechs gleich große Gruppen eingeteilt. Die Gruppen waren wie folgt charakterisiert: Gruppe I: 150 ml (KM-Volumen), 240 mg/ml (Jodkonzentration) bei 4 ml/s (Injektionsgeschwindigkeit); Gruppe II: 120 ml, 300 mg/ml bei 4 ml/s; Gruppe III: 100 ml, 370 mg/ml bei 4 ml/s; Gruppe IV: 150 ml, 240 mg/ml bei 5 ml/s; Gruppe V: 120 ml, 300 mg/ml, 60 ml bei 6 ml/s, 60 ml bei 3 ml/s; Gruppe VI: 100 ml, 370 mg/ml bei 3,3 ml/s. Die Gesamtjodmenge war stets konstant und betrug 36 g. Der Dichteanstieg wurde in der Leber (kra-nial, Mitte, kaudal, linker Leberlappen), im Pankreas, in der Milz und in der Aorta (kranial und kaudal) in der nativen, arteriellen, portal-ven{\"o}sen und Paren-chymphase mit Hilfe einer ROI gemessen. F{\"u}r den statistischen Vergleich der Gruppen wurden der Kruskal-Wallis-Test (Vergleich von mehr als zwei Grup-pen) und der Mann-Whitney-Test (Vergleich von zwei Gruppen) verwendet. Beim Vergleich der Gruppen, die das Kontrastmittel mit gleicher Injektionsge-schwindigkeit erhielten (Gruppe I-III), zeigte sich ein signifikant h{\"o}heres En-hancement (p=0,02) des Pankreas in der arteriellen Phase bei Gabe des Kon-trastmittels mit einer Konzentration von 370 mg/ml (74\&\#61617;20 HE) im Vergleich zur Gabe von Kontrastmitteln mit Konzentrationen von 240 mg/ml (58\&\#61617;15 HE) und 300 mg/ml (62\&\#61617;12 HE). Sowohl beim Vergleich der Gruppen, die das Kon-trastmittel mit gleicher Jodmenge/Zeiteinheit erhielten (Gruppe II, IV und VI) als auch beim Vergleich aller Gruppen zeigten sich keine signifikanten Grup-penunterschiede hinsichtlich des Dichteanstiegs in den untersuchten Organen. Mit Hilfe der vorliegenden Arbeit konnte auf der einen Seite gezeigt werden, dass bei konstanter Jodgesamtmenge und konstanter Injektionsgeschwindig-keit das Kontrastmittel mit der h{\"o}heren Jodkonzentration das Enhancement des Pankreas in der arteriellen Phase signifikant verbessert. Auf der anderen Seite konnte gezeigt werden, dass bei konstanter Jodgesamtmenge und konstanter Jodmenge/Zeiteinheit keine signifikanten Unterschiede zwischen den Jodkon-zentrationen hinsichtlich des Enhancements von Oberbauchorganen bestehen.},
  subject      = {Computertomographie},
  language  = {de}
}
@article{WengKoestlerBleyetal.2021,
  author    = {Weng, Andreas M. and K{\"o}stler, Herbert and Bley, Thorsten A. and Ritter, Christian O.},
  title     = {Effect of short-term smoking \& L-arginine on coronary endothelial function assessed by cardiac magnetic resonance cold pressor testing: a pilot study},
  series = {BMC Cardiovascular Disorders},
  volume    = {21},
  journal   = {BMC Cardiovascular Disorders},
  doi       = {10.1186/s12872-021-02050-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260559},
  year      = {2021},
  abstract  = {Background The effect of smoking on coronary vasomotion has been investigated in the past with various imaging techniques in both short- and long-term smokers. Additionally, coronary vasomotion has been shown to be normalized in long-term smokers by L-Arginine acting as a substrate for NO synthase, revealing the coronary endothelium as the major site of abnormal vasomotor response. Aim of the prospective cohort study was to investigate coronary vasomotion of young healthy short-term smokers via magnetic resonance cold pressor test with and without the administration of L-Arginine and compare obtained results with the ones from nonsmokers. Methods Myocardial blood flow (MBF) was quantified with first-pass perfusion MRI on a 1.5 T scanner in healthy short-term smokers (N = 10, age: 25.0 ± 2.8 years, 5.0 ± 2.9 pack years) and nonsmokers (N = 10, age: 34.3 ± 13.6) both at rest and during cold pressor test (CPT). Smokers underwent an additional examination after administration of L-Arginine within a median of 7 days of the na{\"i}ve examination. Results MBF at rest turned out to be 0.77 ± 0.30 (smokers with no L-Arginine; mean ± standard deviation), 0.66 ± 0.21 (smokers L-Arginine) and 0.84 ± 0.08 (nonsmokers). Values under CPT were 1.21 ± 0.42 (smokers no L-Arginine), 1.09 ± 0.35 (smokers L-Arginine) and 1.63 ± 0.33 (nonsmokers). In all groups, MBF was significantly increased under CPT compared to the corresponding rest examination (p < 0.05 in all cases). Additionally, MBF under CPT was significantly different between the smokers and the nonsmokers (p = 0.002). MBF at rest was significantly different between the smokers when L-Arginine was given and the nonsmokers (p = 0.035). Conclusion Short-term smokers showed a reduced response to cold both with and without the administration of L-Arginine. However, absolute MBF values under CPT were lower compared to nonsmokers independently of L-Arginine administration.},
  language  = {en}
}
@article{WengHeidenreichMetzetal.2021,
  author    = {Weng, Andreas M. and Heidenreich, Julius F. and Metz, Corona and Veldhoen, Simon and Bley, Thorsten A. and Wech, Tobias},
  title     = {Deep learning-based segmentation of the lung in MR-images acquired by a stack-of-spirals trajectory at ultra-short echo-times},
  series = {BMC Medical Imaging},
  volume    = {21},
  journal   = {BMC Medical Imaging},
  doi       = {10.1186/s12880-021-00608-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260520},
  year      = {2021},
  abstract  = {Background Functional lung MRI techniques are usually associated with time-consuming post-processing, where manual lung segmentation represents the most cumbersome part. The aim of this study was to investigate whether deep learning-based segmentation of lung images which were scanned by a fast UTE sequence exploiting the stack-of-spirals trajectory can provide sufficiently good accuracy for the calculation of functional parameters. Methods In this study, lung images were acquired in 20 patients suffering from cystic fibrosis (CF) and 33 healthy volunteers, by a fast UTE sequence with a stack-of-spirals trajectory and a minimum echo-time of 0.05 ms. A convolutional neural network was then trained for semantic lung segmentation using 17,713 2D coronal slices, each paired with a label obtained from manual segmentation. Subsequently, the network was applied to 4920 independent 2D test images and results were compared to a manual segmentation using the S{\o}rensen-Dice similarity coefficient (DSC) and the Hausdorff distance (HD). Obtained lung volumes and fractional ventilation values calculated from both segmentations were compared using Pearson's correlation coefficient and Bland Altman analysis. To investigate generalizability to patients outside the CF collective, in particular to those exhibiting larger consolidations inside the lung, the network was additionally applied to UTE images from four patients with pneumonia and one with lung cancer. Results The overall DSC for lung tissue was 0.967 ± 0.076 (mean ± standard deviation) and HD was 4.1 ± 4.4 mm. Lung volumes derived from manual and deep learning based segmentations as well as values for fractional ventilation exhibited a high overall correlation (Pearson's correlation coefficent = 0.99 and 1.00). For the additional cohort with unseen pathologies / consolidations, mean DSC was 0.930 ± 0.083, HD = 12.9 ± 16.2 mm and the mean difference in lung volume was 0.032 ± 0.048 L. Conclusions Deep learning-based image segmentation in stack-of-spirals based lung MRI allows for accurate estimation of lung volumes and fractional ventilation values and promises to replace the time-consuming step of manual image segmentation in the future.},
  language  = {en}
}
@phdthesis{Welsch2021,
  author    = {Welsch, Stefan},
  title     = {Die Rolle des iFlow-Algortithmus im Rahmen der endovaskul{\"a}ren Therapie von symptomatischen Nierenarterienstenosen},
  doi       = {10.25972/OPUS-22332},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223324},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Das Ziel dieser Arbeit war herauszufinden, ob der iFlow-Algorithmus als zus{\"a}tzlicher Parameter zu Evaluierung des technischen Erfolgs einer Revaskularisation einer Nierenarterienstenose eingesetzt werden kann. Hierf{\"u}r haben wir die „mean time to peak" in Sekunden in den farbcodierten Bildern gemessen, um den Effekt einer Stentimplantation auf den Blutfluss zu eruieren. Im Verlauf haben wir dann getestet, ob unsere Ergebnisse den klinischen Verlauf unserer Patienten wiederspiegeln, um feststellen zu k{\"o}nnen, ob die syngo iFlow-Software den Erfolg der endovaskul{\"a}ren Therapie voraussagen kann.},
  subject      = {endovascular},
  language  = {de}
}
@phdthesis{Weiss2017,
  author    = {Weiß, Sandra Elisabeth},
  title     = {Erstmalige Sauerstoff-basierte MR-Lungenfunktionsanalyse im Schulkindesalter - lassen sich Ver{\"a}nderungen der Ventilation bei ehemals fr{\"u}hgeborenen Kindern nachweisen?},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143730},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Oxygen-enhanced functional low-field MRI of the lung in formerly very low birth weight infants with and without bronchopulmonary dysplasia (BPD) Clemens Wirth1, Sandra Weiß1, Daniel St{\"a}b1, Wolfgang Thomas2, Henning Neubauer1, Helge Hebestreit2, Herbert K{\"o}stler1, Dietbert Hahn1, Meinrad Beer1 1 Institute of Radiology, 2 Department of Pediatrics, University of Wuerzburg, Germany Purpose: To assess functional lung abnormalities in formerly very low birth weight infants (VLBW) with and without BPD compared with children born at term without lung pathology in an oxygen-enhanced open low-field MRI. Materials and methods: 40 children aged 7-12 years were included in this study. 10 children had BPD, 15 were VLBW without BPD (non-BPD) and 15 formerly term infants served as controls (CON). Sagittal T1-weighted single inversion multi-gradientecho sequences were acquired for both lungs at an open low-field MRI (Magnetom Open 0.2 Tesla, Siemens Medical Solutions, Erlangen, Germany). Acquisition was performed in 2 cycles: whilst breathing ambient air, then 100\% oxygen via breathing mask. The mean relative change of the T1 relaxation time (ΔT1) between the two cycles was calculated after pixelwise subtraction of the parameter maps. ΔT1 of the different groups was compared statistically. Results: ΔT1 of the different groups was calculated as follows: CON 10.7 +/- 2.3\%; Non-BPD 10.8 +/- 3.0\%; BPD 9.2 +/- 3.1\%. ΔT1 was significantly lower in the BPD group compared to both other groups (Mann-Whitney-U; p<0.05). There was no significant change of ΔT1 between the Non-BPD and the control group (p=0.93). Subanalysis of the lobes showed inhomogenieties of ΔT1 in the BPD group. Conclusion: Functional oxygen-enhanced MRI shows significant differences of ΔT1 in patients with BPD compared to children without BPD, reflecting probable long term functional sequelae of disturbed pulmonary vascular and alveolar development of the disease.},
  subject      = {MRT},
  language  = {de}
}
@article{WeickBreuerRichteretal.2020,
  author    = {Weick, Stefan and Breuer, Kathrin and Richter, Anne and Exner, Florian and Str{\"o}hle, Serge-Peer and Lutyj, Paul and Tamihardja, J{\"o}rg and Veldhoen, Simon and Flentje, Michael and Polat, B{\"u}lent},
  title     = {Non-rigid image registration of 4D-MRI data for improved delineation of moving tumors},
  series = {BMC Medical Imaging},
  volume    = {20},
  journal   = {BMC Medical Imaging},
  doi       = {10.1186/s12880-020-00439-6},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229271},
  year      = {2020},
  abstract  = {Background To increase the image quality of end-expiratory and end-inspiratory phases of retrospective respiratory self-gated 4D MRI data sets using non-rigid image registration for improved target delineation of moving tumors. Methods End-expiratory and end-inspiratory phases of volunteer and patient 4D MRI data sets are used as targets for non-rigid image registration of all other phases using two different registration schemes: In the first, all phases are registered directly (dir-Reg) while next neighbors are successively registered until the target is reached in the second (nn-Reg). Resulting data sets are quantitatively compared using diaphragm and tumor sharpness and the coefficient of variation of regions of interest in the lung, liver, and heart. Qualitative assessment of the patient data regarding noise level, tumor delineation, and overall image quality was performed by blinded reading based on a 4 point Likert scale. Results The median coefficient of variation was lower for both registration schemes compared to the target. Median dir-Reg coefficient of variation of all ROIs was 5.6\% lower for expiration and 7.0\% lower for inspiration compared with nn-Reg. Statistical significant differences between the two schemes were found in all comparisons. Median sharpness in inspiration is lower compared to expiration sharpness in all cases. Registered data sets were rated better compared to the targets in all categories. Over all categories, mean expiration scores were 2.92 +/- 0.18 for the target, 3.19 +/- 0.22 for nn-Reg and 3.56 +/- 0.14 for dir-Reg and mean inspiration scores 2.25 +/- 0.12 for the target, 2.72 +/- 215 0.04 for nn-Reg and 3.78 +/- 0.04 for dir-Reg. Conclusions In this work, end-expiratory and inspiratory phases of a 4D MRI data sets are used as targets for non-rigid image registration of all other phases. It is qualitatively and quantitatively shown that image quality of the targets can be significantly enhanced leading to improved target delineation of moving tumors.},
  language  = {en}
}
@article{WechAnkenbrandBleyetal.2022,
  author    = {Wech, Tobias and Ankenbrand, Markus Johannes and Bley, Thorsten Alexander and Heidenreich, Julius Frederik},
  title     = {A data-driven semantic segmentation model for direct cardiac functional analysis based on undersampled radial MR cine series},
  series = {Magnetic Resonance in Medicine},
  volume    = {87},
  journal   = {Magnetic Resonance in Medicine},
  number    = {2},
  doi       = {10.1002/mrm.29017},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-257616},
  pages     = {972-983},
  year      = {2022},
  abstract  = {Purpose Image acquisition and subsequent manual analysis of cardiac cine MRI is time-consuming. The purpose of this study was to train and evaluate a 3D artificial neural network for semantic segmentation of radially undersampled cardiac MRI to accelerate both scan time and postprocessing. Methods A database of Cartesian short-axis MR images of the heart (148,500 images, 484 examinations) was assembled from an openly accessible database and radial undersampling was simulated. A 3D U-Net architecture was pretrained for segmentation of undersampled spatiotemporal cine MRI. Transfer learning was then performed using samples from a second database, comprising 108 non-Cartesian radial cine series of the midventricular myocardium to optimize the performance for authentic data. The performance was evaluated for different levels of undersampling by the Dice similarity coefficient (DSC) with respect to reference labels, as well as by deriving ventricular volumes and myocardial masses. Results Without transfer learning, the pretrained model performed moderately on true radial data [maximum number of projections tested, P = 196; DSC = 0.87 (left ventricle), DSC = 0.76 (myocardium), and DSC =0.64 (right ventricle)]. After transfer learning with authentic data, the predictions achieved human level even for high undersampling rates (P = 33, DSC = 0.95, 0.87, and 0.93) without significant difference compared with segmentations derived from fully sampled data. Conclusion A 3D U-Net architecture can be used for semantic segmentation of radially undersampled cine acquisitions, achieving a performance comparable with human experts in fully sampled data. This approach can jointly accelerate time-consuming cine image acquisition and cumbersome manual image analysis.},
  language  = {en}
}