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Purpose We aimed to develop a predictive model of disease severity for cirrhosis using MRI-derived radiomic features of the liver and spleen and compared it to the existing disease severity metrics of MELD score and clinical decompensation. The MELD score is compiled solely by blood parameters, and so far, it was not investigated if extracted image-based features have the potential to reflect severity to potentially complement the calculated score. Methods This was a retrospective study of eligible patients with cirrhosis (n=90) who underwent a contrast-enhanced MR screening protocol for hepatocellular carcinoma (HCC) screening at a tertiary academic center from 2015 to 2018. Radiomic feature analyses were used to train four prediction models for assessing the patient's condition at time of scan: MELD score, MELD score > 9 (median score of the cohort), MELD score > 15 (the inflection between the risk and benefit of transplant), and clinical decompensation. Liver and spleen segmentations were used for feature extraction, followed by cross-validated random forest classification. Results Radiomic features of the liver and spleen were most predictive of clinical decompensation (AUC 0.84), which the MELD score could predict with an AUC of 0.78. Using liver or spleen features alone had slightly lower discrimination ability (AUC of 0.82 for liver and AUC of 0.78 for spleen features only), although this was not statistically significant on our cohort. When radiomic prediction models were trained to predict continuous MELD scores, there was poor correlation. When stratifying risk by splitting our cohort at the median MELD 9 or at MELD 15, our models achieved AUCs of 0.78 or 0.66, respectively. Conclusions We demonstrated that MRI-based radiomic features of the liver and spleen have the potential to predict the severity of liver cirrhosis, using decompensation or MELD status as imperfect surrogate measures for disease severity.

Ziel: Die DRG-ÖRG-IRP (Deutsche Röntgengesellschaft-Österreichische Röntgengesellschaft Internationale Radiomics-Plattform) stellt eine web-/cloudbasierte Radiomics-Plattform auf Grundlage einer öffentlich-privaten Partnerschaft dar. Sie bietet die Möglichkeit der gemeinsamen Nutzung von Daten, Annotation, Validierung und Zertifizierung auf dem Gebiet der künstlichen Intelligenz, Radiomics-Analyse und integrierten Diagnostik. In einer ersten Proof-of-Concept-Studie soll die automatisierte Myokardsegmentation sowie die automatisierte myokardiale Late-Gadolinum-Enhancement (LGE)-Detektion mittels radiomischer Bildmerkmale für Myokarditis-Datensätze evaluiert werden. Material und Methoden: Die DRG-ÖRP-IRP kann zur Erstellung qualitätsgesicherter, strukturierter Bilddaten in Kombination mit klinischen Daten und anschließender integrierter Datenanalyse genutzt werden und zeichnet sich durch die folgenden Leistungskriterien aus: Nutzungsmöglichkeit multizentrischer vernetzter Daten, automatisiert berechnete Qualitätsparameter, Bearbeitung von Annotationsaufgaben, Konturerkennung mittels herkömmlicher Verfahren sowie Verfahren der künstlichen Intelligenz und der Möglichkeit einer gezielten Einbindung von Algorithmen. In einer ersten Studie wurde ein anhand kardialer CINE-Datensätze vortrainiertes neuronales Netz zur Segmentierung von PSIR-Datensätzen evaluiert. In einem zweiten Schritt wurden radiomische Bildmerkmale zur segmentalen Detektion von LGE der gleichen Datensätze, welche multizentrisch über die IRP zu Verfügung gestellt wurden, angewendet. Ergebnisse: Erste Ergebnisse zeigen die Vorteile (Datentransparenz, Zuverlässigkeit, breite Einbindung aller Mitglieder, kontinuierliche Evolution sowie Validierung und Zertifizierung) dieses plattformbasierten Ansatzes auf. In der Proof-of-Concept-Studie konnte im Vergleich zur Segmentierung des Myokards durch den Experten das neuronale Netzwerk einen Dice-Koeffizienten von 0,813 nachweisen. Im Rahmen der segmentbasierten myokardialen LGE-Detektion ergab sich ein AUC von 0,73 bzw. ein AUC von 0,79 nach Ausschluss von Segmenten mit unsicherer Annotation. Die Auswertung und Bereitstellung der Daten findet auf der IRP unter Berücksichtigung der FAT-Kriterien (Fairness, Accountability, Transparency) sowie FAIR-Kriterien (findable, accessible, interoperable, reusable) statt. Schlussfolgerung: Es konnte gezeigt werden, dass die DRG-ÖRP-IRP als Kristallisationspunkt für die Generierung weiterer Einzel- und Verbundprojekte genutzt werden kann. Die Durchführung von quantitativen Analysen mit Verfahren der künstlichen Intelligenz wird hierbei durch den Plattformansatz der DRG-ÖRP-IRP erheblich erleichtert, da vorab trainierte neuronale Netze integriert und wissenschaftliche Gruppen vernetzt werden können. In einer ersten Proof-of-Concept-Studie zur automatisierten Segmentation des Myokards sowie zur automatisierten myokardialen LGE-Detektion konnten diese Vorteile erfolgreich angewendet werden. Somit zeigt sich, dass sich mittels der DRG-ÖRP-IRP strategische Ziele interdisziplinär umsetzen, konkrete alltagstaugliche Proof-of-Concept-Beispiele aufzeigen sowie möglichst partizipativ unter Einbindung aller Gruppierungen eine Vielzahl an Einzel- und Verbundprojekten realisieren lassen.

PURPOSE We present SlicerDMRI, an open-source software suite that enables research using diffusion magnetic resonance imaging (dMRI), the only modality that can map the white matter connections of the living human brain. SlicerDMRI enables analysis and visualization of dMRI data and is aimed at the needs of clinical research users. SlicerDMRI is built upon and deeply integrated with 3D Slicer, a National Institutes of Health-supported open-source platform for medical image informatics, image processing, and three-dimensional visualization. Integration with 3D Slicer provides many features of interest to cancer researchers, such as real-time integration with neuronavigation equipment, intraoperative imaging modalities, and multimodal data fusion. One key application of SlicerDMRI is in neurosurgery research, where brain mapping using dMRI can provide patient-specific maps of critical brain connections as well as insight into the tissue microstructure that surrounds brain tumors. PATIENTS AND METHODS In this article, we focus on a demonstration of SlicerDMRI as an informatics tool to enable end-to-end dMRI analyses in two retrospective imaging data sets from patients with high-grade glioma. Analyses demonstrated here include conventional diffusion tensor analysis, advanced multifiber tractography, automated identification of critical fiber tracts, and integration of multimodal imagery with dMRI. RESULTS We illustrate the ability of SlicerDMRI to perform both conventional and advanced dMRI analyses as well as to enable multimodal image analysis and visualization. We provide an overview of the clinical rationale for each analysis along with pointers to the SlicerDMRI tools used in each. CONCLUSION SlicerDMRI provides open-source and clinician-accessible research software tools for dMRI analysis. SlicerDMRI is available for easy automated installation through the 3D Slicer Extension Manager.

Objective: The cochlear nucleus (CN) is the target of the auditory brainstem implant (ABI). Most ABI candidates have Neurofibromatosis Type 2 (NF2) and distorted brainstem anatomy from bilateral vestibular schwannomas. The CN is difficult to characterize as routine structural MRI does not resolve detailed anatomy. We hypothesize that diffusion tensor imaging (DTI) enables both in vivo localization and quantitative measurements of CN morphology. Study Design: We analyzed 7 Tesla (T) DTI images of 100 subjects (200 CN) and relevant anatomic structures using an MRI brainstem atlas with submillimetric (50 mm) resolution. Setting: Tertiary referral center. Patients: Young healthy normal hearing adults. Intervention: Diagnostic. Main Outcome Measures: Diffusion scalar measures such as fractional anisotropy (FA), mean diffusivity (MD), mode of anisotropy (Mode), principal eigenvectors of the CN, and the adjacent inferior cerebellar peduncle (ICP). Results: The CN had a lamellar structure and ventral-dorsal fiber orientation and could be localized lateral to the inferior cerebellar peduncle (ICP). This fiber orientation was orthogonal to tracts of the adjacent ICP where the fibers run mainly caudal-rostrally. The CN had lower FA compared to the medial aspect of the ICP (0.44 ± 0.09 vs. 0.64 ± 0.08, p < 0.001). Conclusions: 7T DTI enables characterization of human CN morphology and neuronal substructure. An ABI array insertion vector directed more caudally would better correspond to the main fiber axis of CN. State-of-the-art DTI has implications for ABI preoperative planning and future image guidance-assisted placement of the electrode array.

We address the problem of interpolating randomly non-uniformly spatiotemporally scattered uncertain motion measurements, which arises in the context of soft tissue motion estimation. Soft tissue motion estimation is of great interest in the field of image-guided soft-tissue intervention and surgery navigation, because it enables the registration of pre-interventional/pre-operative navigation information on deformable soft-tissue organs. To formally define the measurements as spatiotemporally scattered motion signal samples, we propose a novel motion field representation. To perform the interpolation of the motion measurements in an uncertainty-aware optimal unbiased fashion, we devise a novel Gaussian process (GP) regression model with a non-constant-mean prior and an anisotropic covariance function and show through an extensive evaluation that it outperforms the state-of-the-art GP models that have been deployed previously for similar tasks. The employment of GP regression enables the quantification of uncertainty in the interpolation result, which would allow the amount of uncertainty present in the registered navigation information governing the decisions of the surgeon or intervention specialist to be conveyed.

Knowledge of the exact tumor location and structures at risk in its vicinity are crucial for neurosurgical interventions. Neuronavigation systems support navigation within the patient's brain, based on preoperative MRI (preMRI). However, increasing tissue deformation during the course of tumor resection reduces navigation accuracy based on preMRI. Intraoperative ultrasound (iUS) is therefore used as real-time intraoperative imaging. Registration of preMRI and iUS remains a challenge due to different or varying contrasts in iUS and preMRI. Here, we present an automatic and efficient segmentation of B-mode US images to support the registration process. The falx cerebri and the tentorium cerebelli were identified as examples for central cerebral structures and their segmentations can serve as guiding frame for multi-modal image registration. Segmentations of the falx and tentorium were performed with an average Dice coefficient of 0.74 and an average Hausdorff distance of 12.2 mm. The subsequent registration incorporates these segmentations and increases accuracy, robustness and speed of the overall registration process compared to purely intensity-based registration. For validation an expert manually located corresponding landmarks. Our approach reduces the initial mean Target Registration Error from 16.9 mm to 3.8 mm using our intensity-based registration and to 2.2 mm with our combined segmentation and registration approach. The intensity-based registration reduced the maximum initial TRE from 19.4 mm to 5.6 mm, with the approach incorporating segmentations this is reduced to 3.0 mm. Mean volumetric intensity-based registration of preMRI and iUS took 40.5 s, including segmentations 12.0 s. Keywords: IGNS, Image-guided neurosurgery, Intra-operative ultrasound, MRI, Registration, Segmentation