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Neuroinflammation evaluation after acute ischemic stroke is a promising option for selecting an appropriate post-stroke treatment strategy. To assess neuroinflammation in vivo, translocator protein PET (TSPO PET) can be used. However, the gold standard TSPO PET quantification method includes a 90 min scan and continuous arterial blood sampling, which is challenging to perform on a routine basis. In this work, we determine what information is required for a simplified quantification approach using a machine learning algorithm.We analyzed data from 18 patients with ischemic stroke who received 0-90 min [18F]GE-180 PET as well as T1-weigted (T1w), FLAIR, and arterial spin labeling (ASL) MRI scans. During PET scans, five manual venous blood samples at 5, 15, 30, 60, and 85 min post injection (p.i.) were drawn, and plasma activity concentration was measured. Total distribution volume (VT) was calculated using Logan plot with the full dynamic PET and an image-derived input function (IDIF) from the carotid arteries. IDIF was scaled by a calibration factor derived from all the measured plasma activity concentrations. The calculated VT values were used for training a random forest regressor. As input features for the model, we used three late PET frames (60-70, 70-80, and 80-90 min p.i.), the ASL image reflecting perfusion, the voxel coordinates, the lesion mask, and the five plasma activity concentrations. The algorithm was validated with the leave-one-out approach. To estimate the impact of the individual features on the algorithm's performance, we used Shapley Additive Explanations (SHAP). Having determined that the three late PET frames and the plasma activity concentrations were the most important features, we tested a simplified quantification approach consisting of dividing a late PET frame by a plasma activity concentration. All the combinations of frames/samples were compared by means of concordance correlation coefficient and Bland-Altman plots.When using all the input features, the algorithm predicted VT values with high accuracy (87.8 ± 8.3%) for both lesion and non-lesion voxels. The SHAP values demonstrated high impact of the late PET frames (60-70, 70-80, and 80-90 min p.i.) and plasma activity concentrations on the VT prediction, while the influence of the ASL-derived perfusion, voxel coordinates, and the lesion mask was low. Among all the combinations of the late PET frames and plasma activity concentrations, the 70-80 min p.i. frame divided by the 30 min p.i. plasma sample produced the closest VT estimate in the ischemic lesion.Reliable TSPO PET quantification is achievable by using a single late PET frame divided by a late blood sample activity concentration.

ZusammenfassungZur Behandlung der Borderline-Persönlichkeitsstörung (BPS) liegen mehrere evidenzbasierte Behandlungsmodelle vor. Die derzeitigen Versorgungsstrukturen werden dieser Patient*innengruppe aber so wenig gerecht, dass immer noch der größte Teil der in Deutschland für die BPS aufgewendeten Mittel in stationäre Kriseninterventionen fließt. Diese bleiben ebenso wie geplante stationäre Behandlungen oft Stückwerk, weil keine ambulante Anschlussbehandlung zustande kommt. Viele, gerade schwer kranke Patient*innen finden gar keine ambulante Behandlung. Sofern ambulante Psychotherapien zu Stande kommen, scheitern diese oft in Krisensituationen. Die in den Behandlungsleitlinien explizit empfohlenen integrierten und vernetzten Strukturen einer Komplexbehandlung fehlen bislang weitgehend. Eine Möglichkeit zur Verbesserung dieser Situation kann der Rückgriff auf Strukturen der Integrierten Versorgung (IV) sein, die konzeptuell störungsspezifisch ausgestaltet werden müssen.Mit dem Hamburger Modell der Integrierten Versorgung – Borderline wurde ein DBT-basiertes, multimodales, langfristig angelegtes, krisenfestes Behandlungskonzept für die Behandlung von Patient*innen mit schwerer BPS entwickelt. Vordringliche Ziele sind die Förderung der funktionalen Selbstregulation, vor allem im Bereich der Emotionen, die Verbesserung der Lebensqualität, der Abbau selbstschädigenden Verhaltens und die Reduktion stationärer Kriseninterventionen. Zentrales Element dieses Konzeptes ist ein ambulantes, interdisziplinäres Team, das zugleich IV-Team und DBT-Team ist. Dieses arbeitet in einem psychiatrischen Krankenhaus mit regionalem Versorgungsauftrag und nutzt dessen Strukturen.Erste Evaluationsdaten weisen auf eine Verbesserung des Funktionsniveaus und eine deutliche Reduktion der BPS-Symptomatik hin. Außerdem verringerte sich die Zahl der stationären Krankenhaustage erheblich. Das Modell scheint in der Lage zu sein, schwer kranke Borderline-Patient*innen weitestgehend ambulant erfolgreich zu behandeln. Es könnte also dazu beitragen, die Fragmentierung der Behandlungsangebote für Borderline-Betroffene zu überwinden.

Complicated nonstenosing carotid artery plaques (CAPs) are an under-recognized cause of stroke.The purpose of this study was to determine whether complicated CAP ipsilateral to acute ischemic anterior circulation stroke (icCAP) are associated with recurrent ischemic stroke or transient ischemic attack (TIA).The CAPIAS (Carotid Plaque Imaging in Acute Stroke) multicenter study prospectively recruited patients with ischemic stroke restricted to the territory of a single carotid artery. Complicated (AHA-lesion type VI) CAP were defined by multisequence, contrast-enhanced carotid magnetic resonance imaging obtained within 10 days from stroke onset. Recurrent events were assessed after 3, 12, 24, and 36 months. The primary outcome was recurrent ischemic stroke or TIA.Among 196 patients enrolled, 104 patients had cryptogenic stroke and nonstenosing CAP. During a mean follow-up of 30 months, recurrent ischemic stroke or TIA occurred in 21 patients. Recurrent events were significantly more frequent in patients with icCAP than in patients without icCAP, both in the overall cohort (incidence rate [3-year interval]: 9.50 vs 3.61 per 100 patient-years; P = 0.025, log-rank test) and in patients with cryptogenic stroke (10.92 vs 1.82 per 100 patient-years; P = 0.003). The results were driven by ipsilateral events. A ruptured fibrous cap (HR: 4.91; 95% CI: 1.31-18.45; P = 0.018) and intraplaque hemorrhage (HR: 4.37; 95% CI: 1.20-15.97; P = 0.026) were associated with a significantly increased risk of recurrent events in patients with cryptogenic stroke.Complicated CAP ipsilateral to acute ischemic anterior circulation stroke are associated with an increased risk of recurrent ischemic stroke or TIA. Carotid plaque imaging identifies high-risk patients who might be suited for inclusion into future secondary prevention trials. (Carotid Plaque Imaging in Acute Stroke [CAPIAS]; NCT01284933).

Most Non-Small-Cell lung cancer (NSCLC) patients need systemic treatment. Immunotherapy is now current standard in first- and second-line treatment. In all pivotal studies, staging was performed using conventional computer tomography (CT) scans. PET/CT-based treatment monitoring is on the contrary recommended in NSCLC guidelines. This investigation aims at describing the benefits, challenges and possible pitfalls of using PET/CT-based monitoring for lung cancer during immunotherapy. We analyzed 11 NSCLC patients treated with nivolumab at a German tertiary care lung cancer center between 2015 and 2016. All patients received at least two follow-up PET-CTs. Evaluation of response was based on both Response Evaluation Criteria in Solid Tumors (RECIST) and PET Response Criteria in Solid Tumors (PERCIST) criteria. In 7 out of 11 cases, the RECIST and PERCIST results concurred, but two patients with initial stable disease regarding RECIST were reclassified as progressive metabolic disease based on PERCIST criteria. Additionally we identified one case of pseudoprogression using PERCIST criteria in contrast to stable disease using RECIST criteria and one case showing an early and durable response to nivolumab treatment using RECIST, despite a highly hypermetabolic mediastinal lymph node metastasis. The findings indicate that the PERCIST-based evaluation could identify progressive disease earlier. Early identification of nonresponders could lead to prevention of overtreatment and to an early switch to a more effective therapy.

The underlying etiology of ischemic stroke remains unknown in up to 30% of patients.Objectives: This study explored the causal role of complicated (American Heart Association-lesion type VI) nonstenosing carotid artery plaques (CAPs) in cryptogenic stroke (CS).Methods: CAPIAS (Carotid Plaque Imaging in Acute Stroke) is an observational multicenter study that prospectively recruited patients aged older than 49 years with acute ischemic stroke that was restricted to the territory of a single carotid artery on brain magnetic resonance imaging (MRI) and unilateral or bilateral CAP (≥2 mm, NASCET [North American Symptomatic Carotid Endarterectomy Trial]

Objectives The goal of this study was to compare the risk of stroke between patients with carotid artery disease with and without the presence of intraplaque hemorrhage (IPH) on magnetic r...

Purpose: The aim of this study was to investigate whether the detection of foreign bodies can be improved using dark-field and phase-contrast radiography compared with conventional (transmission) radiographs. Materials and Methods: Experiments were performed using ex vivo pig paws, which were prepared with differently sized foreign bodies of metal, wood, and glass (n = 10 each). Paws without foreign bodies served as controls (n = 30). All images were acquired using an experimental grating-based large object radiography system. Five blinded readers (second- to fourth-year radiology residents) were asked to assess the presence or absence of any foreign body. Sensitivity and specificity for the detection of metal, wood, glass, and any foreign body were calculated and compared using McNemar test and generalized linear mixed models. Results: Sensitivity for the detection of metal foreign bodies was 100% for all readers and image combinations. The sensitivity for the detection of wooden foreign bodies increased from 2% for transmission images to 78% when dark-field images were added (P < 0.0001). For glass foreign bodies, sensitivity increased from 84% for transmission images to 96% when adding phase-contrast images (P = 0.041). Sensitivity for the detection of any foreign body was 91% when transmission, dark-field, and phase-contrast images were viewed simultaneously, compared with 62% for transmission images alone (P < 0.0001). Specificity was 99% to 100% across all readers and radiography modalities. Conclusions: Adding dark-field images substantially improves the detection of wooden foreign bodies compared with the analysis of conventional (transmission) radiographs alone. Detection of glass foreign bodies was moderately improved when adding phase-contrast images.

The results of grinding processes like surface roughness or grinding burn are often characterized by the usage of the tool specification and process parameters but also by the geometrical contact. Whereas the calculation of contact length or contact area as well as the specific removal rate is clearly defined for processes like plane or cylindrical grinding, they are still a field of research in context of continuous generating gear grinding. In the scientific environment the contact parameters for continuous generating grinding have been already computed via numerical simulations. But the dependency of the contact parameters on the simulation software restricts their industrial usability. One of the focuses in the actual gear machining analysis at the Institute of Production Engineering and Machine Tools is the analytical modeling of the geometrical contact values for continuous generating grinding. In this paper the geometrical model of the contact area is presented and validated via numerical simulation. Thereby, a high degree of correlation between calculated and simulated values arises.

In up to 40% of ischemic stroke cases the etiology remains unknown. A substantial proportion of these patients has non- or only mildly stenosing carotid artery plaques not fulfilling common criteria for large artery stroke, but beeing suspicious for arterio-arteriell embolism. Several imaging techniques allow the non-invasive analysis of plaque features. Nevertheless, carotid MRI might be best suited to assess the key features of vulnerable plaques. This review article discusses potential causes of cryptogenic stroke, the role of plaque imaging in non-stenosing plaques and the association of vulnerable plaques and specific plaque features with stroke risk and stroke recurrence.

The goal of this study was to compare the risk of stroke between patients with carotid artery disease with and without the presence of intraplaque hemorrhage (IPH) on magnetic resonance imaging.IPH in carotid stenosis increases the risk of cerebrovascular events. Uncertainty remains whether risk of stroke alone is increased and whether stroke is predicted independently of known risk factors.Data were pooled from 7 cohort studies including 560 patients with symptomatic carotid stenosis and 136 patients with asymptomatic carotid stenosis. Hazards of ipsilateral ischemic stroke (primary outcome) were compared between patients with and without IPH, adjusted for clinical risk factors.IPH was present in 51.6% of patients with symptomatic carotid stenosis and 29.4% of patients with asymptomatic carotid stenosis. During 1,121 observed person-years, 66 ipsilateral strokes occurred. Presence of IPH at baseline increased the risk of ipsilateral stroke both in symptomatic (hazard ratio [HR]: 10.2; 95% confidence interval [CI]: 4.6 to 22.5) and asymptomatic (HR: 7.9; 95% CI: 1.3 to 47.6) patients. Among patients with symptomatic carotid stenosis, annualized event rates of ipsilateral stroke in those with IPH versus those without IPH were 9.0% versus 0.7% (50% stenosis), 18.1% versus 2.1% (50% to 69% stenosis), and 29.3% versus 1.5% (70% to 99% stenosis). Annualized event rates among patients with asymptomatic carotid stenosis were 5.4% in those with IPH versus 0.8% in those without IPH. Multivariate analysis identified IPH (HR: 11.0; 95% CI: 4.8 to 25.1) and severe degree of stenosis (HR: 3.3; 95% CI: 1.4 to 7.8) as independent predictors of ipsilateral stroke.IPH is common in patients with symptomatic and asymptomatic carotid stenosis and is a stronger predictor of stroke than any known clinical risk factors. Magnetic resonance imaging might help identify patients with carotid disease who would benefit from revascularization.

Summary: A key question in vision research concerns how the brain compensates for self-induced eye and head movements to form the world-centered, spatiotopic representations we perceive. Although human V3A and V6 integrate eye movements with vision, it is unclear which areas integrate head motion signals with visual retinotopic representations, as fMRI typically prevents head movement executions. Here we examined whether human early visual cortex V3A and V6 integrate these signals. A previously introduced paradigm allowed participant head movement during trials, but stabilized the head during data acquisition utilizing the delay between blood-oxygen-level-dependent (BOLD) and neural signals. Visual stimuli simulated either a stable environment or one with arbitrary head-coupled visual motion. Importantly, both conditions were matched in retinal and head motion. Contrasts revealed differential responses in human V6. Given the lack of vestibular responses in primate V6, these results suggest multi-modal integration of visual with neck efference copy signals or proprioception in V6. : Neuroscience; Sensory Neuroscience; Techniques in Neuroscience Subject Areas: Neuroscience, Sensory Neuroscience, Techniques in Neuroscience

Our phenomenological experience of the stable world is maintained by continuous integration of visual self-motion with extra-retinal signals. However, due to conventional constraints of fMRI acquisition in humans, neural responses to visuo-vestibular integration have only been studied using artificial stimuli, in the absence of voluntary head-motion. We here circumvented these limitations and let participants to move their heads during scanning. The slow dynamics of the BOLD signal allowed us to acquire neural signal related to head motion after the observer's head was stabilized by inflatable aircushions. Visual stimuli were presented on head-fixed display goggles and updated in real time as a function of head-motion that was tracked using an external camera. Two conditions simulated forward translation of the participant. During physical head rotation, the congruent condition simulated a stable world, whereas the incongruent condition added arbitrary lateral motion. Importantly, both conditions were precisely matched in visual properties and head-rotation. By comparing congruent with incongruent conditions we found evidence consistent with the multi-modal integration of visual cues with head motion into a coherent "stable world" percept in the parietal operculum and in an anterior part of parieto-insular cortex (aPIC). In the visual motion network, human regions MST, a dorsal part of VIP, the cingulate sulcus visual area (CSv) and a region in precuneus (Pc) showed differential responses to the same contrast. The results demonstrate for the first time neural multimodal interactions between precisely matched congruent versus incongruent visual and non-visual cues during physical head-movement in the human brain. The methodological approach opens the path to a new class of fMRI studies with unprecedented temporal and spatial control over visuo-vestibular stimulation.