The laminar organization of cell types in macaque cortex and its relationship to neuronal oscillations

The canonical microcircuit (CMC) has been hypothesized to be the fundamental unit of information processing in cortex. Each CMC unit is thought to be an interconnected column of neurons with specific connections between excitatory and inhibitory neurons across layers. Recently, we identified a conserved spectrolaminar motif of oscillatory activity across the primate cortex that may be the physiological consequence of the CMC. The spectrolaminar motif consists of local field potential (LFP) gamma-band power (40-150 Hz) peaking in superficial layers 2 and 3 and alpha/beta-band power (8-30 Hz) peaking in deep layers 5 and 6. Here, we investigate whether specific conserved cell types may produce the spectrolaminar motif. We collected laminar histological and electrophysiological data in 11 distinct cortical areas spanning the visual hierarchy: V1, V2, V3, V4, TEO, MT, MST, LIP, 8A/FEF, PMD, and LPFC (area 46), and anatomical data in DP and 7A. We stained representative slices for the three main inhibitory subtypes, Parvalbumin (PV), Calbindin (CB), and Calretinin (CR) positive neurons, as well as pyramidal cells marked with Neurogranin (NRGN). We found a conserved laminar structure of PV, CB, CR, and pyramidal cells. We also found a consistent relationship between the laminar distribution of inhibitory subtypes with power in the local field potential. PV interneuron density positively correlated with gamma (40-150 Hz) power. CR and CB density negatively correlated with alpha (8-12 Hz) and beta (13-30 Hz) oscillations. The conserved, layer-specific pattern of inhibition and excitation across layers is therefore likely the anatomical substrate of the spectrolaminar motif.

Significance Statement

Neuronal oscillations emerge as an interplay between excitatory and inhibitory neurons and underlie cognitive functions and conscious states. These oscillations have distinct expression patterns across cortical layers. Does cellular anatomy enable these oscillations to emerge in specific cortical layers? We present a comprehensive analysis of the laminar distribution of the three main inhibitory cell types in primate cortex (Parvalbumin, Calbindin, and Calretinin positive) and excitatory pyramidal cells. We found a canonical relationship between the laminar anatomy and electrophysiology in 11 distinct primate areas spanning from primary visual to prefrontal cortex. The laminar anatomy explained the expression patterns of neuronal oscillations in different frequencies. Our work provides insight into the cortex-wide cellular mechanisms that generate neuronal oscillations in primates.

Method for comparison of data driven gating algorithms in emission tomography

Objective.Multiple algorithms have been proposed for data driven gating (DDG) in single photon emission computed tomography (SPECT) and have successfully been applied to myocardial perfusion imaging (MPI). Application of DDG to acquisition types other than SPECT MPI has not been demonstrated so far, as limitations and pitfalls of current methods are unknown.Approach.We create a comprehensive set of phantoms simulating the influence of different motion artifacts, view angles, moving objects, contrast, and count levels in SPECT. We perform Monte Carlo simulation of the phantoms, allowing the characterization of DDG algorithms using quantitative metrics derived from the data and evaluate the Center of Light (COL) and Laplacian Eigenmaps methods as sample DDG algorithms.Main results.View angle, object size, count rate density, and contrast influence the accuracy of both DDG methods. Moreover, the ability to extract the respiratory motion in the phantom was shown to correlate with the contrast of the moving feature to the background, the signal to noise ratio, and the noise in the data.Significance.We showed that reporting the average correlation to an external physical reference signal per acquisition is not sufficient to characterize DDG methods. Assessing DDG methods on a view-by-view basis using the simulations and metrics from this work could enable the identification of pitfalls of current methods, and extend their application to acquisitions beyond SPECT MPI.

[Ultrasound examination of nerves of the upper extremities]

The ultrasound examination of peripheral nerves has been further developed in recent years and is recognized as an independent discipline by the German Society of Ultrasound in Medicine (DEGUM). A systematic ultrasound examination of the musculoskeletal system is not limited to the joints, muscles and bones but should also include the examination of nerves and blood vessels. Therefore, in the practice of ultrasound examination every rheumatologist should have at least a basic knowledge of the ultrasound examination of the peripheral nerves. In this article the authors present a landmark-based concept in which the three large nerves of the upper extremities can be completely visualized from proximal to distal and evaluated.

Multidimensional immunoimaging to characterize the inflammatory reaction after permanent and temporary coronary artery occlusion in mice

Background

The immune response following acute myocardial infarction encompasses a delicate balance between inflammatory and reparative programs. Our knowledge of these complex mechanisms is mainly derived from studies using a murine model of permanent coronary artery occlusion. In this study we developed, validated and implemented multiparametric imaging methods to investigate cardiac function and the systemic immune response in transient or permanent coronary artery occlusion mouse models.

Methods

The myocardial infarction models encompassed either transient (40 min) or permanent LAD occlusion in C57BL/6 mice, and non-infarcted mice were used as controls. Two or seven days later, the animals subjected to systemic immunoimaging of the bone marrow, spleen and myocardium with late gadolinium enhancement cardiac MRI (LGE cMRI), 18F-fluorodeoxyglucose (18F-FDG) PET, 18F-Fluorothymidine (18F-FLT) PET, 64Cu-CCR2 PET targeting inflammatory monocytes, 89Zr-CD11b nanobody PET and 19F-HDL-PERFECTA MRI, both targeting myeloid cells. In addition, the same myocardial infarction models were applied to atherosclerosis-prone Apoe−/− and systemic inflammation and plaque progression were assessed by flow cytometry and immunohistochemistry four weeks after infarction.

Results

Through LGE cMRI and 18F-FDG PET, we observed that temporary coronary occlusion resulted in a smaller infarct size, better cardiac function and viability compared to permanent occlusion. Multiparametric immunoimaging targeting CD11b+ cells by 89Zr-CD11b nanobody PET and Ly6Chi inflammatory monocytes by 64Cu-CCR2 PET demonstrated that mice subjected to transient coronary occlusion had less immune cell influx to the ischemic myocardium. This finding was confirmed by flow cytometry analysis of the infarct zone. In contrast, both myocardial infarction models cause a similar systemic immune response in the bone marrow and spleen as observed with multimodal imaging with subsequent similar numbers of CD11b+ cells in the blood. Both permanent and temporary coronary artery occlusion aggravate atherosclerosis in Apoe−/− mice with higher macrophage and Ly6Chi monocyte numbers in aortas and larger plaque size compared to Apoe−/− mice without myocardial infarction.

Conclusions

We developed and employed multimodal, multiparametric imaging protocols to characterize the immune response in the heart, bone marrow and spleen in two models of myocardial infarction. While cardiac function was superior in the ischemia reperfusion model, both types of myocardial infarction accelerated atherosclerosis.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): NIH and DFG

Fully automatic AI-based valve motion parameter extraction on long axis CINE images - application on N=11000 patient datasets

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Research support from Siemens Healthineers GmbH.

Background

Mitral valve (MV) motion parameters, assessable using CMR [1, 2], have been shown to help the diagnosis of cardiac dysfunction. To extract valve motion parameters, we propose a fully automatic AI-based prototype system that tracks annulus and apex landmarks by the registration network on time-resolved two- and four-chamber CMR cine views. Parameters such as displacements, velocities, mitral annular plane systolic excursion (MAPSE), or longitudinal shortening (LS) are automatically extracted and evaluated on a large CMR dataset (N=11000).

Methods

The system consists of two sequential neural networks with a processing step in between (Fig. 1a) [3]. Initially, a 2D UNet is applied to localize both MV annulus insertion points as well as the apex. Based on these points, the image processing step consists of rotating, cropping, and interpolating the images, allowing a standardized image impression for both long axis views. Finally, the registration network (VoxelMorph framework [4]) is applied to the processed series and tracks the MV annulus insertion points and apex over the cardiac cycle by the deformation fields obtained by the network. The system was trained on (N=166) multivendor, multi-field strength, ground-truth annotated datasets [5].

A total of 11000 datasets, acquired on a 1.5T scanner (MAGNETOM Aera, Siemens Healthcare, Erlangen, Germany) from January 2016 to September 2017 [6], were used for parameter extraction. 200 of these datasets were additionally annotated semi-automatically for the performance evaluation of the system.

Five motion parameters were automatically derived by the system that are defined as follows (Fig. 1b): (1) The atrioventricular plane displacement (AVPD) as the distance of the plane spanned by the MV annulus points relative to the first frame, (2) the atrioventricular plane velocity (AVPV) as the discrete temporal derivate of the AVPD, (3) the diameter of the annulus as the maximum distance between the MV annulus points, (4) the lateral/inferior and septal/superior MAPSE, as the maximum MV points’ excursion, and (5) the LS as the percentage size difference of the distance between the mid valvular point and the apex point at end-systole and end-diastole.

Results

The accuracy of the system resulted in deviations on the annotated dataset of 1.02 ± 0.87 mm, 0.01 ± 0.02 mm/s, 1.54 ± 1.21 mm, 2.30 ± 1.35 mm, 2.1 ± 1.8 mm for AVPD, AVPV, diameter, MAPSE, and LS respectively. Initial statistics on all datasets (Fig. 2) revealed a mean lateral/inferior, septal/superior MAPSE and LS of 8.7 ± 2.7 mm, 10.5 ± 3.2 mm and 16.3 ± 4.2 % for two-chamber and 9.6 ± 2.6 mm, 8.7 ± 2.6 mm and 15.5 ± 3.9 % for four-chamber views, respectively.

Conclusions

The results demonstrate the versatility of the proposed system for automatic extraction of various MV motion parameters. The proposed system enables automatic extraction of clinically relevant parameters and can improve the automation of MV-based analyses. System overview & Parameter of interestsAnalysis of the extracted parameters

Fully automated machine learning-based selection of optimal bSSFP frequency offset for artifact reduction in cardiac MRI

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Research Support from Siemens Healthineers GmbH.

Background

In bSSFP sequences commonly used for cardiac MRI, signal modulation (e.g. banding artifacts) due to B0 inhomogeneity is often observed, especially at higher field strengths. The spatial position of these artifacts can be shifted by a frequency offset to reduce artifacts in a region of interest (ROI), e.g. the heart. To this end, frequency scout (FS) scans are acquired to visually select the optimal frequency offset [1,2]. In this work, we propose a fully automated image-based system for selecting the optimal frequency offset on FS images based on machine learning.

Methods

The proposed prototype system consists of four main steps (Fig.1). First, a pre-trained deep-learning-based whole heart segmentation network is applied on a four chamber-view FS image to localize the ROI where artifacts should be reduced. Second, high frequency components within the ROI (for each frequency offset in the FS series) are extracted by successive processing of Fourier transformation, high-pass filtering, inverse Fourier transformation and subtraction over series. and N images with the lowest high-frequency content are selected. Third, an adaptive weighting map for each FS image is generated which penalizes signal deviations from a pixel-wise median that is calculated based on the selected images [3]. By averaging the maps and selecting the frame with maximum percentage, the optimal frequency offset is selected.

A total of 38 datasets, acquired on multiple clinical 3T MRI scanners (MAGNETOM Skyra, Vida, Prisma, Lumina; Siemens Healthcare, Erlangen, Germany), were used to evaluate the proposed system. All FS series were annotated manually and used to compare with the system output. The experts were allowed to select multiple possible optimal FS images within a FS series. In case of multiple annotations, the system output was labelled as correct when it selected one of the offsets chosen by the expert. Further, the generated weighting maps were visually evaluated.

Results

The proposed system achieved an accuracy of 92.1% compared to experts’ ground truth annotations. From the failed cases (n=3), the maximum difference was off by 2 frames. Based on the generated weighting maps, a reasonable decision on the selection of the optimal frequency offset is made. The algorithm successfully selects an FS image with minimized banding and flow artifacts within the ROI (Fig. 2a). Further, it reveals that the generated weighting map correctly suppress areas containing artifacts (Fig. 2b).

Conclusions

Initial results demonstrate the feasibility of the proposed system to automatically select the optimal frequency offset on FS scans. Therefore, it can improve the automation of a cardiac MRI workflow. An example of the result of each step

Source-detector trajectory optimization in cone-beam computed tomography: a comprehensive review on today’s state-of-the-art

Cone-beam computed tomography (CBCT) imaging is becoming increasingly important for a wide range of applications such as image-guided surgery, image-guided radiation therapy as well as diagnostic imaging such as breast and orthopaedic imaging. The potential benefits of non-circular source-detector trajectories was recognized in early work to improve the completeness of CBCT sampling and extend the field of view (FOV). Another important feature of interventional imaging is that prior knowledge of patient anatomy such as a preoperative CBCT or prior CT is commonly available. This provides the opportunity to integrate such prior information into the image acquisition process by customized CBCT source-detector trajectories. Such customized trajectories can be designed in order to optimize task-specific imaging performance, providing intervention or patient-specific imaging settings. The recently developed robotic CBCT C-arms as well as novel multi-source CBCT imaging systems with additional degrees of freedom provide the possibility to largely expand the scanning geometries beyond the conventional circular source-detector trajectory. This recent development has inspired the research community to innovate enhanced image quality by modifying image geometry, as opposed to hardware or algorithms. The recently proposed techniques in this field facilitate image quality improvement, FOV extension, radiation dose reduction, metal artifact reduction as well as 3D imaging under kinematic constraints. Because of the great practical value and the increasing importance of CBCT imaging in image-guided therapy for clinical and preclinical applications as well as in industry, this paper focuses on the review and discussion of the available literature in the CBCT trajectory optimization field. To the best of our knowledge, this paper is the first study that provides an exhaustive literature review regarding customized CBCT algorithms and tries to update the community with the clarification of in-depth information on the current progress and future trends.

Binocular Integration in the Primate Primary Visual Cortex

binocular vision, binocular fusion, binocular combination, LGN, V1.

OP0292 CLASSIFICATION OF PSORIATIC ARTHRITIS, SERONEGATIVE RHEUMATOID ARTHRITIS, AND SEROPOSITIVE RHEUMATOID ARTHRITIS USING DEEP LEARNING ON MAGNETIC RESONANCE IMAGING

Background

While MRI evaluation of joints has been primarily used to quantify inflammation at a cross-sectional and longitudinal level, less is known about the potential of MRI in distinguishing different patterns of inflammation in the various forms of arthritis.

Objectives

To evaluate (i) whether deep learning using neural networks can be trained to distinguish between seropositive rheumatoid arthritis (RA+), seronegative RA (RA-), and psoriatic arthritis (PsA) based on structural inflammatory patterns on hand magnetic resonance imaging and (ii) to assess if psoriasis patients with subclinical inflammation fit into such patterns.

Methods

ResNet 3D [1] neural networks were trained to distinguish (i) RA+ vs. PsA, (ii) RA- vs. PsA and (iii) RA+ vs. RA- with respect to hand MRI data. Diagnosis of patients was determined using the following guidelines: ACR/EULAR 2010 [2] for RA and CASPAR [3] for PsA. Results from T1 coronal, T2 coronal, T1 coronal and axial fat suppressed contrast-enhanced (CE) and T2 fat suppressed axial sequences were used. The performance of such trained networks was analyzed by the area-under-the-receiver-operating-characteristic curve (AUROC) with and without imputation of demographic and clinical parameters (Figure 1A). Additionally, the trained networks were applied to psoriasis patients without clinical signs of PsA.

Figure 1.

(A) Neural network combining MR sequences with optional additional clinical data. The prediction for a single case is formed by averaging the prediction of all sequences and the clinical data. (B) Plot of the AUROC for increasing percentages (0.6 – 60%) of training data for the differentiation between RA+ and PsA by the neural network. The light blue area around the dark blue mean indicates the uncertainty measured using a 5-fold cross-validation.

Results

MRI scans from 649 patients (135 RA-, 190 RA+, 177 PsA, 147 psoriasis) were included (Table 1). The AUROC for differentiation between disease entities was 75% (SD 3%) for RA+ vs. PsA, 74% (SD 8%) for RA- vs. PsA, and 67% (6%) for RA+ vs. RA-. All MRI sequences were relevant for classification, however, when deleting CE sequences, the loss of performance was only marginal. The addition of patient-specific data to the networks did not provide significant improvements. Increasing amounts of training data demonstrated improved performance of the networks (Figure 1B). Psoriasis patients were mostly assigned to PsA by the neural networks, suggesting that PsA-like MRI pattern may be present early in the course of psoriatic disease.

Table 1.

Overview of demographic and clinical information.

RA+RA-PsAPsoriasisTotal Number (N)649Number (N)190135177147Age (years), mean±SD56.9±12.660.5±10.356.3±12.049.6±13.8Sex (female/male)126/6493/4292/8571/76BMI (kg/m2), mean±SD26.6±10.527.6 ±9.329.1±11.326.7±6.9Disease duration (years), mean±SD2.6±4.91.3±2.30.8±2.34.2±5.1DAS28, mean±SD3.3±1.33.4±1.23.2±1.3-CRP (mg/L), mean±SD0.9±2.50.7±1.20.5±0.80.5±1.3HAQ, mean±SD0.8±0.60.9±0.80.6±0.60.3±0.4MedicationbDMARD88.46%83.87%81.32%35.01%csDMARD89.52%88.89%80.54%12.28%

Conclusion

Deep learning can be successfully applied to differentiate MRI inflammatory patterns related to RA+, RA-, and PsA. Early changes in psoriasis patients can be recognized by neural networks and are characterized by a pattern that allowed the networks to classify them as PsA.

References

[1]Kensho Hara, Hirokatsu Kataoka, and Yutaka Satoh 2018. Can Spatiotemporal 3D CNNs Retrace the History of 2D CNNs and ImageNet? In Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition (CVPR) (pp. 6546–6555).

[2]Aletaha D, Neogi T et al. 2010 Rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis Rheum. 2010 Sep;62(9):2569-81.

[3]Helliwell PS, Taylor WJ. Classification and diagnostic criteria for psoriatic arthritis. Annals of the Rheumatic Diseases 2005;64:ii3-ii8.

Acknowledgements

The study was supported by the Deutsche Forschungsgemeinschaft (DFG-FOR2886 PANDORA and the CRC1181 Checkpoints for Resolution of Inflammation). Additional funding was received by the Bundesministerium für Bildung und Forschung (BMBF; project MASCARA), the ERC Synergy grant 4D Nanoscope, the IMI funded projects HIPPOCRATES and RTCure, the Emerging Fields Initiative MIRACLE of the Friedrich-Alexander-Universität Erlangen-Nürnberg and the Else Kröner-Memorial Scholarship (DS, no. 2019_EKMS.27). Furthermore, infrastructural and hardware support was provided by the d.hip Digital Health Innovation Platform.

Disclosure of Interests

None declared

Basic knowledge in child protection– evaluation of an online-course for webbased transfer of interprofessional basic knowledge in child protection

Introduction

Insufficient or faulty cooperation between the various child protection professions can have an extremly negative impact on the well-being of the concerned children. Communication problems that were revealed when dealing with cases of child abuse show the importance of adequate cooperation and common language of the involved professions in child protection.

Objectives

An online-course adressing medical-therapeutic professionals, youth welfare as well as judiciary and police was developed to impart skills and knowledge in child protection to create interdisciplinary understanding and improve cooperation between the involved professions.

Methods

The acquisition of competencies, the transfer of learning content into everyday work and the quality of the online-course are determined using an online-survey before starting (t1) and after completing (t2) the course. T1-assessment is currently being evaluated with 1034 datasets, t2-assessment will take place 03/2022.

Results

Intended target groups could be accessed and participated in the online-course, although the ratio of medical-therapeutic participants was greater than of judiciary professionals. Specific results of T1- and T2- assesssment and comparing analyses are expected in March 2022 and will be presented.

Conclusions

Based on existing online-courses developed by the Universityhospital Ulm, the suitability of online-education for training professionals in the field of child protection could be proven. If comparable effects can be shown for this online-course, there is an increase in evaluated offers of high quality. These enable comprehensive and low-threshold access to the subject of interdisciplinary communication and cooperation in child protection for involved professionals.

Disclosure

No significant relationships.

Health professionals' perspectives on child protection capacities, training and need for action

Background

Child maltreatment is because of its prevalence and consequences one of the main reasons for global health inequalities and a major public health problem. The medical field offers many opportunities to support affected children. However, there is often very limited awareness concerning child protection beyond a few engaged professionals. The present work aims to survey the state of knowledge and capacities in view of child protection in the medical field and explores health professionals' perspectives on a potential need for action.

Methods

From 06/2016 until 02/2021 3,360 health professionals were interviewed. Using quantitative and qualitative items the questionnaire gathered demographic and professional background information as well as assessments regarding the awareness of child protection, capacities in child protection among health professionals and training offers in medicine.

Results

The analysis indicated that the topic child protection in medicine is not as present as the high prevalence demands it. The majority (94.0%; n = 3,159) of the probands stated that they need more knowledge and capacities regarding child protection in medicine. More than half of the probands assessed the importance of the issue child protection as low among health professionals. The reasons cited included child protection as being an uncomfortable topic, unwillingness among managers, and a lack of training on the topic.

Conclusions

It turned out that there is too little awareness and importance regarding child protection in the medical field. Hence, it is difficult to ensure an adequate care for those affected. Child protection topics should be made mandatory in the training curricula of all health professionals as well as quality standards for prevention and intervention should be implemented in medical institutions.

Key messages

Too little attention is paid to child protection in the medical field. More training in child protection and quality standards must be established in the medical field.

OP0145 DIFFERENTIAL DIAGNOSIS OF RA AND PSA USING NEURAL NETWORKS ON THREE-DIMENSIONAL BONE SHAPE OF FINGER JOINTS

Background:

Early diagnosis and reliable differentiation between rheumatic diseases (RMDs) are crucial to start an adequate therapy and prevent irreversible damage. Since finger joints are commonly affected in rheumatoid arthritis (RA) and psoriatic arthritis (PsA), imaging of the peripheral skeleton is an essential step of diagnosis at a rheumatologist. High resolution peripheral quantitative computed tomography (HR-pQCT) allows an even more detailed and three-dimensional (3D) illustration of the peripheral bone than conventional radiographs. Segmented scans contain further information, such as the density, microstructure, and shape of the bones, which can be further analyzed by neural networks.

Objectives:

We hypothesize that, based on the shape of the second metacarpophalangeal (MCP) joint from HR-pQCT images, a neural network can be trained to differentiate between RA, PsA, and healthy controls and to reveal regions in the bone shape characteristic for the diseases.

Methods:

HR-pQCT images of MCP joints from patients with classified CCP positive RA, classified PsA, and healthy controls with low motion artifacts and appropriate scan region were selected as reported previously [3]. Scans were performed as part of the clinical routine and patients gave their informed consent to use pseudonymized data (Ethics approval 334_16B). Based on the assumption that pathognomonic changes develop over time, only images were used, where the period between classification and imaging exceeded one year.

Based on previous work [4], a pixel-wise mask of the second metacarpal bone was generated using a neural network based on the HR-pQCT scans of patients. Supervised auto-encoder [1] networks were used to predict the correct class given the bone mask only. For the neural network experiment, the patient scans were split on a patient-level into training (70%), validation (20%), and testing (10%). Guided backpropagation [2] was used as a method to investigate the regions influencing the class prediction most.

Results:

In total, images of 331 patients were included in the experiments. The evaluation of the model on the 33 test cases yielded a high accuracy for the healthy control with 94%, RA patients with 84%, and PsA patients with 89%. An area under the receiver operator curve of 91% could be achieved. The regions of the bone mask influencing the network´s decision most are highlighted exemplary in Figure 1.

Figure 1.

Visualization of the HR-pQCT slices with gradient maps. Higher values (red) represent regions that had a stronger contribution to the classification result. The HR-pQCT images are displayed for reference only. (a) Healthy patient, (b) RA diagnosed patient, and (c) PsA diagnosed patient. The first row shows the single slices with the highest values corresponding to the 3D bone masks in the second row.

Conclusion:

For the first time, a neural network-based approach successfully provides a differential diagnosis of RA and PsA based only on the shape of the second MCP in HR-pQCT images. The evaluation of the test set suggests that high curvatures of the bone surface in the joint region significantly influence the prediction of the network, suggesting an in-depth investigation of these regions for patients affected by RA and PsA. Based on these promising findings, we aim to extend the approach to seronegative RA as well as early RA and PsA.

References:

[1]Le, L. et al. (2018). Supervised autoencoders: Improving generalization performance with unsupervised regularizers. In Advances in Neural Information Processing Systems.

[2]Springenberg, J. T. et al. (2015). Striving for simplicity: The all convolutional net. 3rd International Conference on Learning Representations, ICLR 2015 - Workshop Track Proceedings.

[3]Simon, D. et al. (2017). Age- and Sex-Dependent Changes of Intra-articular Cortical and Trabecular Bone Structure and the Effects of Rheumatoid Arthritis. Journal of Bone and Mineral Research, 32(4), 722–730.

[4]Folle, L. et al. (2021). Fully Automatic Bone Mineral Density Measurements using Deep Learning. Manuscript submitted for publication.

Acknowledgements:

This work was supported by the emerging field initiative (project 4 Med 05 “MIRACLE”) of the University Erlangen-Nürnberg and MASCARA - Molecular Assessment of Signatures Characterizing the Remission of Arthritis grant 01EC1903A.

Disclosure of Interests:

Lukas Folle: None declared, Chang Liu: None declared, David Simon Speakers bureau: Lilly, Novartis, Consultant of: Lilly, Novartis, Gilead, BMS, Abbvie, Grant/research support from: Lilly, Novartis, Timo Meinderink: None declared, Anna-Maria Liphardt Consultant of: Mylan/Meda Pharma, Grant/research support from: Novartis, Gerhard Krönke Speakers bureau: Lilly, Novartis, Consultant of: Lilly, Novartis, Gilead, BMS, Abbvie, Grant/research support from: Lilly, Novartis, Georg Schett Speakers bureau: Lilly, Novartis, Consultant of: Lilly, Novartis, Gilead, BMS, Abbvie, Grant/research support from: Lilly, Novartis, Andreas Maier: None declared, Arnd Kleyer Speakers bureau: Lilly, Novartis, Consultant of: Lilly, Novartis, Gilead, BMS, Abbvie, Grant/research support from: Novartis, Lilly

[Rehabilitation of orphan diseases in adulthood: osteogenesis imperfecta]

Osteogenesis imperfecta (brittle bone disease) is an orphan disease caused by a genetic mutation in collagen metabolism. Bone fractures are the most common symptoms; however, the clinical manifestation can vary widely. Additional features can include blue sclera, dwarfism, bone deformities, muscular weakness, scoliosis, hearing loss and hypermobility of joints. Most patients show a reduction of skeletal function. This leads to an increased risk of being unable to continue their former work and to participate in social life. A comprehensive treatment includes drug therapy, surgery and rehabilitation. This article gives an overview of the current status of rehabilitation in adult patients with osteogenesis imperfecta.

Three-dimensional Monte Carlo-based voxel-wise tumor dosimetry in patients with neuroendocrine tumors who underwent 177Lu-DOTATOC therapy

Background

Patients with advanced neuroendocrine tumors (NETs) of the midgut are suitable candidates for ¹⁷⁷Lu-DOTATOC therapy. Integrated SPECT/CT systems have the potential to help improve the accuracy of patient-specific tumor dosimetry. Dose estimations to target organs are generally performed using the Medical Internal Radiation Dose scheme. We present a novel Monte Carlo-based voxel-wise dosimetry approach to determine organ- and tumor-specific total tumor doses (TTD).

Methods

A cohort of 14 patients with histologically confirmed metastasized NETs of the midgut (11 men, 3 women, 62.3 ± 11.0 years of age) underwent a total of 39 cycles of ¹⁷⁷Lu-DOTATOC therapy (mean 2.8 cycles, SD ± 1 cycle). After the first cycle of therapy, regions of interest were defined manually on the SPECT/CT images for the kidneys, the spleen, and all 198 tracer-positive tumor lesions in the field of view. Four SPECT images, taken at 4 h, 24 h, 48 h and 72 h after injection of the radiopharmaceutical, were used to determine their effective half-lives in the structures of interest. The absorbed doses were calculated by a three-dimensional dosimetry method based on Monte Carlo simulations. TTD was calculated as the sum of all products of single tumor doses with single tumor volumes divided by the sum of all tumor volumes.

Results

The average dose values per cycle were 3.41 ± 1.28 Gy (1.91–6.22 Gy) for the kidneys, 4.40 ± 2.90 Gy (1.14–11.22 Gy) for the spleen, and 9.70 ± 8.96 Gy (1.47–39.49 Gy) for all ¹⁷⁷Lu-DOTATOC-positive tumor lesions. Low- and intermediate-grade tumors (G 1–2) absorbed a higher TTD compared to high-grade tumors (G 3) (signed-rank test, p =  < 0.05). The pre-therapeutic chromogranin A (CgA) value and the TTD correlated significantly (Pearson correlation:  = 0.67, p = 0.01). Higher TTD resulted in a significant decrease of CgA after therapy.

Conclusion

These results suggest that Monte Carlo-based voxel-wise dosimetry is a very promising tool for predicting the absorbed TTD based on histological and clinical parameters.

[Raynaud's phenomenon : Practical management]

Raynaud's phenomenon (RP) is a frequent and painful vasospasm of small arteries localized in acral body regions (most frequently the fingers). The more frequent so-called primary RP is caused merely by a functional dysregulation of the tonus of vascular walls. In contrast, the rarer secondary RP is additionally associated with structural abnormalities of blood vessels. Knowledge of RP is important for rheumatologists because secondary RP can be associated with the presence or development of severe underlying diseases, especially with systemic sclerosis. Thus, the rheumatologist has to be aware of this condition. In this article the diagnostic procedures and the most important treatment approaches are summarized.

Child protection in medicine - closing gaps in continuing education through e-learning

Background

Child abuse is a major problem across Europe. The consequences are often serious and long-lasting disorders which, in addition to the individual burden, are extremely costly for the national health system. It is important to prevent or recognize child abuse at an early stage and to provide adequate help to those affected. Health professionals are privileged first contact persons for the victims. However, the WHO assumes that about 90% of cases of child abuse in medical institutions remain unknown. It is therefore important to train health professionals in this field. For this reason, in Germany an E-Learning course on child protection in medicine is currently being developed and evaluated. This article is intended to present the results of the accompanying evaluation of the E-Learning course.

Methods

The accompanying evaluation collected and analyzed the graduates’ opinion on the course, its contents and the topic of child protection in medicine in general. Knowledge and competence levels were surveyed before and after the course and evaluated with a t-test for related samples.

Results

The evaluation of the course showed a high relevance of the topic of child protection in medicine and the rather low attention paid to the topic in the medical field. The course was, however, assessed very positively and the majority of graduates were already able to apply what they had learnt in their daily work. The pre-post design showed a significant increase in knowledge and skills as a result of the course.

Conclusions

It turned out that the E-Learning course on child protection in medicine closes an existing gap in the continuing medical education system. The evaluation also shows a success of the program and thus a reduction of uncertainties in child protection procedures among health professionals. A corresponding E-Learning offer for other European countries should be considered in order to address the comprehensive problem of child abuse across the whole of Europe.

Key messages

Too little attention is paid to child protection in the medical field. E-Learning can effectively train health professionals in child protection, has a wide reach and is flexible in use.

4323Detection of early inflammation in myocarditis by molecular magnetic resonance imaging of activated platelets

Introduction

A noninvasive imaging strategy for diagnosis and localization of early myocarditis would be of great clinical interest. However, resolution of current imaging techniques is limited. Platelets play an important role in inflammatory processes but the role in myocarditis is unknown. Therefore, the aim of this project was to examine the role of platelets in myocarditis and establish a sensitive non-invasive molecular MRI in-vivo imaging strategy for diagnosis of myocarditis with a contrast agent against activated platelets in mice.

Methods

Myocarditis was induced by subcutaneous injection of an emulsion of porcine cardiac myosin and complete freud's adjuvant (CFA) in Balb/c mice. Inflammatory activity was targeted with a contrast agent against activated platelets consisting of microparticles of iron oxide (MPIO) conjugated to a single chain antibody directed against ligand-induced binding sites (LIBS) on activated glycoprotein IIb/IIIa (=LIBS-MPIO). In comparison, we applied an unspecific control antibody linked to microparticles of iron oxide (control-MPIO) and injected LIBS-MPIO to mice subjected to incomplete freud's adjuvant (iCFA). All imaging results were correlated to immunohistochemistry findings.

Results

Histological evaluation showed significantly higher binding of LIBS-MPIOs to platelet enriched, CD41-positive inflamed myocardium two days after induction of myocarditis in comparison to later time points (7d, 14d, 21d) (p<0.05) and control-MPIO (p<0.05) injection. In iCFA injected mice no significant LIBS-MPIO binding was found (p<0.05). In 3D in-vivo MRI we could specifically detect focal signal effects in LIBS-MPIO injected mice 2 days after induction of myocarditis, whereas in control-MPIO injected mice no signal effect was visible. Quantification of the myocardial MRI signal confirmed a signal decrease after LIBS-MPIO injection and significant fewer signals in comparison to control-MPIO injection (p<0.05).

As a perspective, we also found CD41 positive areas in histology of human myocarditis specimens.

Conclusions

Platelets are involved in the inflammation of myocarditis. Molecular MRI with LIBS-MPIO can image them at an early time point. This noninvasive imaging strategy is of clinical interest for both diagnostic and prognostic purposes, and highlights the potential of molecular MRI for characterization of cardiovascular pathologies such as myocardial inflammation.

Probe-based confocal laser endomicroscopy in detecting malignant lesions of vocal folds

Probe-based confocal laser endomicroscopy (CLE) is an innovative technique for real-time, non-invasive analysis of the surface epithelium. While being successfully used for diagnosis by experts, this method has not yet been established in clinical routine, partly due to the lack of standards and criteria for classifying various lesions. Our aim was to determine the diagnostic value and inter-rater reliability of CLE in detecting malignant lesions of the vocal cords. 58 video sequences were extracted from the probe-based CLE (GastroFlex probe with a Cellvizio^® laser system) examinations of 3 patients with squamous cell carcinomas and 4 patients with benign alterations of the vocal folds. Two ENT surgeons, who were blinded to the histological result, were asked to identify the sequences representing a carcinoma. We showed an accuracy, sensitivity, specificity, PPV and NPV of 91.38-96.55%, 100%, 87.8-95.2%, 77.27-89.47% and 100%, respectively, with an inter-rater reliability of k = 0.89 (“almost perfect agreement”). Probe-based CLE is a promising method for diagnosis and assessment of vocal fold lesions in vivo. Our results suggest that, with adequate training, the diagnostic value of this technique can be improved and potentially provide important information during oncological surgery.

Ärztliche Kompetenzentwicklung im Kinderschutz durch E-Learning

Gegenstand und Ziel: Kindesmisshandlung stellt eine individuelle und gesellschaftliche Belastung dar. Gesundheitsfachkräfte sind hierbei wichtige Akteure, haben aber häufig unzureichende Kompetenzen. Deshalb fördert das Bundesministerium für Gesundheit die Entwicklung eines Online-Kurses zu Kinderschutz in der Medizin. Diese Arbeit stellt erste Ergebnisse der Kursevaluation für die ärztlichen Teilnehmenden vor. Material und Methoden: Vor und nach Bearbeitung des Kurses wurde Bedarf, Qualität und Kompetenzvermittlung des Online-Kurses mittels Fragebögen evaluiert. An der Befragung beteiligten sich 178 ärztliche Absolventen. Ergebnisse: 74,2% der Befragten empfanden die Inhalte des Kurses als genau angemessen. Wissen und Handlungskompetenz nahmen durch Bearbeitung des Kurses signifikant zu (Cohen’s d = 1,28 und 1,06). Der häufigste Grund für den Abbruch des Kurses waren mangelnde zeitliche Ressourcen (68,4%). Schlussfolgerungen: Der Online-Kurs stellt eine gute Möglichkeit dar, notwendige Kenntnisse zu Kinderschutz in der Medizin zu erwerben oder diese auszubauen. Klinische Relevanz: Es müssen Möglichkeiten geschaffen werden, um die Verbreitung der Kursinhalte noch weiter voranzutreiben.

The Dermal Exposure Risk Management and Logic eTookit: Characterizing and managing dermal exposure during emergency management operations

OBJECTIVE

Emergency management and operations (EMO) personnel require up-to-date information to make informed decisions during natural and man-made disasters. However, information gaps present challenges for accessing human health risk assessment and risk management strategies for dermal exposure. This article describes the development of a decision support system, the Dermal Exposure Risk Management and Logic (DERMaL) eToolkit.

DESIGN

The DERMaL eToolkit provides information on key resources used in emergency incidents. Resources were classified according to response phase, resource categories, and information category and evaluated on reliability, accessibility, and preference by subject matter experts in emergency management fields. These rankings were used to generate a value of information score, unique for each resource, which aids in developing reference lists for users during each incident phase.

RESULTS

This tool will identify and prioritize information resources on dermal risks, and can readily find the most relevant information to suit EMO needs.

CONCLUSION

The DERMaL eToolkit can be used as an aid in finding information resources targeted to scenario-driven needs by providing well-vetted and prioritized resources related to dermal hazards, exposure, and risk assessments for EMO.

Durch die kontinuierliche Blutdruckmessung lässt sich ein transienter orthostatischer Blutdruckabfall bei idiopathischer REM-Schlaf-Verhaltensstörung nachweisen

Ziel der Studie Es gibt wenige Daten zum orthostatischen Blutdruck (BD) Verhalten und Veränderungen der Herzratenvariabilität (HRV) bei idiopathischer REM-Schlaf-Verhaltensstörung (iRBD). Unsere Hypothese war, dass orthostatische BD Veränderungen vorübergehend sind.

Methodik Wir untersuchten 16 männliche iRBD Patienten und 15 altersgematchte männliche Kontrollprobanden (HC) im Hinblick auf eine Dysautonomie, HRV und kontinuierliche BD Messung während der Kipptischuntersuchung.

Ergebnisse Die BD Abfälle in den ersten 5 Minuten Stehzeit waren bei iRBD Patienten signifikant größer. IRBD Patienten hatten häufiger eine reduzierte respiratorische Sinusarrhythmie (RSA).

Schlussfolgerungen Mittels kontinuierlicher BD Messung ließen sich transiente orthostatische BD Abfälle bei iRBD detektieren. Longitudinale Daten werden zeigen, ob diese Änderungen Hinweise für eine periphere sympathoneurale Dysfunktion darstellen und frühe Marker einer späteren orthostatischen Hypotonie sein können.

[Merging different biobanks under one roof : Benefits and constraints on the way to a centralized biobank using the example of the BMBH]

Founded in 1386, Heidelberg University is Germany's oldest and one of Europe's most reputable universities. As a scientific hub in Germany, Heidelberg is home to several internationally renowned medical research facilities that have an enormous demand for biomaterial samples and data-especially in the field of translational and cancer research.The main objective of the BMBF-funded project "BioMaterialBank Heidelberg" (BMBH) was the harmonization of local biobanking under the same administrative roof through the implementation of common and standardized project, data, and quality management procedures.In the very beginning, existing structures and processes of the participating biobanks in Heidelberg were identified and a common administrative structure with central representatives for IT and quality management (QM) was established to coordinate all BMBH activities.Over time, implementation of consented structures and processes took place, also revealing organizational challenges that had to be solved concerning, for example, differences in sample handling and the definition of consistent access regulations.We will discuss below these challenges as well as the opportunities of building a centralized biobank and show how issues can be resolved using the example of the BMBH.

Disturbance of verticality perception and postural dysfunction in Parkinson's disease

OBJECTIVES

Verticality perception is known to be abnormal in Parkinson's disease (PD), but in which stage respective dysfunctions arise and how they relate to postural disorders remains to be settled. These issues were studied with respect to different dimensions of the subjective visual vertical (SVV) in relation to clinical parameters of postural control.

MATERIALS & METHODS

All participants had to orientate a luminous line at random planar orientations to a strictly vertical position using an automated operator system. The SVV was analyzed in 58 PD patients and 28 control subjects with respect to (i) the angle between true and subjective vertical (deviation) and (ii) the variability of this across five measurements (variability). Results were referred to the subjective upright head position (SUH), the disease stage, and clinical gait/balance features assessed by the MDS-UPDRS and the Tinetti test.

RESULTS

Parkinson's disease patients had significantly higher SVV deviation and variability than controls. With respect to disease stage, deviation developed before abnormal variability. SVV variability was associated with poor balance and gait performance, as well as postural instability. Deficits in SUH and SVV deviation were correlated and mostly unidirectional, but did not correspond to the side of motor symptom dominance.

CONCLUSIONS

Visual verticality perception in PD is deviated already in early stages, conceivably as a relatively static internal misrepresentation of object orientation. Variability about verticality perception emerges in more advanced stages and is associated with postural and balance abnormalities.

Oxygen beams for therapy: advanced biological treatment planning and experimental verification

Nowadays there is a rising interest towards exploiting new therapeutical beams beyond carbon ions and protons. In particular, [Formula: see text]O ions are being widely discussed due to their increased LET distribution. In this contribution, we report on the first experimental verification of biologically optimized treatment plans, accounting for different biological effects, generated with the TRiP98 planning system with [Formula: see text]O beams, performed at HIT and GSI. This implies the measurements of 3D profiles of absorbed dose as well as several biological measurements. The latter includes the measurements of relative biological effectiveness along the range of linear energy transfer values from  ≈20 up to  ≈750 keV μ [Formula: see text], oxygen enhancement ratio values and the verification of the kill-painting approach, to overcome hypoxia, with a phantom imitating an unevenly oxygenated target. With the present implementation, our treatment planning system is able to perform a comparative analysis of different ions, according to any given condition of the target. For the particular cases of low target oxygenation, [Formula: see text]O ions demonstrate a higher peak-to-entrance dose ratio for the same cell killing in the target region compared to [Formula: see text]C ions. Based on this phenomenon, we performed a short computational analysis to reveal the potential range of treatment plans, where [Formula: see text]O can benefit over lighter modalities. It emerges that for more hypoxic target regions (partial oxygen pressure of  ≈0.15% or lower) and relatively low doses (≈4 Gy or lower) the choice of [Formula: see text]O over [Formula: see text]C or [Formula: see text]He may be justified.

Motion compensation for cone-beam CT using Fourier consistency conditions

In cone-beam CT, involuntary patient motion and inaccurate or irreproducible scanner motion substantially degrades image quality. To avoid artifacts this motion needs to be estimated and compensated during image reconstruction. In previous work we showed that Fourier consistency conditions (FCC) can be used in fan-beam CT to estimate motion in the sinogram domain. This work extends the FCC to [Formula: see text] cone-beam CT. We derive an efficient cost function to compensate for [Formula: see text] motion using [Formula: see text] detector translations. The extended FCC method have been tested with five translational motion patterns, using a challenging numerical phantom. We evaluated the root-mean-square-error and the structural-similarity-index between motion corrected and motion-free reconstructions. Additionally, we computed the mean-absolute-difference (MAD) between the estimated and the ground-truth motion. The practical applicability of the method is demonstrated by application to respiratory motion estimation in rotational angiography, but also to motion correction for weight-bearing imaging of knees. Where the latter makes use of a specifically modified FCC version which is robust to axial truncation. The results show a great reduction of motion artifacts. Accurate estimation results were achieved with a maximum MAD value of 708 μm and 1184 μm for motion along the vertical and horizontal detector direction, respectively. The image quality of reconstructions obtained with the proposed method is close to that of motion corrected reconstructions based on the ground-truth motion. Simulations using noise-free and noisy data demonstrate that FCC are robust to noise. Even high-frequency motion was accurately estimated leading to a considerable reduction of streaking artifacts. The method is purely image-based and therefore independent of any auxiliary data.

Effects of functional endoscopic sinus surgery on the acoustics of the sinonasal tract

BACKGROUND

Nasal and paranasal cavities are supposed to contribute substantially to the vocal tract resonator properties. However, their acoustical effects as well as the effects of sinus surgery on the voice remain unclear. In this work we investigate resonance phenomena of paranasal sinuses prior to and after various rhinosurgical procedures in cadaveric human sinonasal tracts and corresponding 3D casts.

METHODOLOGY

Nasal and paranasal cavities of formalin-preserved cadavers and corresponding 3D replicas were excited by sine-tone sweeps from an earphone placed in the epipharynx. The response was picked up by a microphone at the nostrils. Different FESS procedures were performed and the acoustical responses following excitation were recorded. The measured acoustical changes in the obtained transfer functions were then evaluated.

RESULTS

Marked low frequency dips were detected in the transfer functions when sinus cavities were included in the nasal resonator system. These dips showed a significant correlation with sinus volumes. Following FESS procedures they moved upwards in frequency depending on the extent of the surgical intervention.

CONCLUSIONS

The transfer functions obtained in cadaveric situs and 3D replicas showed dips at the resonance frequencies of the paranasal cavities. Marked acoustic effects in terms of increase in dip frequency following FESS procedures were reproducibly documented.

Assessing cardiac function from total-variation-regularized 4D C-arm CT in the presence of angular undersampling

Time-resolved tomographic cardiac imaging using an angiographic C-arm device may support clinicians during minimally invasive therapy by enabling a thorough analysis of the heart function directly in the catheter laboratory. However, clinically feasible acquisition protocols entail a highly challenging reconstruction problem which suffers from sparse angular sampling of the trajectory. Compressed sensing theory promises that useful images can be recovered despite massive undersampling by means of sparsity-based regularization. For a multitude of reasons-most notably the desired reduction of scan time, dose and contrast agent required-it is of great interest to know just how little data is actually sufficient for a certain task. In this work, we apply a convex optimization approach based on primal-dual splitting to 4D cardiac C-arm computed tomography. We examine how the quality of spatially and temporally total-variation-regularized reconstruction degrades when using as few as [Formula: see text] projection views per heart phase. First, feasible regularization weights are determined in a numerical phantom study, demonstrating the individual benefits of both regularizers. Secondly, a task-based evaluation is performed in eight clinical patients. Semi-automatic segmentation-based volume measurements of the left ventricular blood pool performed on strongly undersampled images show a correlation of close to 99% with measurements obtained from less sparsely sampled data.

Interventional dual-energy imaging-Feasibility of rapid kV-switching on a C-arm CT system

PURPOSE

In the last years, dual-energy CT imaging has shown clinical value, thanks to its ability to differentiate materials based on their atomic number and to exploit different properties of images acquired at two different energies. C-arm CT systems are used to guide procedures in the interventional suite. Until now, there are no commercially available systems that employ dual-energy material decomposition. This paper explores the feasibility of implementing a fast kV-switching technique on a clinically available angiographic system for acquiring dual-energy C-arm CT images.

METHODS

As an initial proof of concept, a fast kV-switching approach was implemented on an angiographic C-arm system and the peak tube voltage during 3D rotational scans was measured. The tube voltage measurements during fast kV-switching scans were compared to corresponding measurements on kV-constant scans. Additionally, to prove stability of the requested exposure parameters, the accuracy of the delivered tube current and pulse width were also recorded and compared. In a first phantom experiment, the voxel intensity values of the individual tube voltage components of the fast kV-switching scans were compared to their corresponding kV-constant scans. The same phantom was used for a simple material decomposition between different iodine concentrations and pure water using a fast kV-switching protocol of 81 and 125 kV. In the last experiment, the same kV-switching protocol as in the phantom scan was used in an in vivo pig study to demonstrate the clinical feasibility.

RESULTS

During rapid kV-switching acquisitions, the measured tube voltage of the x-ray tube during fast switching scans has an absolute deviation of 0.23 ± 0.13 kV compared to the measured tube voltage produced during kV-constant acquisitions. The stability of the peak tube voltage over different scan requests was about 0.10 kV for the low and 0.46 for the high energy kV-switching scans and less than 0.1 kV for kV-constant scans, indicating slightly lower stability for kV-switching scans. The tube current resulted in a relative deviation of -1.6% for the low and 6.6% overestimation for the high tube voltage of the kV-switching scans compared to the kV-constant scans. The pulse width showed no deviation for the longer pulse width and only minor deviations (0.02 ± 0.02 ms) for the shorter pulse widths compared to the kV-constant scans. The phantom experiment using different iodine concentrations showed an accurate correlation (R² > 0.99) between the extracted intensity values in the kV-switching and kV-constant reconstructed volumes, and allows for an automatic differentiation between contrast concentration down to 10% (350 mg/ml iodine) and pure water under low-noise conditions. Preliminary results of iodine and soft tissue separation showed also promising results in the first in vivo pig study.

CONCLUSIONS

The feasibility of dual-energy imaging using a fast kV-switching method on an angiographic C-arm CT system was investigated. Direct measurements of beam quality in the x-ray field demonstrate the stability of the kV-switching method. Phantom and in vivo experiments showed that images did not deviate from those of corresponding kV-constant scans. All performed experiments confirmed the capability of performing fast kV-switching scans on a clinically available C-arm CT system. More complex material decomposition tasks and postprocessing steps will be part of future investigations.

Marker-free motion correction in weight-bearing cone-beam CT of the knee joint

PURPOSE

To allow for a purely image-based motion estimation and compensation in weight-bearing cone-beam computed tomography of the knee joint.

METHODS

Weight-bearing imaging of the knee joint in a standing position poses additional requirements for the image reconstruction algorithm. In contrast to supine scans, patient motion needs to be estimated and compensated. The authors propose a method that is based on 2D/3D registration of left and right femur and tibia segmented from a prior, motion-free reconstruction acquired in supine position. Each segmented bone is first roughly aligned to the motion-corrupted reconstruction of a scan in standing or squatting position. Subsequently, a rigid 2D/3D registration is performed for each bone to each of K projection images, estimating 6 × 4 × K motion parameters. The motion of individual bones is combined into global motion fields using thin-plate-spline extrapolation. These can be incorporated into a motion-compensated reconstruction in the backprojection step. The authors performed visual and quantitative comparisons between a state-of-the-art marker-based (MB) method and two variants of the proposed method using gradient correlation (GC) and normalized gradient information (NGI) as similarity measure for the 2D/3D registration.

RESULTS

The authors evaluated their method on four acquisitions under different squatting positions of the same patient. All methods showed substantial improvement in image quality compared to the uncorrected reconstructions. Compared to NGI and MB, the GC method showed increased streaking artifacts due to misregistrations in lateral projection images. NGI and MB showed comparable image quality at the bone regions. Because the markers are attached to the skin, the MB method performed better at the surface of the legs where the authors observed slight streaking of the NGI and GC methods. For a quantitative evaluation, the authors computed the universal quality index (UQI) for all bone regions with respect to the motion-free reconstruction. The authors quantitative evaluation over regions around the bones yielded a mean UQI of 18.4 for no correction, 53.3 and 56.1 for the proposed method using GC and NGI, respectively, and 53.7 for the MB reference approach. In contrast to the authors registration-based corrections, the MB reference method caused slight nonrigid deformations at bone outlines when compared to a motion-free reference scan.

CONCLUSIONS

The authors showed that their method based on the NGI similarity measure yields reconstruction quality close to the MB reference method. In contrast to the MB method, the proposed method does not require any preparation prior to the examination which will improve the clinical workflow and patient comfort. Further, the authors found that the MB method causes small, nonrigid deformations at the bone outline which indicates that markers may not accurately reflect the internal motion close to the knee joint. Therefore, the authors believe that the proposed method is a promising alternative to MB motion management.

Preoperative Glasgow Prognostic Score as additional independent prognostic parameter for patients with esophageal cancer after curative esophagectomy

BACKGROUND

Inflammation accelerates tumor growth followed by reduced survival in patients with cancer. The aim of this study was to evaluate the prognostic relevance of preoperatively increased levels of C-reactive protein (CRP) and the corresponding Glasgow Prognostic Score (GPS) on patients with esophageal carcinoma undergoing curative esophagectomy.

METHODS

The data of 174 operated esophageal cancer patients were evaluated retrospectively. Patient's demographic and clinico-pathological data, tumor specific data, preoperative plasma levels of CRP and albumin, the corresponding GPS, overall survival (OS) and progression free survival (PFS) were assessed.

RESULTS

103 (59.2%) had adenocarcinoma and 71 (40.8%) had squamous cell carcinoma. 71 patients (43%) had elevated CRP concentrations. 118 patients (71%) had GPS 0, 41 (25%) GPS 1 and 8 (4%) GPS 2. Mean GPS was 0.3 (0-2). 5-year OS was higher in patients with normal CRP than in those with increased CRP (68% vs. 39%; p = 0.007). 5-year OS in patients with GPS 0 and GPS 1 and 2 were 65% and 31% (p = 0.001). 5-year OS for the whole cohort was 56% (1 year: 83%, 3 years: 64%). Recurrence rate was 16.1% closely associated with GPS (p = 0.002). Median follow-up was 23 months (0-118 months). In multivariate analysis GPS, lymph node involvement, T stage and tumor histology were the independent prognostic parameters (p = 0.004, <0.001, 0.035, 0.010).

CONCLUSIONS

Preoperatively increased GPS is significantly associated with reduced postoperative survival and tumor recurrence. The GPS as an independent prognosticator should be interpreted together with the TNM stage when the further postoperative treatment has to be scheduled.

Evaluation of self-swabbing coupled with a telephone health helpline as an adjunct tool for surveillance of influenza viruses in Ontario

Background

Calls to a telephone health helpline (THHL) have been previously evaluated for the ability to monitor specific syndromes, such as fever and influenza-like-illness or gastrointestinal illness. This method of surveillance has been shown to be highly correlated with traditional surveillance methods, and to have potential for early detection of community-based illness. Self-sampling, or having a person take his/her own nasal swab, has also proven successful as a useful method for obtaining a specimen, which may be used for respiratory virus detection.

Methods

This study describes a self-swabbing surveillance system mediated by a nurse-led THHL in Ontario whereby syndromic surveillance concepts are used to recruit and monitor participants with influenza-like illness. Once recruited, participants collect a nasal specimen obtained by self-swabbing and submit for testing and laboratory confirmation. Enumeration of weekly case counts was used to evaluate the timeliness of the self-swabbing surveillance system through comparison to other respiratory virus and influenza surveillance systems in Ontario. The operational efficiency of the system was also evaluated.

Results

The mean and median number of days between the day that a participant called the THHL, to the day a package was received at the laboratory for testing were approximately 10.4 and 8.6 days, respectively. The time between self-swab collection and package reception was 4.9 days on average, with a median of 4 days. The self-swabbing surveillance system adequately captured the 2014 influenza B season in a timely manner when compared to other Ontario-based sources of influenza surveillance data from the same year; however, the emergence of influenza B was not detected any earlier than with these other surveillance systems. Influenza A surveillance was also evaluated. Using the THHL self-swabbing system, a peak in the number of cases for influenza A was observed approximately one week after or during the same week as that reported by the other surveillance systems.

Conclusion

This one-year pilot study suggests that the THHL self-swabbing surveillance system has significant potential as an adjunct tool for the surveillance of influenza viruses in Ontario. Recommendations for improving system efficacy are discussed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3674-9) contains supplementary material, which is available to authorized users.

Die komplizierte Gicht

Ein 57-jähriger Patient wurde aus der internistischen Abteilung einer auswärtigen Klinik übernommen, mit zahlreichen Gichttophi und einer Überwärmung des rechten Knies und des rechten Ellenbogens. Seit 20 Tagen bestand eine probatorische parenterale Antibiotikatherapie. Durch eine sofortige Punktion des rechten Kniegelenks konnte die Diagnose einer bakteriellen Arthritis gestellt werden. Es erfolgte umgehend eine Operation mit Spülung und ausführlichem Debridement unter der Weiterführung der Antibiotikatherapie. Bei Patienten mit Gicht und Verdacht auf eine zusätzliche Infektion muss immer eine vollständige und konsequente Fokussuche und ggf. eine operative Focussanierung durchgeführt werden.