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The development of robotic systems has provided an alternative to frame-based stereotactic procedures. The aim of this experimental phantom study was to compare the mechanical accuracy of the Robotic Surgery Assistant (ROSA) and the Leksell stereotactic frame by reducing clinical and procedural factors to a minimum.To precisely compare mechanical accuracy, a stereotactic system was chosen as reference for both methods. A thin layer CT scan with an acrylic phantom fixed to the frame and a localizer enabling the software to recognize the coordinate system was performed. For each of the five phantom targets, two different trajectories were planned, resulting in 10 trajectories. A series of five repetitions was performed, each time based on a new CT scan. Hence, 50 trajectories were analyzed for each method. X-rays of the final cannula position were fused with the planning data. The coordinates of the target point and the endpoint of the robot- or frame-guided probe were visually determined using the robotic software. The target point error (TPE) was calculated applying the Euclidian distance. The depth deviation along the trajectory and the lateral deviation were separately calculated.Robotics was significantly more accurate, with an arithmetic TPE mean of 0.53 mm (95% CI 0.41-0.55 mm) compared to 0.72 mm (95% CI 0.63-0.8 mm) in stereotaxy (Both the robotic and frame-based approach proved accurate. The robotic procedure showed significantly higher accuracy. For both methods, procedural factors occurring during surgery might have a more relevant impact on overall accuracy.

Objective: The development of robotic systems has brought an alternative to frame-based stereotactic procedures. In this experimental setting we aim to reduce procedural errors to a minimum when comparing the ROSA robot and the Leksell stereotactic system regarding mechanical accuracy. Methods:[for full text, please go to the a.m. URL], 72. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgie

Objectives The aim of this study was to evaluate the reduction of artifacts from deep brain stimulation electrodes (DBS) using an iterative metal artifact reduction algorithm (O-MAR), virtual monoenergetic images (VMI), and both in combination in postoperative spectral detector computed tomography using a dual-layer detector (spectral detector computed tomography [SDCT]) of the head. Material and methods Nonanthropomorphic phantoms with different DBS leads were examined on SDCT; in 1 phantom periprocedural bleeding was simulated. A total of 20 patients who underwent SDCT after DBS implantation between October 2016 and April 2017 were included in this institutional review board-approved retrospective study. Images were reconstructed using standard-of-care iterative reconstruction (CI) and VMI, each with and without O-MAR processing (IR and MAR). Artifacts were quantified by determining the percentage integrity uniformity in an annular region of 1.4 cm around the DBS lead; a percentage integrity uniformity of 100% indicates the absence of artifacts. In phantoms, conspicuity of blood was determined on a binary scale, whereas in patients, image quality, DBS lead assessment, and extent of artifact reduction were assessed on Likert scales by 2 radiologists. Statistical significance was assessed using analysis of variance and Wilcoxon tests; sensitivity and specificity were calculated. Results The O-MAR processing significantly decreased artifacts in phantom and patients (P ≤ 0.05), whereas VMI did not reduce artifact burden compared with corresponding CI (P > 0.05): for example, CI-IR/MAR and 200 keV-IR/MAR for patients: 76.3%/90.7% and 75.9%/91.2%, respectively. Qualitatively, overall image quality was not improved (P > 0.05) and MAR improved DBS assessment (CI-IR/MAR: 2 [1-3]/3 [2-4]; P ≤ 0.05) and reduced artifacts significantly (P ≤ 0.05). The O-MAR processing increased sensitivity for bleeding by 160%. In some cases, new artifacts were induced through O-MAR processing, none of which impaired diagnostic image assessment. Discussion The investigated O-MAR algorithm reduces artifacts from DBS electrodes and should be used in the assessment of postoperative patients; however, combination with VMI does not provide an additional benefit.

Background: Directional deep brain stimulation (DBS) allows steering the stimulation in an axial direction which offers greater flexibility in programming. However, accurate anatomical visualization of the lead orientation is required for interpreting the observed stimulation effects and to guide programming. Objectives: In this study we aimed to develop and test an accurate and robust algorithm for determining the orientation of segmented electrodes based on standard postoperative CT imaging used in DBS. Methods: Orientation angles of directional leads (CartesiaTM; Boston Scientific, Marlborough, MA, USA) were determined using CT imaging. Therefore, a sequential algorithm was developed that quantitatively compares the similarity of the observed CT artifacts with calculated artifact patterns based on the lead’s orientation marker and a geometric model of the segmented electrodes. Measurements of seven ground truth phantoms and three leads with 60 different configurations of lead implantation and orientation angles were analyzed for validation. Results: The accuracy of the determined electrode orientation angles was –0.6 ± 1.5° (range: –5.4 to 4.2°). This accuracy proved to be sufficiently high to resolve even subtle differences between individual leads. Conclusions: The presented algorithm is user independent and provides highly accurate results for the orientation of the segmented electrodes for all angular constellations that typically occur in clinical cases.

Background As irradiated brain volume at 12 Gy (V12) is a predictor for radionecrosis, the purpose of the study was to develop a model for Cyberknife (CK) plans that is able to predict the lowest achievable V12 at a given tumor size and prescription dose (PD), and to suggest a new quality index regarding V12 for optimizing the treatment planning of brain metastases. Method In our model V12 was approximated as a spherical shell around the tumor volume. The radial distance between tumor surface and the 12 Gy isodose line was calculated using an approximation of the mean dose gradient in that area. Assuming a radially symmetrical irradiation from the upper half space, the dose distribution is given by the superposition of single fields. The dose profiles of a single field were derived by the measured off-center ratios (OCR) of the CK system. Using the calculated gradients of the sum dose profiles, minimal-V12 was estimated for different tumor sizes. The model calculation was tested using a phantom dataset and retrospectively applied on clinical cases. Results Our model allows the prediction of a best-case scenario for V12 at a given tumor size and PD which was confirmed by the results of the isocentric phantom plans. The results of the non-isocentric phantom plans showed that an optimization of coverage caused an increase in V12. This was in accordance with the results of the retrospective analysis. V12 s of the clinical cases were on average twice that of the predicted model calculation. A good agreement was achieved for plans with an optimal conformity index (nCI). Re-planning of cases with high V12 showed that lower values could be reached by selecting smaller collimators and by allowing a larger number of total MU and more MU per beam. Conclusions V12 is a main parameter for assessing plan quality in terms of radiotoxicity. The index f12 defined as the ratio of V12 from the actual plan with the evaluated V12 from our model describes the conformity of an optimally possible V12 and thus can be used as a new quality index for optimizing treatment plans. Electronic supplementary material The online version of this article (doi:10.1186/s13014-017-0867-z) contains supplementary material, which is available to authorized users.

Purpose Orientating the angle of directional leads for deep brain stimulation (DBS) in an axial plane introduces a new degree of freedom that is indicated by embedded anisotropic directional markers. Our aim was to develop algorithms to determine lead orientation angles from computed tomography (CT) and stereotactic x-ray imaging using standard clinical protocols, and subsequently assess the accuracy of both methods. Methods In CT the anisotropic marker artifact was taken as a signature of the lead orientation angle and analyzed using discrete Fourier transform of circular intensity profiles. The orientation angle was determined from phase angles at a frequency 2/360° and corrected for aberrations at oblique leads. In x-ray imaging, frontal and lateral images were registered to stereotactic space and sub-images containing directional markers were extracted. These images were compared with projection images of an identically located virtual marker at different orientation angles. A similarity index was calculated and used to determine the lead orientation angle. Both methods were tested using epoxy phantoms containing directional leads (Cartesia™, Boston Scientific) with known orientation. Anthropomorphic phantoms were used to compare both methods for DBS cases. Results Mean deviation between CT and x-ray was 1.5° ± 3.6° (range: -2.3° to 7.9°) for epoxy phantoms and 3.6° ± 7.1° (range: -5.6° to 14.6°) for anthropomorphic phantoms. After correction for imperfections in the epoxy phantoms, the mean deviation from ground truth was 0.0° ± 5.0° (range: -12° to 14°) for x-ray. For CT the results depended on the polar angle of the lead in the scanner. Mean deviation was -0.3° ± 1.9° (range: -4.6° to 6.6°) or 1.6° ± 8.9° (range: -23° to 34°) for polar angles ≤40° or >40°. Conclusions The results show that both imaging modalities can be used to determine lead orientation angles with high accuracy. CT is superior to x-ray imaging, but oblique leads (polar angle >40°) show limited precision due to the current design of the directional marker. This article is protected by copyright. All rights reserved.

Plan comparison and indicators for low or high f12 indices. (DOCX 29Â kb)

Objective: Unwanted side effects, induced by current spread into adjacent structures, limit the efficacy of deep brain stimulation (DBS). In Parkinson’s disease (PD), the corticospinal tract and the medial lemniscus are correlated with motor and sensory side effects from subthalamic nucleus (STN)[for full text, please go to the a.m. URL], 67. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 1. Joint Meeting mit der Koreanischen Gesellschaft für Neurochirurgie (KNS)

This study aims to contribute to the understanding of authenticity on the photo sharing service Instagram by analysing the two accounts @satiregram and @socalitybarbie. The two cases make use of parody and satire in order to poke fun at the dominant Instagram culture, which is according to media characterised by a lack of authenticity. For this reason it is of great interest to examine how the two accounts @satiregram and @socalitybarbie challenge authenticity on Instagram through the platform itself. Moreover, for the purpose of gaining a better understanding of authenticity in regard to Instagram it is analysed which aspects of the idea of authenticity are challenged by two chosen cases. The research furthermore intends to provide a better understanding of the Instagram culture as well as the photo sharing platform itself. In order to investigate the stated questions first of all the concept of authenticity in relation to media in general is discussed. The study then proceeds with introducing Instagram to provide a better understanding of the topic. Subsequently previous research on authenticity in regard to media before and within the advent of social media is presented. The theoretical framework begins by presenting the genres of satire and parody as well as the concept of counterculture as instruments of social critique. Furthermore, the concepts of authenticity contract, authenticity puzzle as well as authenticity scandal are presented. Moreover, a set of norms of Instagram is introduced. Lastly, seven characteristics of mediated authenticity are depicted. For the investigation of the stated questions the content of the two chosen contents is analysed. Moreover, two interviews with the creators of the accounts were conducted in order to obtain background information regarding @satiregram and @socalitybarbie. The gathered data is subsequently applied to the theories present in the theoretical framework. The study is concluded by a discussion on the findings, which amongst others includes the revaluation of the idea of authenticity on Instagram.

Stereotactic radiosurgery of intracranial tumors and vascular malformations can be performed by either a linear accelerator (Linac) or gamma knife. The aim of this first study on patients was to determine the radiation exposure of organs at risk and assess the risk for late effects including secondary tumors and/or hereditary disorders after stereotactic Linac radiosurgery.Thermoluminescent dosimetry (TLD) measurements were done on 21 consecutively admitted patients with various intracranial lesions scheduled for Linac radiosurgery. The TLD chips were placed on the eyelid, thyroid, breast and the regions of the ovary or testes.The mean doses in organs at risk were 276 +/- 200 mGy (eye lens), 155 +/- 83 mGy (thyroid), 47 +/- 22 mGy (breast), 20 +/- 12 mGy (ovary), and 9 +/- 3 mGy (testes). The doses decreased significantly with a larger distance from the isocenter.The absorbed doses to the extracranial organs at risk in patients undergoing Linac radiosurgery were very low, ranging from 0.025% (testes) to 0.76% (eye lens) of the mean maximum target dose (36 Gy). Nevertheless, while the majority of radiosurgery patients have benign tumors or arteriovenous malformations and their life expectancy is long, all doses should be kept as low as reasonably achievable. This could be accomplished by the use of modern irradiation techniques including conformal beams with micro-multileaf collimator and avoiding beams directed to the trunk.

Very high doses are administered in radiocolloid therapy of cystic craniopharyngiomas. However individual dose planning is not common yet mainly due to insufficient image resolution. Our aim was to investigate whether currently available high-resolution image data can be used for voxel-based dose calculation for short-ranged β-emitters ((32)P,(90)Y,(186)Re) and to assess the achievable accuracy. We developed a convolution algorithm based on voxelized dose activity distributions and dose-spread kernels. Results for targets with 5-40 mm diameter were compared with high-resolution Monte Carlo calculations in spherical phantoms. Voxel size was 0.35 mm. Homogeneous volume and surface activity distributions were used. Dose-volume histograms of targets and shell structures were compared and γ index (dose tolerance 5%, distance to agreement 0.35 mm) was calculated for dose profiles along the principal axes. For volumetric activity distributions 89.3% ± 11.9% of all points passed the γ test (mean γ 0.53 ± 0.16). For surface distributions 33.6% ± 14.8% of all points passed the γ test (mean γ 2.01 ± 0.60). The shift of curves in dose-volume histograms was -1.7 Gy ± 7.6 Gy (-4.4 Gy ± 24.1 Gy for (186)Re) in volumetric distributions and 46.3% ± 32.8% in surface distributions. The results show that individual dose planning for radiocolloid therapy of cystic craniopharyngiomas based on high-resolution voxelized image data is feasible and yields highly accurate results for volumetric activity distributions and reasonable dose estimates for surface distributions.

Es wird uber einen 8jahrigen Jungen mit einer seltenen kongenitalen Myopathie (myofibrillare Myopathie mit zytoplasmatischen Einschluskorperchen) und dem klinischen Bild eines Rigid-spine-Syndroms berichtet, bei dem im Rahmen der Behandlung einer Lungentuberkulose eine nachtliche Atemstorung mit REM-assoziierten Hypoventilationen, Hypoxamien und persistierender Hyperkapnie diagnostiziert wurde. Diese bei Myopathien vorkommende Komplikation ist Ausdruck einer Storung der Atempumpe; sie kann zahlreiche negative Auswirkungen nach sich ziehen (u.a. pulmonale Hypertonie, Tagesmudigkeit, Wachstumsverzogerung, Gedeihstorung und weitere Verschlechterung der muskularen Insuffizienz). Exemplarisch werden die Schritte zur Diagnose einer schlafbezogenen Atemstorung bei muskelkranken Kindern aufgezeigt. Schlusfolgerung: Bei angeborenen Myopathien sollte sorgfaltig nach Storungen der muskularen Atempumpe und schlafbezogenen Atemstorungen gefahndet werden. Eine intermittierende nasale Maskenbeatmung stellt eine effektive und nichtinvasive Behandlungsmoglichkeit nachtlicher Hypoventilationssyndrome dar und kann die Lebensqualitat betroffener Patienten erheblich verbessern.

Einleitung: Nicht-IgE-vermittelte gastrointestinale Nahrungsmittelallergien sind selten, sie können in food protein induced enterocolitis syndrom (FPIES), food protein induced proctocolitis (FPIP), food protein induced enteropathy und eosinophilic gastrointestinal disorder (EGID) eingeteilt werden.[for full text, please go to the a.m. URL], Süddeutscher Kongress für Kinder- und Jugendmedizin; 63. Jahrestagung der Süddeutschen Gesellschaft für Kinder- und Jugendmedizin gemeinsam mit der Süddeutschen Gesellschaft für Kinderchirurgie und dem Berufsverband der Kinder- und Jugendärzte e.V. – Landesverband Baden-Württemberg

Denkmalpflege in Baden-Württemberg – Nachrichtenblatt der Landesdenkmalpflege, Bd. 8, Nr. 2 (1965): Nachrichtenblatt der Denkmalpflege in Baden-Württemberg – Organ der Staatlichen Ämter für Denkmalpflege, Beginn und Erscheinungsfrequenz: Ausgaben pro Band: 4

Question This pilot study aimed to assess the therapeutic potential of chronically implanted directional DBS leads in patients with Parkinson’s disease. The therapeutic effect of deep brain stimulation (DBS) in the subthalamic nucleus is frequently limited by side-effects resulting from unintended stimulation of neighboring areas. Recently available chronically implantable DBS leads capable of directional steering might overcome this problem. Methods Randomized, double-blinded, standardized monopolar reviews were conducted in consecutive patients, about one week after implantation of a novel DBS system capable of directional stimulation. Clinical effects and side-effect thresholds were compared between unidirectional and circular DBS. After a two-day double-blind crossover phase, patients were asked to opt for either circular or unidirectional DBS. Results Unidirectional DBS offered increased side-effect thresholds compared to circular DBS depending on stimulation direction. Highest side-effect thresholds were achieved with posteromedial or anterior stimulation in most cases. Conclusions This pilot study provides preliminary evidence for advantages of directional DBS systems. Large cohorts with long-term follow-up are needed to confirm these results.

We have developed a densitometric method for measuring the isocentric accuracy and the accuracy of marking the isocentre position for linear accelerator based radiosurgery with circular collimators and room lasers. Isocentric shots are used to determine the accuracy of marking the isocentre position with room lasers and star shots are used to determine the wobble of the gantry and table rotation movement, the effect of gantry sag, the stereotactic collimator alignment, and the minimal distance between gantry and table rotation axes. Since the method is based on densitometric measurements, beam spot stability is implicitly tested. The method developed is also suitable for quality assurance and has proved to be useful in optimizing isocentric accuracy. The method is simple to perform and only requires a film box and film scanner for instrumentation. Thus, the method has the potential to become widely available and may therefore be useful in standardizing the description of linear accelerator based radiosurgical systems.

Stereotactic radiosurgery is a well established method for the treatment of small arterio-venous malformations and intracranial tumours. The dose distributions are characterised by steep dose gradients and have to be applied with high spatial accuracy. Therefore, radiosurgery is given to an invasively fixed patient in a single session. Compared to single dose irradiation fractionation has some radiobiological advantages and allows an extension of treatment indications. The main problem of fractionation is the loss in spatial accuracy due to the fact, that identical re-fixation of the stereotactic frame over a period of several weeks is not possible and that fixation and positioning with masks is often not precise enough for radiosurgery [1].

In adults suffering from Kartagener's syndrome-which is found in 50% of patients with primary ciliary dyskinesia (PCD)-bronchiectasis is still one of three typical clinical features. In this condition it is caused by chronic bacterial inflammation as a result of impaired mucociliary clearance in congenital ciliary dysfunction. Little information is available on the incidence, age-related development and prophylactic therapy of bronchiectasis in children suffering from PCD.We describe the case of a 2-year old boy with clinical features of Kartagener's syndrome who showed impaired ciliary motility and typical ultrastructural defects of PCD. Bronchiectasis was excluded by bronchography.The diagnosis of PCD implies disturbed ciliary motility and abnormal ultrastructure of the cilia. In 50% of cases PCD is associated with situs inversus and is then referred to as kartagener's syndrome, whereas situs inversus itself does not define Kartagener's syndrome. Bronchiectasis is not necessarily present in children with PCD. Physiotherapy, inhalations, vaccinations and early antibiotic treatment may be of prophylactic value in preventing bronchiectasis. Early start of the life-long treatment depends on early diagnosis which should be based on well-defined criteria.

The thesis explores whether Los Angeles could be regarded as an Arrival City for the Mexican-American protagonists in The Miraculous Day of Amalia Gómez (John Rechy, 2006 [1991]), Their Dogs Came with Them (Helena María Viramontes, 2007), and The Barbarian Nurseries (Héctor Tobar, 2012).\ud The study focuses especially on the depiction of city space within these contemporary LA novels and examines to which extent the protagonists are able to navigate and appropriate these spaces. Arrival is understood here not as a fixed, static goal, but an ongoing process of entries and openings that the protagonists can use to insert themselves into city space. Arrival means a creative usage of city space through the creation of third spaces, borderlands, transculturality, and liminality. Successful arrival processes do not only require these fluid and mobile liminal spaces, but also a sense of emplacement to allow for the chance of participation in actively shape city space.\ud A close reading of the novels suggests that it remains difficult for the protagonists to create a sense of arrival. In The Miraculous Day, city space remains inaccessible behind a maze of stereotypes that hinder an appropriation of space. In Their Dogs, city space itself remains so hostile due to quarantine roadblocks and freeway construction that deconstructions of colonial binaries are only possible on a metatextual level through myth, metaphor, and story. In Nurseries, city space is depicted as a fiction that hinders the protagonists’ arrival at the American Dream, although in the end, there is the possibility of accessing the metaphysical aspect of the Dream, not through city space appropriation, but through the belief in the equality of opportunities.