LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 46

Search options

  1. Article ; Online: Bayesian Reconstruction Algorithms for Low-Dose Computed Tomography Are Not Yet Suitable in Clinical Context.

    Kniep, Inga / Mieling, Robin / Gerling, Moritz / Schlaefer, Alexander / Heinemann, Axel / Ondruschka, Benjamin

    Journal of imaging

    2023  Volume 9, Issue 9

    Abstract: Computed tomography (CT) is a widely used examination technique that usually requires a compromise between image quality and radiation exposure. Reconstruction algorithms aim to reduce radiation exposure while maintaining comparable image quality. ... ...

    Abstract Computed tomography (CT) is a widely used examination technique that usually requires a compromise between image quality and radiation exposure. Reconstruction algorithms aim to reduce radiation exposure while maintaining comparable image quality. Recently, unsupervised deep learning methods have been proposed for this purpose. In this study, a promising sparse-view reconstruction method (posterior temperature optimized Bayesian inverse model; POTOBIM) is tested for its clinical applicability. For this study, 17 whole-body CTs of deceased were performed. In addition to POTOBIM, reconstruction was performed using filtered back projection (FBP). An evaluation was conducted by simulating sinograms and comparing the reconstruction with the original CT slice for each case. A quantitative analysis was performed using peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM). The quality was assessed visually using a modified Ludewig's scale. In the qualitative evaluation, POTOBIM was rated worse than the reference images in most cases. A partially equivalent image quality could only be achieved with 80 projections per rotation. Quantitatively, POTOBIM does not seem to benefit from more than 60 projections. Although deep learning methods seem suitable to produce better image quality, the investigated algorithm (POTOBIM) is not yet suitable for clinical routine.
    Language English
    Publishing date 2023-08-23
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2824270-1
    ISSN 2313-433X ; 2313-433X
    ISSN (online) 2313-433X
    ISSN 2313-433X
    DOI 10.3390/jimaging9090170
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Book ; Online: Pilotfish

    Kniep, Quentin / Kokoris-Kogias, Lefteris / Sonnino, Alberto / Zablotchi, Igor / Zhang, Nuda

    Distributed Transaction Execution for Lazy Blockchains

    2024  

    Abstract: Pilotfish is the first scale-out blockchain execution engine able to harness any degree of parallelizability existing in its workload. Pilotfish allows each validator to employ multiple machines, named ExecutionWorkers, under its control to scale its ... ...

    Abstract Pilotfish is the first scale-out blockchain execution engine able to harness any degree of parallelizability existing in its workload. Pilotfish allows each validator to employ multiple machines, named ExecutionWorkers, under its control to scale its execution layer. Given a sufficiently parallelizable and compute-intensive load, the number of transactions that the validator can execute increases linearly with the number of ExecutionWorkers at its disposal. In addition, Pilotfish maintains the consistency of the state, even when many validators experience simultaneous machine failures. This is possible due to the meticulous co-design of our crash-recovery protocol which leverages the existing fault tolerance in the blockchain's consensus mechanism. Finally, Pilotfish can also be seen as the first distributed deterministic execution engine that provides support for dynamic reads as transactions are not required to provide a fully accurate read and write set. This loosening of requirements would normally reduce the parallelizability available by blocking write-after-write conflicts, but our novel versioned-queues scheduling algorithm circumvents this by exploiting the lazy recovery property of Pilotfish, which only persists consistent state and re-executes any optimistic steps taken before the crash. In order to prove our claims we implemented the common path of Pilotfish with support for the MoveVM and evaluated it against the parallel execution MoveVM of Sui. Our results show that our simpler scheduling algorithms outperforms Sui even with a single execution worker, but more importantly provides linear scalability up to 4 ExecutionWorkers even for simple asset-transfers and to any number of ExecutionWorkers for more computationally heavy workloads.
    Keywords Computer Science - Distributed ; Parallel ; and Cluster Computing
    Subject code 004
    Publishing date 2024-01-29
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  3. Article ; Online: Pulmonary cement embolism is frequently observed but not a contributing factor for death in patients with cemented total hip and knee arthroplasty: a postmortem study.

    Ritter, Jacob / Hubert, Jan / Kniep, Inga / Beil, Frank Timo / Rolvien, Tim / Püschel, Klaus

    International orthopaedics

    2022  Volume 46, Issue 6, Page(s) 1225–1232

    Abstract: Purpose: Bone cement is frequently used for implant fixation in orthopaedic surgery. The occurrence of pulmonary cement embolism (PCE) in hip and knee arthroplasty has been described previously, but the exact extent and frequency have not been ... ...

    Abstract Purpose: Bone cement is frequently used for implant fixation in orthopaedic surgery. The occurrence of pulmonary cement embolism (PCE) in hip and knee arthroplasty has been described previously, but the exact extent and frequency have not been adequately studied. A postmortem cohort provides a unique opportunity for a more detailed analysis of this phenomenon.
    Methods: Through retrospective analysis of whole-body computed tomography (CT) scans and autopsy protocols, we identified 67 cases with previous cemented total hip or knee arthroplasties. A grading system originally developed for PCE after cemented spine procedures was used. Findings were compared with two control groups: 35 individuals with previous cementless total joint arthroplasty as well as 25 individuals without evidence of prostheses.
    Results: PCE was detected in 46.3% of the cases: grade 1 (31.3%), grade 2 (10.5%), and grade 3 (4.5%). No statistically significant difference was found between hip and knee arthroplasties in terms of PCE frequency. Importantly, none of the autopsy reports listed PCE as a cause of death or a contributing factor for the patients' death. In the two control groups, only one case per group was classified as grade 1 PCE, while the remaining cases did not show any evidence of PCE.
    Conclusion: The presented data reveal a high frequency of PCE in hip and knee arthroplasties, which is almost identical to previous findings in patients with cement-augmented interventions in the spine. This way, our results underline the relevance of PCE after arthroplasty, suggesting an adaptation of surgical methods to minimize this complication.
    MeSH term(s) Arthroplasty, Replacement, Hip/adverse effects ; Arthroplasty, Replacement, Knee/adverse effects ; Arthroplasty, Replacement, Knee/methods ; Autopsy ; Bone Cements/adverse effects ; Humans ; Pulmonary Embolism/epidemiology ; Pulmonary Embolism/etiology ; Retrospective Studies ; Spine
    Chemical Substances Bone Cements
    Language English
    Publishing date 2022-03-29
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 80384-4
    ISSN 1432-5195 ; 0341-2695
    ISSN (online) 1432-5195
    ISSN 0341-2695
    DOI 10.1007/s00264-022-05381-6
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: Forensische Pädopathologie: Postmortale Computertomografie (PMCT) bei Kindern

    Kniep, Inga / Heinemann, Axel / Puschel, Klaus

    Päd

    2021  Volume 27, Issue 1, Page(s) 48

    Language German
    Document type Article
    ZDB-ID 1315461-8
    ISSN 0949-7641
    Database Current Contents Medicine

    More links

    Kategorien

  5. Book ; Thesis: Infusion von Etomidate in niedriger Dosierung bei Patienten mit schwerem Hypercortisolismus und Untersuchungen zur Dosiswirkungsbeziehung bei eucortisolämischen Probanden

    Kniep-Friemert, Ilka

    1990  

    Author's details vorgelegt von Ilka Kniep-Friemert
    Size 30 S. : graph. Darst.
    Document type Book ; Thesis
    Thesis / German Habilitation thesis Kiel, Univ., Diss., 1990
    HBZ-ID HT003853785
    Database Catalogue ZB MED Medicine, Health

    Kategorien

  6. Article: COVID-19 lungs in post-mortem computed tomography.

    Kniep, I / Heinemann, A / Edler, C / Sperhake, J P / Püschel, K / Ondruschka, B / Schröder, A S

    Rechtsmedizin (Berlin, Germany)

    2021  Volume 31, Issue 2, Page(s) 145–147

    Abstract: Post-mortem computed tomography (PMCT) is a rapid and noninvasive diagnostic tool for important contributions to the identification of pulmonary findings in the deceased with pneumonia, including cases of coronavirus disease 2019 (COVID-19). Although ... ...

    Abstract Post-mortem computed tomography (PMCT) is a rapid and noninvasive diagnostic tool for important contributions to the identification of pulmonary findings in the deceased with pneumonia, including cases of coronavirus disease 2019 (COVID-19). Although computed tomography (CT) shows a high sensitivity for pneumonia in living persons, it is relatively unspecific for COVID-19 pneumonia clinically. Typical CT findings for viral pneumonia therefore require confirmation by PCR tests (polymerase chain reaction tests), even if lung infections with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) show characteristic patterns, most frequently ground glass opacities (GGO) and a combination of GGO and air space consolidations. In the consecutive autopsy series of SARS-CoV‑2 deaths from Hamburg, Germany, the most frequent cause of death was and still is COVID-19 pneumonia. Typical findings were frequently found in the PMCT in SARS-CoV-2-associated deaths, which were taken into account when classifying the death as COVID-19.
    Language English
    Publishing date 2021-02-15
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 1064911-6
    ISSN 0937-9819
    ISSN 0937-9819
    DOI 10.1007/s00194-021-00462-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Book ; Online: Collaborative Robotic Biopsy with Trajectory Guidance and Needle Tip Force Feedback

    Mieling, Robin / Neidhardt, Maximilian / Latus, Sarah / Stapper, Carolin / Gerlach, Stefan / Kniep, Inga / Heinemann, Axel / Ondruschka, Benjamin / Schlaefer, Alexander

    2023  

    Abstract: The diagnostic value of biopsies is highly dependent on the placement of needles. Robotic trajectory guidance has been shown to improve needle positioning, but feedback for real-time navigation is limited. Haptic display of needle tip forces can provide ... ...

    Abstract The diagnostic value of biopsies is highly dependent on the placement of needles. Robotic trajectory guidance has been shown to improve needle positioning, but feedback for real-time navigation is limited. Haptic display of needle tip forces can provide rich feedback for needle navigation by enabling localization of tissue structures along the insertion path. We present a collaborative robotic biopsy system that combines trajectory guidance with kinesthetic feedback to assist the physician in needle placement. The robot aligns the needle while the insertion is performed in collaboration with a medical expert who controls the needle position on site. We present a needle design that senses forces at the needle tip based on optical coherence tomography and machine learning for real-time data processing. Our robotic setup allows operators to sense deep tissue interfaces independent of frictional forces to improve needle placement relative to a desired target structure. We first evaluate needle tip force sensing in ex-vivo tissue in a phantom study. We characterize the tip forces during insertions with constant velocity and demonstrate the ability to detect tissue interfaces in a collaborative user study. Participants are able to detect 91% of ex-vivo tissue interfaces based on needle tip force feedback alone. Finally, we demonstrate that even smaller, deep target structures can be accurately sampled by performing post-mortem in situ biopsies of the pancreas.

    Comment: Presented at ICRA 2023
    Keywords Computer Science - Robotics ; Computer Science - Machine Learning ; Electrical Engineering and Systems Science - Systems and Control
    Subject code 629
    Publishing date 2023-06-12
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  8. Book ; Online ; Thesis: Erhöhen Patienten-Rückmeldungen die Zufriedenheit von Patienten mit Angststörungen mit der Therapie?

    Kniep, Inga / Naber, Dieter

    eine Interventionsstudie

    2014  

    Author's details Inga Kniep. Betreuer: Dieter Naber
    Language German
    Size Online-Ressource
    Publisher Staats- und Universitätsbibliothek Hamburg
    Publishing place Hamburg
    Document type Book ; Online ; Thesis
    Thesis / German Habilitation thesis Univ.Hamburg, FB Medizin, Diss.--Hamburg, 2014
    Database Former special subject collection: coastal and deep sea fishing

    More links

    Kategorien

  9. Article ; Online: Fatal outcome of SARS-CoV-2 infection (B1.1.7) in a 4-year-old child.

    Menger, Johanna / Apostolidou, Sofia / Edler, Carolin / Kniep, Inga / Kobbe, Robin / Singer, Dominique / Sperhake, Jan-Peter

    International journal of legal medicine

    2021  Volume 136, Issue 1, Page(s) 189–192

    Abstract: This case report highlights details of a case of critical acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) with B1.1.7 variant in a 4-year-old girl who died due to pneumonia and pulmonary hemorrhage. The girl was referred to our University ECMO ...

    Abstract This case report highlights details of a case of critical acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) with B1.1.7 variant in a 4-year-old girl who died due to pneumonia and pulmonary hemorrhage. The girl was referred to our University ECMO Center from another University hospital for veno-arterial extracorporeal membrane oxygenation (VA-ECMO). In the clinical course, superinfection with Pseudomonas aeruginosa was detected. Virological evidence of herpes simplex sepsis was also obtained in blood samples on her day of death. Transcription polymerase chain reaction (PCR) confirmed SARS-CoV-2 infection in lung tissue. Postmortem computed tomography showed pulmonary hemorrhage with inhomogeneous density values in both lungs. Lung tissue showed no ventilated areas. Autopsy revealed a massively congested lung with evidence of acute respiratory distress syndrome (ARDS) and pneumonia with multiple abscesses. Histopathology showed a mixture of diffuse alveolar injury with hyaline membranes, massive hemorrhage, and bronchopneumonia with multiple granulocytic abscesses. Cardiac examination revealed pericarditis. Suspicion of myocarditis or myocardial infarction could not be confirmed microscopically. To our knowledge, this is the first autopsy-based case report of the death of a previously healthy child due to the new variant B 1.1.7 in Germany.
    MeSH term(s) Abscess/pathology ; Abscess/virology ; COVID-19/diagnosis ; Child, Preschool ; Fatal Outcome ; Female ; Germany ; Humans ; Lung/diagnostic imaging ; Lung/pathology ; Respiratory Distress Syndrome/virology ; SARS-CoV-2
    Language English
    Publishing date 2021-09-12
    Publishing country Germany
    Document type Case Reports ; Journal Article
    ZDB-ID 1055109-8
    ISSN 1437-1596 ; 0937-9827
    ISSN (online) 1437-1596
    ISSN 0937-9827
    DOI 10.1007/s00414-021-02687-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  10. Article ; Online: Postmortale Bildgebung der Lunge bei COVID-19-Todesfällen.

    Kniep, I / Lutter, M / Ron, A / Edler, C / Püschel, K / Ittrich, H / Heller, M / Heinemann, A

    Der Radiologe

    2020  Volume 60, Issue 10, Page(s) 927–933

    Abstract: Clinical/methodological issue: COVID-19 is a new viral disease that is associated with inflammatory pulmonary changes which can be detected in computed tomography (CT). So far postmortem CT (PMCT) has not been used as a screening instrument for the ... ...

    Title translation Postmortem imaging of the lung in cases of COVID-19 deaths.
    Abstract Clinical/methodological issue: COVID-19 is a new viral disease that is associated with inflammatory pulmonary changes which can be detected in computed tomography (CT). So far postmortem CT (PMCT) has not been used as a screening instrument for the evaluation of deaths with and without autopsy. In this respect, its validity has to be proved in comparison to clinical-radiological experiences.
    Standard radiological methods: Postmortem CT METHODICAL INNOVATIONS: So far, PMCT can be regarded as a methodological innovation that has not yet been sufficiently evaluated for pneumonia.
    Performance: CT in clinical routine has a high sensitivity for pneumonia. However, to what extent postmortem artifacts are relevant to PMCT still has to be determined.
    Achievements: There is still no standard procedure for the postmortem radiological diagnosis of COVID-19 disease. Despite postmortem artifacts, PMCT can provide valuable information about the presence of pneumonia with interstitial character, especially without autopsy.
    Practical recommendations: PMCT is particularly useful in the assessment of suspected cases of COVID-19 pneumonia for morphological assessment in the context of monitoring deaths in the current pandemic situation.
    MeSH term(s) Autopsy ; Betacoronavirus ; COVID-19 ; Coronavirus Infections ; Pandemics ; Pneumonia, Viral ; SARS-CoV-2 ; Tomography, X-Ray Computed
    Keywords covid19
    Language German
    Publishing date 2020-08-18
    Publishing country Germany
    Document type Journal Article ; Review
    ZDB-ID 505520-9
    ISSN 1432-2102 ; 0033-832X
    ISSN (online) 1432-2102
    ISSN 0033-832X
    DOI 10.1007/s00117-020-00733-y
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top