419 research outputs found

    Prognostic value of clinical and MRI features in the screening of lipomatous lesions

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    BACKGROUND AND OBJECTIVES: Differentiation of lipomatous tumors mostly requires diagnostic biopsy but is essential to decide for the most adequate therapy. This study aims to investigate the prognostic value of available clinical and radiological features with regard to malignancy of the lesion, recurrence and survival. METHODS: In this retrospective cohort study, 104 patients with a biopsy-proven lipomatous tumor between 2010 and 2015 and a minimum clinical follow-up of two years were enrolled. Next to clinical features (age, gender, location of the lesion, histopathologic diagnosis, stage of disease, time to recurrence and death), MRI parameters were recorded retrospectively and blinded to the histological diagnosis. RESULTS: Malignant lipomatous tumors were associated with location in the lower extremities and MRI features like thick septation (>2 mm), presence of a non-adipose mass, foci of high T2/STIR signal and contrast agent enhancement. A non-adipose mass was a predictor for recurrence and inferior overall survival, while lesions with high T2/STIR signal showed higher risk of recurrence only. In combination, clinical and radiological features (lower extremities, septation > 2 mm, existence of non-adipose mass, contrast enhancement, and foci of high T2/STIR signal) predicted a malignant lipomatous tumor with an accuracy of 0.941 (95% CI of 0.899-0.983; 87% sensitivity, 86% specificity). CONCLUSION: Localization and characteristic MR features predict malignancy in most lipomatous lesions. Non-adipose masses are a poor prognostic factor, being associated with tumor recurrence and disease-related death

    Articular degeneration after subchondral cementation for giant cell tumors at the knee

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    PURPOSE To quantify joint degeneration and the clinical outcome after curettage and cementation in subchondral giant cell tumors of the bone (GCTB) at the knee. METHODS We conducted a retrospective analysis of 14 consecutive patients (seven female, seven male) with a mean age of 34 years (range 19-51) who underwent curettage and subchondral cementation for a biopsy-confirmed GCTB at the distal femur or the proximal tibia between August 2001 and August 2017, with a mean follow-up period of 54.6 months (range 16.1-156 months). The Whole-Organ Magnetic Resonance Imaging Score (WORMS), Kellgren-Lawrence (KL) classification, and Musculo-Skeletal Tumor Society (MSTS) score were assessed. RESULTS Radiological degeneration progressed from preoperative to the latest follow-up, with a median WORMS from 2.0 to 4.0 (p = 0.006); meanwhile, the median KL score remained at 0 (p = 0.102). Progressive degeneration (WORMS) tended to be associated with the proximity of the tumor to the articular cartilage (mean 1.57 mm; range 0-12 mm) (p = 0.085). The most common degenerative findings were cartilage lesions (n = 11), synovitis (n = 5), and osteophytes (n = 4). Mean MSTS score increased from 23.1 (preoperatively) to 28.3 at the latest follow-up (p < 0.01). Seven patients (50%) were treated for a local recurrence, with six revision surgeries performed. Removal of the cement spacer and filling of the cavity with a cancellous autograft was performed in seven patients. Conversion to a total knee arthroplasty was performed in one patient for local tumor control. CONCLUSIONS Cementation following the curettage of GCTB around the knee is associated with slight degeneration at medium-term follow-up and leads to a significant reduction in pain. Removal of the cement and reconstruction with an autograft may be beneficial in the long term

    The Charcot foot: a pictorial review.

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    Charcot foot refers to an inflammatory pedal disease based on polyneuropathy; the detailed pathomechanism of the disease is still unclear. Since the most common cause of polyneuropathy in industrialized countries is diabetes mellitus, the prevalence in this risk group is very high, up to 35%. Patients with Charcot foot typically present in their fifties or sixties and most of them have had diabetes mellitus for at least 10 years. If left untreated, the disease leads to massive foot deformation. This review discusses the typical course of Charcot foot disease including radiographic and MR imaging findings for diagnosis, treatment, and detection of complications

    Investigation of Surface Magnetic Noise by Shallow Spins in Diamond

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    We present measurements of spin relaxation times (T1, T1ρ, T2) on very shallow (â‰Č5  nm) nitrogen-vacancy centers in high-purity diamond single crystals. We find a reduction of spin relaxation times up to 30 times compared to bulk values, indicating the presence of ubiquitous magnetic impurities associated with the surface. Our measurements yield a density of 0.01–0.1ÎŒB/nm2 and a characteristic correlation time of 0.28(3) ns of surface states, with little variation between samples and chemical surface terminations. A low temperature measurement further confirms that fluctuations are thermally activated. The data support the atomistic picture where impurities are associated with the top carbon layers, and not with terminating surface atoms or adsorbate molecules. The low spin density implies that the presence of A single surface impurity is sufficient to cause spin relaxation of a shallow nitrogen-vacancy center

    Verifizierung der Parametrisierung von organischen und mineralischen Horizonten mittels Hauptkomponentenanalyse

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    FĂŒr die Erstellung von flĂ€chenhaften thematischen Auswertungskarten fĂŒr organische und mineralische Böden sind Informationen zu dem Ausgangssubstrat an ausgewĂ€hlten Punkten, sowie die dort auftretenden Pedogenesen wesentlich. Basis sind dabei die bodenchemischen und bodenphysikalischen Analysedaten zu den Horizonten. Die Schnittstelle bilden hierbei die Horizont-Substrat-Kombinationen (HSK) fĂŒr die FlĂ€chenbodenformen. Diese Klassifizierung geht mit der AusprĂ€gung von ganz spezifischen Bodeneigenschaften einher. Die Erhebung von Analysedaten ist zeit- und kostenaufwendig. Um diese Aufwendungen zu optimieren ist das Ziel dieser Untersuchung, mit Hilfe einer Hauptkomponentenanalyse (Principal Component Analysis – PCA) zu prĂŒfen, inwieweit dieser methodische Ansatz statistisch begrĂŒndbar ist. Dabei warenim Besonderen folgende Fragestellungen zu beachten: (i) welche physikalischen und/oder chemischen Variablen fĂŒr die HSK merkmalsbestimmend sind, (ii) welche Variablen weniger relevant sind fĂŒr die Einteilung und Abgrenzung der HSK und damit ggf. prioritĂ€r nicht analysiert werden mĂŒssen und (iii) welche alternativen Merkmalsgruppierungen sich ggf. ergeben wĂŒrde. Da sich die Eigenschaften von organischen und mineralischen Böden fundamental voneinander unterscheiden wurden sie jeweils gesondert analysiert. FĂŒr die organischen Horizonte wurde in ErgĂ€nzung zu den HSK-Gruppierungen der Zersetzungsgrad der organischen Substrate berĂŒcksichtigt, da aufgrund bisheriger eigener als auch internationaler Forschungen auf Moorböden zu erwarten war, dass dieser im GelĂ€nde bestimmbarer Parameter einen zusĂ€tzlichen merkmalsbestimmenden Einfluss haben wird. Der Vortrag beinhaltet die Auswertungsergebnisse und gibt Empfehlungen fĂŒr kĂŒnftige Kartier- und Untersuchungsziele vergleichbarer Böden

    Stratigrafia ed assetto geometrico dell’Unità del Sannio nel settore settentrionale dei monti del Matese

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    New stratigraphic and biostratigraphic data arising from the realization of the Sheet No. 405 "Campobasso" of the new Geological map of Italy (1:50.000 scale - CARG Project) allowed, for the first time in this area, to stratigraphically and cartographically define all the ranges composing the basinal Sannio Unit Auct.. Structural analysis and the chronostratigraphic redefinition of siliciclastic deposits covering the Sannio Unit and the carbonate platform successions of the Matese- Frosolone Units, indicate two main evolutionary stages in the Miocene- Pliocene structuring of this portion of the Southern Apennines. In the first stage, starting before Serravallian times, E-verging contraction affected exclusively the basinal units together with their siliciclastic cover. During the second stage, beginning after early Messinian times, NE-verging compression involved both the basinal Sannio Unit and the Matese-Frosolone Units.UnpublishedISPRA - Roma, Italy2.2. Laboratorio di paleomagnetismorestricte

    Cardiac transcriptional and metabolic changes following thoracotomy

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    Non-cardiac surgery is associated with significant cardiovascular complications. Reported mortality rate ranges from 1.9% to 4% in unselected patients. A postoperative surge in pro-inflammatory cytokines is a well-known feature and putative contributor to these complications. Despite much clinical research, little is known about the biomolecular changes in cardiac tissue following non-cardiac surgery. In order to increase our understanding, we analyzed whole-transcriptional and metabolic profiling data sets from hearts of mice harvested two, four, and six weeks following isolated thoracotomy. Hearts from healthy litter-mates served as controls. Functional network enrichment analyses showed a distinct impact on cardiac transcription two weeks after surgery characterized by a downregulation of mitochondrial pathways in the absence of significant metabolic alterations. Transcriptional changes were not detectable four and six weeks following surgery. Our study shows distinct and reversible transcriptional changes within the first two weeks following isolated thoracotomy. This coincides with a time period, in which most cardiovascular events happen

    Augmented Reality-Guided Lumbar Facet Joint Injections

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    OBJECTIVES The aim of this study was to assess feasibility and accuracy of augmented reality-guided lumbar facet joint injections. MATERIALS AND METHODS A spine phantom completely embedded in hardened opaque agar with 3 ring markers was built. A 3-dimensional model of the phantom was uploaded to an augmented reality headset (Microsoft HoloLens). Two radiologists independently performed 20 augmented reality-guided and 20 computed tomography (CT)-guided facet joint injections each: for each augmented reality-guided injection, the hologram was manually aligned with the phantom container using the ring markers. The radiologists targeted the virtual facet joint and tried to place the needle tip in the holographic joint space. Computed tomography was performed after each needle placement to document final needle tip position. Time needed from grabbing the needle to final needle placement was measured for each simulated injection. An independent radiologist rated images of all needle placements in a randomized order blinded to modality (augmented reality vs CT) and performer as perfect, acceptable, incorrect, or unsafe. Accuracy and time to place needles were compared between augmented reality-guided and CT-guided facet joint injections. RESULTS In total, 39/40 (97.5%) of augmented reality-guided needle placements were either perfect or acceptable compared with 40/40 (100%) CT-guided needle placements (P = 0.5). One augmented reality-guided injection missed the facet joint space by 2 mm. No unsafe needle placements occurred. Time to final needle placement was substantially faster with augmented reality guidance (mean 14 ± 6 seconds vs 39 ± 15 seconds, P < 0.001 for both readers). CONCLUSIONS Augmented reality-guided facet joint injections are feasible and accurate without potentially harmful needle placement in an experimental setting
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