Ιατρικά Άρθρα: 03/06/17

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Δευτέρα 6 Μαρτίου 2017

No catheter angiography is needed in patients with an obscure acute gastrointestinal bleed and negative CTA

Publication date: May–June 2017
Source:Clinical Imaging, Volume 43
Author(s): Pratik A. Shukla, Adam Zybulewski, Marcin K. Kolber, Erik Berkowitz, James Silberzweig, Morris Hayim
PurposeTo evaluate the negative predictive power of computed tomography angiography (CTA) for the identification of obscure acute gastrointestinal (GI) bleeding (GI bleeding not visualized/treated by endoscopy) on subsequent mesenteric angiography (MA) with the intention to treat.Materials and methodsA retrospective chart review of patients was performed who underwent mesenteric angiography for the evaluation/treatment of acute GI bleeding between November 2012 and July 2016. Patients with negative CTA examinations that proceeded to MA were identified. Negative predictive value (NPV) was calculated.Results20 patients (14 male, 6 female; average age: 73.1±12.8years) underwent 20 negative CTA examinations for the evaluation and treatment of GI bleeding followed by mesenteric angiography. Eighteen of 20 patients had negative subsequent MA (negative predictive value, NPV=90%). Both false negative cases were upper GI bleed (vs 0 lower GI bleed); this difference was significant (p<0.05).ConclusionsThe high NPV of CTA for the evaluation of GI bleeding suggests utility for excluding patients that are unlikely to benefit from MA and subsequent endovascular therapy. CTA may be considered for the first line diagnostic study for the evaluation of obscure GI bleeding.

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Fluorocholine PET/CT predicts skeletal progression, skeletal event and cancer specific survival in patients with biochemical relapse for prostate cancer

Publication date: May–June 2017
Source:Clinical Imaging, Volume 43
Author(s): Fabio Zattoni, Emanuela Agostini, Francesco Cattaneo, Marco Maruzzo, Umberto Basso, Filiberto Zattoni, Laura Evangelista
PurposeThe aim of our study is to evaluate the prognostic impact of ¹⁸F-Choline (FCh) positron emission tomography (PET)/computed tomography (CT), CT alone and methylene diphophonate bone scan (MDP-BS) in prostate cancer (PCa) patients with biochemical relapse.MethodsWe retrospectively selected 58 patients who underwent, between June 2010 and February 2013, both FCh-PET/CT and MDP-BS within a maximum time interval of 5months. All patients had a biochemical PCa recurrence after radical prostatectomy and/or radiation therapy. Two independent observers reviewed FCh-PET/CT and MDP-BS images. The bone window of CT portion from FCh-PET/CT was separately assessed. Time to progression (TTP), skeletal event free survival (SES) and cancer specific survival (CSS) were defined as the length of time between imaging and progression of disease, skeletal related events and cancer specific mortality, respectively. A patient based and a K agreement analysis was used to compare the findings of all three imaging modalities. Kaplan-Meier and log-rank analysis were computed for survival assessment. A multivariate Cox regression analysis was used to identify the independent predictors for TTP.ResultsBone metastases were detected in 22 (38%) patients at FCh-PET/CT, in 27 (47%) at MDP-BS and in 24 (41%) at CT. The agreement between FCh-PET/CT and MDP-BS, CT and MDP-BS, and FCh-PET/CT and CT were moderate/fair (respectively, k: 0.474, 0.267 and 0.424; all p<0.05). After 38months (IQR: 27–54months) of follow-up, 33 (57%) patients had a new recurrence of disease, 12 (21%) had skeletal related events and 19 (33%) died. Three subjects (5%) were lost during the observational period. At survival analyses, a worse TTP, SES and CSS were found in patients with a positive FCh-PET/CT at bone level than those with a negative scan (all p≤0.05). Conversely, any significant difference in TTP, SES and CSS was found for patients with both a positive MDP-BS and CT scan. At univariate analysis, a positive FCh-PET/CT at skeletal level was associated with all events (all p<0.05). However, only a positive FCh-PET/CT at any site was an independent prognostic variable of TTP (HR: 3.08; CI 95%: 1.85–9.05; p=0.04).ConclusionsPET/CT should be preferred to CT and BS in patients with prostate cancer with bone metastasis because it allows a better stratification of TTP, SES and CCS compared to CT and BS.

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Robust detection and segmentation of cell nuclei in biomedical images based on a computational topology framework

Publication date: Available online 6 March 2017
Source:Medical Image Analysis
Author(s): Rodrigo Rojas-Moraleda, Wei Xiong, Niels Halama, Katja Breitkopf-Heinlein, Steven Dooley, Luis Salinas, Dieter W. Heermann, Nektarios A. Valous
The segmentation of cell nuclei is an important step towards the automated analysis of histological images. The presence of a large number of nuclei in whole-slide images necessitates methods that are computationally tractable in addition to being effective. In this work, a method is developed for the robust segmentation of cell nuclei in histological images based on the principles of persistent homology. More specifically, an abstract simplicial homology approach for image segmentation is established. Essentially, the approach deals with the persistence of disconnected sets in the image, thus identifying salient regions that express patterns of persistence. By introducing an image representation based on topological features, the task of segmentation is less dependent on variations of color or texture. This results in a novel approach that generalizes well and provides stable performance. The method conceptualizes regions of interest (cell nuclei) pertinent to their topological features in a successful manner. The time cost of the proposed approach is lower-bounded by an almost linear behavior and upper-bounded by O(n2) in a worst-case scenario. Time complexity matches a quasilinear behavior which is O(n1+ɛ) for ε < 1. Images acquired from histological sections of liver tissue are used as a case study to demonstrate the effectiveness of the approach. The histological landscape consists of hepatocytes and non-parenchymal cells. The accuracy of the proposed methodology is verified against an automated workflow created by the output of a conventional filter bank (validated by experts) and the supervised training of a random forest classifier. The results are obtained on a per-object basis. The proposed workflow successfully detected both hepatocyte and non-parenchymal cell nuclei with an accuracy of 84.6%, and hepatocyte cell nuclei only with an accuracy of 86.2%. A public histological dataset with supplied ground-truth data is also used for evaluating the performance of the proposed approach (accuracy: 94.5%). Further validations are carried out with a publicly available dataset and ground-truth data from the Gland Segmentation in Colon Histology Images Challenge (GlaS) contest. The proposed method is useful for obtaining unsupervised robust initial segmentations that can be further integrated in image/data processing and management pipelines. The development of a fully automated system supporting a human expert provides tangible benefits in the context of clinical decision-making.

Graphical abstract

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Impact of osteopathic therapy on pro-prioceptive balance and quality of life in patients with dizziness

Publication date: Available online 6 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): L. Papa, A. Amodio, F. Biffi, A. Mandara
The aim of the study was to evaluate the efficacy of osteopathic manipulative treatment (OMT) in patients with Benign-Paroxysmal-Positional Vertigo (BPPV).Thirty-one patients with BPPV were randomly assigned into two groups: 19 patients received osteopathic treatments (TG) and 12 patients received sham therapy (SG), both in four weekly sessions. Before the first and the last treatment, those patients were evaluated using Dizziness Handicap Inventory (DHI) and stabilometric platform to assess lifestyle modification and balance functions.After the treatment session, TG compared to SG showed an improvement in DHI global (p=0.02), functional (p=0.03) and physical (p=0.03) components, as well as a reduction of swinging area (p=0.02). An association between swinging area and lifestyle measures (global [r=0.53; p=0.02]; functional [r=0.50; p=0.03]; physical [r=0.60; p= 0.01]) changes were found in TG.These findings suggest that OMT could be a useful approach to reduce imbalance symptoms and to improve the quality of life in patients suffering from dizziness.

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The Rebound Boots Change the Lower Limb Muscle Activation and Kinematics During Different Fitness Exercises

Publication date: Available online 6 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): Mateus Rossato, Rodolfo André Dellagrana, Juliane Cristine Lopes dos Santos, Felipe P. Carpes, Rodrigo Ghedini Gheller, De Angelys de Ceselles Seixas da Silva, Ewertton de Souza Bezerra, João Otacílio Libardoni dos Santos
The purpose of this study was to evaluate electromyography and kinematic parameters of the lower limbs using rebound boots (RB) and barefoot during a gym workout. This information can be helpful to practitioners to schedule the rehabilitation and training programs. Ten women (25 ± 9 years) volunteered for the study; inclusion criteria were as follows: subjects must have experienced the RB and the analyzed exercises for at least 6 months, and have no previous injuries in the lower limbs. Seven exercises were performed for 30 seconds with the RB and subsequently on barefoot. Data from muscle activation of vastus lateralis (VL), biceps femoris (BF), lateral gastrocnemius (LG) and 2D kinematics were collected. The RB triggered postural changes, characterized by larger hip extension (4 exercises) and knee extension (6 exercises) for the landing. RB reduced activation mainly in LG (6 exercises) while no changes were observed for VL (except exercise 1) and BF. RB change kinematics and muscle activation suggesting changes in the way the legs absorb and transmit force during jumps. LG was the main muscle affected by the use of RB.

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Within-day and between-day reliability of thickness measurements of abdominal muscles using ultrasound during abdominal hollowing and bracing maneuvers

Publication date: Available online 6 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): Mahnaz Aboufazeli, Nima Afshar-Mohajer
Ultrasonography imaging has been used as a non-invasive method to estimate the thickness and relative activities of the abdominal muscles in patients with lower back pain (LBP). However, the statistical reliability of US thickness measurements of abdominal muscles, including transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) muscles during abdominal hollowing (AH) and abdominal bracing (AB) maneuvers has not been well-investigated. This study was performed on a total of 20 female subjects (10 with LBP and 10 without LBP) in the age range of 25 to 55 years to assess within-day and between-day reliability of the measurements. US measurements on maneuvers were repeated after two hours for the within-day reliability and after five days for the between-day reliability assessment. High intra-class correlation coefficient (ICC) values (>0.75) for within-day and between-day reliability assessments during AH maneuver were concluded. The ICC values were moderate for reliability assessment during AB. The ICC values for AH were greater than AB both for within- and between-day reliabilities. The small standard error of measurement and minimal detectable change values (0.16 to 0.78 and 0.44 to 2.15, respectively) were found for both AH and AB. We recommend real-time US imaging as a reliable way of determining the thicknesses of the TrA and IO muscle (and to some extent, EO muscle) for both healthy and LBP patients.

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The effects of dorso-lumbar motion restriction on EMG activity of selected muscles during running

Publication date: Available online 6 March 2017
Source:Journal of Bodywork and Movement Therapies
Author(s): Joseph J. Morley, Edward Traum
AbstractThe effects of restricting dorso-lumbar spine mobility on electromyographic activity of the erector spinae, quadriceps femoris, hamstrings and gastrocnemius muscles in runners was investigated. Thermoplastic casting material was fashioned into a rigid orthosis and used to restrict spinal motion during running. Volunteers ran on a treadmill at 2.78 m/sec, under normal conditions and with spinal motion restricted. Surface electromyographic data was collected during both sets of trials. Normal electromyographic data was also compared with previous authors to determine similarity with their electromyographic data.ResultsCasted running resulted in an increase in erector spinae (p < 0.01) and quadriceps femoris (p= 0.02) electromyography activity. Total stride time and swing time of gait were decreased during casted running (p < 0.01), indicating a shift towards shorter and thus more frequent steps to run the same distance. The normal electromyographic data collected was in agreement with previously reported work.ConclusionsNeurological control over muscle and the fascia surrounding it is responsible for joint movement and load transfer. Experimentally restricting spinal motion during running demonstrated an increase in erector spinae and rectus femoris electromyographic activity. This lends support to the hypothesis that decreased spinal mobility may be a contributing factor to overuse muscle injuries in runners.

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Δευτέρα 6 Μαρτίου 2017

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