Semi-automated Tracing Research Articles

The architectural characteristics of the hamstring muscles do not differ between male and female elite-level rugby union players.

Purpose: To determine whether differences exist in the architectural characteristics of the hamstring muscles of elite-level male and female rugby union players. Methods: Forty elite-level rugby union players (male n = 20, female n = 20) participated in this cross-sectional study. A sonographer acquired static ultrasound images using a 92mm linear transducer to quantify (via a semi-automated tracing software tool) the architectural characteristics (muscle length, fascicle length, pennation angle, and muscle thickness) of the biceps femoris long head and semimembranosus muscles of participants' left limb. Muscle length and muscle thickness of the biceps femoris short head and semitendinosus muscles of participants' left limb were also quantified. Bonferroni adjusted independent samples t-tests were performed to evaluate whether differences exist in the architectural characteristics of the hamstring muscles of elite-level male and female rugby union players. Results: There were no significant differences in fascicle length or pennation angle of the hamstring muscles of elite-level male and female rugby union players. Some significant differences in muscle thickness (biceps femoris short head, and semimembranosus) and muscle length (biceps femoris short head, biceps femoris long head, semitendinosus, and semimembranosus) were observed; in all cases the male players had thicker and longer muscles. Conclusion: At a group level, hamstring muscle fascicle length and pennation angle are unlikely to be a sex-specific intrinsic risk factor for Hamstring strain injuries.

Comparison of Accuracy and reliability of Automated tracing Android app with Conventional and Semiautomated Computer aided tracing software for cephalometric Analysis – A cross-sectional study

Introduction Cephalometry used as an adjuvant tool in orthodontic diagnosis has undergone significant changes from manual tracing to computer assisted digital tracing cephalometric analysis system. The smart phone apps running in android or other operating systems were introduced recently for doing cephalometric analysis. Hence this study was done comparing the accuracy and reliability of automated tracing (Webceph Android app) with gold standard manual tracing and semi-automatic tracing (NemoCeph). Materials and Methods The study was performed on 39 Pre-treatment lateral cephalograms. 10 angular and 11 linear skeletal, dental and soft tissue parameters were assessed by tracing the cephalograms manually, digitally using Nemoceph software and Webceph app. The mean and standard deviation were calculated, the overall intergroup comparisons were done using ANOVA test and individual intergroup comparisons were done by post-hoc analysis using Sidak Test. The overall interclass correlation coefficient (ICC) was calculated between the three groups. Results Angular measurements such as Occlusal plane to SN (P< 0.05) and Nasolabial angle (P< 0.05) showed significant difference between the different tracing methods and the linear parameters such as N perpendicular to Point A (P< 0.05) and Wits Appraisal (P< 0.05) showed significant difference between the different tracing methods. The overall reliability statistics showed good agreement (P<0.05) among all three groups. Conclusion Automated tracing (WebCeph) had more landmark identification errors when compared with manual or semi- automatic tracing (Nemoceph). Both WebCeph and Nemoceph were superior in their reliability when compared to manual tracing, with Nemoceph demonstrating greater efficacy compared to WebCeph.

Mapping meningeal vasculature in non-human primates

Background. The blood-brain barrier has been the focus of most prior work examining intracranial vasculature in the context of various brain diseases.1 Recently, meningeal vasculature has become more widely recognized as a key contributor to brain clearance and its immune function.2 Meninges are highly vascularized and complex tissue. Vessels of the outer dural layer comprise an extensive, parallel intracranial vascular bed, which lies outside the brain and subarachnoid space. In addition to the blood vasculature, meninges harbor lymphatic channels that potentially provide extra capacity for clearance of proteinaceous fluid and immune cell trafficking. Most of our knowledge of the meningeal vasculature, including lymphatics, comes from rodent models. Rodent meninges are readily available, small, thin and optically transparent. These characteristics permit imaging in whole-mount flat preparations.3 Technical barriers, however, remain high for imaging studies of the meninges of larger mammals. This is especially true for primates, and ultimately humans. Non-human primate (NHP) and human dura is large, thick and opaque, with a high content of connective tissue. These characteristics limit options for routine high-resolution imaging and leave unanswered questions about the architecture of blood and lymphatic vessels in primate dura. So far, the presence of lymphatic vessels in primates has been demonstrated by non-invasive techniques like magnetic resonance imaging (MRI) or on sections of paraffin-embedded specimens. Neither of the techniques fully addresses spatial and phenotypical features of the vascular networks. In our work, we provide solutions for these technical barriers using new clearing and imaging protocols to successfully visualize blood and lymphatic vessels in NPH dura in their entirety.
 Methods. Here we used novel approaches to tissue clearing and resonance scanning confocal imaging of large areas with sickness over 1000 M.
 Results. Our approach revealed extensive and dense vascular networks in NHP dura probed with vascular marker CD31 (Figure 1). Image clarity and resolution is sufficient for visualization of the smallest vessels. In the dura, blood vessels are mostly represented by veins. Vascular networks can be further analyzed with semi-automated tracing and quantitative metrics in 3D space. We showed that lymphatic vessels in NPH dura are located similarly to that in rodents: in the area of the superior sagittal sinus (SSS) and along the middle meningeal artery (MMA). They are also present in the major dural fold, tentorium cerebelli, which is underdeveloped in rodents. Unlike previously described in mice, these vessels are negative for LYVE-1 lymphatic marker but strongly positive for podoplanin. In the area of SSS, there is a large plexus of branching irregular blind-ended sacs with a wide range of diameters. Vessels in the MMA region have a different appearance. Two vessels always run along the veins flanking MMA that follow the artery branching. Our protocol also permits imaging of the extracellular matrix and the cells that reside in the dural environment.
 Conclusions. We developed clearing, mounting and imaging protocols that permitted panoramic fluorescence-based microscopy of NPH dura. These new techniques are directly applicable to primate models of neurodegenerative diseases with a focus on the complex interplay between meningeal arteries, veins, and lymphatics.

Semi-automated left ventricular endocardial detection versus hand-tracing in the measurement of left ventricular volumes and ejection fraction in daily clinical practice

Abstract Background The common method of assessing left ventricle (LV) volumes and ejection fraction (EF) is hand-tracing Biplane Simpson method. Alternatively, ultrasound vendors offer different semi-automated LV endocardial border detection software with anatomical intelligence to assess LV volumes and EF. By using speckle-tracking technique, this software tracks the LV endocardium throughout the cardiac cycle and computes the LV volumes in every image frame using the disk summation method from which a volume-curve is generated, and the EF is calculated using the maximum and minimum volumes obtained. Data on the performance of this method in comparison with the hand-tracing Biplane Simpson method in daily clinical practice is scarce. Purpose To determine the accuracy of LV volumes and EF using semi-automated LV endocardial detection tracing, and to compare the reproducibility of this method with the hand-tracing Biplane Simpson method, among operators with varying level of experience in echocardiography. Methods This was a single center retrospective observational study, conducted in year 2020. 127 patients, aged >18 years, who underwent clinically indicated transthoracic echocardiography were recruited. The echocardiographic images were analyzed independently in a blinded fashion by 3 operators – a sonographer, a fellow-in-training and a cardiologist specialized in echocardiography. The LV volumes and EF were first measured using hand-tracing Biplane Simpson method, then repeated using semi-automated tracing at a different time and the operator were blinded to the initial hand-tracing measurements. Results The mean age of patients was 50±16 years, 35.4% were male, mean body surface area was 1.62±0.18m2, 92.1% were in sinus rhythm, and 61.4% had good acoustic window. Table 1 shows the LV end-diastolic volume (EDV), end-systolic volume (ESV) and EF, measured using different method, by the 3 operators. There were excellent correlation and agreement between semi-automated tracing measurements and hand-tracing measurements of LV EDV (r=0.985, LOA [mean ± 1.96 SD] 16.9 ml, ICC 0.991), ESV (r=0.990, LOA 12.7 ml, ICC 0.994) and EF (r=0.962, LOA 7.43%, ICC 0.967) by experienced cardiologist. The limit of agreement (LOA) between cardiologist and sonographer for semi-automated tracing measurement of LV EDV, ESV and EF were 29.13 ml, 19.74 ml and 9.25% respectively, which was comparable with that of hand-tracing measurement. The agreement between cardiologist and fellow-in-training for semi-automated tracing measurement of LV volumes and EF was slightly better than hand-tracing method, with a LOA of 25.60 ml, 17.48 ml and 7.08%, for EDV, ESV and EF respectively (Table 2). Conclusion In daily clinical practice, measurement of LV volumes and EF using semi-automated LV endocardial tracing method is accurate and demonstrates comparable reproducibility with hand-tracing Biplane Simpson method among operators with different level of experience in echocardiography. Funding Acknowledgement Type of funding sources: None.

Semi-automated Tracing of Hamstring Muscle Architecture for B-mode Ultrasound Images.

Hamstring strains are the most prevalent injury sustained by field-sport athletes. Insufficiencies in the architectural characteristics of the hamstring muscles can heighten an athlete's risk of incurring a hamstring strain. To evaluate the influence of hamstring muscle architectural characteristics (i. e., fascicle length, pennation angle, muscle thickness) on injury risk, it is necessary to precisely evaluate these characteristics. Considering this, our aim was to develop and evaluate the precision of a novel semi-automated tracing software to measure the architectural characteristics of the biceps femoris long head (the most commonly injured hamstring muscle) in B-mode ultrasound images. We acquired static sonograms of the biceps femoris long head from ten healthy male field-sport athletes. The architectural characteristics (fascicle length, pennation angle, and muscle thickness) of participants' biceps femoris long head were evaluated 10 times using the tracing software, with the specific purpose of determining its measurement precision. The tracing software precisely measured the architectural characteristics of the participants' biceps femoris long head: fascicle length (% CV: 0.64-1.12), pennation angle (% CV: 2.58-10.70), muscle thickness (% CV: 0.48-2.04) Our semi-automated skeletal muscle tracing algorithm precisely measures fascicle length, pennation angles, and muscle thickness of the biceps femoris long head in static B-mode ultrasound images.

Improving the Usability of Virtual Reality Neuron Tracing with Topological Elements.

Researchers in the field of connectomics are working to reconstruct a map of neural connections in the brain in order to understand at a fundamental level how the brain processes information. Constructing this wiring diagram is done by tracing neurons through high-resolution image stacks acquired with fluorescence microscopy imaging techniques. While a large number of automatic tracing algorithms have been proposed, these frequently rely on local features in the data and fail on noisy data or ambiguous cases, requiring time-consuming manual correction. As a result, manual and semi-automatic tracing methods remain the state-of-the-art for creating accurate neuron reconstructions. We propose a new semi-automatic method that uses topological features to guide users in tracing neurons and integrate this method within a virtual reality (VR) framework previously used for manual tracing. Our approach augments both visualization and interaction with topological elements, allowing rapid understanding and tracing of complex morphologies. In our pilot study, neuroscientists demonstrated a strong preference for using our tool over prior approaches, reported less fatigue during tracing, and commended the ability to better understand possible paths and alternatives. Quantitative evaluation of the traces reveals that users' tracing speed increased, while retaining similar accuracy compared to a fully manual approach.

Left ventricular ejection fraction using manual and semi-automated biplane method of discs in very preterm infants.

Biplane left ventricular ejection fraction (LVEF) is a valuable echocardiographic parameter for assessment of LV systolic pump efficiency in adults and children, but not often reported in preterm infants. The primary aim of this study was to longitudinally measure biplane LVEF in very preterm infants during the neonatal intensive care period. Secondary aim was to compare manual and semi-automatic determination of LVEF for agreement and variability. Stable preterm infants less than 30weeks gestation were scanned on day 3, day 28, and at 36weeks postmenstrual age. The LV endocardium was traced manually and semi-automatically using integrated speckle tracking software in apical 4-chamber and apical 3-chamber images to obtain end-diastolic volume and end-systolic volume, and calculate LVEF. Agreement between methods and variability within and between observers was determined using an interclass correlation coefficient (ICC) and Bland-Altman analysis. Sixty-six preterm infants with a mean birth weight of 1100 (239)g were analyzed. The average manual biplane LVEF was 58 (3)%, 59 (3)%, and 55 (4)% at the three respective time points. Manual LVEF showed good agreement with semi-automatic LVEF (ICC 0.76) with a small bias of -1.5 (3.0)%. Interobserver variability of LVEF improved with semi-automatic tracing of the LV endocardial border (ICC manual 0.68 vs semi-automatic 0.80). Left ventricular systolic pump efficiency in preterm infants remains stable during the neonatal intensive care period. Semi-automatic biplane LVEF has less interobserver variability and can be used interchangeably with manual biplane LVEF.

Stromal Nerve Imaging and Tracking Using Micro-Optical Coherence Tomography.

PurposeTo image, track and map the nerve fiber distribution in excised rabbit corneas over the entire stromal thickness using micro-optical coherence tomography (µOCT) to develop a screening tool for early peripheral neuropathy.MethodsExcised rabbit corneas were consecutively imaged by a custom-designed µOCT prototype and a commercial laser scanning fluorescence confocal microscope. The µOCT images with a field of view of approximately 1 × 1 mm were recorded with axial and transverse resolutions of approximately 1 µm and approximately 4 µm, respectively. In the volumetric µOCT image data, network maps of hyper-reflective, branched structures traversing different stromal compartments were segmented using semiautomatic image processing algorithms. Furthermore, the same corneas received βIII-tubulin antibody immunostaining before digital confocal microscopy, and a comparison between µOCT image data and immunohistochemistry analysis was performed to validate the nerval origin of the tracked network structures.ResultsSemiautomatic tracing of the nerves with a high range of different thicknesses was possible through the whole corneal volumes, creating a skeleton of the traced nerves. There was a good conformity between the hyper-reflective structures in the µOCT data and the stained nerval structures in the immunohistochemistry data.ConclusionsThis article demonstrates nerval imaging and tracking as well as a spatial correlation between µOCT and a fluorescence corneal nerve standard for larger nerves throughout the full thickness of the cornea ex vivo.Translational RelevanceOwing to its advantageous properties, µOCT may become useful as a noncontact method for assessing nerval structures in humans to screen for early peripheral neuropathy.

Novel semi-automated algorithm for high-throughput quantification of adipocyte size in breast adipose tissue, with applications for breast cancer microenvironment

ABSTRACT The size distribution of adipocytes in fat tissue provides important information about metabolic status and overall health of patients. Histological measurements of biopsied adipose tissue can reveal cardiovascular and/or cancer risks, to complement typical prognosis parameters such as body mass index, hypertension or diabetes. Yet, current methods for adipocyte quantification are problematic and insufficient. Methods such as hand-tracing are tedious and time-consuming, ellipse approximation lacks precision, and fully automated methods have not proven reliable. A semi-automated method fills the gap in goal-directed computational algorithms, specifically for high-throughput adipocyte quantification. Here, we design and develop a tool, AdipoCyze, which incorporates a novel semi-automated tracing algorithm, along with benchmark methods, and use breast histological images from the Komen for the Cure Foundation to assess utility. Speed and precision of the new approach are superior to conventional methods and accuracy is comparable, suggesting a viable option to quantify adipocytes, while increasing user flexibility. This platform is the first to provide multiple methods of quantification in a single tool. Widespread laboratory and clinical use of this program may enhance productivity and performance, and yield insight into patient metabolism, which may help evaluate risks for breast cancer progression in patients with comorbidities of obesity. ABBREVIATIONS: BMI: body mass index.

A Method to Measure Myeloarchitecture of the Murine Cerebral Cortex in vivo and ex vivo by Intrinsic Third-Harmonic Generation.

A new label-free method is presented for measuring myeloarchitecture of the murine cerebral cortex in vivo and ex vivo. Growing evidence suggests that cortical myelination plays significant roles in neuronal plasticity and pathologies, such as multiple sclerosis (MS), but illuminating the mechanism requires longitudinal imaging of the same brains. Here we demonstrate imaging unlabeled myelinated fibers in a live mouse brain by third-harmonic generation (THG). Contrary to other label-free microscopies based on reflectance, fibers of all orientations could be visualized, i.e., radial and tangential to the pia, which is suitable for revealing the three-dimensional connectivity. The depth of THG imaging in an intact brain was approximately 200 μm, so the network of myelinated fibers could be captured into layers 2/3 in vivo. THG provides a novel base for reconstruction of morphology. Semi-automatic tracing of THG-positive axons unraveled the depth-dependent distribution of the myelin lattice. Finally, a unique light property of THG was exploited for the estimation of the g-ratio. The demonstrated THG morphometry of the length density, orientation, and sheath thickness of cortical myelin could be useful for elucidating its function and how it is modulated during learning and disease.

Multispectral tracing in densely labeled mouse brain with nTracer.

SummaryThis note describes nTracer, an ImageJ plug-in for user-guided, semi-automated tracing of multispectral fluorescent tissue samples. This approach allows for rapid and accurate reconstruction of whole cell morphology of large neuronal populations in densely labeled brains.Availability and implementationnTracer was written as a plug-in for the open source image processing software ImageJ. The software, instructional documentation, tutorial videos, sample image and sample tracing results are available at https://www.cai-lab.org/ntracer-tutorial.Supplementary information Supplementary data are available at Bioinformatics online.

Test-retest reliability of echo intensity parameters in healthy Achilles tendons using a semi-automatic tracing procedure.

To evaluate the test-retest reliability of the ultrasound echo intensity parameters on healthy Achilles tendon using a semi-automatic tracing procedure. Eighteen healthy volunteers participated. B-mode images were acquired in the transverse plane (mid-tendon; insertion) and used to analyze tendon echogenicity. Grayscale distribution of the pixels within the selected ROIs was represented as a histogram. Descriptive statistics of the grayscale distribution (mean, variance, skewness, kurtosis, and entropy) and parameters from the co-occurrence matrix (contrast, energy, and homogeneity) were calculated. Reliability of echo intensity parameters of the mid-Achilles tendon ranged from high to very high with an ICC2.k of 0.94 for echogenicity, 0.87 for variance, 0.80 for skewness, 0.72 for kurtosis, 0.89 for entropy, 0.90 for contrast, 0.91 for energy, and 0.93 for homogeneity, while for tendon insertion they ranged from moderate to high with an ICC2.k of 0.74 for echogenicity, 0.88 for variance, 0.75 for skewness, 0.55 for kurtosis, 0.87 for entropy, 0.70 for contrast, 0.77 for energy, and 0.56 for homogeneity. Ultrasound echo intensity is a reliable technique to characterize the internal structure of the Achilles tendon.

Kidney volume measurement methods for clinical studies on autosomal dominant polycystic kidney disease.

BackgroundIn autosomal dominant polycystic kidney disease (ADPKD), total kidney volume (TKV) is regarded as an important biomarker of disease progression and different methods are available to assess kidney volume. The purpose of this study was to identify the most efficient kidney volume computation method to be used in clinical studies evaluating the effectiveness of treatments on ADPKD progression.Methods and findingsWe measured single kidney volume (SKV) on two series of MR and CT images from clinical studies on ADPKD (experimental dataset) by two independent operators (expert and beginner), twice, using all of the available methods: polyline manual tracing (reference method), free-hand manual tracing, semi-automatic tracing, Stereology, Mid-slice and Ellipsoid method. Additionally, the expert operator also measured the kidney length. We compared different methods for reproducibility, accuracy, precision, and time required. In addition, we performed a validation study to evaluate the sensitivity of these methods to detect the between-treatment group difference in TKV change over one year, using MR images from a previous clinical study. Reproducibility was higher on CT than MR for all methods, being highest for manual and semiautomatic contouring methods (planimetry). On MR, planimetry showed highest accuracy and precision, while on CT accuracy and precision of both planimetry and Stereology methods were comparable. Mid-slice and Ellipsoid method, as well as kidney length were fast but provided only a rough estimate of kidney volume. The results of the validation study indicated that planimetry and Stereology allow using an importantly lower number of patients to detect changes in kidney volume induced by drug treatment as compared to other methods.ConclusionsPlanimetry should be preferred over fast and simplified methods for accurately monitoring ADPKD progression and assessing drug treatment effects. Expert operators, especially on MR images, are required for performing reliable estimation of kidney volume. The use of efficient TKV quantification methods considerably reduces the number of patients to enrol in clinical investigations, making them more feasible and significant.

Cross-Modality Validation of Acetabular Surface Models Using 3-D Ultrasound Versus Magnetic Resonance Imaging in Normal and Dysplastic Infant Hips

Current imaging diagnosis of developmental dysplasia of the hip (DDH) in infancy relies on 2-D ultrasound (US), which is highly operator-dependent. 3-D US offers more complete, and potentially more reliable, imaging of infant hip geometry. We sought to validate the fidelity of acetabular surface models obtained by 3-D US against those obtained concurrently by magnetic resonance imaging (MRI). 3-D US and MRI scans were performed on the same d in 20 infants with normal to severely dysplastic hips (mean age, 57 d; range 13–181 d). 3-D US was performed by two observers using a Philips VL13-5 probe. Coronal 3-D multi-echo data image combination (MEDIC) magnetic resonance (MR) images (1-mm slice thickness) were obtained, usually without sedation, in a 1.5 T Siemens unit. Acetabular surface models were generated for 40 hips from 3-D US and MRI using semi-automated tracing software, separately by three observers. For each hip, the 3-D US and MRI models were co-registered to overlap as closely as possible using Amira software, and the root mean square (RMS) distances between points on the models were computed. 3-D US scans took 3.2 s each. Inter-modality variability was visually minimal. Mean RMS distance between corresponding points on the acetabular surface at 3-D US and MRI was 0.4 ± 0.3 mm, with 95% confidence interval <1 mm. Mean RMS errors for inter-observer and intra-observer comparisons were significantly less for 3-D US than for MRI, while inter-scan and inter-modality comparisons showed no significant difference. Acetabular geometry was reproduced by 3-D US surface models within 1 mm of the corresponding 3-D MRI surface model, and the 3-D US models were more reliable. This validates the fidelity of 3-D US modeling and encourages future use of 3-D US in assessing infant acetabulum anatomy, which may be useful to detect and monitor treatment of hip dysplasia.

Toward automated classification of acetabular shape in ultrasound for diagnosis of DDH: Contour alpha angle and the rounding index

Background and objectivesThe diagnosis of Developmental Dysplasia of the Hip (DDH) in infants is currently made primarily by ultrasound. However, two-dimensional ultrasound (2DUS) images capture only an incomplete portion of the acetabular shape, and the alpha and beta angles measured on 2DUS for the Graf classification technique show high inter-scan and inter-observer variability. This variability relates partly to the manual determination of the apex point separating the acetabular roof from the ilium during index measurement. This study proposes a new 2DUS image processing technique for semi-automated tracing of the bony surface followed by automatic calculation of two indices: a contour-based alpha angle (αA), and a new modality-independent quantitative rounding index (M). The new index M is independent of the apex point, and can be directly extended to 3D surface models. MethodsWe tested the proposed indices on a dataset of 114 2DUS scans of infant hips aged between 4 and 183 days scanned using a 12MHz linear transducer. We calculated the manual alpha angle (αM), coverage, contour-based alpha angle and rounding index for each of the recordings and statistically evaluated these indices based on regression analysis, area under the receiver operating characteristic curve (AUC) and analysis of variance (ANOVA). ResultsProcessing time for calculating αA and M was similar to manual alpha angle measurement, ∼30s per image. Reliability of the new indices was high, with inter-observer intraclass correlation coefficients (ICC) 0.90 for αA and 0.89 for M. For a diagnostic test classifying hips as normal or dysplastic, AUC was 93.0% for αA vs. 92.7% for αM, 91.6% for M alone, and up to 95.7% for combination of M with αM, αA or coverage. ConclusionsThe rounding index provides complimentary information to conventional indices such as alpha angle and coverage. Calculation of the contour-based alpha angle and rounding index is rapid, shows potential to improve the reliability and accuracy of DDH diagnosis from 2DUS, and could be extended to 3D ultrasound in future.

Identification of a definite diabetic cardiomyopathy in type 2 diabetes by comprehensive echocardiographic evaluation: A cross‐sectional comparison with non‐diabetic weight‐matched controls

Subclinical left ventricular (LV) dysfunction is prevalent in type 2 diabetes (T2DM). As obesity has been proposed as one causal factor in the disease process, this could bias the reported prevalences. We wanted to characterize echocardiographic LV dysfunction in obese T2DM subjects as compared to non-diabetic obese controls. One hundred patients with T2DM without clinical signs of heart failure (29% females, mean ± SD age 58.4 ± 10.5 years, body mass index (BMI) 30.1 ± 5.5 kg/m(2), blood pressure (BP) 141 ± 18/83 ± 9 mmHg) and 100 non-diabetic controls (29% females) matched for age (58.6 ± 10.5 years), BMI (29.8 ± 4.0 kg/m(2) and systolic BP (140 ± 14 mmHg) underwent echocardiography and color tissue Doppler imaging (TDI). Diastolic function was evaluated with conventional Doppler recordings and early (e') and late (a') myocardial velocities. The ratio between early transmitral filling (E) and the corresponding myocardial tissue velocity (e') served as an index of LV filling pressure. T2DM patients had more concentric hypertrophy with a relative wall thickness of 0.42 ± 0.07 vs controls 0.38 ± 0.07, P < 0.001. The T2DM group had signs of diastolic dysfunction with lower E/A ratio (0.91 ± 0.27 vs. 1.12 ± 0.38, P < 0.001), deceleration time (195 ± 49 vs 242 ± 72 ms, P < 0.001), e' (5.7 ± 2.0 vs. 6.6 ± 1.8 cm/s, P = 0.001), and a' (6.5 ± 2.0 vs. 7.6 ± 1.5 cm/s, P < 0.001) compared to the controls, and higher E/e' (13.3 ± 4.7 vs. 11.1 ± 3.5, P < 0.001). Thus, there were indications of pseudo normalization and increased filling pressure in the T2DM group, whereas the controls had evidence for relaxation abnormalities without elevated filling pressure. Compared to a non-diabetic obese group, more advanced subclinical impairment of diastolic function was seen in T2DM.

Tracing the boundaries of Cenozoic volcanic edifices from Sardinia (Italy): a geomorphometric contribution

Abstract. Unequivocal delimitation of landforms is an important issue for different purposes, from science-driven morphometric analysis to legal issues related to land conservation. This study is aimed at giving a new contribution to the morphometric approach for the delineation of the boundaries of volcanic edifices, applied to 13 monogenetic volcanoes (scoria cones) related to the Pliocene–Pleistocene volcanic cycle in Sardinia (Italy). External boundary delimitation of the edifices is discussed based on an integrated methodology using automatic elaboration of digital elevation models together with geomorphological and geological observations. Different elaborations of surface slope and profile curvature have been proposed and discussed; among them, two algorithms based on simple mathematical functions combining slope and profile curvature well fit the requirements of this study. One of theses algorithms is a modification of a function introduced by Grosse et al. (2011), which better performs for recognizing and tracing the boundary between the volcanic scoria cone and its basement. Although the geological constraints still drive the final decision, the proposed method improves the existing tools for a semi-automatic tracing of the boundaries.

A fluorescence microplate screen assay for the detection of neurite outgrowth and neurotoxicity using an antibody against βIII-tubulin

The majority of environmental and commercial chemicals have not been evaluated for their potential to cause neurotoxicity. We have investigated if neuron specific anti-βIII-tubulin antibodies are useful in a microplate assay of neurite outgrowth of retinoic acid-induced neurons from mouse P19 embryonal carcinoma cells. By incubating the P19-derived neurons with the primary anti-βIII-tubulin antibody and a secondary Alexa Fluor 488-conjugated antibody, followed by measuring the fluorescence in a microplate reader, a time-dependent increase in anti-βIII-tubulin immunofluorescence was observed. The relative fluorescence units increased by 4.3-fold from 2 to 10days in culture. The results corresponded well with those obtained by semi-automatic tracing of neurites in fluorescence microscopy images of βIII-tubulin-labeled neurons. The sensitivity of the neurite outgrowth assay using a microplate reader to detect neurotoxicity produced by nocodazole, methyl mercury chloride and okadaic acid was significantly higher than for a cell viability assay measuring intracellular fluorescence of calcein-AM. The microplate-based method to measure toxicity targeting neurites using anti-βIII-tubulin antibodies is however less sensitive than the extracellular lactate dehydrogenase activity assay to detect general cytotoxicity produced by high concentrations of clomipramine, or glutamate-induced excitotoxicity.In conclusion, the fluorescence microplate assay for the detection of neurite outgrowth by measuring changes in βIII-tubulin immunoreactivity is a rapid and sensitive method to assess chemical- or toxin-induced neurite toxicity.

Relationship between serum fibroblast growth factor 23 levels and left ventricular mass measured by three-dimensional echocardiography in patients with end-stage renal disease

Purpose: In patients with chronic renal insufficiency traditional risk factors of left ventricular (LV) hypertrophy include hypertension, overhydration, anemia and impaired calcium-phosphate homeostasis. Fibroblast growth factor 23 (FGF-23) is a phosphaturic hormone secreted by osteoblasts and a rising biomarker associated with LV hypertrophy and mortality in patients with end-stage renal disease (ESRD). We sought to determine the relationship between serum FGF-23 levels and left venticular mass measured by three-dimensional (3D) echocardiography in ESRD patients. Methods: This retrospective cohort study included 44 patients (mean age 48±13 years, 54% men) with ESRD on three times per week maintenance hemodialysis. Exclusion criteria were previous history of diabetes and any significant cardiac disease. Beyond conventional transthoracic echocardiographic examination, 3D recordings were obtained using multi-beat reconstruction from 6 consecutive cardiac cycles (GE Vivid E9). After semi-automated tracing of LV endo- and epicardial surface at end-diastolic frame, LV mass was calculated using dedicated software (GE 4D Auto LVQ). Serum FGF-23 levels were measured by enzyme-linked immunosorbent assay (Merck Millipore). Overhydration evaluated by bioimpedance (Fresenius Body Composition Monitor), laboratory test results (including serum calcium, phosphate, parathormone, total iron binding capacity levels) and blood pressure were recorded and averaged in the three previous months. Relationships were calculated by Spearman correlation test and multivariate linear regression. Results: The median value of LV mass measured in ESRD patients was 244 grams (interquartile range 97.5). Serum FGF-23 levels ranged between 34 and 6848 with a median of 687 pg/ml. Serum levels of FGF-23 (ρ=0.52), phosphate (ρ=0.55), parathormone (ρ=0.38), total iron binding capacity (ρ=0.61), systolic blood pressure (ρ=0.38) and pulse pressure (ρ=0.47, all p<0.05) correlated significantly with LV mass. FGF-23 correlated with serum phosphate (ρ=0.83) and parathormone (ρ=0.53, both p<0.001) levels. In a multivariate linear regression model, FGF-23 (β=0.42, p<0.001), total iron binding capacity (β=0.49, p<0.001) and systolic blood pressure (β=0.37, p<0.01) were found to be independent predictors of LV mass. Conclusions: To the best of our knowledge, this is the first study which demonstrates the strong correlation between serum FGF-23 levels and LV mass measured by 3D echocardiography. Beside the chronic volume- and pressure overload, LV hypertrophy is strongly determined by the endocrine effects of FGF-23 in patients with ESRD.

Going beyond ejection fraction - CMR assessment of ventricular-vascular coupling and LV remodeling predicts diastolic dysfunction in advanced ischemic cardiomyopathy

Background Increased ventricular and arterial stiffness is associated with diastolic dysfunction (DDFx) in patients with heart failure and preserved systolic function. Limited information is available regarding the impact of aortic biomechanics and the ventricular-vascular coupling (VVC) on DDFx in those patients with advanced ischemic cardiomyopathy (ICM). In addition, it is not known if cardiac magnetic resonance (CMR) measurements of LV remodeling (sphericity and scar burden) can also contribute to prediction of DDFx in these patients. We sought to examine the relationship between aortic biomechanical properties (ascending and descending distensibility, arch pulse wave velocity), ventricular-ventricular coupling (defined as the ratio between LV end-systolic elastance and effective arterial elastance), LV remodeling assessed by CMR and diastolic function assessed by echocardiography in patients with advanced ICM. Methods Patients were selected if they had undergone TTE and CMR studies within 7 days (median=1 day). 354 patients with LVEF ≤ 40% and ≥ 70% stenosis in ≥ 1c oronary artery but without prior mitral valve surgery, fused E/A waves, atrial fibrillation or > moderate mitral regurgitation were screened. Of those, 84 patients were excluded due to poor CMR image quality from artifacts and/or suboptimal temporal resolution. A total 270 charts were reviewed for demographic and laboratorial data. Diastolic function assessment was performed as per guidelines. Aortic biomechanics were measured using previously validated software (ARTFUN, INSERM U678, Paris, France) using semi-automated tracing of aortic contours with phase-contrast images and through-plane velocity encoding of the ascending and descending aorta. CMR evaluation also included long and short axis assessment of LV sphericity and function respectively on balanced steady state free precession images along with assessment of myocardial scar (on phase-sensitive inversion recovery DHE-CMR sequence ~ 10-20 minutes). Multivariate linear regression analysis was done to identify the independent predictors of DDFx. Results Males represented 76% of the cohort with a mean age of 62 ± 10 years. Mean LVEF was 23 ± 5% and DDFx was classified as either: stage 1 (44%), stage 2 (25%) or stage 3 (31%). The independent predictors of impaired diastolic function (stage > 1) are listed on Table 1. Conclusions In patients with advanced ICM, CMR assessment of VVC, LV sphericity and scar burden are independent predictors of DDFx. Aortic biomechanical properties are not independently associated with diastolic dysfunction. Funding None.