Quantification of LV Volumes with 4D Real-Time Echocardiography

This paper presents a new 4D (3D+Time) expansion of echocardiographic volumes on complex exponential wavelet-like basis functions called Brushlets. Brushlet functions offer good localization in time and frequency and decompose a signal into distinct patterns of oriented textures, invariant to intensity and contrast range. Automatic left ventricle (LV) endocardial border detection is carried out in the transform domain where speckle noise is attenuated while cardiac structure location is preserved. Quantitative validation and clinical applications of this new spatio-temporal analysis tool are reported with results on phantoms and clinical data sets to quantify LV volumes and ejection fraction

Spatio-temporal directional analysis of 4D echocardiography

Speckle noise corrupts ultrasonic data by introducing sharp changes in an echocardiographic image intensity profile, while attenuation alters the intensity of equally significant cardiac structures. These properties introduce inhomogeneity in the spatial domain and suggests that measures based on phase information rather than intensity are more appropriate for denoising and cardiac border detection. The present analysis method relies on the expansion of temporal ultrasonic volume data on complex exponential wavelet-like basis functions called Brushlets. These basis functions decompose a signal into distinct patterns of oriented textures. Projected coefficients are associated with distinct 'brush strokes' of a particular size and orientation. 4D overcomplete brushlet analysis is applied to temporal echocardiographic values. We show that adding the time dimension in the analysis dramatically improves the quality and robustness of the method without adding complexity in the design of a segmentation tool. We have investigated mathematical and empirical methods for identifying the most 'efficient' brush stroke sizes and orientations for decomposition and reconstruction on both phantom and clinical data. In order to determine the 'best tiling' or equivalently, the 'best brushlet basis', we use an entropy-based information cost metric function. Quantitative validation and clinical applications of this new spatio-temporal analysis tool are reported for balloon phantoms and clinical data sets

LV Volume Quantification via Spatiotemporal Analysis of Real-Time 3-D Echocardiography

This paper presents a method of four-dimensional (4-D) (3-D+Time) space-frequency analysis for directional denoising and enhancement of real-time three-dimensional (RT3D) ultrasound and quantitative measures in diagnostic cardiac ultrasound. Expansion of echocardiographic volumes is performed with complex exponential wavelet-like basis functions called brushlets. These functions offer good localization in time and frequency and decompose a signal into distinct patterns of oriented harmonics, which are invariant to intensity and contrast range. Deformable-model segmentation is carried out on denoised data after thresholding of transform coefficients. This process attenuates speckle noise while preserving cardiac structure location. The superiority of 4-D over 3-D analysis for decorrelating additive white noise and multiplicative speckle noise on a 4-D phantom volume expanding in time is demonstrated. Quantitative validation, computed for contours and volumes, is performed on in vitro balloon phantoms. Clinical applications of this spatiotemporal analysis tool are reported for six patient cases providing measures of left ventricular volumes and ejection fraction

Lv volume quantification via spatiotemporal analysis of real-time 3-d echocardiography

Abstract—This paper presents a method of four-dimensional (4-D) (3-D + Time) space–frequency analysis for directional denoising and enhancement of real-time three-dimensional (RT3D) ultrasound and quantitative measures in diagnostic cardiac ultrasound. Expansion of echocardiographic volumes is performed with complex exponential wavelet-like basis functions called brushlets. These functions offer good localization in time and frequency and decompose a signal into distinct patterns of oriented harmonics, which are invariant to intensity and contrast range. Deformable-model segmentation is carried out on denoised data after thresholding of transform coefficients. This process attenuates speckle noise while preserving cardiac structure location. The superiority of 4-D over 3-D analysis for decorrelating additive white noise and multiplicative speckle noise on a 4-D phantom volume expanding in time is demonstrated. Quantitative validation, computed for contours and volumes, is performed on in vitro balloon phantoms. Clinical applications of this spaciotemporal analysis tool are reported for six patient cases providing measures of left ventricular volumes and ejection fraction. Index Terms—Echocardiography, LV volume, spaciotemporal analysis, speckle denoising. I

脊椎椎弓根スクリュー誤挿入後,再挿入を行った際の引き抜き強度についての研究

Screw malposition, such as lateral wall breach or end-plate breach, is one of the main pitfalls of inserting pedicle screws. Methods: From 17 fresh spines 54 vertebrae were harvested. In each vertebra on one pedicle the screw was inserted correctly down the axis of the pedicle, while on the other pedicle the screw was inserted to breach the lateral wall or the end-plate. The 18 pedicle screws that breached the lateral wall were then removed and re-directed along the correct axis of the pedicle. The 18 pedicle screws that breached the end-plate were removed and re-directed along the correct axis of the pedicle. The 18 other pedicle screws that had breached the end-plate were not removed. The pullout force of pedicle screws was measured. Results: 1) The mean pullout strength for the re-directed screws following lateral wall breach was 24.0% less as compared to the correctly aligned screws; 2) The mean pullout strength for the re-directed screws following end-plate breach was 23.3% less as compared to the correctly aligned screws; 3) The mean pullout strength for the pedicle screws end-plate breach was 7.6% less as compared to the correctly aligned screws. Conclusion: The pullout strength of re-directed pedicle screws after either a lateral pedicle breach or end-plate breach is significantly less than the pullout strength of correctly aligned screw. A pedicle screw that is not re-directed after end-plate breach is weaker than a pedicle screw correctly aligned, however the difference is not significant

Latitudinal cline in the foraging dichotomy of loggerhead sea turtles reveals the importance of East China Sea for priority conservation

Special Issue: Biological traits, geographic distributions and species conservation in aquatic ecosystems[Aim]Quantifying the importance of habitat areas for conservation of highly migratory marine species with complex life histories can be challenging. For example loggerhead turtles (Caretta caretta) nesting in Japan forage both oceanically and neritically after their reproductive period. Here, we aimed to quantify the proportions of turtles using these two contrasting habitats (foraging dichotomy) to suggest priority conservation areas. [Location]North Pacific Ocean. [Methods]We examined the occurrence of foraging dichotomy at three nesting sites (Ishigaki, Okinoerabu Islands and Ichinomiya) based on stable isotope analysis of the egg yolks for 82 turtles and satellite tracking of post-nesting migration for 12 turtles. Moreover, we used the data of three other sites from previous studies (Yakushima Island, Minabe and Omaezaki). [Results]Two neritic foraging grounds (East China Sea and the coastal area of the Japanese archipelago), and an oceanic ground (North Pacific Ocean) were identified. We found a latitudinal cline with respect to the occurrence of foraging dichotomy; >84% of the females nesting at southern sites (Ishigaki and Okinoerabu Islands), 73% at middle sites (Yakushima Island and Minabe) and <46% at northern sites (Omaezaki and Ichinomiya) were neritic foragers; the proportion of oceanic foragers increased at northern sites. Based on the annual number of nests in the entire nesting region of Japan, satellite tracking and the latitudinal cline of foraging dichotomy, we estimated that 70% and 9% of annual nesting females in Japan utilize the neritic foraging habitat in the East China Sea and the coastal area of the Japanese archipelago, respectively, and that and 22% utilize the oceanic habitat of the North Pacific Ocean. [Main conclusions]The East China Sea represents a critical foraging habitat for the North Pacific populations of endangered loggerhead sea turtles. Our findings emphasize the need for international management to ensure their protection

Combined assessment of serum folate and hemoglobin as biomarkers of brain amyloid β accumulation.

A relationship between Alzheimer's disease (AD) and folate has been reported. Amyloid positron emission tomography (PET) is currently one of the most reliable biomarkers for AD. We investigated the correlation between serum folate levels and amyloid imaging to clarify whether serum folate could be a biomarker for AD. We also examined the usefulness of a combined assessment of serum folate levels and red blood cell hemoglobin content. Apolipoprotein E (APOE) gene polymorphisms were also assessed. Serum folate levels and hemoglobin content were evaluated by receiver operating characteristic analysis for their diagnostic capability as AD biomarkers relating to brain amyloid β accumulation. The area under the ROC curve (AUC) for serum folate was 0.136 (95% confidence interval [CI]: 0.000-0.312; p = 0.016). The AUC for hemoglobin content was 0.848 (95% CI: 0.661-1.000; p = 0.021). Therefore, the folate deficiency with low folate levels or the non-anaemia with high hemoglobin content levels were found to have a high probability of also testing positive for amyloid. Furthermore, eight patients were found to be folate deficiency and non-anaemia, those who were consist of 7 amyloid positive patients (87.5%), and only one of the amyloid negative patients (12.5%). These results suggest that a deficiency of serum folate and high hemoglobin levels may reflect an increased risk of amyloid β accumulation in the brain. Additionally, we demonstrated that these biomarkers could enhance the effectiveness of APOE as an AD biomarker. This study reveals that the combined assessment of serum folate levels and red blood cell hemoglobin content may be a useful biomarker for amyloid β accumulation in the brain. We also found that the combination of serum folate levels and hemoglobin content is a more specific and sensitive blood biomarker for AD than APOE or folate alone. These findings may be used to support clinical diagnosis of AD using a simple blood test

Directional representations of 4D echocardiography for temporal quantification of LV volume

Abstract. Real-time acquisition via four-dimensional (3D plus time) ultrasound obviates the need for slice registration and reconstruction, leaving segmentation as the only barrier to an automated, rapid, and clinically applicable calculation of accurate left ventricular cavity volumes and ejection fraction. Speckle noise corrupts ultrasound data by introducing sharp changes in an image intensity profile, while attenuation alters the intensity of equally significant cardiac structures, depending on orientation with respect to the position of the ultrasound beam. These properties suggest that measures based on phase information rather than intensity are appropriate for denoising and boundary (surface) detection. Our method relies on the expansion of temporal volume data on a family of basis functions called Brushlets. These basis functions decompose a signal into distinct patterns of oriented textures. Projected coefficients are associated with distinct “brush strokes ” of a particular size (width) and orientation (direction). Brushlet decompositions are invariant to intensity (contrast range) but depend on the spatial frequency content of a signal. Preliminary results of this directional spacefrequency analysis applied to both phantoms and clinical data are presented. The method will be used to clinically evaluate 4D data and to extract and quantify heart LV volumes.

Prevalence of the APOE-epsilon 4 allele in amyloid positive and amyloid negative patients.

<p>Eight of the 11 (72.7%) amyloid positive patients also carried the APOE-epsilon 4 allele, with it occurring in only one of the six (16.7%) amyloid negative patients. The difference between the two groups was statistically significant (p = 0.027).</p