Classifying tissue and structure in echocardiograms

The authors present a system to automatically classify structures and tissues in echocardiogram images. The approach uses a multiple-feature, hierarchical, fuzzy, neural network fusion solution to the problem. The technique appears to work well. The technique is general and can be applied to a variety of image processing problems not only in the medicine but other areas as well. The processing presented here is computationally expensive; every pixel is processed independently. However, there are several ways to improve performance. The most obvious is to take advantage of the parallelism. In addition, every pixel need not be processed. If only large cardiac structures, such as the left ventricle, need be classified, then processing of the compressed image through the binary nets is sufficient. Neighboring class information may be used as well. Finally, the authors have not accounted for time in the processing. There is a high degree of redundancy in the successive frames of video images. It is anticipated that including temporal information will increase both statistical and computational performance. Temporal information will also force smoothing of the images over time and give better classification performance to even those areas that do not move     

The prediction of the three-dimensional turbulent flow field in a flow-splitting tee-junction

Coarse-grid predictions of the steady turbulent flow in a right-angled tee-junction are presented, attention being confined to the cylindrical “horizontal” portion of the tee.The finite-difference forms of the conservation equations of mass and momentum governing the flow in a tee-junction are solved by using a three-dimensional version of the SIMPLE algorithm of Patankar and Spalding. The kinetic-energy and dissipation-rate equations of a model of turbulence are also solved.The predictions show that the calculation procedure is capable of producing physically realistic predictions.     

Public mental health service and diagnostic trends regarding individuals who are deaf or hard of hearing.

From a pool of 84,437 public mental health case records in Rochester, NY, 544 pertained to deaf or hard of hearing (DHH) patients. Proportional comparisons of demographic, service, and diagnostic patterns revealed significant differences between DHH and comparison samples. Women, children, and non-Caucasians were underrepresented in the DHH sample; male and elderly DHH patients were overrepresented. DHH patients were overrepresented in 4 small but communicatively accessible programs that provided a limited range of services. When served by community services, DHH patients received fewer clinical services and more continuing treatment and case management services. Axis II diagnoses of mental retardation were more frequent in the DHH sample, and clinicians were less able to rule out Axis II pathology. It is suggested that observed differences reflect service accessibility and clinician expertise problems rather than clinical distinctions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of enzyme-linked immunosorbent assay for the determination of polycyclic aromatic hydrocarbons in house dust and residential soil

Two commercially available enzyme-linked immunosorbent assays (ELISA) for total polycyclic aromatic hydrocarbon (PAH) and carcinogenic PAH (C-PAH) were evaluated. The testing procedures were refined for application to screening PAH and C-PAH in house dust and soil samples for human exposure studies. The overall method precision expressed as percent relative standard deviation (%RSD) of triplicate real world dust and soil samples was within +/- 29% (12-29%) for PAH ELISA and +/- 21% (5.9-21%) for C-PAH ELISA. Spike recoveries from real world dust/soil samples were 114 +/- 30% for phenanthrene from PAH ELISA and 120 +/- 8.2% for benzo[a]pyrene from C-PAH ELISA. The overall method accuracy for PAH and C-PAH assays cannot be assessed for multiple PAH components in dust/soil samples (which represent real-world samples), because of the assays' cross reactivities with other PAH components. Over 100 dust/soil samples from 13 North Carolina homes and 22 Arizona homes were analyzed by PAH and C-PAH assays, as well as by the conventional gas chromatography/mass spectrometry (GC/MS) method. Statistical analysis showed that dust/soil PAH data from ELISA and GC/MS methods are significantly different. In general PAH ELISA responses were higher than PAH GC/MS responses. The regression analysis showed that the linear relationship between ELISA and GC/MS measurements is not strong in the combined data. The relationship became stronger for the data from the same type of dust/soil samples. The screening performance of ELISA was evaluated based on the frequency distribution of ELISA and GC/MS data. The results indicated that the ELISA PAH and C-PAH assays cannot be used as a quantitative analytical tool for determining PAH in real-world dust/soil samples. However, the ELISA is an effective screening tool for ranking PAH concentrations in similar types of real world dust/soil samples.     

Energy-based scatter corrections for scintillation camera images of iodine-131

The use of high-dose 131I antibody therapy requires accurate measurement of normal tissue uptake to optimize the therapeutic dose. One of the factors limiting the accuracy of such measurements is scatter and collimator septal penetration. This study evaluated two classes of energy-based scatter corrections for quantitative 131I imaging: window-based and spectrum-fitting. METHODS: The window-based approaches estimate scatter from data in two or three energy windows placed on either side of the 364-keV photopeak using empirical weighting factors. A set of images from spheres in an elliptical phantom were used to evaluate each of the window-based corrections. The spectrum-fitting technique estimates detected scatter at each pixel by fitting the observed energy spectrum with a function that models the photopeak and scatter, and which incorporates the response function of the camera. This technique was evaluated using a set of Rollo phantom images. RESULTS: All of the window-based methods performed significantly better than a single photopeak window (338-389 keV), but the weighting factors were found to depend on the object being imaged. For images contaminated with scatter, the spectrum-fitting method significantly improved quantitation over photopeak windowing. Little difference, however, between any of the methods was observed for images containing small amounts of scatter. CONCLUSION: Most clinical 131I imaging protocols will benefit from qualitative and quantitative improvements provided by the spectrum-fitting scatter correction. The technique offers the practical advantage that it does not require phantom-based calibrations. Finally, our results suggest that septal penetration and scatter in the collimator and other detector-head components are important sources of error in quantitative 131I images.     

Mixing between a sharp-edged rectangular jet and a transverse cross flow

The scalar mixing field of a turbulent rectangular jet issuing from a sharp-edged orifice with an aspect ratio of 10 into a cross stream flow in a square duct is investigated using marker nephelometry. Jet-to-cross stream velocity ratios of 2.0 and 3.4 are examined in this work. Results include contour plots and transverse profiles of the mean and concentration fluctuation intensity and jet trajectory paths and half concentration lengths expressed as a function of downstream position along the jet trajectory.     

Accommodative esotropia during the first year of life

Two infants developed accommodative esotropia during their first six months of life. One infant, whose age at onset was 4 1/2 months, had 4.50 diopters of hyperopia. The second infant, whose age at onset was 5 months, had 3.50 diopters of hyperopia. In both infants, the eyes completely aligned with hyperopic correction. Two points are stressed. First, when the amount of hyperopia exceeds +3.00, consideration should be given to an accommodative element as the cause of the esotropia, even if the child is only 4 to 6 months old. Second, even with small angles of esotropia, an accommodative element should be considered, if there is a substantial amount of hyperopia.