SPIHT-based echocardiogram compression: clinical evaluation and recommendations of use.

This paper describes an echocardiogram coding method that takes into account the visualization modes in order to compress efficiently the echocardiogram, a methodology to evaluate compressed echocardiograms and the evaluation of the compression method using the proposed evaluation methodology. The compression method takes advantage of the particular characteristics of each visualization mode and uses different compression techniques for each mode to compress efficiently the echocardiogram. A complete evaluation has been designed in order to recommend a minimum transmission rate for each operation mode that guarantees sufficient clinical quality. The evaluation of the echocaradiograms compressed with the proposed method has been carried out. The recommended transmission rates have been established as the following: 200 kbps for the 2D and the color Doppler modes, and 40 kbps for the M and the pulsed/continuous Doppler modes. These rates, especially the latter, are very low compared to previous results. These recommendations are valid for all devices and images compressed with the proposed method. The evaluation process can be applied to any compression method.

Plasma amino acid and protein concentrations in infants fed human milk or a whey protein hydrolysate formula during the first month of life.

The aim of the study was to compare growth parameters, biochemical indices of protein metabolism and plasma amino acid concentrations in infants fed either human milk (n = 12) or a whey protein hydrolysate formula (n = 13) during the first month of life. Growth and gain in skin fold thickness were similar in both groups whereas serum protein concentration was significantly decreased (57.4 +/- 3.9 versus 61.2 +/- 2.9 g/l) in the infants fed the whey hydrolysate formula. The discrepancies between the plasma amino acid pattern of the whey hydrolysate formula group and that of the human milk group lessened during the first month. Nevertheless, at a mean age of 33 days the plasma threonine concentration remained twice as high and the plasma tyrosine, phenylalanine and proline concentrations were significantly lower in the whey hydrolysate formula group than in the human milk group. Thus, compared with breast-fed infants, growth and most of the biological indices of protein metabolism were satisfactory in infants fed during the first month of life on a whey protein hydrolysate formula. Nevertheless, the decrease in total plasma protein concentration needs to be confirmed in a larger cohort of infants. In addition, further research is necessary to investigate the possible ways of reducing the hyperthreoninemia and preventing other plasma amino acid disturbances since it would be desirable to obtain plasma amino acid levels similar to those of breast-fed infants.

Lumbar bone mineral content measured by dual energy X-ray absorptiometry in newborns and infants.

Dual energy X-ray absorptiometry (DXA), a non-invasive method for measuring small amounts of mineral, was used to assess the bone mineral content (BMC) and bone mineral density (BMD) of the lumbar spine (5 vertebrae) in 57 newborns (on day 1-2) and 22 infants (1-24 months of age). A modified high-resolution program (Hologic) allowed us to assess BMC and BMD with a precision higher than 2.4% and 1.5%, respectively. In newborns, BMC and BMD correlated positively with birth weight, body area, length and gestational age: r = 0.73, 0.71, 0.63 and 0.60, respectively, for BMC; and r = 0.59, 0.58, 0.54 and 0.53, respectively, for BMD. In infants, both BMC and BMD were highly correlated with weight, age, length and body area over two years (r = 0.94 or better in each instance). The data provide normal values for lumbar spine BMC and BMD in newborns (gestational age 31-40) and infants up to two years of age; DXA appears to be an excellent and safe tool for pediatric bone mineral measurements.