Comparison of iopromide and iopamidol in left ventricular angiography and in coronary angiography.

A double blind randomized trial of two non-ionic contrast media--iopamidol and iopromide--was performed on 101 patients undergoing left ventriculography and coronary angiography. Both products performed well in the trial and there were no statistically significant differences in side effects, cardiovascular parameters, blood analysis or film quality between the two products.

The acidogenic microbial composition of dental plaque from caries-free and caries-prone people.

Plaque samples collected from caries-free and caries-prone subjects were analysed for total bacteria, the ratio of acidogenic to total organisms and the proportions of streptococci, Streptococcus mutans and Actinomyces. The acidogenic composition of plaque reflected the dietary habits and caries status of an individual. A high acidogenic ratio was found in individuals with active lesions or recent restorations; individuals who were caries-free or had no recent lesions had a lower ratio although total organisms were similar. The ratio remained constant in sequential samples from caries-prone subjects but was increased by frequent exposure to sugar. Streptococci, Actinomyces and Strep. mutans were isolated from all samples but no consistent relationship was found between either their isolation frequency or proportions and caries status.

Color and conspicuousness.

The principle that things are easier to find if they contrast with their environment is expressed quantitatively. Two indices of conspicuousness, relative fixation rate and search time, are shown to be related to the color difference between the target and background objects. The color difference equations used are CIELAB, CIELUV, and the Judd modification of the index of fading. None of the equations is superior to the others. Furthermore, neither Judd's modification nor Semmelroth's adjustment accounts for effects of surround lightness. It is suggested that color difference be used as a tool for design and evaluation of visual displays, for construction of color codes to optimize search time, and as a generalization of chromatic contrast in psychophysical research.

High-contrast sets of colors.

A method is presented for choosing high-contrast sets of colors for additive color mixers (e.g., CRT). The method is based on data about target-location performance of human observers and adapts the color sets to the gamut of the color processor in use. The method produces any specified number of colors spread as far from each other as possible in color space to maximize contrast. Applications of high-contrast sets of colors are indicated, illustrative results are presented and discussed, and variations of the method are suggested.

Improved sensitivity of colour Doppler flow imaging of colorectal hepatic metastases using galactose microparticles: a preliminary report.

The clinical application of ultrasonographic contrast agents in colour Doppler flow imaging of hepatic tumours is receiving increasing attention. Levovist is a suspension of galactose microparticles that provides reproducible concentrations of stabilized air bubbles with transpulmonary stability. Its effect on colour Doppler imaging was assessed in 26 patients with colorectal cancer and histologically proven hepatic metastases. Colour Doppler flow imaging was performed before and after intravenous injection of 10 ml Levovist 300 mg/ml. At 5-10 s after injection there was significant enhancement of the hepatic lesions with colour Doppler signals in 23 patients, lasting for a mean(s.d.) of 180(45) s. A consistent pattern of colour Doppler signal was observed, with increased enhancement predominantly around the tumour periphery and little or no central enhancement. These data suggest that Levovist may increase the sensitivity and specificity of colour Doppler flow imaging of colorectal hepatic metastases.

Superparamagnetic iron oxide particles (SH U 555 A): evaluation of efficacy in three doses for hepatic MR imaging.

PURPOSE: To evaluate the efficacy of SH U 555 A in three doses for magnetic resonance (MR) imaging in the liver and to establish the best postinjection time point for liver MR imaging. MATERIALS AND METHODS: Pre- and postcontrast image sets obtained in 169 patients after injection of SH U 555 A (randomly, 4, 8, or 16 mumol of iron per kilogram of body weight). Three blinded readers evaluated the precontrast and 10- and 40-minute postcontrast MR images of 54, 58, and 57 patients, respectively. RESULTS: Statistically significant differences were observed in diagnostic confidence between images obtained with a dose of 4 or 16 mumol Fe/kg (P = .011) and in good or excellent improvement, respectively, in delineation of lesions on 10-minute postcontrast images (P = .001). No apparent differences in the efficacy evaluation were seen between the 10- and 40-minute postcontrast imaging time points. CONCLUSION: There was a dose-dependent postcontrast improvement in evaluated efficacy parameters (diagnostic confidence, visual evaluations) after injection of SH U 555 A. Accumulation phase imaging could begin as early as 10 minutes after administration.