|| Checking for direct PDF access through Ovid
By using digital ROI (region of interest) processing techniques, we measured and compared directly the angiographic opacification of ioxaglate and iodixanol in an experimental circulation model.A pulsatile pump circulated water into a 2-mm plastic tube for digital subtraction angiography (DSA). Altogether, 90 digital imaging series were registered during injections of two contrast media with 320, 300, and 270 mg/mL iodine concentrations. By selecting a “vessel” ROI and a subtracted background ROI, a time-density curve (TDC) was created. From the TDC, the average density of contrast media and the appearance time of contrast media into the selected ROI were measured.The average density was statistically different (P < .01) among three various iodine concentrations of the contrast media, but no difference was found between the two contrast media. The appearance times of ioxaglate with 320 mg/mL iodine concentration were statistically shorter (P < .01) than those of iodixanol. In both contrast medium groups, the appearance times were statistically shorter (P < .05) with 270 mg/mL iodine concentration than with two higher iodine concentrations.The current experimental set-up facilitates reproducible measurement of angiographic opacification during the injection of contrast media. The average densities between ioxaglate and iodixanol are the same, but are significantly different among three iodine concentrations. The different appearance times of the two CM and the three iodine concentrations may be caused by the various viscosities of the contrast media.