英语翻译Interstitial space (including plasma volume)different in

英语翻译
Interstitial space (including plasma volume)
different in blood (about 55%) and tissues (about 5-25%)
increased in inflammation,vascular edema,many tumors
decreased in cellular edema
The specific distribution is,however,transient; in many cases,it can be observed only for seconds after rapid intravascular injection during the first pass of the contrast agent through the tissues and disappears after recirculation.Therefore,rapid and repeated scanning of the whole volume of interest is required to make use of the specific dynamics and early distribution pattern.
The term 'nonspecific' was coined for the class of CM to which iopromide belongs at a time when radiographic imaging was either not capable of detecting the iodine concentrations in the interstitial space of tissues or not fast enough to image the very short period of contrast medium distribution before an equilibrium is reached,which equalizes fast and slow perfusion and diffusion into the tissue.
Contrast medium injection rate,concentration,and dose
With a few exceptions (e.q,display of blood-brain barrier disturbance),the specificity of non-ionic contrast agents following intravascular injection lasts only for seconds to a few minutes.Therefore in many cases rapid injection is necessary to visualize pathology (see figure 3).Since attenuation depends exclusively on iodine,the injection rate has to be related to the amount of iodine injected per second (-'iodine delivery rate').The injection rate should be as fast as possible but it is limited by the caliber of the cannula,the outflow of the vein selected for injection and the viscosity of the contrast agent.The latter may be reduced by choosing a not too high iodine concentration and by warming up the contrast medium to 37°C Applying hand injection,the same or higher iodine delivery rates were obtained for a 370 mgl/ml concentration than for a preparation containing 400 mgl/ml.9 Using a different catheter,Jung et aI.reached slightly higher iodine delivery rates with a 300 mg l/ml iopromide solution than with 370 mgI/ml or iopamidol 370 mgl/ml.10The advantage of less concentrated (e.g.300 mgl/ml) over more concentrated low osmolar contrast media in respect of injection and iodine delivery rates at room temperature and at 37°C was confirmed.11,12 In vivo,a slightly slower intravenous injection of concentrated contrast media may be compensated or even overcompensated because a higher concentration may be maintained after dilution by a given rate of blood flow.In practice,this small difference is lost because concentrated