, Aspiring pilot, Alaskan. 1  Well, if you want to be a USAF drone pilot, the process is 5+ years, and relatively difficult, the most difficult section being the flight training itself. Manned flight school has a ~30% washout rate, so I assume the drone program is similar.
A bottle of Omniscan contrast agent. MRI contrast agents are a group of contrast media used to improve the visibility of internal body structures in magnetic resonance imaging (MRI). The most commonly used compounds for contrast enhancement are gadolinium-based.
A second generation of contrast agents was developed; the air in the bubble was changed to higher-molecular-weight gases which resulted in more stable bubbles. SonoVue, Optison, and Luminity (marketed in North America as Definity) are the main representatives of this group (Table 1).