抄録
In order to obtain the optimal conditions for cranial MRA by a rapid imaging method(fast card STAR), to which the principle of signal targeting with alternating radiofrequency(STAR method) was applied, we carried out a basic study on normal volunteers. According to the results, the vascular signal was weaker with FA 10 degrees, and ghost artifact was observed above 60 degrees. The FA at which good imaging of even peripheral vessels could be obtained was about 30 degrees. The visibility of the peripheral part increased with increased in-flow inversion time(TI), but at TI 500ms, some weakening of the vascular signals was observed. Considering the imaging of peripheral vascularity and vascular contrast, TI 400ms seemed to be most suitable. Regarding VPS(views per segment:collecting number of k-space lines during one cardiac pulse), slight blurring was observed at VPS 16, and this blurring caused a marked decrease in visibility at VPS 32. Although the VPS setting depends on imaging time, the imaging time for VPS 8 was short(about 30-60 sec) and artifact noise was slight. Thus, it was considered to be useful. This method reduced artifact noise under the optimal conditions for FA, TI and VPS and provided good images of blood vessels, showing that this method is useful.
