This study together with related reports indicated that an effective way of controlling film mottle was to refrain from usmg too high tube voItage and too big intensifying screen factor which translated into too small mAs value.

• 本研究结果并结合有关文献表明：控制X线照片斑点的主要措施是管电压不要过高，所用稀土增感因数不宜过大，即所用mAs值不宜过小。