To achieve maximum differential absorption by the tissues for high-quality fluoroscopic images, what should be selected correctly?

To achieve maximum differential absorption by the tissues, selecting the peak kilovolts (kVp) is crucial because it directly impacts the penetration power of the X-rays during fluoroscopy. The kVp level influences the energy of the X-rays produced, which in turn affects how different tissues in the body absorb these X-rays.

Higher kVp settings result in X-rays that can penetrate tissues more effectively, allowing for better differentiation between various structures based on their density and composition. This is important for producing high-quality images where soft tissues can be contrasted against denser structures like bones. The choice of kVp determines the range of energies that will be used to interact with the anatomical structures, optimizing the contrast needed for diagnostic purposes.

In contrast, while factors like milliamperage, distance, and time also play roles in fluoroscopy, they do not influence the differential absorption in the same direct manner as kVp. Milliamperage affects the quantity of X-ray production, distance influences the intensity reaching the image receptor, and time is associated with exposure duration. However, it is the proper selection of kVp that primarily ensures the optimal imaging quality by maximizing the contrast through differential absorption of various tissues.