Aspects of Imaging and Counting in Nuclear Medicine Using Scintillation and Semiconductor Detectors

In the interest of minimizing patient irradiation, while maximizing diagnostic image quality, it is desirable to utilize all of the radiation emerging from the patient. For optimum utilization, it appears to be necessary to allow photons with different energies to contribute to the image with different weights. Optimum weights have been determined for the most common case of noise-limited images, where it is assumed that the weights should be chosen so as to maximize the signal-to-noise ratio. For less noisy images, sharpening may be achieved by assigning negative weights to scattered photons; that is, by scatter subtraction. In general, image formation with multiple weighted channels provides a greater degree of flexibility than is possible with a single channel.