STUDIES IN METHODS IN INSTRUMENTS TO IMPROVE THE LOCALIZATION OF RADIOACTIVE MATERIALS IN THE BODY WITH SPECIAL REFERENCE TO THE DIAGNOSIS OF BRAIN TUMORS, AND THE USE OF ULTRASONIC TECHNIQUES

摘要

Poise width discrimination is destined to become a practical system. The empirical data presented was obtained with relatively bad photomultiplier tubes from the standpoint of signal-to-noise ratios. None of the tubes would be acceptable by commercial companies for their amplitude discrimination scintillation counters. In spite of this, the improvement offered by the pulse width method is great enough to allow the application of a scintillation counter for such problems as low level sample counting. The selection of better PM tubes would result in shifting the point where the improvement ratio equals 1.0 to the higher background regions.