Ultrasonic exposure in static and real time echography.
Measurement of ultrasonic output from static and real time devices has shown both types of equipment to emit approximately the same amount of energy per pulse and the same peak instantaneous intensity. The major differences in exposure were related to the amount of energy used to produce an image, the total amount of energy used to perform an examination, and the amount of energy passing through a single point in tissue. the highest single point exposure occurred during static M-mode examinations when an energy exposure of 120 mJ per minute was measured. By comparison a real time B-mode examination resulted in a single point exposure of 0.018 mJ/echogram or 27 mJ/min. The single point exposure per echogram in a static examination was 0.12 mJ for a simple scan and 1.15 mJ for a compound scan with contact equipment, and 0.01 and 0.08 mJ for simple and compound scans using water path equipment.
D014465:Ultrasonics / Q000295:instrumentation; D014463:Ultrasonography