A new method for determining the area of the gestation sac by thread planimetry is described. Mean weekly values with two standard deviations were determined on a series of 237 measurements of gestation sac area, age five to 11 weeks, in normal pregnancies. The gestation sac area grows curvilinearly from 1.85 cm2 at five weeks to 15 cm2 at 11 weeks. The mean diameter was calculated from the gestation sac area by using an adequate approximation of the irregular gestation sac shape to a circle of the same area. The dependence of the mean gestation sac diameter on gestation age is defined by the regression equation y = 0.46x - 0.95 and the correlation factor r = 0.92. Practical applications of gestation sac planimetry include the determination of gestation age in early pregnancy, and the follow-up of growth or determination of delayed growth in disturbed or failed early pregnancy.
A recently developed active electronic personal dosemeter (AEPD) was utilised in order to measure the levels and the structure of occupational exposure to scattered X-ray radiation of medical staff who performed percutaneous revascularisation therapy that involves interventional radiology (IR) on the pelvis and upper leg arteries. The AEPDs, placed on the operators' and assistants' chests, that is, above the protective apron, continuously measured and recorded the received doses and, as a novelty, dose rates as a function of time, thus yielding a unique record of occupational doses and dose rates pattern at the working place. This paper presents and discusses one typical daily pattern in which seven percutaneous interventions were performed.
Because of progressive development and extended use of interventional radiology (IR) procedures it is highly recommended that all individuals involved in the process should be aware of the potential for both stochastic and deterministic effects due to occupational exposure. IR procedures are performed in such a manner that certain number of medical staff are always needed near the patient, near the X-ray unit. The new challenge to regular radiation protection is to ensure 'safe' working environment in such radiation X-ray field geometry. In this work the patient is physically regarded as a secondary radiation source emitting scattered X-rays. Passive dosemeters will give us clear data only about the monthly integrated occupational dose; there is concern over the frequency and duration, actual pattern of receiving this dose. We have developed active electronic dosemeter (AED) device, which provides additional dosimetry data about the frequency and duration of professional low level X-ray exposure burden.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.