Salud Y Odontologia

Introducción La práctica cardiológica ac-tual ha incorporado los es-tudios hemodinámicos y angiográficos como un procedimiento cotidiano que se ha expandido de lo esencialmente diagnóstico a la acción terapéutica, en un espectro amplio que comprende desde la pato-logía del ...

Entrance surface air kerma (ESAK) values and image quality parameters were measured and compared for two biplane angiography x-ray systems dedicated to paediatric interventional cardiology, one equipped with image intensifiers (II) and the other one with dynamic flat detectors (FDs). Polymethyl methacrylate phantoms of different thicknesses, ranging from 8 to 16 cm, and a Leeds TOR 18-FG test object were used. The parameters of the image quality evaluated were noise, signal-difference-to-noise ratio (SdNR), high contrast spatial resolution (HCSR) and three figures of merit combining entrance doses and signal-to-noise ratios or HCSR. The comparisons showed a better behaviour of the II-based system in the low contrast region over the whole interval of thicknesses. The FD-based system showed a better performance in HCSR. The FD system evaluated would need around two times more dose than the II system evaluated to reach a given value of SdNR; moreover, a better spatial resolution was measured (and perceived in conventional monitors) for the system equipped with flat detectors. According to the results of this paper, the use of dynamic FD systems does not lead to an automatic reduction in ESAK or to an automatic improvement in image quality by comparison with II systems. Any improvement also depends on the setting of the x-ray systems and it should still be possible to refine these settings for some of the dynamic FDs used in paediatric cardiology.

Background: Exposure to ionizing radiation is a known hazard of radiological procedures. Aim: To compare the emission of secondary ionizing radiation from two coronary angiographic equipments, one with digital and the other with analog image generation. To evaluate the effectiveness of external radiological protection devices. Material and methods: Environmental and fluoroscopy generated radiation in the cephalic region of the patient

In pediatric interventional cardiology, cardiol-ogists need to stay closer to the patient than during adult catheterization, and the use of biplane systems increases the scatter radiation. Occupational radiation risk is rather high, and estimation of lens doses ...

Background: Exposure to ionizing radiation is a known hazard of radiological procedures. Aim: To compare the emission of secondary ionizing radiation from two coronary angiographic equipments, one with digital and the other with analog image generation. To evaluate the effectiveness of external radiological protection devices. Material and methods: Environmental and fluoroscopy generated radiation in the cephalic region of the patient was measured during diagnostic coronary angiographies. Ionizing radiation generated in anterior left oblique projection (ALO) and in anterior right oblique projection (ARO) were measured with and without leaded protections. In 19 patients (group 1), a digital equipment was used and in 21 (group 2), an analog equipment. Results: Header radiation for groups 1 and 2 was 1194 ± 337 and 364 ± 222 µGray/h respectively (p

SUMMARY In order to know the irradiation parameters in infants in Chile, the first data of entrance surface air kerma (ESAK) was determined from X-ray tube output and effective dose by software simulations with PCXMC for pelvis AP projection, in 69 pediatric patients aged between 3 and 6 months, in Arica city.. Results of mean effective dose ±st.dev. (mSv) were: 0.0353 ±0.0276 in colon; 0.0909 ±0.0830 in ovaries/testes and 0.1338 ±0.1082 in bladder. Meanwhile, the mean ±st. dev. ESAK estimated for the entire sample was 0.1160 ±0.0187mGy, with a 75 th percentile of 0.1176mGy, constituting our reference dose level, which is 20% above the proposed value in Europe. Of all the variables, it was determined that the most influential one in ESAK was the tube charge (mAs), so that it should be the focus when optimizing radiation protection of patients.

Mammography is currently considered to be the best tool for early detection of breast cancer. The target groups of most of the population-based screening programmes are women aged between 50 and 65 years. A recent study has also shown mortality benefit in the age group 40-49 (Hellquist, et al, 2010). Screen-film mammography has been to date the traditional test for breast screening having been shown its efficacy in reducing breast cancer mortality in large randomised trials (Duffy, et al, 2006). The potential advantages of digital mammography over screen-film techniques have been the subject of several investigations which provides an improved diagnosis in dense breasts and an increase in breast cancer detection rate (Pisano et al, 2006; Hendrick et al, 2010).

Area monitoring ensures radiation exposure at an acceptable level, which must be lower than the legal limit. Experimental measurements were taken in an ionizing radiation calibration laboratory. The specified reference radiation to radiation protection N80 was used. Five area monitors were used. The ranges of dose rate inaccuracy measured in rate mode for times ≤ 2 and ≥ 3s were from 10 to 48% and from 1 to 15%, respectively. The inaccuracy ranges measured in integrated mode for times ≤ 2 and ≥ 3s were from 4 to 8% and from 0 to 22%, respectively.

The aim of this study was to present the results of a pilot program on patient dosimetry carried out in Chile during the last 5 yr, using a biplane x-ray angiography system settled for pediatrics. This research was conducted in Latin America under the auspices of the International Atomic Energy Agency (IAEA) supporting programs on radiological protection (RP) of patients. Methods: Patient age, gender, weight, height, number of cine series, total number of cine frames, fluoroscopy time, and two dosimetric quantities [air kerma-area product (P ka) and cumulative dose (CD) at the patient entrance reference point] were recorded for each procedure. Results: The study includes 544 patients grouped into four age groups. The distributions by age group were 150 for <1 yr; 203 for 1 to <5 yr; 97 for 5 to <10 yr; and 94 for 10 to <16 yr. Median values of P ka and CD for the four age groups were 0.94, 1.46, 2.13, and 5.03 Gy cm 2 and 23.9, 26.8, 33.5, and 51.6 mGy, respectively. No significant statistical differences were found between diagnostic and therapeutic procedures. A moderate correlation (r ¼ 0.64) was seen between P ka and patient weight. Conclusions: The dose values reported in this paper were lower than those published in the previous work for the same age groups as a result of the optimization actions carried out by cardiologists and medical physicists with the support of the IAEA. Methodology and results will be used as a starting point for a wider survey in Chile and Latin America with the goal to obtain regional diagnostic reference levels as recently recommended by the International Commission on Radiological Protection for interventional procedures. V