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Radiation application in medicine offers extraordinary benefits. But radiation is like a double-edged sword, it has both benefits and associated risks on the community in contact. To justify the safety of workers and members of the public, regulated use of radiation is assessed by the radiation protection protocols. The aim of this study is to design a Computed Tomography (CT) facility with a simplified model of CT scanner, whose shielding follows the guidelines of National Council on Radiation Protection and Measurements (NCRP) Report No. 147. To design the study model, Monte Carlo (MC) radiation transport code in MCNPX 2.6.0 was used for the simulation. Furthermore, MCNPX was used to measure the photon flux in a vicinity or the detector cell. To validate the functioning of the X-ray tube, the experimental results were compared with the X-ray Transition Energies Database of National Institute of Standards and Technology, U.S. Department of Commerce. The results obtained were within 0.60% of relative error. To confirm the functioning of shielding design, radiation protection quantity, air kerma was measured at several points outside, and inside of the CT room and they were under the radiation dose recommended by NCRP, which demonstrates that the shielding design wassuccessful in blocking the radiation. The study can be used for an easy evaluation of any CT room within the framework of the model of the study.

Yeast cultures of Saccharomyces cerevisiae were exposed to pulsed magnetic fields of low intensity. Field intensities from 0.92 mT to 2.73[Formula: see text]mT and frequencies of 20, 77.5, 135, 192.5 and 250[Formula: see text]Hz were employed. Proliferation and cell viability measurements were made in exposed and control cultures. For the frequency of 20[Formula: see text]Hz, statistically significant differences were found ([Formula: see text]) in cell proliferation using field intensities of 1.81 and 2.71[Formula: see text]mT. No changes were observed at this frequency for lower field strengths. At 77.5[Formula: see text]Hz, only changes in proliferation were observed for 0.92[Formula: see text]mT ([Formula: see text]). No changes were observed to any other frequency or intensity of the magnetic field. The cell viability studies were performed at different times, from 4 to 12[Formula: see text]h of exposure. At 1.81[Formula: see text]mT and 20[Formula: see text]Hz, an increase in colony-forming units (CFUs) of 26.1% was observed ([Formula: see text]) at 4[Formula: see text]h, and after 10[Formula: see text]h of exposure the increase in CFUs was 51.5% ([Formula: see text]). But when exposing the cells for 9[Formula: see text]h to a magnetic field of 2.71[Formula: see text]mT at 20[Formula: see text]Hz, the CFUs decreased by 25.9% ([Formula: see text]), and at 0.92[Formula: see text]mT and 77.5[Formula: see text]Hz, a decrease in CFUs of 18.6% was observed ([Formula: see text]) at 4[Formula: see text]h, while after 12 h of exposure an increase in CFU of 23.5% ([Formula: see text]) was determined. These results suggest the presence of a frequency window between 20[Formula: see text]Hz and 77.5[Formula: see text]Hz, where the effects of the magnetic field are significant.

In this work a comparative theoretical analysis vs. experimental study on human blood under a magnetic field stimulation is presented. Twenty samples of leukoreduced human blood were stimulated with an alternant magnetic field using a Helmholtz coil system; this magnetic field induced an electromotive force in them. Theoretical calculations were performed for the induced electromotive force in a simple model of blood tissue under magnetic stimulation at frequencies: 50 Hz, 100 Hz, 800 Hz, and 1500 Hz. Experimental measurement was performed at the same frequencies for comparison purposes. Results show a high correlation between theoretical and experimental study, as well as effects of agglutination in the stimulated blood cells.

Cultures of yeast Saccharomyces cerevisiae were exposed to pulsed magnetic fields of low intensity. Field intensities from 0.92 mT to 2.73 mT and frequencies of 20, 77.5, 135, 192.5 and 250 Hz were employed. Proliferation and cell viability measurements were made in exposed cultures and the results were compared with control cultures. For the frequency of 20 Hz, statistically significant differences were found (p < 0.001) in cell proliferation using field intensities of 1.81 and 2.71 mT. No changes were observed at this frequency for lower field strengths. At 77.5 Hz, only changes in proliferation were observed for 0.92 mT. No changes were observed to any other frequency or intensity of the magnetic field. The cell viability studies were performed at different times, from 4 to 12 hours of exposure. At 1.81 mT and 20 Hz, an increase in colony forming units (CFU) of 26.1% was observed (p < 0.001) at 4 hours, and after 10 hours of exposure the increase in CFU was 51.5% (p < 0.024). But when exposing the cells for 9 hours to a magnetic field of 2.71 mT at 20 Hz the CFUs decreased by 25.9% (p < 0.003). These results suggest the presence of a frequency window between 20 Hz and 77.5 Hz where the effects of the field are important.

In this work a novel approach based on differences of intensities is presented for vascular structures identification in MRI studies such as the time of flight method (TOF). The plating method states that given the high intensities belonging to the vascular system, TOF images can be segmented by thresholding of the histogram. The enhancement of vascular structures is performed by applying a Vesselness filter, and upon completion of a decision based on fuzzy thresholding the error is minimized in the selection of vascular structures. A brief introduction to vascular system problems and how images have helped diagnosis is summarized as well as the history of the different imaging modalities and the evolution of digital images with computers. Segmentation and 3-D reconstruction became image type time of flight; these images are typically used in medical diagnosis of cerebrovascular diseases. The proposed method has less error in segmentation and reconstruction of volumes related to the vascular system, represented in clearer images and less noise compared to edge detection methods.

Sound transmission has been used for diagnosis of hip dysplasia in newborns and infants with tunning fork and sthetoscope. The study aims to identify the validity of a device based on sound transmission. Male and female newborns from Celaya, Gto, ranging from 4 to 28-day-old were selected for the study. The sound transmission device was used both, in bilateral assessment (compared sound transmission) and on each hip separately (sound transmission with extension/flexion). In the first application if the sound is lower by a digit, there is a hip unhealthy. In the second application if the sound is increased by a digit, there is also an alteration of the hip. A hip ultrasound was applied using the Graf technique as a gold standard. Sensitivity, specificity and predictive values were calculated to identify validity. The intra-observer and inter-observer Kappa Test was applied to identify reliability. The hips of 103 newborns were assessed, obtaining a sensitivity of 60.9%, and a specificity of 92%; it should be a positive predictive value of 51.9% and a negative predictive value of 95% for the compared sound transmission test. In the sound transmission test with extension/flexion, the values were 82.6%, 96.2%, 73.1% and 97.8% for sensitivity, specificity, positive predictive value and negative predictive value, respectively. The result of the intra-observer kappa was 0.80 and the inter-observer was 0.70 for the compared sound transmission. The intra-observer Kappa was 0.88 and the inter-observer was 0.78 for the compared sound transmission test with extension/flexion. The device for sound transmission is valid and reliable for the diagnosis of dysplastic development hip disease in newborns.

The developmental dysplasia of the hip disease is in 1% of newborns, and it is a risk factor for dislocation of the hip; only 1 from 7000 newborns develops dislocation of the hip. Newborns were selected from public and private hospitals in Celaya, Guanajuato. Parents were asked to sign informed consent. Clinical maneuvers were applied for diagnosis of developmental dysplasia of the hip, on three consecutive occasions, two by the same investigator and the third by a different observer: Ortolani, Barlow, Piston, Galeazzi, Peter Baden, the comparative sound transmission test, and comparative sound transmission with extension/flexion test were applied. The diagnosis was confirmed with ultrasound of hip, technique Graf, I healthy hip, II functionally immature, III subluxation, and IV dislocation. Sample size was 8 affected hips and 56 healthy hips. Kappa for intra observer and inter observer reliability were measured; the validity was measured by sensitivity, specificity, positive and negative predictive values, using the ultrasound diagnosis as the gold standard. The sample consisted of 78 neonates hips with female’s predominance. With comparative sound transmission test was obtained Kappa intra observer 0.80, Kappa inter observer 0.93, sensitivity 45.45%, specificity 96.27%, positive predictive value 66.67% and negative predictive value 91.49%; with comparative sound transmission with extension/flexion, was 0.83, 0.92, 72.73%, 95.52%, 72.73%, and 95.52%, respectively. The tests compared the sound transmission help better diagnose developmental dysplasia disease of the hip.

The use of ultrasound equipment in routine clinical evaluation of the gastrointestinal tract is still standby. Objective: to show an alternative application of ultrasound technique for monitoring peristalsis and gastric emptying through an executable routine implemented in LabVIEW. Methods: an ultrasound equipment (Medison SONACE 800 SE) was used in ten healthy subjects and four patients; dominant peristalsis frequency and gastric emptying were measured after fasting nights of the patients; subjects ingested, first 300 mL of water and then a solid meal (240 kCal). Results: the video acquisition in M mode and imaging processing were performed in a LabVIEW platform, as long as digital signal processing was carried out in matlab 2008a; peristaltic frequency of 2.4 cpm (cycles per minute) and a half time of the gastric emptying around 35 s were found. Discussion: these findings are congruent with similar evaluations of GI tract obtained by using the gold standard technique. So, ultrasound technique is now an alternative procedure for gastric evaluation with the advantage that patients are free of ionizing radiation, and these equipments are amply available in the world hospitals.

An analysis of the reproducibility from signal record bioelectric heart activity is presented. The measurements were carried out with a recently patented medical device, which one is able to record the curves of pressure arterial and venous as those obtained using the gold standard technique in these evaluations, the cardiac catheterization technique. The measurements were carried out 15 health subjects and patients; each one was measured 5 times in order to have auto-correlations and correlations of these records. Analysis indicates correlations from 0.9 to 1 as long as p values were below 0.05. It is indicated an excellent reproducibility of evaluated patients.

En este trabajo se presenta un análisis y modelado de espectros de impedancia eléctrica aplicados al estudio de datos experimentales de tejido sanguíneo y sus principales componentes: glóbulos rojos, blancos y plasma. Usando la teoría de circuitos eléctricos se obtienen las funciones de transferencia y la representación gráfica de Bode y Nyquist. Se puede ver en este trabajo el potencial de la técnica experimental para diferenciar los elementos que forman al tejido sanguíneo, así como la utilidad de desarrollar modelos precisos para su análisis.

Magnetic stimulation (MS), a non-invasive technique to stimulate different kind of cells by a sinusoidal magnetic signal through a coil put on the scalp have been widely used in studies in clinical treatments on human. A modality of this MS technique to stimulate cell viability, proliferation and longevity, of human lymphocytes by using magnetic field is presented. AC magnetic stimulation was applied in a human range of audible frequency. A computer algorithm was implemented, which is combined with a power system to generate a cell magnetic stimulus via a coil variation. To generate and increase the stimulation, a ferromagnetic fluid is added on the cell culture medium, demonstrating, in this pilot study, that a sinusoidal magnetic signal applied on cell culture can increase cell longevity and produce proliferation without changes in cell viability.

En este trabajo se presentan los resultados obtenidos de la aplicación de Campos Magnéticos (CM) tanto pulsados (CMP) como estáticos (CME) en la morfología de osteoblastos humanos. El efecto de dichos campos ha sido medido por medio del análisis de la estructura de la β-tubulina, la cual es una proteína que forma parte del citoesqueleto celular. El campo magnético aplicado fue de 0.65 mT en el caso del CMP y de 0.5 mT en el caso del CME. La aplicación de los CM provoca alteración en el patrón de distribución normal de las redes de microtúbulos, dando lugar a la formación de agregados fluorescentes en la región cortical de la membrana celular. Las observaciones obtenidas con respecto a loscambios morfológicos de los osteoblastos, indican claramente que éstos son sensibles a la estimulación con CM, alterando su actividad celular a través de cambios en la estructuradel citoesqueleto celular.