[en] Hydatid disease is caused by Echinococcus granulosus. The most common locations for hydatid cysts are lung and liver. The central nervous system is involved in only 2% of cases, and these cysts are usually located in the brain parenchyma. Primary involvement of the bones of the skull is very uncommon. We report the case of a child with cranial echinococcosis which presented in the form of an osteolytic lesion with an extradural cyst. This was the unique feature of the disease. The CT and MR findings are described. This presentation has rarely been reported in the literature. (Author) 5 refs

[en] To determine normal umbilical circulation patterns by means of Doppler ultrasound scan in a healthy gestating population without risk factors and with normal perinatal results, and to evaluate any occurring modifications relative to gestational age by obtaining records kept during pregnancy. One hundred and sixteen pregnant women carrying a single fetus have been studied. These women had no risk factors, with both clinical and analytical controls, as well as ultrasound scans, all being normal. There were performed a total of 193 Doppler ultrasound scans between weeks 15 and 41 of gestation, with blood-flow analysis in the arteries and vein of the umbilical cord. The obtained information was correlated with parameters that evaluate fetal well-being (fetal monitoring and/or oxytocin test) and perinatal result (delivery type, birth weight, Apgar score). Statistical analysis was performed with the programs SPSS 6.0.1 for Windows and EPIINFO 6.0.4. With pulsed Doppler, the umbilical artery in all cases demonstrated a biphasic morphology with systolic and diastolic components and without retrograde blood flow. As the gestation period increased, there was observed a progressive decrease in resistance along with an increase in blood-flow velocity during the diastolic phase. The Doppler ultrasound scan is a non-invasive method that permits the hemodynamic study of umbilical blood circulation. A knowledge of normal blood-flow signal morphology, as well as of the normal values for Doppler indices in relation to gestational age would permit us to utilize this method in high-risk pregnancies. (Author) 30 refs

[en] Cerebro-hepato-renal syndrome is a rare disorder that is transmitted by autosomal recessive inheritance. Children with this syndrome present mongoloid facies and severe muscle hypotonic at birth. Scimitar-like knee calcifications are considered a pathognomonic feature of this disorder. We present two patients with Zellweger syndrome, according to the diagnosis suggested by our Radiodiagnostic Service. Our objective is to stress the importance of the radiological findings, which in many cases are decisive in establishing the definitive diagnosis. (Author) 10 refs

[en] Description of the semiology of the chronic nasosinusal inflammatory diseases by CT. 2. Correlation of the findings of sinusitis with the permeability grade of the drainage pathways: classification into five patterns: Their frequency. 110 CT have been reviewed in patients with chronic sinusitis and acute recurrent sinusitis of both genders whose ages ranged from 5 to 89 years. Axial and coronal cuts were performed, with a thickness of 5 and 3 mm respectively. These are cases that have been verified, either by endoscopic surgery of after clinical and radiological follow-up to the patient. We found signs of non-complicated sinusitis in 77 patients (70%), complicated sinusistis in eight (7%), other conditions in 16 (15%) and nine (8%) did not show any alterations. We detected signs of inflammatory disease in the nasal pits in 41% of the cases (bone alterations. mucosa alterations and post-surgical changes). In 92% of the cases, there were alterations in the paranasal sinuses (of ventilation, bone, mucosa and post-surgical changes). Correlating these findings with the permeability grado of the sinonasal drainage, five involvement patterns can be established. In our series, the most frequent was obstruction of the osteomeatal complex (36%). Following these, in order of frequency, were the sporadic pattern (30%), nasosinusal polyposis (18%), pattern of infundibular obstruction (12%) and obstruction of the sphenoethmoidal recess (45%). The CT is an excellent method dto detect signs of nasosinusal inflammatory disease. By classification of these conditions into patterns, those patients that can undergo treatment with endoscopic surgery can be selected. The approach route, extension of the intervention and its possible complications can be considered. (Author)

[en] In this work, the advances of a serial of measurements of relative efficiency thermoluminescent of heavy charged particles (PCP) with respect to gamma radiation for TLD-100, dosemeters of LiF: Mg,Ti manufactured by the Harshaw-Bicron company are reported. The PCP are essentials in the implementation of dosimetry associated with medical applications. The measurements before gamma radiation were carrying out using the Vickrad irradiator of the National Institute of Nuclear Research at dose of 1.663 Gy. The measures which are reported about protons, helium and carbon were realized using the Pelletron accelerator of the Physics Institute of the UNAM. (Author)

No abstract available

[en] In Mexico there are several programs for early detection of breast cancer based on mammography studies, however mortality rates have increased. To carry out these studies in 2016 there were approximately 1,474 mammography units belonging to the public, private and social sectors, of which approximately 882 are in the health sector and of these around 794 are digital, without knowing how they perform. There are two official Mexican standards NOM-229-SSA1-2002 and NOM-041-SSA2-2011 that deal with monitoring the operation of mammography units; however, they do not specify the quality control tests that must be performed. apply to equipment that has digital image receptors, whether of the ^computed radiography (CR) type that uses photostimulable plates as detectors that are read in a CR digitizer or ^digital radiography (DR) whose detector consists of an active matrix of detector elements that constitute a flat panel capable of delivering a digital image. Worldwide, there are various quality control protocols, including those published by the European Federation of Medical Physics Organizations (2015) and the American College of Radiology (2016). The aim of this work is to carry out the mammography quality control tests proposed in the two aforementioned protocols. The results of these tests will be compared and analyzed in order to propose a simple protocol that can be proposed for inclusion in the national regulations regarding digital mammography. The theoretical part of the comparison and some preliminary results are presented, since the study could not be concluded as a consequence of the Covid-19 contingency. (author)

No abstract available

[en] Considering one of the guides emitted by the National Commission of Nuclear Security and Safeguards, was realized the report of radiological safety for a micro tomography by positrons emission that is part of Bimodal System of Images developed in their entirety for personnel of the Physics Institute of UNAM. With this system is sought to obtain tomography images of small animals using non destructive methods, such as computerized micro tomography and micro tomography by positrons emission. In this work each one of the report points is enumerated and only it is described, to big features on that consist, due to the great extension of each one of them. The report has two parts; the first is denominated -Of the installation and the Organization- and is given to know the interior and external characteristics of the installation, besides how and under which authority the activities will be executed inside the laboratory. The second part is called -of the Radiological Protection- and has for objective to describe the radiation sources that will be used, as well as the measures of radiological protection foreseen inside the laboratory. The most important part in the report consists on the description of the three radionuclides to use: ¹⁸F, ¹¹C and ¹³N, as well as the methods for the shielding calculation and for the estimate of the dose equivalent during the normal operation of the equipment. These methods were applied three times, because the calculation was made for each radionuclide. The results of these calculations show that: 1) it not is necessary to have a structural shielding, due to the activity sources very reduced, and 2) the dose limit per year (according to the ICRP-60) it will not be surpassed neither in the case of the occupationally exposed personnel, neither on the public in general. (Author

No abstract available