Detection of Mycoplasma pulmonis in laboratory rats and technicians

Five species of mycoplasma are associated with several rat diseases. Mycoplasma pulmonis is the most important and most studied, possibly causing disease in rats and undermining the validity of laboratory experiments. M. pulmonis was isolated in 144/240 laboratory rats and identified by PCR in 155/240. This species was also detected in 12 human individuals (technicians of a laboratory animal house hold) in contact with these rats. The results were confirmed by sequencing of DNA products. Mycoplasma species are host specific; however, M. pulmonis was identified in humans, suggesting a case of unspecific colonization. Statistical analysis shows a greater risk for M. pulmonis colonizing individuals who are exposed to infected rats in animal facilities than individuals who do not. The detection of M. pulmonis in humans indicates a new status for this mollicute mycoplasmas in animal-holding facilities.

Entrance surface dose measurements in pediatric radiological examinations

A survey of pediatric radiological examinations was carried out in a reference pediatric hospital of the city of Sao Paulo. in order to investigate the doses to children undergoing conventional X-ray examinations. The results showed that the majority of pediatric patients are below 4 years, and that about 80% of the examinations correspond to chest projections. Doses to typical radiological examinations were measured in vivo with thermoluminescent dosimeters (LiF: Mg, Ti and LiF: Mg, Cu, P) attached to the skin of the children to determine entrance surface dose (ESD). Also homogeneous phantoms were used to obtain ESD to younger children, because the technique uses a so small kVp that the dosimeters would produce an artifact image in the patient radiograph. Four kinds of pediatric examinations were investigated: three conventional examinations (chest, skull and abdomen) and a fluoroscopic procedure (barium swallow). Relevant information about kVp and mAs values used in the examinations was collected, and we discuss how these parameters can affect the ESD. The ESD values measured in this work are compared to reference levels published by the European Commission for pediatric patients. The results obtained (third-quartile of the ESD distribution) for chest AP examinations in three age groups were: 0.056 mGy (2-4 years old); 0,068 mGy (5-9 years old)-. 0.069 mGy (10-15 years old). All of them are below the European reference level (0.100mGy). ESD values measured to the older age group in skull and abdomen AP radiographs (mean values 3.44 and 1.20mGy, respectively) are above the European reference levels (1.5mGy to skull and 1.0 mGy to abdomen). ESD values measured in the barium swallow examination reached 10 mGy in skin regions corresponding to thyroid and esophagus. It was noticed during this survey that some technicians use, improperly, X-ray fluoroscopy in conventional examinations to help them in positioning the patient. The results presented here are a preliminary survey of doses in pediatric radiological examinations and they show that it is necessary to investigate the technical parameters to perform the radiographs. to introduce practices to control pediatric patient`s doses and to improve the personnel training to perform a pediatric examination. (c) 2007 Elsevier Ltd. All rights reserved.

Thermoluminescence measurements of entrance surface skin dose in exams of dog's chest in veterinary radiology

This study aims to determine the entrance surface skin doses in dogs (with suspected pulmonary metastasis) submitted to chest X-rays using the technique of thermoluminescence (TL) dosimetry. Twenty seven radiologic exams of dogs of different breed and sizes were performed. The radiation doses were assessed using thermoluminescent dosimeters of calcium sulphate doped with dysprosium (CaSO(4):Dy) produced at Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN). The entrance surface skin dose range evaluated in this type of procedure was between 0.43 mGy to small size dogs and 4.22 mGy to big size dogs with repeated exams. The obtained results indicate that is extremely important the assessment of radiation doses involved in veterinary diagnostic radiology procedures, to evaluate the delivered doses to the animals, to be used as a parameter in the individual monitoring of pet's owners, who assist the animal positioning, and to protect occupationally exposed workers at the Veterinary Radiology Clinics. (C) 2010 Elsevier Ltd. All rights reserved.

Study of entrance surface skin dose in veterinary radiology

This study aims the evaluation of the radiation dose levels involved in veterinary radiology and to contribute to review the procedures for performing radiographic exams in animals in the Department of Veterinary Radiology of Faculdade de Medicina Veterinária e Zootecnia of Universidade Estadual Paulista (FMVZ-UNESP/Brazil). The obtained results has shown to be extremely important the assessment of doses involved in veterinary diagnostic radiology procedures both to protect the occupationally exposed workers and to optimize the delivered doses to the animals. © 2009 Springer-Verlag.

Clinical radiology and postmortem imaging (Virtopsy) are not the same: Specific and unspecific postmortem signs

The aim of this article is to disclose the characteristics of postmortem forensic imaging; give an overview of the several possible findings in postmortem imaging, which are uncommon or new to clinical radiologists; and discuss the possible pitfalls. Unspecific postmortem signs are enlisted and specific signs shall be presented, which are typical for one cause of death. Unspecific signs. Livor mortis may not only be seen from the outside, but also inside the body in the lungs: in chest CT internal livor mortis appear as ground glass opacity in the dependent lower lobes. The aortic wall is often hyperdense in postmortem CT due to wall contraction and loss of luminal pressure. Gas bubbles are very common postmortem due to systemic gas embolism after major open trauma, artificial respiration or initial decomposition; in particular putrefaction produces gas bubbles globally. Specific signs. Intracranial bleeding is hyperattenuating both in radiology and in postmortem imaging. Signs of strangulation are hemorrhage in the soft tissue of the neck like skin, subcutaneous tissue, platysma muscle and lymph nodes. The "vanishing" aorta is indicative for exsanguination. Fluid in the airways with mosaic lung densities and emphysema (aquosum) is typical for fresh-water drowning.

One small scan for radiology, one giant leap for forensic medicine - Post-mortem imaging replaces forensic autopsy in a case of traumatic aortic laceration

The questions of cause and manner of death are the most pressing ones in any forensic investigation. Traditionally, autopsy is the means to provide answers to these questions and despite the increasing use of CT and MR in the post-mortem setting, imaging has usually been an adjunct to forensic autopsy. Here we describe a case where post-mortem CT and MR were performed instead of autopsy, at the request of the responsible public prosecutor. The forensic conclusions derived from imaging, including cause and manner of death were accepted by the legal authorities, thereby setting precedence for future cases. This case represents a landmark in forensic medicine and is another step toward the full realization of minimally invasive forensic autopsy.