Radio Frequency MRI coils and safety: how infrared thermography can support quality assurance

Abstract Background The safety controls in Resonance Magnetic Imaging (MRI) diagnostic site are numerous and complex. Some of these are contained in international directives and regularly conducted by medical physics expert after acceptance tests, consisting of a series of checks, measurements, evaluations called quality controls (QCs) and made to guarantee the image quality of the equipment. In this context, ensuring that the coils are in proper operating conditions is important to prevent and reduce errors in use and to preserve patient safety. Results A study by thermography was conducted to evaluate temperature changes of MRI coils during Quality Control (QC), in order to prevent any problems for the patient due to Radio Frequency waves. This experiment involves use of a thermal camera to detect temperature variations during MRI scans using head and body coils of two different tomography 1.5 T and 3.0 T static magnetic field. Thermal camera was positioned inside the MRI room to acquire images every 15 s for all the scansions duration. The observations have shown a temperature increase only for body coil of 1.5 MRI tomography, whereas no significative temperature variation has occurred for the other coils under observation. This temperature increase was later related to a fault of such coil. Conclusions The authors believe this simple method useful as first approach, during routinely QCs, to verify coils functioning and so to avoid patient hazards and are preparing a methodological study about functioning of the coils with respect to their temperature variation

recombinant human erythropoietin influences revascularization and healing in a rat model of random ischaemic flaps

In order to ascertain whether erythropoietin plays a role in early and late repair processes following ischaemic skin flap injury, a dorsal, caudally based skin flap was created in rats. The rats were successively divided into four groups. Group 1 was not treated. The other groups were treated with a subcutaneous administration of 0.9% NaCl saline solution (group 2), a subcutaneous administration of vehicle (group 3) or a subcutaneous administration of 300 IU/kg/day of recombinant human erythropoietin (group 4). We evaluated the possible relationships between neutrophil accumulation, myeloperoxidase activity and content in flap tissue, flap survival, flap temperature (using telethermography) and flap revascularization (using videocapillaroscopy). Necrosis in the flap was significantly less extensive in group 4 than in groups 1, 2 and 3. A significant increase in neutrophil infiltration occurred between the 1st and 24th hour in these groups, but this was not observed in group 4. These findings were confirmed by biochemical data of myeloperoxidase activity and malonyldialdehyde content. Between the 1st and 7th days, we recorded an increase of about 20% in flap temperature in groups 1, 2 and 3, whereas no significant variation was observed in group 4. On the 7th day, videocapillaroscopic findings showed an increase in the mean vascularization index in group 4. Our findings suggest that recombinant human erythropoietin administration can improve the wound healing process, in both early and late stages of injury, by reducing inflammatory response, increasing the density of capillaries in ischaemic flaps and allowing earlier repair of a damaged area

Assessment of Exposure to Spatially Varying Magnetic Fields in MRI Environments: Modeling Analysis for Simulation Tools

Magnetic resonance imaging (MRI) is a non-invasive diagnostic technique widely used in medicine with more than 60 million exams per year performed worldwide. MRI personnel are always exposed to static and spatially heterogeneous magnetic fields (fringe or stray fields) and motion-induced time-varying magnetic fields during the working day. This kind of exposure can evoke vertigo and other sensory perceptions such as nausea, visual sensations, and a metallic taste which are not considered hazardous per se, but can be disturbing and may impair working ability. Up to now, no standardized procedures have been available in the literature for the assessment of occupational exposure in an MRI environment. The goal of this paper is to give some indications about the analytical models underlying the development of digital tools for occupational exposure assessment in MRI environments, to have easy but interactive educational tools, for educating MRI staff to avoid higher-risk conditions, and to draw up the best practices. Analysis of the models for the estimation of the magnetic field spatial distribution and the representation of the workers’ movements is described and finally, some recommendations for an accurate methodology to use in simulation tools for exposure assessment are given

Irradiation with Polychromatic Incoherent Low Energy Radiation of Human Peripheral Blood Mononuclear Cells In Vitro: Effects on Cytokine Production

(1) Background: Physical stimuli may activate peripheral blood mononuclear cells (PBMCs) to secrete cytokines, which may favor pro-inflammatory responses or trigger reparative phenomena. The purpose of this study is to evaluate the action of Polarized Polychromatic Incoherent Low Energy Radiation (PILER) on human in vitro PBMCs, by detection of the possible effects on cytokine production; (2) Methods: isolated PBMCs were irradiated with a PILER lamp at different exposure times, at a distance of 10 cm, before incubation. The supernatants were collected after 24 h and 48 h and cytokines evaluated by ELISA; (3) Results: Our results showed a decrease in the levels of pro-inflammatory IL-12p70, IL-17A, IFN-γ, and TNF-α cytokines, whereas IL-10 and TGF-β1 with regulatory activity increased; (4) Conclusions: PILER irradiation affected the cytokine production by isolated PBMCs driving the immune response toward an anti-inflammatory/reparative profile

Use of Raman Spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy in a Multi-Technique Approach for Physical Characterization of Purple Urine Bag Syndrome

Purple urine bag syndrome (PUBS) is a rare condition characterized by purple discoloration of urine and urine bags. Although it is benign, it represents an alarming symptom to the patients and their relatives because of purple discoloration. We have physically characterized urine and urine bags belonging to a patient suffering from PUBS using an approach that combines Raman spectroscopy (RS) and scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX). Five “blue” discolored bags and one sterile urine bag, representing the control, were cut into 1 cm2 square samples and analyzed by using RS and SEM + EDX technique. RS enabled us to identify the presence of indigo, a metabolite of tryptophan, while SEM analysis showed the biofilm deposit, probably due to the presence of microorganisms, and the EDX measurements exhibited the elemental composition of the bags. In particular, urine bags before and after the presence of PUBS urine showed an increase of ~32% of Cl, ~33% of O, ~667% of Ca, ~65% of Al and Mg, while C decreased by about 41%. Our results, to be taken as a proof-of-principle study, are promising for the aim to characterizing the urine bags in a flexible, inexpensive, and comprehensive manner

dB/dt Evaluation in MRI Sites: Is ICNIRP Threshold Limit (for Workers) Exceeded?

The Directive 2013/35/EU establishes standards for workers exposed to static and time varying magnetic fields. These limits are based on ICNIRP guidelines expressed in terms of the electric field induced in the body. The complexity of this measurement led to theoretical models being developed. In this study, the experimental evaluation included varying magnetic field exposures for two classes of MRI workers. The measurements are conducted on four different MRI Systems including one 0.35 T, two 1.5 T, and one 3.0 T. Pocket magnetic dosimeters were used and it was carried out during routine conditions, emergency conditions, and cold-head maintenance/substitution. The acquired data has been processed and the corresponding dB/dt curves have been computed as the first time derivative of the dataset. The weighted peak approach was also implemented for the compliance assessment with regulatory limits. The dB/dt peak values have been compared with the reference level (RL) proposed by ICNIRP. The results show that the RL always exceeds during measurements on the 3.0 T scanner and sometimes on 1.5 T. In light of the foregoing, the diffusion of ultra-high field MRI scanners involves the introduction of behavioral rules that could be more useful than a numerical action level

Mobile Spectroscopy in Archaeometry: Some Case Study

We provide an overview of recent results obtained by the innovative application of mobile spectroscopy for in situ investigation in archaeometry. Its growing relevance is linked to the great advantages of avoiding the transport and eventual damage of precious artifacts and of allowing the analysis of those specimens that are, for example, built into infrastructures or in some way permanently affixed. In this context, some case studies of combined instrumental approaches, involving X-ray fluorescence (XRF) and Raman spectroscopy, integrated by infrared thermography (IRT), are, in particular, discussed: the archaeological site of Scifì (Forza d’Agrò, province of Messina, Italy) and the Abbey of SS. Pietro e Paolo d’Agrò (Casalvecchio Siculo, province of Messina, Italy). In the first case, the elemental composition, as obtained by XRF, of two types of mortars belonging to two different chronological phases, dated back between the 3rd and the 5th century AD, allowed us to hypothesize a same origin area of their raw materials and a different production technique. Again, the combined use of XRF and Raman spectroscopies, supported by IRT technique, on pottery fragments of Greek-Hellenistic age and late imperial period, furnished important information concerning the receipts for the pigmenting agents of the finishing layer, allowing in some cases their unambiguous identification. In the second case, XRF data collected on bricks and stones from the external facade of the abbey allowed us to make some hypothesis concerning the provenance of their constituents materials, supposed to be in the area of valley of the river Agrò

Early Antibody Dynamics in a Prospective Cohort of Children At Risk of Celiac Disease

Introduction: The purpose of this study was to identify possible serum biomarkers predicting celiac disease (CD) onset in children at risk. Methods: A subgroup from an ongoing, international prospective study of children at risk of CD was classified according to an early trajectory of deamidated gliadin peptides (DGPs) immunoglobulin (Ig) G and clinical outcomes (CD, potential CD, and CD autoimmunity). Results: Thirty-eight of 325 children developed anti-tissue transglutaminase IgA antibody (anti-tTG IgA) seroconversion. Twenty-eight of 38 children (73.6%) showed an increase in anti-DGPs IgG before their first anti-tTG IgA seroconversion. Discussion: Anti-DGPs IgG can represent an early preclinical biomarker predicting CD onset in children at risk