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

Sistemi informativi geografici per l’analisi multicriterio nell’ottimizzazione delle prestazioni di una linea di trasporto pubblico locale

Dottorato di Ricerca in "Ingegneria dei Materiali e delle Strutture" Ciclo XXVII, a.a. 20014Università della Calabriahttp://dx.doi.org/10.13126/UNICAL.IT/DOTTORATI/120

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

Short Communication: Use of Infrared Thermometers for Cutaneous Temperature Recording: Agreement with the Rectal Temperature in Felis catus

In veterinary medicine, the gold standard for assessing body temperature is rectal temperature assessment. Considering that this procedure is stressful for many species, in particular for cats, it could be clinically important to consider an alternative approach for the monitoring of core body temperature. The aim of this study was to test if cutaneous temperature measurements by means of different infrared thermometers are in agreement with the most commonly used method for body temperature measurement in cats. The cutaneous temperature was recorded in the jugular, shoulder, rib, flank, and inner thigh, using three different non-contact infrared thermometers (IR1, IR2, and IR3) in 20 cats. The cutaneous temperature was then compared to the rectal temperature, recorded by means of a digital thermometer. The obtained data indicated that the cutaneous temperature recorded by the infrared thermometers was not in agreement with the data recorded by the digital thermometer in the rectum. In cats, the use of non-contact infrared thermometers gave no reproducible or constant data to justify their application for the recording of body temperature instead of rectal temperature recording. In addition, the infrared temperature measurement devices generated results that were not in good agreement among themselves, providing a novel result of clinical importance

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

Frequency of Left Ventricular Hypertrophy in Non-Valvular Atrial Fibrillation

Left ventricular hypertrophy (LVH) is significantly related to adverse clinical outcomes in patients at high risk of cardiovascular events. In patients with atrial fibrillation (AF), data on LVH, that is, prevalence and determinants, are inconsistent mainly because of different definitions and heterogeneity of study populations. We determined echocardiographic-based LVH prevalence and clinical factors independently associated with its development in a prospective cohort of patients with non-valvular (NV) AF. From the "Atrial Fibrillation Registry for Ankle-brachial Index Prevalence Assessment: Collaborative Italian Study" (ARAPACIS) population, 1,184 patients with NVAF (mean age 72 \ub1 11 years; 56% men) with complete data to define LVH were selected. ARAPACIS is a multicenter, observational, prospective, longitudinal on-going study designed to estimate prevalence of peripheral artery disease in patients with NVAF. We found a high prevalence of LVH (52%) in patients with NVAF. Compared to those without LVH, patients with AF with LVH were older and had a higher prevalence of hypertension, diabetes, and previous myocardial infarction (MI). A higher prevalence of ankle-brachial index 640.90 was seen in patients with LVH (22 vs 17%, p = 0.0392). Patients with LVH were at significantly higher thromboembolic risk, with CHA2DS2-VASc 652 seen in 93% of LVH and in 73% of patients without LVH (p <0.05). Women with LVH had a higher prevalence of concentric hypertrophy than men (46% vs 29%, p = 0.0003). Logistic regression analysis demonstrated that female gender (odds ratio [OR] 2.80, p <0.0001), age (OR 1.03 per year, p <0.001), hypertension (OR 2.30, p <0.001), diabetes (OR 1.62, p = 0.004), and previous MI (OR 1.96, p = 0.001) were independently associated with LVH. In conclusion, patients with NVAF have a high prevalence of LVH, which is related to female gender, older age, hypertension, and previous MI. These patients are at high thromboembolic risk and deserve a holistic approach to cardiovascular prevention