RF Burns

This study is being carried out in order to establish guidelines in the use and application of radiofrequency, mostly in terms of its safety and prevention of injuries. Body Causes 1. Heating of implants An RF pulse would often be transmitted by the MRI to stimulate protons through energy exchange. The pulse is an electromagnetic wave coming from the RF coils (Lin, 2008). RF power during MR scans are changed into heat within the tissue of the patient due to resistive losses (Eising et.al., 2010). This absorption of energy is specifically considered the SAR (Specific Absorption Rate). The specific effects of heating during MR scanning and burns usually refer to conductive implants and normal tissue. Most studies discuss the impact of conductive wires, including pacemaker cables, ECG cables, and metallic stents (Eising et.al., 2010). Issues in the use of aneurysm clips in the brain, cochlear implants, implanted spinal cord stimulator, metallic implants, and metal fragments in one or both eyes can also cause burns (Premier Diagnostic Center, n.d). Based on an experimental study by Nakamura et al. (2001), 55-235 volts could be induced with the RF irradiation in a metallic loop placed inside the bore of a 0.5-T scanner. A resistor which was inserted sparked and then burned out (Nakamura et al., 2001). This was seen only with the axis of loops being parallel to the linearly polarized transmitting field. For cables, heatings at 20 degrees Celsius, 26 Celsius, and 63.5 Celsius have been assessed. Assessments indicate that the heating of the ECG cable is known to cause fire. Small implants can lead to issues with the heating of skin seen in tattooed patients caused by the heating of metallic elements of the ink used for the tattoo (Klitscher et al., 2010). Implants (Wills.com, n.d.) Some reports on excessive heating or burns have also been seen for iron-based oxide tattoos and transdermal patches added with metal elements. these patches may include testosterone, nicotine, and clonidine patches (Tope and Shellock, 2002). Tattoos using ferromagnetic compounds can cause react to the MRI machine (Ross and Metava, 2011). In general, the image would somehow appear distorted following the MRI. however, the injuries usually represent burns on the patient’s skin. As such, any redness or apparent injury on the skin has to be managed medically (Ross and Matava, 2011). As seen in the image below, the ferromagnetic compounds of the tattoo caused the RF burns, mostly manifesting as burns and redness on the patient’s skin on the site of the tattoo. Tattoo with ferromagnetic compounds following MRI (Melina, 2010) Currents may be triggered by two fields. The first is the pulsed magnetic-gradient field, and the second being the pulsed radiofrequency field (Jacob et al., 2010). These two fields increase their intensity over time and may eventually cause an electromotive force through a conductive loop. Heating will then come about from the current originating from the loop. with the amount of heating based on the resistance in the conductive processes (Dempsey and Condon, 2001). The pulsed magnetic field is triggered by a large coil which encompasses the coils and is often found near the patient to be scanned. The issue of excessive heating is based on the distance of the RF coil to the patient,