This article proposes the design of an educational MR safety module using an available comprehensive multiple-choice exam for instructing medical students about basic MR and patient related safety.
The MR safety course material can be implemented as a traditional didactic or interactive lecture in combination with hands-on safety demonstrations.
The goal of the course is to ensure that medical students receive a basic understanding of MR principles and safety considerations. This course should prepare medical students for consideration of patient screening and safety when ordering MR studies. A multiple-choice exam can be used to document the proficiency in MR safety of the medical students. The course can be used by various medical school programs and may help to ensure consistent quality of teaching materials and MR safety standards.
Magnetic Resonance Imaging MRI is a cross-sectional imaging technique with superior soft-tissue contrast compared to other imaging modalities e. MRI has lead to new insights in anatomical, physiological and functional imaging. The continued growth of MRI in the last decades has led to more than 25, MRI scanners that were sold world wide, millions of MRI exams performed, and thousands of healthcare professionals that were educated in MRI safety to protect patients and other healthcare workers from the hazards associated with MRI 1.
The purpose of this article is to describe a comprehensive approach to educate medical students who will be the physicians of the future in the safety aspects of MRI. There are multiple commercial MRI safety courses available that are offered online 2 - 6. The expected audiences of these courses are participants in the field of medical imaging including MR technologists, radiologists and medical physicists.
The content of most of these courses follow the ACR Guidance Document for Safe MR practices but none of these courses focus specifically on medical students 7.
Arteriovenous fistula complication following MRI
Medical students do not necessarily have the same technical background as specialists in the field of medical imaging. Nevertheless, medical students will become the MRI-referring physicians of the future and would benefit from having a comprehensive MRI safety training included in their medical school curriculum.
The course proposed here will focus on medical students because as physicians they will refer patients for MRI exams and will often have to evaluate MRI safety and compatibility of new medical devices and implants. They will also often be the first health care professionals who will talk to their patients about the MRI exam, potential risks, and MRI safety 8.
Referring physicians who understand the principles of MRI safety can help contribute to MRI safety screening since they know the patient's medical history better than the radiologists or technologists who will only meet a patient very briefly during screening and preparation for an exam.
A pre-screening of patients before their MRI exam by a referring physician offers an additional safety check which can streamline procedures directly before the exam in a radiological imaging facility and can improve MR imaging results 9. This article proposes a comprehensive MRI safety course for medical students that includes the basics of bio-effects and risks of the magnetic fields that interact with patients and health care professionals in an MRI suite The following four and half hour, 7 module course about basic MR and patient-related safety is proposed for inclusion in medical school curricula 10Magnetic resonance imaging MRI has a superior soft-tissue contrast compared to other radiological imaging modalities and its physiological and functional applications have led to a significant increase in MRI scans worldwide.
A comprehensive MRI safety training to protect patients and other healthcare workers from potential bio-effects and risks of the magnetic fields in an MRI suite is therefore essential. The purpose of this article is to give an overview of current magnetic resonance safety guidelines and discuss the safety risks of magnetic fields in an MRI suite including forces and torque of ferromagnetic objects, tissue heating, peripheral nerve stimulation, and hearing damages. This is a preview of subscription content, log in to check access.
Rent this article via DeepDyve. Chakeres DW, de Vocht F Static magnetic field effects on human subjects related to magnetic resonance imaging systems. Prog Biophys Mol Biol 87 2—3 — Feychting M Health effects of static magnetic fields—a review of the epidemiological evidence. Shellock FG Magnetic resonance procedures: health effects and safety. Google Scholar. Karpowicz J, Gryz K Health risk assessment of occupational exposure to a magnetic field from magnetic resonance imaging devices.
Magn Reson Imaging 31 6 — Sammet S Implementation of a comprehensive MR safety course for medical students. Philadelphia: Lippincott-Raven. Simmons A, Hakansson K Magnetic resonance safety. Methods Mol Biol — Bioelectromagnetics 34 1 — Radiographics 35 6 — BioMed Res Int Bioelectromagnetics 28 5 — International Electrotechnical Commission IEC Medical electrical equipment, particular requirements for the safety of magnetic resonance equipment for medical diagnosis. International Standard IEC Accessed 1 Mar J Neurol Neurosurg Psychiatry 47 3 — Induced alignment of flowing sickle erythrocytes in a magnetic field.
A preliminary report.This study investigates physiologic vital signs in subjects, with and without cerebral pathologies, undergoing ultra-high-field UHF 8T MR imaging.
Physiologic vital signs measured included systolic blood pressure, diastolic blood pressure, mean arterial pressure, electrocardiogram, heart rate HRrespiratory rate RRand pulse oxygen saturation rate. They were collected before, during, and after imaging. Mean vital sign values at different stages were calculated and compared. Subjects were interviewed after imaging.
No adverse vital sign change was detected. Statistically significant changes after imaging included a HR decrease from One normal subject and one subject with cerebral pathology reported an episode of nausea and vomiting. The current neurologic human MR imaging procedure at 8T UHF has no serious adverse effects on major physiologic vital signs in either normal subjects or patients.
Transient vertigo, nausea, and vomiting were identified as potential risks. Most MR imaging systems operate at a field strength of 1. MR imaging theory, however, points to significant advantages if higher magnetic fields are used. Most notably, increasing the magnetic field strength enhances signal intensity to noise, magnetic susceptibility, and chemical shift dispersion phenomena. Despite the FDA ruling, the goal of this study is to add to the existing set of safety data by examining physiologic vital signs and sensations in human subjects undergoing imaging at 8T field strength.
Both normal subjects and subjects with neurologic disease were examined. In this manner, the combination of strong magnetic fields, oscillating gradients, and RF pulses in the 8T environment can be further characterized in human subjects. A set of asymmetric head gradient coils was used in this study. The RF transmitter is a strut transverse electromagnetic TEM coil with a cm inner diameter and a cm length with 4-port excitation configuration.
From October to October92 subjects 66 with histopatho-logically confirmed brain tumors, 8 with confirmed cerebrovascular diseases, and 18 normal subjects consented to 8T UHF MR imaging under 3 different research protocols approved by the institutional review board. A standard pre-MR-screening questionnaire obtained from each subject was used to exclude subjects with MR-sensitive foreign bodies or implants.
Subjects were also excluded if their baseline vital signs fell outside a predetermined normal physiologic range. Subjects were also excluded if they experienced claustrophobia during initial placement of the TEM coil over the head. Imaging was terminated if any vital signs fell outside the above physiologic limits or subjects refused to continue.
Vital signs were collected at 3 different stages: before, during, and after MR imaging in the presence of a licensed physician. The subject was supine during all vital sign measurements. An MR-compatible automatic Omni-Trak Invivo Research, Orlando, Fla remote monitoring system was used to monitor vital signs during the whole procedure.
These vital signs were measured at a 5-minute interval before imaging and minute intervals during imaging and immediately after imaging, respectively.The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology.
Bax, Philipp A. The potential risks associated with cardiovascular imaging CVI have recently been debated, partly triggered by the rapid increase in the use of imaging procedures and new imaging modalities such as cardiac computed tomography CT. Even more important, the test must be related to the benefit of performing or not performing the test with the risk and drawbacks associated with the disease remaining undetected. We aimed to create a balanced analysis of immediate, short- and long-term risks associated with CVI in relation to the natural course of coronary artery disease CAD and to therapeutic interventions.
We analysed: i the risk of major cardiac events MCEs for each component of imaging test; ii the upper limit for each risk, in order to avoid underestimation of a risk; iii composite risks calculated for selected common diagnostic tests for CAD; iv the risks compared with the risk of the disease itself, to assess the potential benefits of tests; and v comparison with risks in regular life activities and that associated with trivial long-term prophylactic interventions such as aspirin use.
This analysis is based on the data available from the literature. Data for risks related to some of the procedures are quite limited, for some variable, and for some of limited quality. Still we sought to present risk estimations from all the procedures using reliable studies and databases available from an extensive search of the literature. The detailed information about risk assessments is shown in Supplementary material. In the literature, risks are described in many different ways, e.
In this analysis, they are defined as complications or side effects that are not life threatening. Dynamic exercise and different pharmacological stress agents including vasodilators adenosine, dipyridamole, selective A2A receptors agonists and inotropic-chronotropic agents dobutamine are employed.
The overall hard events rate of dynamic exercise has been reported to be in the range of 1. Recently, A2A selective agonists have been approved as stressors.
The incidence of serious AEs and side effects appears significantly lower than with adenosine. Strong static magnetic field as such is unlikely to cause significant adverse biological effects. RF energy applied to the body may be responsible for tissue heating. Quickly changing magnetic fields may generate electrical currents in electrically conductive devices with potential risk of arrhythmia induction in patients with pacemaker leads.
Significant increase of DNA double-strand breaks have been detected after routine 1. In this paper, we estimated accidents in 0. Since no data are currently available about the clinical events caused by MR-induced DNA damage, this risk was not included. Biological effects of diagnostic ultrasound have been documented in experimental studies conducted on molecular, cellular and animal level. The effects may broadly be classified into thermal and mechanical effects.Dj3
With current diagnostic ultrasound technology, biological effects are unlikely to be caused directly by tissue heating. Among possible mechanical effects of ultrasound, a potential risk is cavitation: formation and rhythmic oscillation of microbubbles produced from gasses dissolved in living tissue. The mechanical index has been developed as predictor of acoustic cavitation and is displayed as a safety parameter on modern ultrasound scanners.
Capillary rupture can be demonstrated when tissues containing gas-filled contrast agents are exposed to ultrasound, 19 but so far there is no evidence of significant health risk from exposure to medical ultrasound for patients or clinical staff members. Diagnostic invasive coronary angiography CAGlike most invasive procedures, may cause serious complications.Table representation of search results timeline featuring number of search results per year.
Per page 10 20 50 Save citations to file Selection: All results on this page All results Selection. Create file Cancel. Email citations Subject:. Selection: All results on this page All results Selection. Format: Summary Summary text Abstract Abstract text. Send email Cancel. Send citations to clipboard Selection: All results on this page All results Selection.
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This case describes a haemodialysis patient who experienced pain, swelling and bruising over a radiocephalic fistula following MRI.
Plausible explanations include a radio frequency-induced electrical current being formed at the arteriovenous fistula, or varying gradients of the MRI sequence stimulating peripheral nerves, leading to a site of increased tissue stimulation. Nevertheless, these previously undocumented observations suggest that careful patient and fistula monitoring is required when completing MRI scans in those with an arteriovenous fistula.
In patients with chronic kidney disease, a surgically formed arteriovenous fistula in the arm is the preferred and recommended form of vascular access due to increased longevity, reduced need for maintenance and less risk of vascular and infective complications compared to other types of vascular access. This case study reports an arteriovenous fistula complication following MRI.
Our patient was a year-old man with stage 5 chronic kidney disease secondary to hypertension and type II diabetes mellitus. His medical history included ischaemic heart disease and peripheral vascular disease. The patient was positioned supine, arms by his sides, feet first into the scanner, and landmarked such that the upper thigh was centred in the body coil.
These symptoms worsened as the scan progressed but ceased immediately when the scan was complete. After the scan, signs included instant swelling at both needling sites and a slight bruising at the arteriovenous fistula site several hours following the scan.
Before each MRI scan, specific safety screening was carried out on two separate occasions. Among other questions, this screening involved specific questions relating to the presence of any metal implants or potential shrapnel fragments in the body. Furthermore, x-ray did not reveal the presence of any foreign bodies at the fistula site, ruling out any potential heating effects due to implanted devices see figure 1. White blood cell counts during the time of the scans were within the normal range of 4.
The observed symptoms and signs pain, swelling and bruising occurred during and immediately after both MRI scans, highly suggestive of causality. No specific treatment was prescribed for the symptoms and signs of pain, swelling and bruising. The patient has been excluded from all future MRI scans that contain high-resolution fast field echo-based sequences.
Chronic kidney disease patients will often be referred for morphological and diagnostic MRI scans for reasons ranging from investigating renal parenchyma to identifying vascular complications. Previously reported complications of MRI in kidney disease occurred as a result of magnetic resonance angiograms that is, contrast-induced nephropathy and nephrogenic systemic fibrosis. There are several possible explanations for this observation.
During the MRI scan, the forearm fistula was positioned at the outer edge of the radio frequency and gradient coils, and thus would be within the region of radio frequency excitation and varying field gradients.
It is possible that a small, radio frequency-induced, electrical current may have been formed at the arteriovenous fistula. The anastomosis of the vein and the artery in the forearm could have potentially formed a loop or circuit through which the flowing blood acted as a conductor.
Implementation of a Comprehensive MR Safety Course for Medical Students
It is unknown as to whether or not the stenosis observed after the second scan was caused by the MRI scan per se.If the period is 0, or not given, BigML will automatically learn the period in your data. The range of successive instances to build the time series. Multiplicative seasonality models are only available when the objective field has strictly positive values (greater than 0).
Example: 2 tags optional Array of Strings A list of strings that help classify and index your time series.
If absent, the first datetime field in the dataset whose values are continuously either decreasing or increasing. If not given, the server will auto-detect the first sequential datetime field in the dataset. All fields are optional: giving any two among start, end, and interval are enough for a full specification, since the remaining one can always be computed.
If you give all three, end is ignored and recomputed using start and interval. After the initial pass through the input data, the value of end will be adjusted to coincide with the last non-missing objective value.
If the objective field has missing values at its tail, then this adjusted value will differ from the one specified or computed from start and interval. If you do not specify an objective field, BigML. Once a time series has been successfully created it will have the following properties. Each field's id has a list of objects with the following properties: The property forecast is a dictionary keyed by each field's id in the source.
Each field's id has a list of objects with the following properties: In addition to the ETS models, BigML also provides simple forecast models for each field, to be used as references for the performance of the ETS models. Due to their trivial nature, these are always computed regardless of what ETS parameters are selected in the input. Currently, we offer three simple model types: naive, mean, and drift.
Naive: this model always forecasts the last value of the observed time series. For seasonal models, it repeats the last m values of the training series, where "m" is the given period length for the field. The parameters for this field are as follows: Mean: this model always forecasts the mean of the objective field. For seasonal models, it is similar to the naive model since the model cycles the same sequence of values for forecasts, but instead of using the last set of m values, BigML computes the mean sequence of the naive values.
The parameters for this field are as follows: Drift: Draws a straight line between the first and last values of the training series. Forecasts are performed by extending that line. The parameters for this field are as follows: Creating a time series is a process that can take just a few seconds or a few days depending on the size of the dataset used as input and on the workload of BigML's systems.
The time series goes through a number of states until its fully completed. Through the status field in the time series you can determine when time series has been fully processed and ready to be used to create forecasts. Thus when retrieving a timeseries, it's possible to specify that only a subset of fields be retrieved, by using any combination of the following parameters in the query string (unrecognized parameters are ignored): Fields Filter Parameters Parameter TypeDescription fields optional Comma-separated list A comma-separated list of field IDs to retrieve.
To update a time series, you need to PUT an object containing the fields that you want to update to the time series' base URL. Once you delete a time series, it is permanently deleted. If you try to delete a time series a second time, or a time series that does not exist, you will receive a "404 not found" response.