Safety Of Magnetic Resonance Imaging Research Articles

A Novel Hands-on Approach Towards Teaching Diagnostic Radiology Residents MRI Scanning and Physics

Traditional approaches towards teaching magnetic resonance imaging (MRI) scanning and physics have limitations that a hands-on course may help overcome. A dedicated week of MRI instruction may help improve radiology resident confidence and competence. Additional benefits may include improved physician-technologist communication and accelerated mastery of MRI safety. Surveys and tests were approved by our Program Evaluation Committee and administered at the beginning and at the end of this one-week course. The course consisted of protected reading time as well as practice scanning with a research magnet and assisting with clinical scanning under the close supervision of a licensed MRI technologist. Eighteen senior residents (nine third-year and nine fourth-year) participated in this course during its first year. Few residents had previous experience with MRI physics, scanning, or research prior to residency. After this course, mean resident confidence increased by 0.47 points (3.33 vs 2.86; p=0.01) on a five-point Likert scale. Understanding of MRI physics, as measured by pre- and post-tests, increased by 22% (0.72 vs 0.50; p<0.01), corresponding to a large effect size of 1.29 (p<0.001). Resident feedback reported that this course was efficacious (5/5), engaging (4.9/5), and had optimal faculty oversight. The most highly rated component of the course was the opportunity to experiment with the research MR scanner (5/5). A dedicated week of MRI education was highly rated by residents and associated with improvements in confidence and understanding, suggesting a positive correlation between confidence and competence. Additional metrics, such as trends in scores on the American Board of Radiology's Core Examination over the next several years, may further support the apparent benefits of this hands-on MR course.

Assessment of the knowledge and attitude regarding magnetic resonance imaging safety among the general population in Saudi Arabia

Assessment of the knowledge and attitude regarding magnetic resonance imaging safety among the general population in Saudi Arabia

Risk of magnetic resonance imaging-induced magnet dislocation for different types of cochlear implants: a single-center retrospective study

BackgroundWhen performing magnetic resonance imaging (MRI) in patients with a cochlear implant (CI), complication rates vary widely in the literature. The primary objective of this retrospective study was to determine the prevalence of complications, in particular magnet dislocation, in patients with CI undergoing 1.5 Tesla (T) MRI. As a secondary objective, the prevalence of magnet dislocation for specific cochlear implant device types was elaborated.MethodsIn a single-center retrospective study, all patients with a cochlear implant presenting for an MRI examination at 1.5 T at our institution between January 1st, 2010 and December 31st, 2020 were included. Implants with axial and diametrical magnets were included in the study. MRI safety measures were applied before imaging. The prevalence of complications was evaluated. Magnet dislocation rates were calculated for device types with at least 20 MRI exposures.ResultsDuring the study period, 196 MRI examinations were performed in a total of 128 patients, accounting for 149 different implants (21 implanted bilaterally) with a total of 231 implant exposures to MRI (average 1.69 ± 1.57; min. 1, max. 12). Complications were reported in 50 out of 231 cochlear implant exposures (21.6%). Magnet dislocation occurred in a total of 27 cases (11.7%). Dislocation rates were 29.6% for the Cochlear® CI500 series (24 dislocations from 81 exposures), 1.1% for the Cochlear® CI24RE series (1 from 87) and 0% for the MED-EL® Synchrony (0 from 36). The dislocation rate for the CI500 was significantly higher than for the CI24RE (χ2(1) = 26.86; p < 0.001; ϕ = 0.40) or the Synchrony (χ2(1) = 13.42; p < 0.001; ϕ = 0.34).ConclusionsFor 1.5 T MRI, the risk of magnet dislocation ranges from 0 to 29.6% and depends on the CI device type. Implants with a diametrical magnet can be considered potentially MRI-safe, whereas in CIs with axial magnets, the CI500 is at high risk of magnet dislocation. Therefore, apart from a strict indication for an MRI and adherence to safety protocols, post-MRI follow-up examination to rule out magnet dislocation is recommended.Graphical

MRI diagnose post-operative anastomotic leak in patients with rectal cancer: preliminary experience

BackgroundAnastomotic leakage (AL) is one of the most serious postoperative complications after colorectal anastomosis. This study aims to evaluate the feasibility and diagnostic accuracy of magnetic resonance imaging (MRI) in the early detection of AL in patients with clinically suspected AL after rectal anterior resection.MethodsThis was a prospective study including patients who underwent anterior resection and postoperative MRI examination. AL was diagnosed by comprehensive indictors, which were mainly confirmed by clinical signs, symptoms, and retrograde contrast enema (RCE) radiography. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of diagnosing AL with MRI were calculated.ResultsIn total, 347 patients received anterior resection for rectal cancer, and 28 patients were suspected to have AL. Finally, 23 patients were included and received MRI examination. The median time interval from surgery to MRI was 10 days (3–21 days). The median distance from anastomosis to anal verge was 4.0 cm (2.0–10 cm), and 11 patients underwent diverted ileostomy. Eighteen patients had an anastomotic leak, including one patient who had a pelvic abscess and five patients who had no evidence of AL in the MRI examination. The overall sensitivity and specificity were 94.4% (95% CI 70.6% to 99.7%) and 80% (95% CI 29.8% to 98.9%), respectively. The PPV was 0.94 (95% CI 0.71 to 0.99) and the NPV was 0.80 (95% CI 0.29 to 0.99). For patients who had anastomosis less than 5 cm, the diagnostic accuracy of MRI was 93.7% (15/16). T2-weighted imaging with fat suppression can effectively reveal the leak track.ConclusionsThe accuracy of plain MRI examination in diagnosing AL was favorable for patients with a suspected AL. T2-weighted imaging with fat suppression was the best imaging modality to diagnose AL. A multicenter prospective study with more samples is needed to further determine the safety and feasibility of MRI in the diagnosis of AL.

Mobile Technology in Medicine: Development and Validation of an Adapted System Usability Scale (SUS) Questionnaire and Modified Technology Acceptance Model (TAM) to Evaluate User Experience and Acceptability of a Mobile Application in MRI Safety Screening.

Background Magnetic resonance imaging (MRI) safety screening is a crucial procedure for patient preparation before entering into MRI room. Many hospitals in Malaysia are still using the MRI safety checklist printed form. Besides, clinicians will not get a definite conclusion about whether the patient is contraindicated for MRI or not. Hence, we have created one mobile application named MagnetoSafe to overcome this issue. The application will provide an instant decision on whether the patient has no contraindication, relative contraindication, or absolute contraindicated for MRI. We need to check for acceptability and user experience for any newly created mobile application. Objective This study was designed to check the validity of the adapted Technology Acceptance Model (TAM) and System Usability Scale (SUS) Questionnaire. Method The validity and reliability of the questionnaire were investigated. Subsequently, 52 fully completed responses were collected. Results Face and content validity of the questionnaires are considered acceptable with only minor changes to Item 10 of SUS. The Cronbach's alpha for the SUS questionnaire (10 questions) is -0.49, which is not acceptable. The Cronbach's alpha for TAM questionnaire (3 domains; 14 questions) is acceptable, which is 0.910 for perceived usefulness, 0.843 for perceived ease of use, and 0.915 for intention to use. Conclusion Face validity of the adapted SUS and modified TAM questionnaires is acceptable with only minor changes to Item 10 in SUS. Content validity with experts is good. However, the reliability of the SUS questionnaire is not acceptable and therefore adapted SUS will not be used for assessing user experience. The reliability of the modified TAM questionnaire with the original three-factor structure is considered acceptable and can be used to evaluate the user's acceptability of MagnetoSafe.

3 Tesla magnetic resonance imaging in patients with cardiac implantable electronic devices: a single centre experience.

Three Tesla (T) magnetic resonance imaging (MRI) provides critical imaging information for many conditions. Owing to potential interactions of the magnetic field, it is largely withheld from patients with cardiac implantable electronic devices (CIEDs). Therefore, we assessed the safety of 3T MRI in patients with '3T MRI-conditional' and 'non-3T MRI-conditional' CIEDs. We performed a retrospective single-centre analysis of clinically indicated 3T MRI examinations in patients with conventional pacemakers, cardiac resynchronization devices, and implanted defibrillators from April 2020 to May 2022. All CIEDs were interrogated and programmed before and after scanning. Adverse events included all-cause death, arrhythmias, loss of capture, inappropriate anti-tachycardia therapies, electrical reset, and lead or generator failure during or shortly after MRI. Changes in signal amplitude and lead impedance were systematically assessed. Statistics included median and interquartile range. A total of 132 MRI examinations were performed on a 3T scanner in 97 patients. Thirty-five examinations were performed in patients with 'non-3T MRI-conditional' CIEDs. Twenty-six scans were performed in pacemaker-dependent patients. No adverse events occurred during or shortly after MRI. P-wave or R-wave reductions ≥ 50 and ≥ 25%, respectively, were noted after three (2.3%) scans, all in patients with '3T MRI-conditional' CIEDs. Pacing and shock impedance changed by ± 30% in one case (0.7%). Battery voltage and stimulation thresholds did not relevantly change after MRI. Pending verification in independent series, our data suggest that clinically indicated MRI scans at 3T field strength should not be withheld from patients with cardiac pacemakers or defibrillators.

Safety of Bedside Portable Low-Field Brain MRI in ECMO Patients Supported on Intra-Aortic Balloon Pump.

(1) Background: Fifty percent of patients supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO) are concurrently supported with an intra-aortic balloon pump (IABP). Acute brain injury (ABI) is a devastating complication related to ECMO and IABP use. The standard of care for ABI diagnosis requires transport to a head CT (HCT) scanner. Recent data suggest that point-of-care (POC) magnetic resonance imaging (MRI) is safe and may be effective in diagnosing ABI in ECMO patients; however, no data exist in patients supported on ECMO with an IABP. We report pre-clinical safety data and a case series to evaluate the safety and feasibility of POC brain MRI in ECMO patients supported with IABP. (2) Methods: Prior to patient use, ex vivo testing with an IABP catheter within the Swoop® Portable MRI (0.064 T) System™ was conducted. After IRB approval, clinical testing was performed for the safety and feasibility of early ABI detection. (3) Results: No deflection force was measured with a 7.5 French Maquet Linear IABP within the 0.064 T field. Three adult ECMO patients (average age: 40 years; 67% female) supported with IABP completed four POC brain MRI exams (median exam time: 30 min). Multiple signal abnormalities were detected on the POC brain MRI, corresponding to HCT results. (4) Conclusions: Our preliminary results suggest that adult VA-ECMO patients with IABP support can be safely imaged with low-field POC brain MRI in the intensive care unit, allowing for the early and bedside imaging of patients.

Off-Label Magnetic Resonance Imaging (MRI) in Patients with Persistent Pain with Spinal Cord Stimulators: A Case Series.

Advances in spinal cord stimulator (SCS) technology and increasing prevalence of magnetic resonance imaging (MRI) diagnostic testing require empirical evidence describing the presence of MRI-related SCS adverse events related to off-label use of imaging. MRI safety recommendations vary based on the type of stimulator used with scant availability regarding adverse events associated with off-label MRI use. The aim of this case series is to describe the type and frequency of adverse events associated with off-label MRI use in patients with implanted SCSs. Convenient samples of records of patients who had SCS and subsequently underwent MRI were included. Descriptive data including patient demographics, stimulator information, and frequency of adverse events were described. Sixty-nine individuals with implanted SCSs were included. The total number of scans was 78. Sixty-two percent of the sample was female. Over 92% of the MRI scans were considered off-label and the overall adverse event rate for off-label use was 9.72%. No serious adverse events were reported. Seven clinical adverse events were reported, all of which were related to the spinal cord stimulation and resolved. This case series demonstrates that individuals implanted with SCSs experienced no serious adverse events associated with off-label MRI use. While these results represent a convenient sample, they provide important preliminary information about using MRI when medically necessary for patients with older spinal cord stimulator models. Specifically, these data demonstrate that the rate of observed adverse events related to MRI was low and suggest that the benefits of acquiring these images for pain management may outweigh the risks of not acquiring MRI for appropriate pain management.

The Effect of Long-Term Moderate Static Magnetic Field Exposure on Adult Female Mice.

Because of the high cost and safety of ultra-high magnetic resonance imaging (MRI), its application has certain limitations. Whereas 0.5-3 T MRI has been widely applied in hospitals, static magnetic fields (SMFs) have been shown to improve mice mental health and have anti-tumor potentials. Here, we compared the effects of the upward and downward 150 mT SMF groups with the sham group on C57BL/6J adult female mice. Locomotor and exploratory activity were also measured by behavioral tests, including the open field and elevated plus test. Additionally, physiology, pathology indicators and gut microbiota were examined. We found that 150 mT SMFs long-term exposure enhanced locomotive and exploratory activity of mice, especially the downward 150 mT SMF. Compared with the downward 150 mT SMF group, the movement speed and distance in the center area of the sham group were increased by 65.99% (p &lt; 0.0001) and 68.58% (p = 0.0038), respectively. Moreover, compared to the sham group, downward 150 mT SMF increased the number of entrances to the center area by 67.0% (p = 0.0082) and time in the center area by 77.12% (p = 0.0054). Additionally, we observed that upward 150 mT SMF improved the number of follicles (~2.5 times, p = 0.0325) and uterine glands through increasing the total antioxidant capacity and reducing lipid peroxidation level in mice. Gut microbiome analysis showed that 150 mT SMFs long-term exposure improved the microbiota abundance (Clostridium, Bifidobacterium, Ralstonia and Yaniella) in the genus level, which may affect metabolism, anxiety and behavior in adult female mice. Our results demonstrated that 150 mT SMFs long-term exposure not only had good biosafety, but also improved athletic performance, emotion and the function of ovarian, uterine and gut microbiota abundance in adult female mice, which unraveled the potential of moderate long-term SMF exposure in clinical applications.

Percutaneous MR Imaging–Guided Laser Ablation for the Treatment of Symptomatic Cervicofacial Vascular Malformations

PurposeTo evaluate the safety and effectiveness of percutaneous magnetic resonance (MR) imaging–guided laser ablation for the treatment of symptomatic soft tissue vascular malformations (VMs) in the face and neck. Materials and MethodsAn institutional review board–approved retrospective review was undertaken of all consecutive patients who underwent MR imaging–guided and monitored laser ablation for treatment of symptomatic, cervicofacial soft tissue VM. Preablation and postablation MR imaging findings were independently reviewed. Preablation and postablation VM sizes were documented. Preablation T2 signal characteristics and enhancement patterns as well as postablation change in both signal and enhancement were semiquantitatively assessed. Changes in VM size were compared using a paired t test. ResultsThirteen patients (women, 9; age, 14.5–69.5 years) with 13 VMs were treated for moderate-to-severe pain (n = 4), swelling/mass effect (n = 8), or predominantly cosmesis (n = 1) with 22 total ablation sessions. The baseline maximum VM diameter was 5.7 cm ± 4.2. At baseline, all VMs (100%) demonstrated variable T2-weighted signal hyperintensity and enhancement. For painful VM, the baseline pain score was 8 ± 1. Clinical follow-up was available for 10 patients. Of patients with available follow-up, 3 (100%) treated for moderate-to-severe pain and 7 (100%) treated for swelling/mass effect reported subjective complete or partial symptomatic relief. The patient treated predominantly for cosmetic reasons was lost to follow-up. Two patients (15.4%) experienced minor adverse events by the Society of Interventional Radiology standards. There were no major adverse events. ConclusionsMR imaging–guided and monitored percutaneous laser ablation is safe and effective for the treatment of symptomatic, cervicofacial VMs.

A practical guide for radiographers focussing on safety during magnetic resonance imaging

Magnetic resonance imaging (MRI) poses some risk when adequate safety measures are not adhered to. Despite efforts on MRI safety, incidents still occur in MRI. Extensive training on MRI safety is essential to protect patients, staff and the public from the risks associated with magnetic fields. Safety issues in MRI include projectile and torque effects on ferromagnetic objects, thermal effects, claustrophobia and adverse reactions to contrast agents. Radiographers operating MRI scanners play a vital role in ensuring that all who enter the MRI environment adhere to the safety measures. However, radiographers are faced with challenges that impact how safety issues are monitored. This Continuing Professional Development article is aimed at highlighting these challenges and providing radiographers with some practical guidelines for these challenges.

Efficacy Evaluation of Modified Siwu Decoction to Treat Osteoporosis in Patients with Poststroke Hemiplegia by Using the Magnetic Resonance Imaging Features

This study was focused on the clinical efficacy and safety of magnetic resonance imaging (MRI)-based Siwu decoction for poststroke hemiplegia complicated with osteoporosis. 120 patients with poststroke hemiplegia and osteoporosis were divided into an observation group (modified Siwu decoction based on the treatment scheme of control group, 60 cases) and a control group (conventional drugs in neurology + neurology-based rehabilitation training treatment of muscle enhancement surgery, 60 cases). They all underwent MRI scans. The results showed that the bone mineral density (BMD) of lumbar spine, ipsilateral femoral neck, and ipsilateral patella in the observation group was higher than that in the control group 180 days after treatment ( P &lt; 0.05 ). MRI showed restricted diffusion and edema in the left frontoparietal cortex and subcortical white matter. The levels of 25-hydroxy-vitamin D (25-OH-VD) and bone gla-containing protein (BGP) in the observation group 180 days after treatment were higher, and the type I collagen n-terminal propeptide (PINP) and type I collagen cross-linked C-terminal telopeptide (β-CTX) were lower ( P &lt; 0.05 ). The visual analogue scale (VAS) score of the observation group at 180 days after treatment was lower, while the quality of life score was higher ( P &lt; 0.05 ). The median cell count in the observation group at 180 days after treatment was less, while the lymphocytes showed a higher level ( P &lt; 0.05 ). In conclusion, the Siwu decoction could effectively improve the bone metabolism of patients with poststroke hemiplegia and osteoporosis, promote the proliferation and differentiation of osteocytes, and improve the BMD and quality of life of patients.

Magnetic resonance imaging in patients with temporary external pacemakers.

To describe safety and feasibility of magnetic resonance imaging (MRI) in patients with transvenous temporary external pacemakers and whether artefacts affect the diagnostic image quality during cardiac MRI. We reviewed records of all patients treated with temporary external pacing between 2016 and 2020 at a tertiary centre. Temporary pacing was established using a transvenous standard active fixation pacing lead inserted percutaneously and connected to a MRI-conditional pacemaker taped to the skin. All patients undergoing cardiac or non-cardiac MRI during temporary transvenous pacing were identified. Before MRI, devices were programmed according to guidelines for permanent pacemakers, and patients were monitored with continuous electrocardiogram during MRI. Of 827 consecutive patients receiving a temporary external pacemaker, a total of 44 (5%) patients underwent MRI (mean age 71 years, 13 [30%] females). Cardiac MRI was performed in 22 (50%) patients, while MRI of cerebrum, spine, and other regions was performed in the remaining patients. Median time from implantation of the temporary device to MRI was 6 (3-11) days. During MRI, we observed no device-related malfunction or arrhythmia. Nor did we detect any change in lead sensing, impedance, or pacing threshold. We observed no artefacts from the lead or pacemaker compromising the diagnostic image quality of cardiac MRI. MRI provided information to guide the clinical management in all cases. MRI is feasible and safe in patients with temporary external pacing established with a regular MRI-conditional pacemaker and a standard active fixation lead. No artefacts compromised the diagnostic image quality.

Argentine National Cardiac Magnetic Resonance Imaging Registry (RENAREC)

Background: The usefulness of cardiac magnetic resonance imaging (MRI) has greatly increased in the last years. Different international registries have been published on its use; however, there is no data available from Argentina. Objective: The aim of this study was to evaluate different indications, protocols, safety and therapeutic consequences of cardiac MRI in Argentina. Methods: A prospective national registry was designed with collection of demographic data, indications for cardiac MRI, associated complications, diagnoses and therapeutic consequences. Results: A total of 34 centers from 10 provinces of Argentina (85% private and 59% with inpatient capacity) participated in the study, including 1131 patients (mean age 54±18 years and 61% males). The main indications for cardiac MRI were hypertrophic cardiomyopathy (13.9%), and ventricular arrhythmia (12.3%). In 99.7% of cases, no study complications were reported. The most frequent results of cardiac MRI were: normal (31.2%), non-ischemic cardiomyopathy (14.7%), ischemic-necrotic cardiomyopathy (11.6%) and hypertrophic cardiomyopathy (8.9%). Clinical suspicion was confirmed in 23.6% of cases and cardiac MRI generated an unsuspected new diagnosis in 48.7% of cases. The main therapeutic consequences were hospital discharge (31.6%) followed by change in medication (28.1%). Conclusions: Cardiac MRI is widely used in Argentina, mainly in private centers with a very low incidence of complications. Cardiomyopathies (hypertrophic and dilated) and ventricular arrhythmia are its main indication, and it provides a new unsuspected diagnosis in almost half of the cases. Further studies are required to assess its clinical and therapeutic impact.

Awareness And Knowledge Of MRI Safety Among Radiological Students, Interns, Fresh Graduates And Trainees

Background — Magnetic resonance imaging (MRI) is a safe imaging technique that provides superior soft tissue contrast compared to other radiological imaging modalities. The main objective of this study was to measure awareness and knowledge of radiology students, interns, new graduates, and trainees regarding the safety of MRI. Material and Methods— To measure awareness and knowledge of the safety of MRI use, data was collected using a questionnaire from 166 subjects (age: 20-60 years) from August to September 2020 at Najran University and all hospitals and dispensaries in Najran region. Results — A total of 166 participants (45.2% male and 54.8% female) were included in the study. The participants were students (44%) from multiple levels (level 3-9), interns (17%), new graduates (19%), and trainees (20%). Our results showed that MRI is a safe method of evaluation and is superior to other tests in terms of safety and accuracy. Pregnant women can do the MRI scan after the end of the first 3 months. Conclusion — The MRI scan is safe but it has some risks that must be considered. There are different levels of knowledge and awareness regarding the safety of MRI use among the students, interns, fresh graduates, and trainees from all hospitals.

Association of White Blood Cell Count With Clinical Outcome Independent of Treatment With Alteplase in Acute Ischemic Stroke.

IntroductionHigher white blood cell (WBC) count is associated with poor functional outcome in acute ischemic stroke (AIS). However, little is known about whether the association is modified by treatment with intravenous alteplase.MethodsWAKE-UP was a randomized controlled trial of the efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in unknown onset stroke. WBC count was measured on admission and again at 22–36 h after randomization to treatment (follow-up). Favorable outcome was defined by a score of 0 or 1 on the modified Rankin scale (mRS) 90 days after stroke. Further outcome were stroke volume and any hemorrhagic transformation (HT) that were assessed on follow-up CT or MRI. Multiple logistic regression analysis was used to assess the association between outcome and WBC count and treatment group.ResultsOf 503 randomized patients, WBC count and baseline parameters were available in 437 patients (μ = 64.7 years, 35.2% women) on admission and 355 patients (μ = 65.1 years, 34.1% women) on follow-up. Median WBC count on admission was 7.6 × 109/L (interquartile range, IQR, 6.1–9.4 × 109/L) and 8.2 × 109/L (IQR, 6.7–9.7 × 109/L) on follow-up. Higher WBC count both on admission and follow-up was associated with lower odds of favorable outcome, adjusted for age, National Institutes of Health (NIH) Stroke Scale Score, temperature, and treatment (alteplase vs. placebo, adjusted odds ratio, aOR 0.85, 95% confidence interval [CI] 0.78–0.94 and aOR 0.88, 95% CI 0.79–0.97). No interaction between WBC count and treatment group was observed (p = 0.11). Furthermore, WBC count on admission and follow-up was significantly associated with HT (aOR 1.14, 95% CI 1.05–1.24 and aOR 1.13, 95% CI 1.00–1.26). Finally, WBC count on follow-up was associated with larger stroke volume (aOR 2.57, 95% CI 1.08–6.07).ConclusionHigher WBC count is associated with unfavorable outcome, an increased risk of HT, and larger stroke volume, independent of treatment with alteplase. Whether immunomodulatory manipulation of WBC count improves stroke outcome needs to be tested.Trial RegistrationClinicalTrials.gov Identifier: NCT01525290.

MRI safety, imaging artefacts, and grid distortion evaluated for FFP3 respiratory masks worn throughout the COVID-19 pandemic

AIMTo determine which filtering face piece (FFP3) respirators worn throughout the COVID-19 pandemic are safe for magnetic resonance imaging (MRI).MATERIALS AND METHODSThree clinical MRI sequences were performed to assess imaging artefacts, grid distortion, and local heating for eight commercially available FFP3 respirators. All examinations were performed at Cardiff University Brain Research Imaging Centre using a 3 T Siemens Magnetom Prisma with a 64-channel head and neck coil. Each FFP3 mask was positioned on a custom-developed three-dimensional (3D) head phantom for testing.RESULTSFive of the eight FFP3 masks contained ferromagnetic components and were regarded as “MRI unsafe”. One mask was considered “MRI conditional” and only two masks were deemed “MRI safe” for both MRI staff and patients. Temperature strips positioned at the nasal bridge of the phantom did not exhibit local heating. A maximum grid distortion of 5 mm was seen in the anterior portion of the head of the ferromagnetic FFP3 masks.CONCLUSIONThis study has demonstrated the importance of assessing respiratory FFP3 masks for use in and around MRI machines. Future research involving FFP3 masks can be conducted safely by following the procedures laid out in this study.

Magnetic resonance imaging in patients with cardiac implantable electronic devices: A prospective study

BackgroundThe number of patients with cardiac implantable electronic devices in whom magnetic resonance imaging (MRI) is indicated is constantly increasing. The potential risk of electromagnetic interference has limited its use and it is still contraindicated by the Food and Drug Administration in some cases. The aim of this study is to evaluate the safety and efficacy of MRI in these patients. MethodsA prospective registry comprising patients with a pacemaker (PM) or implantable cardioverter-defibrillator (ICD), MRI-conditional or not, who were candidates for MRI (at 1.5 T) with no suitable alternative diagnostic technique. All devices were programmed before the procedure and patients were monitored throughout the test. Clinical, electrical, and technical parameters were evaluated before and after MRI. Results147 MRI examinations (132 PM and 15 ICD) were performed. There were no clinical events or significant differences in the electrical parameters of the leads after MRI. A variation in the impedance of the ventricular leads was detected, although the difference was not clinically relevant. In one patient with a PM, a failure in release of the safety impulse was detected in the auto-threshold test, although the threshold was correctly determined. In 11 of the 17 thoracic MRIs, image artifacts were detected, preventing the diagnosis in two of them. ConclusionsIn patients with cardiac implantable electronic devices, MRIs performed under a specific protocol has been shown to be safe in the short term even in the thoracic region, as well as interpretable in most cases.

Assessing the SAfety and FEasibility of bedside portable low-field brain Magnetic Resonance Imaging in patients on ECMO (SAFE-MRI ECMO study): study protocol and first case series experience

BackgroundTo assess the safety and feasibility of imaging of the brain with a point-of-care (POC) magnetic resonance imaging (MRI) system in patients on extracorporeal membrane oxygenation (ECMO). Early detection of acute brain injury (ABI) is critical in improving survival for patients with ECMO support.MethodsPatients from a single tertiary academic ECMO center who underwent head CT (HCT), followed by POC brain MRI examinations within 24 h following HCT while on ECMO. Primary outcomes were safety and feasibility, defined as completion of MRI examination without serious adverse events (SAEs). Secondary outcome was the quality of MR images in assessing ABIs.ResultsWe report 3 consecutive adult patients (median age 47 years; 67% male) with veno-arterial (n = 1) and veno-venous ECMO (n = 2) (VA- and VV-ECMO) support. All patients were imaged successfully without SAEs. Times to complete POC brain MRI examinations were 34, 40, and 43 min. Two patients had ECMO suction events, resolved with fluid and repositioning. Two patients were found to have an unsuspected acute stroke, well visualized with MRI.ConclusionsAdult patients with VA- or VV-ECMO support can be safely imaged with low-field POC brain MRI in the intensive care unit, allowing for the assessment of presence and timing of ABI.

P 68 Unintentional maladjustment of a shunt valve due to electromagnetic door locks – A case report

Normal-pressure hydrocephalus is caused by dilatation of the internal cerebrospinal fluid spaces at normal intracranial pressure. The resulting progressive accumulation of CSF in the brain space can cause permanent damage and, if left untreated, complete loss of brain tissue [2, 4]. The standard treatment for hydrocephalus in children and adults is the implantation of a ventriculo-peritoneal shunt (VP shunt). Most of the currently used shunt systems have a valve to control pressure and drain CSF if necessary [4]. In recent years, malfunction of programmable VP shunts has been reported in patients exposed to strong electromagnetic fields, such as those generated during magnetic resonance imaging (MRI) [1, 3]. However, little is known about the effects of weak magnetic fields on VP shunts. We present the case of a 53 -year-old forensic psychiatric patient in whom the pressure setting of an implanted Codman-Hakim programmable shunt valve changed during passage through various ward doors, leading to the onset of psychiatric symptoms. During the inpatient stay, the valve's pressure setting changed at least six times randomly despite frequent reprogramming and monitoring. References 1 Akbar M, Aschoff A, Georgi JC, Nennig E, Heiland S, Abel R, Stippich C (2010) Adjustable Cerebrospinal Fluid Shunt Valves in 3.0-Tesla MRI: a Phantom Study using Explanted Devices. Rofo 182(7):594-602 2 Kahle KT, Kulkarni AV, Limbrick DD, Warf BC (2016) Hydrocephalus in children. Lancet 387(10020):788–799 3 Mirzayan MJ, Klinge PM, Samii M, Goetz F, Krauss JK (2012) MRI safety of a programmable shunt assistant at 3 and 7 Tesla. Br J Neurosurg 26(3):397-400 4 Portillo Medina SA, Franco JVA, Ciapponi A, Garotte V, Vietto V (2017) Ventriculo-peritoneal shunting devices for hydrocephalus. Cochrane Database Syst Rev. 2017(7): CD012726 Figure 1. Scetch of a Codman-Hakim shunt valve. Figure 2. Image of a Codman-Hakim VP shunt before and after passing a door.