MRI safety screening of children with implants: updates and challenges.

MRI is the imaging modality of choice for assessing many pediatric medical conditions. Although there are several inherent potential safety risks associated with the electromagnetic fields exploited for MRI, they are effectively mitigated through strict adherence to established MRI safety practices, enabling the safe and effective use of MRI in clinical practice. The potential hazards of the MRI environment may be exacerbated by/in the presence of implanted medical devices. Awareness of the unique MRI safety and screening challenges associated with these implanted devices is critical to ensuring MRI safety for the affected patients. In this review article, we will discuss the basics of MRI physics as they relate to MRI safety in the presence of implanted medical devices, strategies for assessing children with known or suspected implanted medical devices, and the particular management of several well-established common, as well as recently developed, implanted devices encountered at our institution.

Respiratory-Triggered Flow-Independent Noncontrast Non-ECG-Gated MRV (REACT) Versus CE-MRV for Central Venous Evaluation in Children and Young Adults: A Six-Reader Study.

BACKGROUND. Contrast-enhanced MRI is commonly used to evaluate thoracic central venous patency in children and young adults. A flow-independent noncontrast non-ECG-gated 3D MRA-MR venography (MRV) technique described in 2019 as "relaxation-enhanced angiography without contrast and triggering (REACT)" may facilitate such evaluation. OBJECTIVE. The purpose of our study was to compare image quality, diagnostic confidence, and interreader agreement between respiratory-triggered REACT and 3D Dixon-based contrast-enhanced MRV (CE-MRV) for evaluating thoracic central venous patency in children and young adults. METHODS. This retrospective study included 42 consecutive children and young adults who underwent MRI of the neck and chest to evaluate central venous patency between August 2019 and January 2021 (median age, 5.2 years; IQR, 1.4-15.1 years; 22 female patients and 20 male patients). Examinations included respiratory-triggered REACT and navigator-gated CE-MRV sequences based on the institution's standard-of-care protocol. Six pediatric radiologists from four different institutions independently reviewed REACT and CE-MRV sequences; they assessed overall image quality (scale, 1-5; 5 = excellent), diagnostic confidence (scale, 1-5; 5 = extremely confident), and presence of clinically relevant artifact(s). Readers classified seven major central vessels as normal or abnormal (e.g., narrowing, thrombosis, or occlusion). Analysis used Wilcoxon signed rank and McNemar tests and Fleiss kappa coefficients. RESULTS. The distribution of overall image quality scores was higher (p = .02) for REACT than for CE-MRV for one reader (both sequences: median score, 5). Image quality scores were not significantly different between the sequences for the remaining five readers (all p > .05). Diagnostic confidence scores and frequency of clinically relevant artifact(s) were not significantly different between sequences for any reader (all p > .05). Interreader agreement for vessel classification as normal or abnormal was similar between sequences for all seven vessels (REACT: κ = 0.37-0.81; CE-MRV: κ = 0.34-0.81). Pooling readers and vessels, 65.4% of vessels were normal by both sequences; 18.7%, abnormal by both sequences; 9.8%, abnormal by REACT only; and 6.1%, abnormal by CE-MRV only. CONCLUSION. Respiratory-triggered REACT, in comparison with CE-MRV, showed no significant difference in image quality (aside from for one of six readers), diagnostic confidence, or frequency of artifact(s), with similar interreader agreement for vessel classification as normal or abnormal. CLINICAL IMPACT. High-resolution 3D MRV performed without IV contrast material can be used to assess central venous patency in children and young adults.

Effects of medical training scenarios on heart rate variability and motivation in students and simulated patients.

CONTEXT: Research regarding the experience of stress during medical training scenarios using standardised patients (SPs) has been primarily qualitative and has focused on the SPs. The purpose of this study was to quantitatively evaluate stress and motivation in both students and SPs during these scenarios by measuring heart rate variability (HRV) and administering the German version of the Questionnaire on Current Motivation (QCM). METHODS: A total of 44 medical students (23 women, 21 men) participated in two medical history-taking training scenarios. In one scenario the SP role-played a patient with a somatic disease; in the other the SP played a patient with a psychosomatic disease, creating easy and difficult scenarios, respectively, for the student. Each student interviewed one of 11 SPs (five women, six men), using the same SP in both scenarios. Heart rate variability was measured during baseline periods and during the training scenarios in both students and SPs. Motivation was assessed before each training scenario. RESULTS: Heart rate variability was lower in both students and SPs during the scenarios compared with baseline values, but did not differ by scenario type. For students, motivation increased when the first scenario involved psychosomatic illness, but decreased when the first condition was somatic. For SPs motivation was consistent over time for scenarios involving psychosomatic disease, but decreased for somatic disease-related scenarios. CONCLUSIONS: The training scenarios induced stress in both students and SPs, as indicated by decreased HRV. Student motivation was high, indicating that SP scenarios represent a valid teaching method. Further studies in the natural setting of SP examinations are needed.