The purpose of this study was to introduce and evaluate a novel 2D wideband black-blood (BB) LGE sequence, incorporating wideband inversion recovery, wideband T2 preparation, and non-rigid motion correction (MOCO) reconstruction, to improve myocardial scar detection and address artifacts associated with implantable cardioverter defibrillators (ICDs).

The wideband MOCO free-breathing BB-LGE sequence was tested on a sheep with ischemic scar and in 22 patients with cardiac disease, including 15 with cardiac implants, at 1.5T. Wideband MOCO free-breathing BB-LGE sequence was compared with conventional and wideband breath-held PSIR-LGE and conventional and wideband breath-held BB-LGE techniques. Image sharpness, entropy, and scar-to-blood, scar-to-myocardium, and blood-to-myocardium contrast were analyzed and reconstruction times were measured. Two expert readers assessed the image quality, ICD artifact severity, and the diagnostic confidence with scar extent. Finally, for the animal study, a histology of the heart was performed to confirm the presence and localization of scar tissue.

In the animal, wideband MOCO free-breathing BB-LGE were reconstructed in 0.6 s and demonstrated a 200 % improvement in scar-to-blood contrast compared to wideband breath-held PSIR-LGE, with significant improvement in image sharpness and reduction in entropy. It also effectively minimized ICD artifacts and accurately detected scars. In patients, wideband MOCO free-breathing BB-LGE were reconstructed in 1.5 ± 0.4 (standard deviation) s per slice. Seventeen patients (17/22; 77%) with myocardial scars were confidently diagnosed with wideband MOCO free-breathing BB-LGE, compared to 11 (11/22; 50 %) with wideband breath-held PSIR-LGE (P < 0.01).

Free-breathing wideband T2-prepared black-blood LGE imaging, combined with motion-corrected reconstruction, offers a promising diagnostic approach for the evaluation of myocardial lesions in patients with ICDs.

The historical restriction of magnetic resonance imaging (MRI) for patients with cardiac implantable electronic devices (CIEDs) has been lifted by certified MRI-conditional systems in recent years. Mixed-brand CIED systems consisting of a generator from one manufacturer and at least one lead from another manufacturer are not certified for MRI. We evaluated the temporal trend in the prevalence of mixed-brand systems in the era of MRI-conditional systems. Data were analyzed on 5853 CIEDs implanted de novo between 2012 and 2022 in 81 Italian centers linked to the nationwide Home Monitoring Expert Alliance network. The percentage of mixed-brand implants was calculated by device type (pacemaker, implantable cardioverter-defibrillator [ICD], cardiac resynchronization therapy [CRT] device) and over time. A mixed-brand system was implanted in 4.1% (95% CI, 3.6-4.6%) of analyzed patients or, by device type, in 4.5% (3.5-5.7%) of pacemaker patients, 1.1% (0.7-1.7%) of ICD patients, and 6.8% (5.7-7.9%) of CRT pacemaker/defibrillator patients (p < 0.001). Prevalence of mixed-brand implants exhibited significant temporal fluctuations, first declining from 6.6% (2012-2014) to 1.3% (2019), and then increasing to 5.1% (2022). Temporal changes were statistically significant for pacemakers (p < 0.001) and CRT devices (p = 0.001), but not for ICDs (p = 0.438). In the decade between 2012 and 2022, mixed-brand CIED systems were more prevalent in patients treated with pacemakers and CRT devices than in ICD recipients. A decline in the prevalence of mixed-brand systems was observed after the introduction of MRI-conditional systems, reaching a minimum in 2019, followed by a progressive increase in the subsequent years.

Cardiovascular magnetic resonance imaging (MRI) in patients with cardiac implants, such as pacemakers and defibrillators, has gained importance in recent years with the development of modern cardiac implantable electronic devices. The increasing clinical need to perform MRI examinations in patients with cardiac implants has driven the development of new advanced MRI sequences to mitigate image artifacts associated with cardiac implants. More specifically, advances in imaging techniques, such as wideband late gadolinium enhancement imaging, wideband T1 mapping, and wideband perfusion, have been designed to improve image quality and examinations in patients with cardiac implants, enabling a comprehensive and more reliable diagnosis, which was previously unattainable in these patients. This review article explores recent developments and applications of wideband techniques in the field of cardiovascular MRI, offering insights into their transformative potential. Clinical applications of wideband cardiovascular MRI are highlighted, particularly in assessing myocardial viability, guiding ventricular tachycardia ablation, and characterizing myocardial tissue.

Despite increasing evidence demonstrating the safety of magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs), this procedure is often neglected in this population. This Spanish registry aimed to determine the proportion of MRI referrals and performance among patients with pacemakers (PMs) or implantable cardioverter defibrillators (ICDs).

This prospective, multicentre, open-label registry involved 21 Spanish centres. Data were collected upon implant of PMs or ICDs from BIOTRONIK and one year after, and included the number of MRIs and computed tomography scans prescribed, performed and denied, and reasons for denial. Data from 1105 patients (mean age: 74.2 years) were analysed and 982 completed the follow-up. Of them, 82.2% had a PM and 17.8% an ICD. A total of 351 imaging tests were prescribed in 220 patients (19.9%), including 52 MRIs in 39 patients (3.5%) and 299 computed tomography scans in 196 patients (17.8%). Among the MRIs, 44 (84.6%) were performed, five (9.6%) were not performed, and three (5.8%) were replaced by an alternative test. Most of the indicated computed tomography scans were performed (97.7%). The proportion of patients with an MRI scan referral was 4.6% during the pre-COVID-19 period and 2.6% during the COVID-19 period. No MRI-related arrhythmic ventricular event was reported.

This registry revealed that only 3.5% of patients with CIEDs had an MRI referral over the study, with rates decreasing to 2.6% during the COVID-19 period. These rates contrast with the 85 MRIs conducted per 1000 inhabitants in Spain in 2020.

MRI (magnetic resonance imaging) represents the diagnostic image modality of choice in several conditions. With an increasing number of patients requiring MRI for diagnostic purposes, the issue of safety in patients with cardiac implantable electronic devices (CIED) undergoing this imaging modality will play an ever more important role. The purpose of this study was to assess the safety and device function following MRI in an unrestricted real-world cohort of patients with a wide array of cardiac devices.

We conducted a retrospective single-center study including 1010 MRI studies conducted in adult patients (≥18 years) with an implanted CIED treated in the University Hospital of Munich (LMU) between July 2012 and March 2024. Patients with non-MR conditionally labeled leads, abandoned or epicardial leads, as well as lead fragments, were included for analysis.

Across a total of 1010 MRIs (920 total MR-conditional device generators) performed in patients with an implanted CIED, there were no deaths, reports of discomfort, palpitations, heating, or ventricular arrythmias in the 24 h following MRI. Only 2/1010 MRIs were followed by a reported atrial arrhythmia within 24 h, both in patients with an MR-conditional pacemaker (PM) device without an abandoned lead. No significant changes in device function following MRI from baseline were observed across all included CIEDs. Lastly, no instances of severe malfunction, such as generator failure, loss of capture, electrical reset, or inappropriate inhibition of pacing, were found in post-MRI interrogation reports across all MRI studies.

Based on the analysis of 1010 MRIs undergone by patients with CIEDs, following standardized device interrogation, manufacturer-advised device programming, monitoring of vital function, and manufacturer-advised reprogramming, MRI can be performed safely and without adverse events or changes in device function.

Implanted Cardioverter Defibrillators (ICDs) induce a large (100 parts per million) inhomogeneous magnetic field in the magnetic resonance imaging (MRI) scanner which cannot be corrected by the scanner's built-in shim coils, leading to significant image artifacts that can make portions of the heart unreadable. To compensate for the field inhomogeneity, an active shim coil capable of countering the field deviation in user-defined regions was designed that must be optimally placed at patient-specific locations. We aim to develop and evaluate an MR-safe robotic solution for automated shim coil positioning.

We designed and fabricated an MR-safe Cartesian platform that holds the shim coil inside the scanner. The platform consists of three lead screw stages actuated by pneumatic motors, achieving decoupled translations of 140 mm in each direction. The platform is made of plastics and fiberglass with the control electronics placed outside the scanner room, ensuring MR safety. Mechanical modeling was derived to provide design specifications.

Experiments show that the platform achieves less than 2 mm average motion error and 0.5 mm repeatability in all directions, and reduces the adjustment time from 5 min to a few seconds. Phantom and animal trials were conducted, showing that the proposed system is able to position a heavy shim coil ( kg) for improved ICD artifact suppression.

This robotic platform provides an effective method for reliable shim coil positioning inside the scanner.

This work contributes to improving cardiac MRI quality that could facilitate accurate diagnosis and treatment planning for patients with implanted ICDs.

Radiofrequency (RF) induced tissue heating during magnetic resonance imaging (MRI) is the predominant safety risk for patients with active electronic implants such as cardiac implantable electronic devices (CIEDs) which typically have elongated conductive leads. Currently, abandoned CIED leads, as well as CIEDs with epicardial leads, are contraindicated for MRI exams. Recent studies have demonstrated the superior safety of vertical, open-bore MRI systems regarding RF heating compared to conventional closed-bore scanners. However, these studies only investigated deep brain stimulation (DBS) and passive devices. In this study, we compared the RF heating of three commercially available epicardial leads in clinically available closed-bore and open-bore MRI systems. Results from the phantom experiments revealed significantly lower RF heating with up to a nine-fold reduction in the mean temperature rise in the tissue-mimicking gel. Our results are in line with previous findings, suggesting that vertical MRI systems can offer a potentially safer platform for imaging this patient population.

Persistent reluctance to perform magnetic resonance imaging (MRI) in patients with abandoned and/or epicardial leads of cardiac implantable electronic devices is related to in vitro studies reporting tip heating. While there is a plethora of data on the safety of MRI in conditional and non-conditional implantable devices, there is a clear lack of safety data in patients with abandoned and/or epicardial leads.

Relevant literature was identified in Medline and CINAHL using the key terms 'magnetic resonance imaging' AND 'abandoned leads' OR 'epicardial leads'. Secondary literature and cross-references were supplemented. For reporting guidance, the Preferred Reporting Items for Systematic reviews and Meta-Analyses 2020 was used. International Prospective Register of Systematic Reviews (PROSPERO) registration number 465530. Twenty-one publications with a total of 656 patients with 854 abandoned and/or epicardial leads and 929 MRI scans of different anatomical regions were included. No scan-related major adverse cardiac event was documented, although the possibility of under-reporting of critical events in the literature should be considered. Furthermore, no severe device dysfunction or severe arrhythmia was reported. Mainly transient lead parameter changes were observed in 2.8% in the subgroup of patients with functional epicardial leads. As a possible correlate of myocardial affection, subjective sensations occurred mainly in the subgroup with abandoned epicardial leads (4.0%), but no change in myocardial biomarkers was observed.

Existing publications did not report any relevant adverse events for MRI in patients with abandoned and/or epicardial leads if performed according to strict safety guidelines. However, a more rigorous risk-benefit calculation should be made for patients with epicardial leads.

Myocardial fibrosis (MF) is defined as excessive production and deposition of extra-cellular matrix proteins that result in pathologic myocardial remodeling. Three types of MF have been identified: replacement fibrosis from tissue necrosis, reactive fibrosis from myocardial stress, and infiltrative interstitial fibrosis from progressive deposition of nondegradable material such as amyloid. Although echocardiography, nuclear medicine, and CT play important roles in the assessment of MF, MRI is pivotal in the evaluation of MF, with the late gadolinium enhancement (LGE) technique used as a primary end point. The LGE technique focuses on the pattern and distribution of gadolinium accumulation in the myocardium and assists in the diagnosis and establishment of the cause of both ischemic and nonischemic cardiomyopathy. LGE MRI also aids prognostication and risk stratification. In addition, LGE MRI is used to guide the management of patients considered for ablation for arrhythmias. Parametric mapping techniques, including T1 mapping and extracellular volume measurement, allow detection and quantification of diffuse fibrosis, which may not be detected by LGE MRI. These techniques also allow monitoring of disease progression and therapy response. This review provides an update on the imaging of MF, including prognostication and risk stratification tools, electrophysiologic considerations, and disease monitoring.

Conventional pacing systems consist of a pacemaker and one or more leads threaded from the device pocket through veins into the heart conducting the pacing therapy to the desired pacing site. Although these devices are effective, approximately one in eight patients treated with these traditional pacing systems experiences a complication attributed to the pacemaker pocket or leads. With the technological advances in electronics, leadless pacemakers that small enough to implant within the heart were introduced. Leadless pacemakers have been developed to overcome many of the challenges of transvenous pacing including complications related to leads or pacemaker pockets. This review aims to provide an overview of advantages of leadless pacemaker, complications and limitations of leadless pacemaker, leadless pacemaker candidate, and future directions of this promising technology.

Current socket-based methods of prosthetic limb attachment are responsible for many of the dominant problems reported by persons with amputation. In this work, we introduce a new paradigm for attachment via electromagnetic attraction between a bone-anchored ferromagnetic implant and an external electromagnet. Our objective was to develop a design framework for electromagnetic attachment, and to evaluate this framework in the context of transfemoral amputation.

We first used inverse dynamics to calculate the forces required to suspend a knee-ankle-foot prosthesis during gait. We then conducted cadaveric dissections to inform implant geometry and design a surgical methodology for covering the implant. We also developed an in silico framework to investigate how electromagnet design affects system performance. Simulations were validated against benchtop testing of a custom-built electromagnet.

The physical electromagnet matched simulations, with a root-mean-square percentage error of 4.2% between measured and predicted forces. Using this electromagnet, we estimate that suspension of a prosthesis during gait would require 33 W of average power. After 200 and 1000 steps of simulated walking, the temperature at the skin would increase 2.3 °C and 15.4 °C relative to ambient, respectively.

Our design framework produced an implant and electromagnet that could feasibly suspend a knee-ankle-foot prosthesis during short walking bouts. Future work will focus on optimization of this system to reduce heating during longer bouts.

This work demonstrates the initial feasibility of an electromagnetic prosthetic attachment paradigm that has the potential to increase comfort and improve residual limb health for persons with amputation.

Magnetic resonance imaging (MRI) is now an indispensable diagnostic tool in medicine due to its outstanding contrast resolution and absence of radiation exposure, enabling detailed tissue characterization and three-dimensional anatomical representation. This is especially important when evaluating individuals with congenital heart disease (CHD) who frequently require cardiac implantable electrical devices (CIEDs). While MRI safety issues have previously limited its use in patients with CIEDs, new advances have called these limitations into question. However, difficulties persist in the pediatric population due to the continued lack of specific safety data both related to imaging young children and the specific CIED devices they often require. This paper discusses MRI safety considerations related to imaging patients with CIEDs, investigates pediatric-specific problems, and describes thorough methods for safe MRI access, highlighting the significance of specialized institutional guidelines.

Active implanted medical devices (AIMDs) enable therapy and patient monitoring by way of electrical activity and typically have a battery and electrical leads. The most common types of AIMDs include cardiac implantable electronic devices (CIEDs), spinal cord stimulators, deep brain stimulators, bone growth or fusion stimulators, other neurostimulators, and drug infusion pumps. As more patients with AIMDs undergo MRI, it is important to consider the safety of patients who have these implanted devices during MRI. The authors review the physics concepts related to MRI safety, such as peak spatial gradient magnetic field, specific absorption rate, root mean square value of the effective magnetic component of the transmitted RF pulse, and gradient slew rate, as well as the parameters necessary to remain within safety limits. The roles of MRI safety personnel, as set forth by the International Society of Magnetic Resonance in Medicine, are emphasized. In addition, the relevant information provided in vendor manuals is reviewed, with a focus on how to obtain relevant up-to-date information. The radiologist should be able to modify protocols to meet safety requirements, address possible alternatives to MRI, and weigh the potential benefits of MRI against the potential risks. A few more advanced topics, such as fractured or abandoned device leads and patients with multiple implanted medical devices, also are addressed. Recommended workflows for MRI in patients with implanted medical devices are outlined. It is important to implement an algorithmic MRI safety process, including a review of the MRI safety information; patient screening; optimal imaging; and monitoring patients before, during, and after the examination. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material. See the invited commentary by Shetty et al in this issue.

This study aimed to characterise the level of access to magnetic resonance imaging (MRI) in Australian hospitals for patients with MR-conditional and non-MR-conditional cardiac implantable electronic devices (CIED), and to identify any barriers impeding this access.

All Australian Tertiary Referral Public Hospitals (n=38) were surveyed with a mixed qualitative and quantitative questionnaire. Provision of MRI to patients with MR-conditional and non-MR-conditional CIEDs; patient monitoring strategies during scan and personnel in attendance; barriers impeding MRI access.

Of the 35 (92%) hospitals that completed the survey, a majority (85.7%) scan MR-conditional CIEDs, while a minority (8.6%) scan non-MR-conditional CIEDs. MR-conditional device scanning is often limited to non-pacing dependent patients, excluding implantable cardioverter-defibrillators. In total, 21% of sites exclude thoracic MR scans for CIED patients. Although most centres scan on 1.5 Tesla (T) machines (59%), 10% scan at 3T and 31% scan at both strengths. Sites vary in patient monitoring strategies and personnel in attendance; 80% require staff with Advanced Cardiac Life Support to be present. Barriers to service expansion include an absence of national guidelines, formal training, and logistical device support.

Most surveyed Australian hospitals offer MRI for patients with MR-conditional CIEDs, however many still have exclusions for particular patient groups or scan requests. Only three surveyed sites offer MRI for patients with non-MR-conditional CIEDs in Australia. A national effort is needed to address the identified barriers including the development of national guidelines, formal training, and logistical support.

In the US, 1.4 million people have implanted ICDs for reducing the risk of sudden death due to ventricular arrhythmias. Cardiac MRI (cMR) is of particular interest in the ICD patient population as cMR is the optimal imaging modality for distinguishing cardiac conditions that predispose to sudden death, and it is the best method to plan and guide therapy. However, all ICDs contain a ferromagnetic transformer which imposes a large inhomogeneous magnetic field in sections of the heart, creating large image voids that can mask important pathology. A shim system was devised to resolve these ICD issues. A shim coil system (CSS) that corrects ICD artifacts over a user-selected Region-of-Interest (ROI), was constructed and validated.

A shim coil was constructed that can project a large magnetic field for distances of ~15 cm. The shim-coil can be positioned safely anywhere within the scanner bore. The CSS includes a cantilevered beam to hold the shim coil. Remotely controlled MR-conditional motors allow 2 mm-accuracy three-dimensional shim-coil position. The shim coil is located above the subjects and the imaging surface-coils. Interaction of the shim coil with the scanner's gradients was eliminated with an amplifier that is in a constant current mode. Coupling with the scanners' radio-frequency (rf) coils, was reduced with shielding, low-pass filters, and cable shield traps. Software, which utilizes magnetic field (B0) mapping of the ICD inhomogeneity, computes the optimal location for the shim coil and its corrective current. ECG gated single- and multiple-cardiac-phase 2D GRE and SSFP sequences, as well as 3D ECG-gated respiratory-navigated IR-GRE (LGE) sequences were tested in phantoms and N = 3 swine with overlaid ICDs.

With all cMR sequences, the system reduced artifacts from >100 ppm to <25 ppm inhomogeneity, which permitted imaging of the entire left ventricle in swine with ICD-related voids. Continuously acquired Gradient recalled echo or Steady State Free Precession images were used to interactively adjust the shim current and coil location.

The shim system reduced large field inhomogeneities due to implanted ICDs and corrected most ICD-related image distortions. Externally-controlled motorized translation of the shim coil simplified its utilization, supporting an efficient cardiac MRI workflow.

Conducting channels (CCs) detected by late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) are related to ventricular tachycardia (VT). The aim of this work was to study the ability of post-ablation LGE-CMR to evaluate ablation lesions.

This is a prospective study of consecutive patients referred for a scar-related VT ablation. LGE-CMR was performed 6-12 months prior to ablation and 3-6 months after ablation. Scar characteristics of pre- and post-ablation LGE-CMR were compared. During the study period (March 2019-April 2021), 61 consecutive patients underwent scar-related VT ablation after LGE-CMR. Overall, 12 patients were excluded (4 had poor-quality LGE-CMR, 2 died before post-ablation LGE-CMR, and 6 underwent post-ablation LGE-CMR 12 months after ablation). Finally, 49 patients (age: 65.5 ± 9.8 years, 97.9% male, left ventricular ejection fraction: 34.8 ± 10.4%, 87.7% ischaemic cardiomyopathy) were included. Post-ablation LGE-CMR showed a decrease in the number (3.34 ± 1.03 vs. 1.6 ± 0.2; P < 0.0001) and mass (8.45 ± 1.3 vs. 3.5 ± 0.6 g; P < 0.001) of CCs. Arrhythmogenic CCs disappeared in 74.4% of patients. Dark core was detected in 75.5% of patients, and its presence was not related to CC reduction (52.2 ± 7.4% vs. 40.8 ± 10.6%, P = 0.57). VT recurrence after one year follow-up was 16.3%. The presence of two or more channels in the post-ablation LGE-CMR was a predictor of VT recurrence (31.82% vs. 0%, P = 0.0038) with a sensibility of 100% and specificity of 61% (area under the curve 0.82). In the same line, a reduction of CCs < 55% had sensibility of 100% and specificity of 61% (area under the curve 0.83) to predict VT recurrence.

Post-ablation LGE-CMR is feasible, and a reduction in the number of CCs is related with lower risk of VT recurrence. The dark core was not present in all patients. A decrease in VT substrate was also observed in patients without a dark core area in the post-ablation LGE-CMR.

Boston Scientific INGEVITY+ pacing lead (Boston Scientific, Marlborough, MA, USA) has been upgraded to INGEVITY. The performance of the INGEVITY+ pacing lead has not yet been reported. This study aimed to evaluate the short- and long-term safety, effectiveness, and handling experience of INGEVITY+ leads.

Consecutive patients were included from 9 institutions in Korea, where 400 leads (200 right ventricular active fixation leads and 200 right atrial active fixation leads) were implanted or attempted in 200 subjects.

During the implantation, only one patient required a lead change because of lead screw failure. The handling questionnaires of the lead received very positive feedback with 88% of operators agreeing that it is easy for leads to pass through small vessels or vessels with multiple leads. At the 3-month follow-up, 95.7% of RA leads and 99.5% of RV leads had pacing thresholds less than 1.5 V. A total of 92.4% of atrial leads had amplitudes greater than 1.5 mV, and 96.5% of ventricular leads had sensing amplitudes greater than 5 mV at 3 months. A total of 99.8% had impedances between 300 and 1,300 ohms. The lead-related complication-free rate for all leads during follow-up was 100%, and the overall rates of lead dislodgment, perforation, and pericardial effusion were all 0.0%.

The INGEVITY+ pacing lead exhibited exceptional clinical performance, with a high complication-free rate throughout the 3-month follow-up period. In addition, the lead displayed excellent electrical characteristics, and the lead-handling experience was reported to be very good.

To determine whether paediatric congenital heart disease (CHD) patients with epicardial cardiac implantable electronic devices (CIEDs) receive high cumulative effective doses (CEDs) of ionizing radiation from medical imaging tests.

We compared 28 paediatric CHD patients with epicardial CIEDs (cases) against 40 patients with no CIED matched by age at operation, sex, surgical era, and CHD diagnosis (controls). We performed a retrospective review of radiation exposure from medical imaging exams between 2006 and 2022. Radiation dose from computed tomography (CT) and X-ray radiography was calculated using the National Cancer Institute Radiation Dosimetry Tool. We performed univariate analysis to compare the CED between the two groups. In the case subgroup, we convened experts' review to adjudicate the prevalence of CT exams that should have been performed with magnetic resonance imaging (MRI) in the absence of a CIED. Children (median age 2.5 years at implant) with CIEDs received significantly higher median CED compared with matched controls (6.90 vs. 1.72 mSv, P = 0.0018). In cases, expert adjudication showed that 80% of the CT exams would have been performed with MRI in the absence of a CIED. This resulted, on average, a five-fold increase in the effective dose (ED) from post-lead implant CTs.

Paediatric CHD patients with CIED received four times higher CED than matched controls. Improved access to medical imaging tests without ionizing radiation, such as MRI, could potentially reduce the ED in CIED patients by up to five times.

Whole-body F-18 FDG PET has been included in the 2014 Heart Rhythm Society guidelines for cardiac sarcoidosis evaluation to identify alternate sites of biopsy prior to endomyocardial biopsy. The purpose of this study was to evaluate the diagnostic yield of whole-body F-18 FDG PET/CT.

All adult patients with suspected cardiac sarcoidosis undergoing same-day cardiac F-18 FDG PET/CT and whole-body F-18 FDG PET/CT between 10/1/2016 and 6/14/2021 to assess potential biopsy sites were retrospectively identified. Clinical indications, findings, recommendations, and outcomes were assessed.

Eighty-eight patients were included. Extracardiac PET findings suggestive of sarcoidosis were present in 30 patients (34%), 27 of which had thoracic findings (90%). Sarcoidosis was diagnosed in 11% of patients. Only 1% (1/88) was diagnosed by extrathoracic biopsy of a whole-body PET finding. Incidental findings were common (31%), resulting in 11 additional tests or interventions. Recommendations from extrathoracic findings affected treatment in one case: a drainage catheter placement into an unsuspected pelvic abscess.

Addition of whole-body F-18 FDG PET/CT to cardiac F-18 FDG PET/CT for the identification of extrathoracic sites of biopsy in patients with suspected cardiac sarcoidosis has marginal diagnostic yield but commonly results in incidental findings that rarely affect patient outcome.

This study focused on the potential risks of radiofrequency-induced heating of cardiac implantable electronic devices (CIEDs) in children and adults with epicardial and endocardial leads of varying lengths during cardiothoracic MRI scans. Infants and young children are the primary recipients of epicardial CIEDs, though the devices have not been approved as MR conditional by the FDA due to limited data, leading to pediatric hospitals either refusing the MRI service to most pediatric CIED patients or adopting a scan-all strategy based on results from adult studies. The study argues that risk-benefit decisions should be made on an individual basis. We used 120 clinically relevant epicardial and endocardial device configurations in adult and pediatric anthropomorphic phantoms to determine the temperature rise during RF exposure at 1.5 T. The results showed that there was significantly higher RF heating of epicardial leads than endocardial leads in the pediatric phantom, but not in the adult phantom. Additionally, body size and lead length significantly affected RF heating, with RF heating up to 12 °C observed in models based on younger children with short epicardial leads. The study provides evidence-based knowledge on RF-induced heating of CIEDs and highlights the importance of making individual risk-benefit decisions when assessing the potential risks of MRI scans in pediatric CIED patients.

Image acquisition involves the use of static magnetic fields, field gradients and radiofrequency waves. These elements make the MRI a different modality. More and more centers work with 3.0 T equipment that present higher risks for the patient, compared to those of 1.5 T. Therefore, there is a need for updating for radiology staff that allows them to understand the risks and reduce them, since serious and even fatal incidents can occur. The objective of this work is to present a review and update of the risks to which patients are subjected during the performance of a magnetic resonance imaging (MRI) study.

Magnetic resonance imaging (MRI) safety in patients with an epicardial cardiac implantable electronic device (CIED) is uncertain.

The purpose of this study was to assess the safety and adverse effects of MRI in patients who had surgically implanted epicardial CIED.

Patients with surgically implanted CIEDs who underwent MRI with an appropriate cardiology-radiology collaborative protocol between January 2008 and January 2021 were prospectively studied in 2 clinical centers. All patients underwent close cardiac monitoring through MRI procedures. Outcomes were compared between the epicardial CIED group and the matched non-MRI-conditional transvenous CIED group.

Twenty-nine consecutive patients with epicardial CIED (41.4% male; mean age 43 years) underwent 52 MRIs in 57 anatomic regions. Sixteen patients had a pacemaker, 9 had a cardiac defibrillator or cardiac resynchronization therapy-defibrillator, and 4 had no device generator. No significant adverse events occurred in the epicardial or transvenous CIED groups. Battery life, pacing, sensing thresholds, lead impedance, and cardiac biomarkers were not significantly changed, except 1 patient had a transient decrease in atrial lead sensing function.

MRI of CIEDs with epicardially implanted leads does not represent a greater risk than transvenous CIEDs when performed with a multidisciplinary collaborative protocol centered on patient safety.

With the increased availability of magnetic resonance imaging (MRI) and a progressive rise in the frequency of cardiac device implantation, there is an increased chance that patients with implanted cardiac devices require MRI examination during their lifetime. Though MRI is generally contraindicated in patients who have undergone pacemaker implantation with electronic circuits, the recent introduction of MR Conditional pacemaker allows physicians to take advantage of MRI to assess these patients during diagnosis and treatment. When MRI examinations of patients with pacemaker are requested, physicians must confirm whether the device is a conventional pacemaker or an MR Conditional pacemaker by reviewing chest radiographs or the electronic medical records (EMRs). The purpose of this study was to evaluate the utility of a deep convolutional neural network (DCNN) trained to detect pacemakers on chest radiographs and to determine the device's subclassification. The DCNN perfectly detected pacemakers on chest radiographs and the accuracy of the subclassification of pacemakers using the internal and external test datasets were 100.0% (n = 106/106) and 90.1% (n = 279/308). The DCNN can be applied to the radiologic workflow for double-checking purposes, thereby improving patient safety during MRI and preventing busy physicians from making errors.

Cardiac implantable electronic devices (CIEDs) have traditionally been a contraindication for magnetic resonance imaging (MRI). However, there is an increasing amount of literature to suggest that MRI can be safely performed in select patients with pacemakers and implantable cardioverter defibrillators by following a standardized protocol. We created an institutional protocol, made accessible as an online form, that is primarily technologist-driven and does not require direct electrophysiologist supervision. The purpose of this study was to evaluate the PACEDMRI protocol for screening and completing MRI in patients with MR conditional CIEDs.

After the implementation of our standardized PACED-MRI protocol, patients with MR conditional CIEDs who were referred for MRI were included in the study. On the day of the MRI, the device company representative utilized our protocol accessed through PACEDMRI.com. If all parameters and criteria within the protocol were met, the examination proceeded. The device representative programed the CIED to the appropriate mode for MRI as instructed by the PACED-MRI protocol. CIED interrogation was performed immediately before and after MRI. The on-call electrophysiology nurse practitioner was notified only if the protocol instructed the team to not proceed with MRI. CIED programming changes, malfunctions, and intraprocedural events were documented. Additionally, any adverse outcomes were recorded including peri-MRI symptom onset, arrhythmia, and death.

One hundred thirty-eight MRI examinations were performed on patients with MR conditional CIEDs (100 pacemakers: 38 implantable cardiac defibrillators). There was no incidence of symptom onset requiring early termination of the MRI, death, or arrhythmic events during or after MRI. No significant changes in lead parameters, including sensing amplitudes, lead thresholds, or lead impedances were noted on post-MRI device interrogation. Out of the 138 completed MRIs, the on-call electrophysiology provider was notified on one, non-urgent occasion.

The implementation of the standardized, technologists-driven PACED-MRI protocol allowed for a multidisciplinary approach to MRI for patients with MR conditional CIEDs. This study demonstrates that the PACED-MRI protocol can be used for patients with MR conditional CIEDs undergoing MRI without the need for direct electrophysiologist supervision.

Since the advent of magnetic resonance imaging (MRI) nearly four decades ago, there has been a quest for ever-higher magnetic field strengths. Strong incentives exist to do so, as increasing the magnetic field strength increases the signal-to-noise ratio of images. However, ensuring patient safety becomes more challenging at high and ultrahigh field MRI (i.e., ≥3 T) compared to lower fields. The problem is exacerbated for patients with conductive implants, such as those with deep brain stimulation (DBS) devices, as excessive local heating can occur around implanted lead tips. Despite extensive effort to assess radio frequency (RF) heating of implants during MRI at 1.5 T, a comparative study that systematically examines the effects of field strength and various exposure limits on RF heating is missing.

This study aims to perform numerical simulations that systematically compare RF power deposition near DBS lead models during MRI at common clinical and ultra-high field strengths, namely 1.5, 3, 7, and 10.5 T. Furthermore, we assess the effects of different exposure constraints on RF power deposition by imposing limits on either the B1+ or global head specific absorption rate (SAR) as these two exposure limits commonly appear in MRI guidelines.

We created 33 unique DBS lead models based on postoperative computed tomography (CT) images of patients with implanted DBS devices and performed electromagnetic simulations to evaluate the SAR of RF energy in the tissue surrounding lead tips during RF exposure at frequencies ranging from 64 MHz (1.5 T) to 447 MHz (10.5 T). The RF exposure was implemented via realistic MRI RF coil models created based on physical prototypes built in our institutions. We systematically examined the distribution of local SAR at different frequencies with the input coil power adjusted to either limit the B1+ or the global head SAR.

The MRI RF coils at higher resonant frequencies generated lower SARs around the lead tips when the global head SAR was constrained. The trend was reversed when the constraint was imposed on B1+.

At higher static fields, MRI is not necessarily more dangerous than at lower fields for patients with conductive leads. Specifically, when a conservative safety criterion, such as constraints on the global SAR, is imposed, coils at a higher resonant frequency tend to generate a lower local SAR around implanted leads due to the decreased B1+ and, by proxy, E field levels.

Although myocardial scar assessment using late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging is frequently indicated for patients with implantable cardioverter defibrillators (ICDs), metal artefact can degrade image quality. With the new wideband technique designed to mitigate device related artefact, CMR is increasingly used in this population. However, the common clinical indications for CMR referral and impact on clinical decision-making and prognosis are not well defined. Our study was designed to address these knowledge gaps.

One hundred seventy-nine consecutive patients with an ICD (age 59 ± 13 years, 75% male) underwent CMR using cine and wideband pulse sequences for LGE imaging. Electronic medical records were reviewed to determine the reason for CMR referral, whether there was a change in clinical decision-making, and occurrence of major adverse cardiac events (MACEs). Referral indication was the most common evaluation of ventricular tachycardia (VT) substrate (n = 114, 64%), followed by cardiomyopathy (n = 53, 30%). Overall, CMR resulted in a new or changed diagnosis in 64 (36%) patients and impacted clinical management in 51 (28%). The effect on management change was highest in patients presenting with VT. A total of 77 patients (43%) experienced MACE during the follow-up period (median 1.7 years), including 65 in patients with evidence of LGE. Kaplan-Meier analysis showed that ICD patients with LGE had worse outcomes than those without LGE (P = 0.006).

The clinical yield from LGE CMR is high and provides management changing and meaningful prognostic information in a significant proportion of patients with ICDs.

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.

Chest X-ray (CXR) use in pre-MRI safety screening, such as for lead-less implanted electronic device (LLIED) recognition, is common. To assist CXR interpretation, we "pre-deployed" an artificial intelligence (AI) model to assess (1) accuracies in LLIED-type (and consequently safety-level) identification, (2) safety implications of LLIED nondetections or misidentifications, (3) infrastructural or workflow requirements, and (4) demands related to model adaptation to real-world conditions.

A two-tier cascading methodology for LLIED detection/localization and identification on a frontal CXR was applied to evaluate the performance of the original nine-class AI model. With the unexpected early appearance of LLIED types during simulated real-world trialing, retraining of a newer 12-class version preceded retrialing. A zero footprint (ZF) graphical user interface (GUI)/viewer with DICOM-based output was developed for inference-result display and adjudication, supporting end-user engagement and model continuous learning and/or modernization.

During model testing or trialing using both the nine-class and 12-class models, robust detection/localization was consistently 100%, with mAP 0.99 from fivefold cross-validation. Safety-level categorization was high during both testing ( AUC ≥ 0.98 and ≥ 0.99 , respectively) and trialing (accuracy 98% and 97%, respectively). LLIED-type identifications by the two models during testing (1) were 98.9% and 99.5% overall correct and (2) consistently showed AUC ≥ 0.92 (1.00 for 8/9 and 9/12 LLIED-types, respectively). Pre-deployment trialing of both models demonstrated overall type-identification accuracies of 94.5% and 95%, respectively. Of the small number of misidentifications, none involved MRI-stringently conditional or MRI-unsafe types of LLIEDs. Optimized ZF GUI/viewer operations led to greater user-friendliness for radiologist engagement.

Our LLIED-related AI methodology supports (1) 100% detection sensitivity, (2) high identification (including MRI-safety) accuracy, and (3) future model deployment with facilitated inference-result display and adjudication for ongoing model adaptation to future real-world experiences.

Cardiac magnetic resonance tomography (CMR) in patients with implanted cardiac devices is a challenge. This is due to artifacts that can occur in the presence of metallic implants such as device leads and generators and can ultimately lead to impaired or non-diagnostic images. Preliminary studies indicate that by employing newly developed MRI sequences together with well-established sequences, these problems can be mitigated. To aid in daily routine, an adaptive imaging workflow has been proposed which allows for tailored image acquisition.

To theoretically investigate the feasibility of a novel procedure for testing the MRI gradient-induced heating of medical devices and translating the results into clinical practice.

The concept of index of stress is introduced by decoupling the time waveform characteristics of the gradient field signals from the field spatial distribution within an MRI scanner. This index is also extended to consider the anisotropy of complex bulky metallic implants. Merits and drawbacks of the proposed index of stress are investigated through virtual experiments. In particular, the values of the index of stress evaluated for realistic orthopedic implants placed within an ASTM phantom are compared with accurate heating simulations performed with 2 anatomic body models (a man and a woman) implanted through a virtual surgery procedure.

The manipulation of the proposed index of stress allows to identify regions within the MRI bore where the implant could affect the safety of the examinations. Furthermore, the conducted analysis shows that the power dissipated into the implant by the induced eddy currents is a dosimetric quantity that estimates well the maximum temperature increase in the tissues surrounding the implant.

The results support the adoption of an anisotropic index of stress to regulate the gradient-induced heating of geometrically complex implants. They also pave the way for a laboratory characterization of the implants based on electrical measurements, rather than on thermal measurements. The next step will be to set up a standardized experimental procedure to evaluate the index of stress associated with an implant.

Patients with congenital heart defects, inherited arrhythmia syndromes, and congenital disorders of cardiac conduction often receive a cardiac implantable electronic device (CIED). At least 75% of patients with CIEDs will need magnetic resonance imaging (MRI) during their lifetime. In 2011, the US Food and Drug Administration approved the first MR-conditional CIEDs for patients with endocardial systems, in which leads are passed through the vein and affixed to the endocardium. The majority of children, however, receive an epicardial CIED, where leads are directly sewn to the epicardium. Unfortunately, an epicardial CIED is a relative contraindication to MRI due to the unknown risk of RF heating. In this work, we performed anthropomorphic phantom experiments to investigate differences in RF heating between endocardial and epicardial leads in both pediatric and adult-sized phantoms, where adult endocardial CIED was the control. Clinical Relevance-This work provides a quantitative comparison of MRI RF heating of epicardial and endocardial leads in pediatric and adult populations.

Flagging the presence of cardiac devices such as pacemakers before an MRI scan is essential to allow appropriate safety checks. We assess the accuracy with which a machine learning model can classify the presence or absence of a pacemaker on pre-existing chest radiographs. A total of 7973 chest radiographs were collected, 3996 with pacemakers visible and 3977 without. Images were identified from information available on the radiology information system (RIS) and correlated with report text. Manual review of images by two board certified radiologists was performed to ensure correct labeling. The data set was divided into training, validation, and a hold-back test set. The data were used to retrain a pre-trained image classification neural network. Final model performance was assessed on the test set. Accuracy of 99.67% on the test set was achieved. Re-testing the final model on the full training and validation data revealed a few additional misclassified examples which are further analyzed. Neural network image classification could be used to screen for the presence of cardiac devices, in addition to current safety processes, providing notification of device presence in advance of safety questionnaires. Computational power to run the model is low. Further work on misclassified examples could improve accuracy on edge cases. The focus of many healthcare applications of computer vision techniques has been for diagnosis and guiding management. This work illustrates an application of computer vision image classification to enhance current processes and improve patient safety.

Sacral neuromodulation (SNM) is a minimally invasive technique that provides effective treatment for the management of refractory overactive bladder (OAB), non-obstructive urinary retention (NOUR), and fecal incontinence (FI). This study assessed patient preferences between the currently available non-rechargeable SNM device and a new, full-body magnetic resonance imaging (MRI)-safe, smaller, rechargeable device.

An online cross-sectional survey was conducted among French OAB, NOUR, FI patients, recruited via a market research vendor. To assess their preferences, patients were asked to indicate their level of agreement with 10 statements regarding the size of the device, its rechargeability, and the role of MRI using a 6-item Likert scale. A descriptive statistical analysis was performed.

In all, 95 patients (68% women), mean age 50 years, were included in the study: 51% were treated for OAB; 44% received an oral treatment and 28% had SNM. Overall, 71% of the 95 patients indicated a preference for the new device; 75% considered that recharging the device would not impact their lifestyle; 74% believed that the smaller size of the rechargeable device would facilitate their choice to be treated with SNM; 80% found full-body MRI compatibility important.

Most patients may prefer the new rechargeable SNM device over the current "standard". Compatibility with full-body MRI and the smaller device size seemed the key features of the newer device that would influence their choice of being treated with SNM. Future national and international recommendations should consider a shared decision-making process between the physician and the patient.