A comparative study of MRI-induced RF heating in pediatric and adult populations with epicardial and endocardial implantable electronic devices

Jiang, Fuchang; Bhusal, Bhumi; Sanpitak, Pia; Webster, Gregory; Popescu, Andrada; Kim, Daniel; Bonmassar, Giorgio; Golestanirad, Laleh

doi:10.1109/embc48229.2022.9871087

Cited by 11 publications

(7 citation statements)

References 21 publications

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“…Therefore, it is critical to understand lead heading performance in the capped and uncapped status to allow for patient-specific estimations of average-case and worst-case heating scenarios. Because epicardial leads follow a substantially different trajectory than endocardial leads, their RF heating profile during MRI is also intrinsically different, warranting studies with clinically relevant trajectories [21,22].…”

Section: Discussionmentioning

confidence: 99%

RF-induced heating of capped and uncapped abandoned epicardial leads during MRI at 1.5 T and 3 T

Jiang,

Henry,

Bhusal

et al. 2023

2023 45th Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

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There is a paucity of data regarding the safety of magnetic resonance imaging (MRI) in patients with abandoned epicardial leads. Few studies have reported temperature rises up to 76 °C during MRI at 1.5 T in gel phantoms implanted with epicardial leads; however, lead trajectories used in these experiments were not clinically relevant. This work reports patient-specific RF heating of both capped and uncapped abandoned epicardial lead configurations during MRI at both 1.5 T and 3 T field strengths. We found that leads routed along realistic, patient-derived trajectories generated substantially lower RF heating than the previously reported worst-case phantom experiments. We also found that MRI at the head imaging landmark leads to substantially lower RF heating compared to MRI at the chest or abdomen landmarks at both 1.5 T and 3 T. Our results suggest that patients with abandoned epicardial leads may safely undergo MRI for head imaging, but caution is warranted during chest and abdominal imaging.

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Section: Discussionmentioning

confidence: 99%

RF-induced heating of capped and uncapped abandoned epicardial leads during MRI at 1.5 T and 3 T

Jiang,

Henry,

Bhusal

et al. 2023

2023 45th Annual International Conference of the IEEE Engineering in Medicine &Amp; Biology Society (EMBC)

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“…It is established that the trajectory of an elongated lead and its position within the MRI coil strongly affects its RF heating [24][25][26][27][28][29][30]. The extracranial DBS lead trajectories (i.e., the trajectory of the portion of the lead that is outside of the brain and placed over the skull) vary substantially from patient to patient, depending on the surgeon's practice styles.…”

Section: Dbs Lead Models With Realistic Trajectoriesmentioning

confidence: 99%

Effect of field strength on RF power deposition near conductive leads: A simulation study of SAR in DBS lead models during MRI at 1.5 T - 10.5 T

Kazemivalipour

Sadeghi‐Tarakameh

Keil

et al. 2022

Preprint

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Background: 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. Purpose: 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. Methods: 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. Results: 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+. Conclusion: 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.

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“…Unfortunately, once epicardial leads have been implanted, patients face restrictions against MRI exams due to the elevated risk of RF heating of epicardial leads. [3][4][5] MR-conditional CIEDs with endocardial leads have been approved by the Food and Drug Administration (FDA) for adults, allowing patients to receive MRIs under conditions that assure safety. However, no MR-conditional system is currently available for children, in whom epicardial leads are used more frequently than in adults.…”

Section: Introductionmentioning

confidence: 99%

“…The optimal approach to affixing a CIED to the heart of a young patient is to open the chest and surgically suture the cardiac lead to the myocardium (“epicardial leads”), as opposed to passing it through veins and affixing it to the inside of the heart (“endocardial leads”). Unfortunately, once epicardial leads have been implanted, patients face restrictions against MRI exams due to the elevated risk of RF heating of epicardial leads 3–5 . MR‐conditional CIEDs with endocardial leads have been approved by the Food and Drug Administration (FDA) for adults, allowing patients to receive MRIs under conditions that assure safety.…”

Section: Introductionmentioning

confidence: 99%

Modifying the trajectory of epicardial leads can substantially reduce MRI‐induced RF heating in pediatric patients with a cardiac implantable electronic device at 1.5T

Jiang,

Bhusal,

Nguyen

et al. 2023

Magnetic Resonance in Med

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PurposeAfter epicardial cardiac implantable electronic devices are implanted in pediatric patients, they become ineligible to receive MRI exams due to an elevated risk of RF heating. We investigated whether simple modifications in the trajectories of epicardial leads could substantially and reliably reduce RF heating during MRI at 1.5 T, with benefits extending to abandoned leads.MethodsElectromagnetic simulations were performed to assess RF heating of two common 35‐cm epicardial lead trajectories exhibiting different degrees of coupling with MRI incident electric fields. Experiments in anthropomorphic phantoms implanted with commercial cardiac implantable electronic devices confirmed the findings. Both electromagnetic simulations and experimental measurements were performed using head‐first and feet‐first positioning and various landmarks. Transfer function approach was used to assess the performance of suggested modifications in realistic body models.ResultsSimulations (head‐first, chest landmark) of a 35‐cm epicardial lead with a trajectory where the excess length of the lead was looped and placed on the inferior surface of the heart showed an 87‐fold reduction in the 0.1 g–averaged specific absorption rate compared with the lead where the excess length was looped on the anterior surface. Repeated experiments with a commercial epicardial device confirmed this. For fully implanted systems following low–specific absorption rate trajectories, there was a 16‐fold reduction in the average temperature rise and a 28‐fold reduction for abandoned leads. The transfer function method predicted a 7‐fold reduction in the RF heating in 336 realistic scenarios.ConclusionSurgical modification of epicardial lead trajectory can substantially reduce RF heating at 1.5 T, with benefits extending to abandoned leads.

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A comparative study of MRI-induced RF heating in pediatric and adult populations with epicardial and endocardial implantable electronic devices

Cited by 11 publications

References 21 publications

RF-induced heating of capped and uncapped abandoned epicardial leads during MRI at 1.5 T and 3 T

RF-induced heating of capped and uncapped abandoned epicardial leads during MRI at 1.5 T and 3 T

Effect of field strength on RF power deposition near conductive leads: A simulation study of SAR in DBS lead models during MRI at 1.5 T - 10.5 T

Modifying the trajectory of epicardial leads can substantially reduce MRI‐induced RF heating in pediatric patients with a cardiac implantable electronic device at 1.5T

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