Purpose
Human body modelling and simulation have been widely used in industry, academia, and government for medical devices efficacy and safety testing in various areas, including optics, electromagnetics, mechanics, ultrasound, etc. Even though Magnetic Resonance Imaging (MRI) is generally considered safe, clinical MRI studies are increasing, and new safety challenges appear, such as paediatric MRI in patients with implants. Every existing whole-body and partial voxel model included between 10 and 78 tissue compartments and were modeled with different ages ranging from newborns to 84-year-old. However, every...
Methods and materials
Development and validation of the numerical model:
The first step was to select a patient with available whole-body sequences without major deformities as well as multiple sequences that would facilitate the segmentation process. Whole-body MRIs were acquired using MRRAGE, T2 FLAIR, Inversion Recovery, T1, Echo Planar Fast Spin Echo, T2 Fast Spin Echo, Radial VIBE sequences, and dual-energy CT scans, which were used to segment the various tissue compartments. We then pulled all the available MRI and CT scans from the database of the Boston...
Results
The pilot use case for MRI RF safety simulation:
As an example of an MRI safety study of an Active Implantable Medical Device (AMID), we show the application of the new FDA TS 10974:2018 guidelines to a pediatric Vagus Nerve Stimulation (VNS) implant at 1.5T. Tier 3 and tier 4 simulations were performed using dielectric properties at 64 MHz that are appropriate for a 29-month-old child. The VNS lead was connected to an implantable pulse generator (IPG) and was placed inside MARTIN with the guidance...
Conclusion
We have introduced MARTIN, a detailed whole-body model for a male 29-month-old child, using the new automated segmentation tools for specific brain structures, as well as a manual segmentation performed by expert segmentors. Our model has been extensively validated, and our recently published manuscript9 suggests how to perform MRI safety simulations on an AIMD by following the latest guidelines from the International Organization for Standardization. The model will be available on the Analogue Brain Imaging Laboratory (ABILAB) at the AthinoulaA. Martinos Center for Biomedical Imaging...
Personal information and conflict of interest
M. Alhilani:
Nothing to disclose
H. Jeong:
Nothing to disclose
G. Ntolkeras:
Nothing to disclose
S. R. Atefi:
Nothing to disclose
L. Zöllei:
Nothing to disclose
A. Pourvaziri:
Nothing to disclose
M. H. Lev:
Nothing to disclose
E. P. Grant:
Nothing to disclose
G. Bonmassar:
Nothing to disclose
References
(1) Lee A, Byun JK, Park JS, Choi H Do, Yun J. Development of 7-year-old Korean child model for computational dosimetry. ETRI J. 2009;31(2):237–9. (2) Zankl M, Veit R, Williams G, Schneider K, Fendel H, Petoussi N, et al. The construction of computer tomographic phantoms and their application in radiology and radiation protection. Radiat Environ Biophys. 1988;27(2):153–64. (3) Norris H, Zhang Y, Bond J, Sturgeon GM, Minhas A, Tward DJ, et al. A set of 4D pediatric XCAT reference phantoms for multimodality research. Med Phys....