Computational Tool Comprising Visible Human Project® Based Anatomical Female CAD Model and Ansys HFSS/Mechanical® FEM Software for Temperature Rise Prediction Near an Orthopedic Femoral Nail Implant During a 1.5 T MRI Scan

Abstract

This medical device development tool (MDDT) is categorized as a non-clinical assessment model (NAM). This MDDT is a computational modeling and simulation tool. It can predict heating of metallic orthopedic implants with the radio frequency (RF) electromagnetic fields in the magnetic resonance imaging (MRI) coils while targeting a mid-aged and elderly female population primarily affected by osteoporosis and the associated bone fracture.This MDDT uses a high resolution anatomical female CAD (computer aided design) model coupled with the proven multiphysics finite element method (FEM) software (Ansys Workbench) to simulate the complete MRI environment. The environment is consisting of a tuned MRI coil with the given output power, detailed heterogeneous human model within the coil at the given landmark and a properly embedded metallic implant within the anatomical model to compute the extent of heating generated around the implant.Specifically, this MDDT is the in silico analog of an MRI scan for an elderly female subject with a metallic orthopedic implant at 1.5 T in a full-body birdcage RF coil.

An In-Silico Testbed for Fast and Accurate MR Labeling of Orthopaedic Implants

“…Along with the required yet not entirely anatomical ASTM phantom test and other similar phantom tests [5], [19], [21], [22], [25], [26], numerical simulations with virtual human models generate accurate predictions of temperature rise [20], [21], [22], [24], [27], [28] accepted by the FDA [28]. The electromagnetic and thermal simulation algorithms based on finite element, finite difference, and boundary element methods are reasonably well developed [29], [30], [33], [34]. However, accessible, full body, detailed anatomical virtual human models reflecting major age, sex, race, and obesity variations are severely lacking.…”

“…The primary target is MR labeling of large orthopaedic implants. The testbed has recently been approved by the US Food and Drug Administration (FDA) as a medical device development tool (MDDT) [11] for 1.5 T orthopaedic implant examinations.…”

An in silico testbed for fast and accurate MR labeling of orthopedic implants

“…Along with the required yet not entirely anatomical ASTM phantom test and other similar phantom tests ( US Department of Health and Human Services et al, 2021 ; Song et al, 2018 ; Winter et al, 2021 ; Wooldridge et al, 2021 ; Bassen and Zaidi, 2022 ; Arduino et al, 2022b ), numerical simulations with virtual human models generate accurate predictions of temperature rise ( Al-Dayeh et al, 2020 ; Winter et al, 2021 ; Wooldridge et al, 2021 ; Arduino et al, 2022a ; Clementi et al, 2022 ; Oberle, 2021 ) accepted by the FDA ( Oberle, 2021 ). The electromagnetic and thermal simulation algorithms based on finite element, finite difference, and boundary element methods are reasonably well developed ( Makarov et al, 2017 ; Noetscher et al, 2023 ; Noetscher et al, 2021 ; Noetscher, 2021 ). However, accessible, full body, detailed anatomical virtual human models reflecting major age, sex, race, and obesity variations are severely lacking.…”

“…Fig.1shows surface CAD meshes for the VHP-Female model[27 ],[31 ] (with some muscles removed for clarity) and examples of passive femoral implants embedded into the model. The corresponding physical femoral implants are shown on the top right of the figure.…”