Study on the searching strategies of assessing the MRI RF-induced heating for an implantable plate and screw system

摘要

This paper presents a comparison study of searching strategies for the worst-case construct for an implantable internal fixation system under 1.5T MRI radio frequency (RF) birdcage coil. An example of the generic plate and screw system is used as the device of interest. Based on the combinations of the values of the six device parameters, 576 models are studied and the peak 1 g averaged specific absorption rate (SAR) near devices are extracted to build a dataset for searching. Three searching strategies, which are sequential one-dimension searching, searching based on various sequences and searching with multi-iterations, are investigated. It is found that the searching sequences and initial values of the device parameters have effects on the searched worst-case results. The possibility of getting the failed search results when searching with random sequence and initial parameter values can be high. Searching with multi-iterations can improve the accuracy of correctly identifying the worst-case heating construct.