Affiliations: [a] Department of Orthopaedics, People’s Hospital of Zhongjiang County, Zhongjiang, Sichuan, China | [b] Neijiang City Engineering Technology Research Center of Neurological Disease Information Interference, Neijiang, Sichuan, China
Correspondence:
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Corresponding author: Kai Li, Department of Orthopaedics, People’s Hospital of Zhongjiang County, Zhongjiang, Sichuan, China. E-mail: 442644280@qq.com.
Abstract: BACKGROUND: Humeral fracture is a common long bone fracture in orthopedic clinical diagnosis and treatment. OBJECTIVE: To investigate the local temperature increase owing to changes in the specific absorption ratio (SAR) of the human body caused by humeral bone nails during magnetic resonance imaging (MRI). METHODS: A refined geometric model of the upper body was constructed via data segmentation and post-processing using the digital human image dataset. Finally, the geometric model was imported into COMSOL, a 3-T magnetic resonance coil was built, and the operating frequency (128 MHz) was set to analyze the SAR of the bone-nail pair and temperature changes. RESULTS: The analysis of the changes after bone-nail implantation under different tissue conditions revealed that the SAR and temperature after implantation and fixation were three times higher than those before, and the areas with abrupt changes in SAR and temperature were primarily concentrated in the bone-nail area. CONCLUSION: In MRI, metal implants can cause local elevation of the SAR near the implant in the human body, resulting in a temperature increase around the implant. Consequently, long-term scanning can damage the human body.
Keywords: Bone nails, magnetic resonance imaging, temperature rise effect, specific absorption ratio, digital human
