Method for monitoring corrosion degradation of bioabsorbable implant and for semi-quantification of relative weight loss ratio of corrosion product thereof

Abstract

The invention provides a method for monitoring the corrosion degradation of a bioabsorbable implant and for the semi-quantification of the relative weight loss ratio of the corrosion degradation of the implant and a corrosion product of the implant. The monitoring method comprises the following steps: performing MR imaging of the implantation part of an individual with an implanted bioabsorbable implant at the predetermined at least two implantation time points respectively; and with the same imaging sequence, comparing the artifact sizes of the MRI images of the implant at the time points, wherein if the artifact size is gradually reduced along with the time increase, the corrosion degradation degree of the implant is deepened. The semi-quantification method comprises the following steps: with the same imaging sequence, performing MR imaging of the implant in the individual or a corrosion product thereof at different implantation time points; selecting an index plane, and establishing a function relation curve between the maximum artifact size value of the index plane and the weight loss ratio of the implant body or corrosion product thereof at the time points; and determining the relative weight loss ratio of the implant or corrosion product thereof according to the function relation curve and the monitored artifact size value of the implant or corrosion product thereof.

Description

technical field [0001] This invention relates to a non-invasive method for monitoring the corrosion degradation of bioabsorbable implants, in particular to a method for monitoring the corrosion degradation of magnetic bioabsorbable implants with magnetic resonance imaging (MRI) and the relative weight loss of corrosion degradation of implants A semi-quantitative method for the rate and relative weight loss rate of implant corrosion products. Background technique [0002] At present, most implanted medical devices (hereinafter referred to as implants) are made of non-degradable metal materials, which have good mechanical strength and biocompatibility, but due to their own non-degradability, they are not practical in practice. Many potential problems arise during the application process. For example, vascular stent products, long-term follow-up results show that the rate of in-stent restenosis of bare metal stents is relatively high, and drug-eluting stents have safety proble...

AI Technical Summary

Problems solved by technology

In terms of MSCT imaging quality, MSCT at common anatomical positions of the human body can provide data for medical diagnosis without creating a contrast agent, but for intravascular MSCT imaging pictures, it is necessary to inject contrast agents into the patient to enhance vascular imaging; in addition, clinical use The resolution of MSCT is usually between tens of microns and hundreds of microns, and the unit size of most cardiovascular bioabsorbable implants is usually around tens of microns. At the same time, if the bioabsorbable implant is Metal materials, under X-ray irradiation, will have artifacts, so MSCT cannot effectively monitor the corrosion degradation of bioabsorbable implants whose structural unit size is between tens of microns and hundreds of microns

As far as ultrasound monitoring is concerned, if esophageal ultrasound or extracorporeal ultrasound is used for follow-up of patients implanted with bioabsorbable implants, contrast agent injection is not required, and non-invasive testing can be performed. Minimally invasive surgery, in addition, the ultrasonic resolution is low, and it is impossible to monitor implants whose structural units are between tens of microns and hundreds of microns

For OCT technology, it is favored because of its high resolution and good imaging effect. It is a commonly used follow-up method, but OCT is a minimally invasive imaging method, and a large amount of contrast agent needs to be injected during the imaging process. , physically affecting the patient

To sum up, on the one hand, using ultrasound, OCT and MSCT as clinical follow-up methods will cause physical discomfort to patients and often lead to the loss of long-term follow-up patients; on the other hand, although ultrasound and MSCT do not require minimally invasive surgery It can be detected, but the resolution of these two follow-up methods is limited, and it is impossible to monitor the corrosion degradation of bioabsorbable implants with structural unit sizes ranging from tens of microns to hundreds of microns

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