Evaluation of the Susceptibility Artifacts and Tissue Injury Caused by Implanted Microchips in Dogs on 1.5T Magnetic Resonance Imaging

Abstract

ABSTRACT. Performing magnetic resonance imaging (MRI) in patients with a metallic implant raises concern over the potential complications, including susceptibility artifacts, implant migration, and heat injury. The purpose of this study was to investigate these complications in dogs with implanted microchips by evaluating MR images and the histopathological changes after 1.5 Tesla (T) MRI. Five dogs underwent microchip implantation in the cervicothoracic area. One month later, the area was imaged using 1.5T MRI in three dogs. The microchips were removed surgically together with the surrounding tissue in all dogs. There was significant signal loss and image distortion over a wide range around the area where the microchip was implanted. This change was consistent with susceptibility artifacts, which rendered the affected area including the spinal cord undiagnostic. The artifact was more extensive in T2*-weighted images (gradient-echo) and less extensive in proton density-weighted images (fast spin-echo with short echo time). Histopathologically, all microchips were well-encapsulated with granulation tissue, and there were no evidence of migration of microchips. Cell debris and a moderate number of degenerated cells with fibrin were seen in the inner layer of the granulation tissue in each dog that underwent MRI. These changes were very subtle and did not seem to be clinically significant. The results of this study suggest that, in 1.5T MRI, susceptibility artifacts produced by implanted microchips can be marked, although the dogs with implants appeared to be scanned safely.KEY WORDS: heat injury, microchip, MRI, susceptibility artifacts.

Beyond AI: Multi-Intelligence (MI) Combining Natural and Artificial Intelligences in Hybrid Beings and Systems

“…Thus, individuals are improvising their own insideables and internet of the body as large organizations promote wearables and the internet of things. This practice has emerged from recognition among its pioneers that the new practice of implanting microchips into pets could be transferred easily to human beings [90,91]. Such improvised DIY practices can suddenly start and spread to bring erratic non-linear interactions with top-down planned systems.…”

Functionality of Veterinary Identification Microchips Following Low‐ (0.5 Tesla) and High‐field (3 Tesla) Magnetic Resonance Imaging

“…There are several ways in which the MRI scanner and the microtransponder might interact: for example, the magnetic forces or the radio waves involved in each technology may interfere with one another. Deterioration of image quality due to susceptibility of artifacts, movement of microchips, and the heating of the transponder is documented . The technical components of the transponder could be damaged by heating.…”

“…Temperature increases as high as 25°C in a brain stimulation implant (1.5 Tesla), 48°C in intravascular guidewires (1.5 Tesla), 63°C in a cardiac‐pacing electrode (1.5 Tesla), and 64°C in an intracranial pressure transducer (3 Tesla) have been reported. Recent studies have looked for alteration in function of identification microchips in 1.0 (41 dogs; 53 dogs) and 1.5 Tesla MR scanners (three dogs) . The results showed that under the practical conditions of a routine MR study, the identification number allocated on the implanted microchips was displayed correctly.…”

Evaluation of intraorbital prosthetic pigmentation using 0.3 and 1.5Tesla magnetic resonance imaging and computed tomography

“…Various publications have reported advanced imaging susceptibility artifacts as well as techniques to reduce these artifacts . In a recent case report, a brown‐pigmented intraorbital prosthetic caused a significant susceptibility artifact on MR images that precluded adequate visualization of intracranial structures in a patient with neurologic disease .…”

“…1 Various publications have reported advanced imaging susceptibility artifacts as well as techniques to reduce these artifacts. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] In a recent case report, a brown-pigmented intraorbital prosthetic caused a significant susceptibility artifact on MR images that precluded adequate visualization of intracranial structures in a patient with neurologic disease. 18 Since this publication, to the authors' knowledge, no studies have evaluated the effects of other commonly used intraorbital prosthetics on MRI or CT images or potential techniques to reduce this artifact.…”