MRI helps visualize presence of microplastics on imaging for 1st time
New data suggest that microplastics can be visualized on MRI exams, potentially complicating interpretations for radiologists.
Nanoplastics and microplastics are synthetic pollutants that have been accumulating in the environment for decades, and their presence in the tissues of living organisms has become increasingly common in recent years. Data has suggested that plastics can harm the human body, but exactly how said harm manifests is difficult to quantify, as tissue concentrations can only be detected using post-mortem, destructive techniques.
“Bioaccumulation of [plastics] in human tissues such as the liver, kidneys, blood, placenta and brain, is similarly increasing with time,” Dr. Walter Backes, with the department of radiology and nuclear medicine at Maastricht University Medical Center in the Netherlands, and colleagues write in the European Journal of Radiology. “The potential impact of [plastics] on human health remains unclear, in part due to the difficulty of observing [them] in-vivo.”
Researchers recently conducted an analysis using phantom devices to determine if microplastic materials could be detected on various MRI sequences. Two phantoms were used—one with several concentrations of plastics suspended in agar solution and one with 3D-printed plastic flakes, also in agar solution. Three sequences were tested: T1 and T2 weighted scans, which measure tissue-specific decay of the magnetic signal, and T2* weighted scans that offer visualization of the changes that create extra signal loss caused by tiny flaws in the magnetic field.
The team was not able to visualize the presence of nano or microplastics on the regular T1 or T2 weighted scans. However, their aggregates were seen on the magnetic susceptibility T2* weighted scans. On those sequences, plastics appeared as tiny hypointensities. As the aggregates get larger, the extent of the magnetic field distortions grows.
“Susceptibility-weighted imaging and computational modeling show that nano and microplastic aggregates create localized magnetic field inhomogeneities, acting as magnetic susceptibility dipoles and appearing as millimeter-sized hypointensities on T2* images,” the team explained.
This, the team suggested, has the potential to complicate MR imaging interpretations. Specifically, they indicated that the hypointensities could mimic cerebral microbleeds. While more in vivo research is needed, the researchers signaled that their findings represent an important first step in understanding how microplastic accumulation affects the body over time.
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In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.