Lung cysts and surrounding tissues in a patient with lymphangioleiomyomatosis (LAM) seen more clearly using high-performance low field MRI compared to standard MRI. [Image from the NIH]
The high-performance, low magnetic-field MRI system is designed to improve the image quality of the lungs and other internal structures. It is also designed for patients who have pacemakers and defibrillators and is compatible with interventional devices that could help diagnose and treat disease.
Modern MRI systems have higher magnetic field strengths to produce clearer images of the brain. The NIH and Siemens researchers determined that they could modify the strength of the magnetic field strengths to get high-quality images of the heart and lungs. They also found that metal devices that were at risk of heating in the high-field system could be safe for real-time image-guided procedures like heart catheterization.
“We continue to explore how MRI can be optimized for diagnostic and therapeutic applications,” Robert Balaban, scientific director of the division of intramural research and chief of the laboratory of cardiac energetics at NHLBI, said in a news release. “The system reduces the risk of heating – a major barrier to the use of MRI-guided therapeutic approaches that have hampered the imaging field for decades.”
The researchers found that lung imaging was improved using the high-performance, low-magnetic field MRI system and oxygen could be observed in tissue and blood better than in a lower magnetic field.
“MRI of the lung is notoriously difficult and has been off-limits for years because air causes distortion in MRI images,” staff scientist in the cardiovascular branch at NHLBI Adrienne Campbell-Washburn, who was also the study’s author, said. “A lot-field MRI system equipped with contemporary imaging technology allows us to see the lungs very clearly. Plus, we can use inhaled oxygen as a contrast agent. This lets us study the structure and the function of the lungs much better.”
Researchers saw lung cysts and surrounding tissue in patients with lymphangioleiomyomatosis more clearly than images obtained at 1.5T. They also found that inhaled oxygen increased the brightness of lung tissue more effectively using lower magnetic strength when compared to higher strengths. The researchers found that low-field MRI during heart catheterization had similar advantages.
The researchers suggest that the system could make medical imaging more affordable and accessible. It could also allow for increased flexibility in image acquisition and the system could be used in new clinical applications.
“We can start thinking about doing more complex procedures under MRI-guidance now that we can combine standard devices with good quality cardiac imaging,” Campbell-Washburn said.
The study was funded by the National Heart Lung and Blood Institute, part of the National Institutes of Health, and was published in the journal Radiology.
