Stories about: magnetic resonance imaging

Why is one twin sometimes smaller than the other? The answer may lie in the placenta

placental oxygen transport may help determine fetal size

When a baby is born small, it’s often chalked up to genetics or to maternal risk factors like poor nutrition or smoking. A study of twin pregnancies, published today in Scientific Reports, finds another factor that can be measured prentally: slower transport of oxygen from mother to baby across the placenta.

The study, part of the NIH-funded Human Placenta Project, is the first to make a direct connection between placental oxygen transport and birth outcomes. It relies on a new, noninvasive technique called Blood-Oxygenation-Level-Dependent (BOLD) MRI. Developed by P. Ellen Grant, MD, director of the Fetal-Neonatal Neuroimaging and Developmental Science Center at Boston Children’s Hospital and Elfar Adalsteinsson, PhD at MIT, it maps oxygen delivery across the placenta in real time.

“Until now, we had no way to look at regional placental function in vivo,” says Grant.

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Harnessing MRI to steer drugs to hard-to-reach targets

drug delivery propelled by MRI

Once a drug is injected systemically, can you steer it to where you want it under MRI guidance? Pierre Dupont, PhD, and colleagues saw this as an engineering problem. Solving it could enable concentrated drug delivery to, say, a deep tumor in the lungs while simultaneously taking images.

Labeling drugs with magnetized particles is the first step, allowing the MRI scanner’s magnetic pulses to propel them. The next step is to be able to actively steer the particles through a series of branching vessels to a desired location. But getting a scanner to both image and propel particles forcefully enough to overcome the force of the blood flow is easier said than done.

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Bringing MRI to vulnerable newborns

Premature newborn in small-bore MRI magnet-courtesy Cincinnati Children's
A 4.2-lb baby girl in the new 1.5 Tesla MRI magnet, designed for use in the NICU. (Images courtesy of Cincinnati Children’s Hospital Medical Center)
Charles Dumoulin, PhD, is the director of the Imaging Research Center at Cincinnati Children’s Hospital Medical Center (CCHMC) and a professor of pediatric radiology at University of Cincinnati College of Medicine. He led the team of scientists and engineers from CCHMC’s Imaging Research Center who won the Clinical Innovation Award at Boston Children’s Hospital’s National Innovation Pediatric Summit + Awards in September.

Experience suggests that magnetic resonance imaging (MRI) and advanced MR techniques such as spectroscopy and diffusion imaging offer substantial benefits when diagnosing problems in premature babies. However, today’s MR systems poses significant logistical barriers to imaging these infants. We have been working to change that.

MRI provides an unparalleled ability to visualize anatomy without the hazards of ionizing radiation. Yet premature and sick babies in neonatal intensive care units (NICUs) are usually too delicate to leave the unit. The few babies who receive MRI today must be accompanied by NICU staff during transport to and from the Radiology Department. This process is often a multi-hour ordeal and reduces the staff available to care for other babies in the NICU. Moreover, infants must be imaged in an adult-sized MRI scanner

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