Advanced Imaging Technologies for Young Brains: Mapping Blood Flow and Brain Development without Radiation

by Micaela Harris-Kim
November 25, 2025

Monitoring cerebral blood flow is a necessary key in clinicians tracking brain development in pediatric patients. It offers clinicians insight on how developmental brains receive oxygen and nutrients to the brain, while also removing metabolic waste. There are a handful of therapies that assess cerebral blood flow, but many of these therapies require radiation exposure. In addition, many other imaging techniques require patients to digest other external substances, like contrast dye, which presents many limits for what is suitable for pediatric populations. Therefore, there has been increasing interest in using other means to monitor cerebral blood flow, such as arterial spin labeling, which is a noninvasive means to measure blood flow by labeling molecules in the inflowing arterial blood and observing their movement within the brain tissue. However, the variability in age-related changes to arterial transit time have yet to be studied. There is insufficient understanding of blood flow changes in the developing brain which leads to significant challenges in the precise quantification of cerebral blood flow and arterial transit time. Furthermore, understanding how the brain changes due to age is necessary for accurate arterial spin labeling interpretation and understanding in pediatric populations.

Additionally, this therapy offers many other benefits: straightforward clinical implementation, applicability to premature babies or newborns, and suitability for follow-up studies as it allows for absolute cerebral blood flow quantification. Excitingly, this study is the first to directly compare single-delay and multi-delay arterial spin labeling in pediatric patients.

The researchers found that single-delay measurements can lead to inaccuracy in cerebral blood flow reporting in children due to the variability in arterial transit times. Moreover, the study demonstrates that multi-delay ASL yields robust measurements of cerebral perfusion in the developing brain and more accurately captures its hemodynamic changes. These findings indicate that multi-arterial spin labeling protocols may yield more reliable cerebral blood flow measurements than single-arterial spin labeling protocols and can lead to thorough understanding in pediatric brain development, suggesting that future exploration using studies could further elucidate blood flow in a typically developing brain. Because ASL does not require external contrast agents or radioactive tracers, it not only improves safety for young patients but also significantly reduces medical waste, offering a more sustainable and environmentally responsible approach to brain imaging.

“Our results underscore the importance of designing brain imaging techniques to the unique physiology of the developing brain in children,” said Dr. Zhao. “Advanced and pediatric-specific multi-delay ASL not only improves accuracy, but also opens new possibilities for noninvasive, repeatable monitoring of brain health in vulnerable pediatric populations.”

The research was an international collaboration among teams at Stanford University, Charles University in Prague, The Czech Republic, Western Lisbon Hospital Centre in Lisbon, Portugal, and the Institute of Radiopharmaceutical Cancer Research in Dresden, Germany.

Additional Stanford Cardiovascular Institute members include Sasha Alexander, Michael Moseley, Kristen Yeom, and Elizabeth Tong.