A new study published in Radiology is an important step forward in confirming 4D flow MRI as a noninvasive, reproducible, and reliable tool for measuring cerebrovascular health.
Cerebrovascular and neurologic health are of primary national concern, with over $300 billion being spent on care for Alzheimer disease and related dementias in 2022. To monitor the risk of vascular disorders and cerebral diseases, two markers – blood flow rate and pulsatility – are commonly used.
This might sound simple, but accurately measuring blood flow in the brain has been a recurring challenge to researchers and clinicians. Transcranial Doppler ultrasound was error-prone, while phase-contrast (PC) MRI demanded scan times that were clinically unfeasible. The development of 4D flow MRI – with scan times of only minutes – offered new possibilities for measurements of cerebrovascular function.
However, for this technology to be useful as a clinical tool, it’s imperative to establish reference values for the markers.
The study at hand – co-authored by Howard Rowley, MD, Oliver Wieben, PhD, Kevin Johnson, PhD, and Laura Eisenmenger, MD – aimed to do just that.
The authors used 4D flow MRI scan data from 759 middle-aged (45-65 years old) and older (>65 years) adults to establish normative values for blood flow rate and pulsatility indexes across a wide age spectrum. They calculated descriptive statistics for each marker in each of the major intracranial arteries and veins of the brain and analyzed how these values vary across age, biological sex, and vessel location.
Their findings were consistent with previous studies using 2D cine PC MRI. In addition, their method – demanding only 5-7 minutes of acquisition time and 5 minutes of interactive data processing time – could potentially accommodate even busy radiology workflows.
Before 4D flow MRI can be implemented as a routine clinical tool, practical challenges and technical concerns must be resolved. Still, this ground-breaking study demonstrates the potential of 4D flow MRI as a tool in studying cerebrovascular health and disease.
Read an editorial review of the article, which dives deeper into the paper and its significance to the field, here.