Hyperpolarized 129Xe Time-of-Flight MR Imaging of Perfusion and Brain Function.

Yurii Shepelytskyi,Vira Grynko,Ayman Hassan,Mitchell S Albert,Tao Li,Francis T Hane

doi:10.3390/diagnostics10090630

Abstract

Perfusion measurements can provide vital information about the homeostasis of an organ and can therefore be used as biomarkers to diagnose a variety of cardiovascular, renal, and neurological diseases. Currently, the most common techniques to measure perfusion are 15O positron emission tomography (PET), xenon-enhanced computed tomography (CT), single photon emission computed tomography (SPECT), dynamic contrast enhanced (DCE) MRI, and arterial spin labeling (ASL) MRI. Here, we show how regional perfusion can be quantitively measured with magnetic resonance imaging (MRI) using time-resolved depolarization of hyperpolarized (HP) xenon-129 (129Xe), and the application of this approach to detect changes in cerebral blood flow (CBF) due to a hemodynamic response in response to brain stimuli. The investigated HP 129Xe Time-of-Flight (TOF) technique produced perfusion images with an average signal-to-noise ratio (SNR) of 10.35. Furthermore, to our knowledge, the first hemodynamic response (HDR) map was acquired in healthy volunteers using the HP 129Xe TOF imaging. Responses to visual and motor stimuli were observed. The acquired HP TOF HDR maps correlated well with traditional proton blood oxygenation level-dependent functional MRI. Overall, this study expands the field of HP MRI with a novel dynamic imaging technique suitable for rapid and quantitative perfusion imaging.

Highlights

Perfusion measurements can provide vital information about the homeostasis of an organ [1] and can be used as biomarkers to diagnose cardiovascular [2,3], renal [4], and neurological [5,6,7]diseases
computed tomography (CT) requires high-dose ionizing radiation, positron emission tomography (PET) and single photon emission computed tomography (SPECT) rely on injection of radioactive contrast agents and the acquired PET images are of low Diagnostics 2020, 10, 630; doi:10.3390/diagnostics10090630
The most commonly used gadolinium-based contrast agents are uncapable of crossing the blood–brain barrier [24,25,26], which makes cerebral perfusion imaging with these agents more challenging

Summary

Introduction

Perfusion measurements can provide vital information about the homeostasis of an organ [1] and can be used as biomarkers to diagnose cardiovascular [2,3], renal [4], and neurological [5,6,7]diseases. The most commonly used techniques to measure perfusion are 15 O positron emission tomography (PET) [8,9,10], xenon-enhanced computed tomography (CT) [11,12], single photon emission computed tomography (SPECT) [3,8,13], and arterial spin labeling (ASL) magnetic resonance imaging (MRI) [1,14,15,16,17,18]. Dynamic susceptibility contrast (DSC) and dynamic contrast enhanced (DCE) MRI are frequently used for perfusion imaging [19,20,21]. These techniques are well-established, each has some serious drawbacks. The most commonly used gadolinium-based contrast agents are uncapable of crossing the blood–brain barrier [24,25,26], which makes cerebral perfusion imaging with these agents more challenging

Methods

Results

Conclusion