Noninvasive photoacoustic computed tomography of mouse brain metabolism in vivo

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2013-01, Vol.64, p.257-266
• Main Authors: Yao, Junjie, Xia, Jun, Maslov, Konstantin I., Nasiriavanaki, Mohammadreza, Tsytsarev, Vassiliy, Demchenko, Alexei V., Wang, Lihong V.
• Format: Article
• Language: English
• Subjects: 2-NBDG; 4-Chloro-7-nitrobenzofurazan - analogs & derivatives; 4-Chloro-7-nitrobenzofurazan - pharmacokinetics; Acoustics; Animals; Biological and medical sciences; Brain imaging; Cerebral circulation. Blood-brain barrier. Choroid plexus. Cerebrospinal fluid. Circumventricular organ. Meninges; Contrast Media - pharmacokinetics; Deoxyglucose - analogs & derivatives; Deoxyglucose - pharmacokinetics; Elasticity Imaging Techniques - methods; Female; Forepaw stimulation; Fundamental and applied biological sciences. Psychology; Glucose - metabolism; Hemodynamic response; Mice; Photoacoustic computed tomography; Photoacoustic Techniques - methods; Somatosensory Cortex - metabolism; Tissue Distribution; Tomography, X-Ray Computed - methods; Vertebrates: nervous system and sense organs
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2012.08.054

We have demonstrated the feasibility of imaging mouse brain metabolism using photoacoustic computed tomography (PACT), a fast, noninvasive and functional imaging modality with optical contrast and acoustic resolution. Brain responses to forepaw stimulations were imaged transdermally and transcranially. 2-NBDG, which diffuses well across the blood–brain-barrier, provided exogenous contrast for photoacoustic imaging of glucose response. Concurrently, hemoglobin provided endogenous contrast for photoacoustic imaging of hemodynamic response. Glucose and hemodynamic responses were quantitatively decoupled by using two-wavelength measurements. We found that glucose uptake and blood perfusion around the somatosensory region of the contralateral hemisphere were both increased by stimulations, indicating elevated neuron activity. While the glucose response area was more homogenous and confined within the somatosensory region, the hemodynamic response area had a clear vascular pattern and spread wider than the somatosensory region. Our results demonstrate that 2-NBDG-enhanced PACT is a promising tool for noninvasive studies of brain metabolism. ► We imaged mouse brain metabolic responses by photoacoustic computed tomography. ► 2-NBDG provided exogeneous contrast for imaging of glucose response. ► Hemoglobin provided endogenous contrast for imaging of hemodynamic response. ► Glucose response area was homogenous and confined within the somatosensory region. ► Hemodynamic response area had a clear vascular pattern and spread wider.