Research Papers

Noninvasive monitoring of cerebral blood flow by a dye bolus method: Separation of brain from skin and skull signals

[+] Author Affiliations
Matthias Kohl-Bareis

Humboldt University, Charite´ Hospital, Department of Neurology, Schumannstrasse 20/21, 10117?Berlin, Germany

and University of Applied Sciences Koblenz, Rhein Ahr Campus, Suedallee 2, 53424?Remagen, Germany

Hellmuth Obrig, Jens Steinbrink, Jasmin Malak, Kamil Uludag, Arno Villringer

Humboldt University, Charite´ Hospital, Department of Neurology, Schumannstrasse 20/21, 10117?Berlin, Germany

J. Biomed. Opt. 7(3), 464-470 (Jul 01, 2002). doi:10.1117/1.1482719
History: Received Sep. 20, 2001; Revised Feb. 7, 2002; Accepted Feb. 11, 2002; Online August 01, 2002
Text Size: A A A

Tracking a bolus of contrast agent traveling through the cerebral vasculature provides a measure of the blood flow velocity in the respective cerebral tissue. This principle has been the basis for the first approaches in functional magnetic resonance (MR) imaging and is of great value for investigating patients with vascular disease, especially stroke. While bolus measurements are a standard procedure in MR imaging, optical bolus tracking is as yet not established. Here we study optical absorption changes induced by a bolus of the dye indocyanine-green with near infrared spectroscopy in healthy volunteers. The aim is to assess the latency and shape of the change in absorption. Since application in the adult human critically depends on differentiation between extra- and intracerebral vascular compartments we focus on an approach for such a separation. To do this frequency-domain and multidistance measurements are analyzed by a Monte Carlo based model for photon transport in tissue. Based on measurements of both the photon’s mean time of flight (phase) and the intensity, our results allow differentiation between an upper (skin and skull) and a lower layer (brain). The bolus in the deeper tissue layers has a peak of about 10 s width, while the change in absorption in the upper layers shows a much longer recovery time. This is in qualitative agreement with MR imaging results using a gadolinium bolus. This result is promising with respect to the potential of bedside monitoring of mean transit time (MTT) changes in patients with stroke or related vascular disease. © 2002 Society of Photo-Optical Instrumentation Engineers.

© 2002 Society of Photo-Optical Instrumentation Engineers

Citation

Matthias Kohl-Bareis ; Hellmuth Obrig ; Jens Steinbrink ; Jasmin Malak ; Kamil Uludag, et al.
"Noninvasive monitoring of cerebral blood flow by a dye bolus method: Separation of brain from skin and skull signals", J. Biomed. Opt. 7(3), 464-470 (Jul 01, 2002). ; http://dx.doi.org/10.1117/1.1482719


Tables

Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

PubMed Articles
Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.