Abstract
We investigate a scheme for noninvasive continuous monitoring of absolute cerebral blood flow (CBF) in adult human patients based on a combination of time-resolved dynamic contrast-enhanced near-infrared spectroscopy (DCE-NIRS) and diffuse correlation spectroscopy (DCS) with semi-infinite head model of photon propogation. Continuous CBF is obtained via calibration of the DCS blood flow index (BFI) with absolute CBF obtained by intermittent intravenous injections of the optical contrast agent indocyanine green. A calibration coefficient (?) for the CBF is thus determined, permitting conversion of DCS BFI to absolute blood flow units at all other times. A study of patients with acute brain injury (N 7) is carried out to ascertain the stability of ?. The patientaveraged DCS calibration coefficient across multiple monitoring days and multiple patients was determined, and good agreement between the two calibration coefficients measured at different times during single monitoring days was found. The patient-averaged calibration coefficient of 1.24 × 109 omL/100 g/ min/ocm2/sp was applied to previously measured DCS BFI from similar brain-injured patients; in this case, absolute CBF was underestimated compared with XeCT, an effect we show is primarily due to use of semi-infinite homogeneous models of the head.
Original language | English |
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Article number | 045006 |
Journal | Neurophotonics |
Volume | 5 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Oct 2018 |
Bibliographical note
Funding Information:We gratefully acknowledge Eileen Maloney, Elizabeth Mahanna, Suzanne Frangos, and Timothy Prior from Neurosurgery Clinical Research Division for clinical support. We thank Riley Wilson from 3M for sending us the double-sided tape. We thank Andre Liemert for providing the two-layer TR-NIRS forward solver. We acknowledge support from the National Institutes of Health (R01-NS082309-01A1, R01-NS060653, and P41-EB015893).
Publisher Copyright:
© The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License 2017.
Keywords
- absolute cerebral blood flow
- brain-injured patients
- continuous monitoring.
- diffuse correlation spectroscopy
- time-resolved contrast-enhanced near-infrared spectroscopy
ASJC Scopus subject areas
- Neuroscience (miscellaneous)
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging