Accuracy of oxygen saturation and total hemoglobin estimates in the neonatal brain using the semi-infinite slab model for FD-NIRS data analysis

作者：Barker Jeffrey W^*; Panigrahy Ashok; Huppert Theodore J

来源：Biomedical Optics Express, 2014, 5(12): 4300-4312.

DOI：10.1364/BOE.5.004300

Frequency domain near-infrared spectroscopy (FD-NIRS) is a non-invasive method for measuring optical absorption in the brain. Common data analysis procedures for FD-NIRS data assume the head is a semi-infinite, homogenous medium. This assumption introduces bias in estimates of absorption (mu(a)), scattering (mu(s)'), tissue oxygen saturation (StO2), and total hemoglobin (HbT). Previous works have investigated the accuracy of recovered mu(a) values under this assumption. The purpose of this study was to examine the accuracy of recovered StO7 and HbT values in FD-NIRS measurements of the neonatal brain. We used Monte Carlo methods to compute light propagation through a neonate head model in order to simulate FD-NIRS measurements at 690 nm and 830 ma We recovered mu(a), mu s', StO2, and HbT using common analysis procedures that assume a semi-infinite, homogenous medium and compared the recovered values to simulated values. Additionally, we characterized the effects of curvature via simulations on homogenous spheres of varying radius. Lastly, we investigated the effects of varying amounts of extra-axial -fluid. Curvature induced underestimation of mu(a), mu(s)', and HbT, but had minimal effects on StO2. For the morphologically normal neonate head model, uhe mean absolute percent errors (MAPE) of recovered mu a values were 12% and 7% for 690 nm and 830 nm, respectively, when source-detector separation was at least 20 mm The MAPE for recovered SP? and IlbT were 6% and 9%, respectively. Latzer relative errors were observed (similar to 20-30%), especially as StO2 and HbT deviated from normal values. Excess CSF around the brain caused very large errors in mu(a), mu(s'), and HbT, but had little effect on StO2.

• 出版日期2014-12-1