Spatial sensitivity of near-infrared spectroscopic brain imaging based on three-dimensional monte carlo modeling

Mansouri, C.; Kashou, Nasser H.

doi:10.1109/iembs.2009.5332919

Cited by 5 publications

(4 citation statements)

References 12 publications

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“…The dependencies of the remission ratio R on blood vessel orientation and fiber‐to‐vessel distance (Figure a) can be explained by the spatial distribution of paths associated with photons that emanate from the emission fiber and arrive at the detection fiber as sketched in Figure . This distribution, which is well‐known in diffuse reflectance spectroscopy as photon banana , can be derived from Monte Carlo simulations . The flux line density, encoding the density of the above‐mentioned photon paths in case no blood vessel is present, is a measure for the sensitivity of the recorded remission spectra, and thus the remission ratio R , to the local absorption.…”

Section: Discussionmentioning

confidence: 99%

Remission spectrometry for blood vessel detection during stereotactic biopsy of brain tumors

et al. 2016

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Stereotactic biopsy is used to enable diagnostic confirmation of brain tumors and treatment planning. Despite being a well-established technique, it is related to significant morbidity and mortality rates mostly caused by hemorrhages due to blood vessel ruptures. This paper presents a method of vessel detection during stereotactic biopsy that can be easily implemented by integrating two side-view fibers into a conventional side-cutting biopsy needle. Tissue within the needle window is illuminated through the first fiber; the second fiber detects the remitted light. By taking the ratio of the intensities at two wavelengths with strongly differing hemoglobin absorption, blood vessels can be recognized immediately before biopsy sampling. Via ray tracing simulations and phantom experiments, the dependency of the remission ratio R = I /I on various parameters (blood oxygenation, fiber-to-vessel and inter-fiber distance, vessel diameter and orientation) was investigated for a bare-fiber probe. Up to 800-1200 µm away from the probe, a vessel can be recognized by a considerable reduction of the remission ratio from the background level. The technique was also successfully tested with a real biopsy needle probe on both optical phantoms and ex-vivo porcine brain tissue, thus showing potential to improve the safety of stereotactic biopsy. Dual-wavelength remission measurement for the detection of blood vessels during stereotactic biopsy.

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Section: Discussionmentioning

confidence: 99%

Remission spectrometry for blood vessel detection during stereotactic biopsy of brain tumors

et al. 2016

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“…The behavioural difference between incongruent and congruent stimuli is called the Stroop effect, which has been used as an index of cognitive control. 101 Since the prefrontal cortex plays a predominant role in cognitive control 102 and has shown to be affected by MCI, 23 fNIRS optodes will be placed on the prefrontal cortex.…”

Section: Methods and Analysismentioning

confidence: 99%

Multimodal measurement approach to identify individuals with mild cognitive impairment: study protocol for a cross-sectional trial

et al. 2021

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IntroductionThe diagnosis of mild cognitive impairment (MCI), that is, the transitory phase between normal age-related cognitive decline and dementia, remains a challenging task. It was observed that a multimodal approach (simultaneous analysis of several complementary modalities) can improve the classification accuracy. We will combine three noninvasive measurement modalities: functional near-infrared spectroscopy (fNIRS), electroencephalography and heart rate variability via ECG. Our aim is to explore neurophysiological correlates of cognitive performance and whether our multimodal approach can aid in early identification of individuals with MCI.Methods and analysisThis study will be a cross-sectional with patients with MCI and healthy controls (HC). The neurophysiological signals will be measured during rest and while performing cognitive tasks: (1) Stroop, (2) N-back and (3) verbal fluency test (VFT). Main aims of statistical analysis are to (1) determine the differences in neurophysiological responses of HC and MCI, (2) investigate relationships between measures of cognitive performance and neurophysiological responses and (3) investigate whether the classification accuracy can be improved by using our multimodal approach. To meet these targets, statistical analysis will include machine learning approaches.This is, to the best of our knowledge, the first study that applies simultaneously these three modalities in MCI and HC. We hypothesise that the multimodal approach improves the classification accuracy between HC and MCI as compared with a unimodal approach. If our hypothesis is verified, this study paves the way for additional research on multimodal approaches for dementia research and fosters the exploration of new biomarkers for an early detection of nonphysiological age-related cognitive decline.Ethics and disseminationEthics approval was obtained from the local Ethics Committee (reference: 83/19). Data will be shared with the scientific community no more than 1 year following completion of study and data assembly.Trial registration numberClinicalTrials.gov, NCT04427436, registered on 10 June 2020, https://clinicaltrials.gov/ct2/show/study/NCT04427436.

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“…Monte Carlo simulations have been used extensively to model the transport of light in NIRS applications for the head [19,[24][25][26][27][28][29][30][31], but to our knowledge it has not been related to the detection of intracranial hematomas or the monitoring of peri-hematomal progression of TBI. We use Monte Carlo simulations to explore the potential of fNIRS as a pre-hospital screening tool to detect hematomas or as a continuous bedside monitor of TBI progression.…”

Section: Introductionmentioning

confidence: 99%

NIR light propagation in a digital head model for traumatic brain injury (TBI)

Francis

Khan²,

Alexandrakis

et al. 2015

Biomed. Opt. Express

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Near infrared spectroscopy (NIRS) is capable of detecting and monitoring acute changes in cerebral blood volume and oxygenation associated with traumatic brain injury (TBI). Wavelength selection, sourcedetector separation, optode density, and detector sensitivity are key design parameters that determine the imaging depth, chromophore separability, and, ultimately, clinical usefulness of a NIRS instrument. We present simulation results of NIR light propagation in a digital head model as it relates to the ability to detect intracranial hematomas and monitor the perihematomal tissue viability. These results inform NIRS instrument design specific to TBI diagnosis and monitoring.

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Spatial sensitivity of near-infrared spectroscopic brain imaging based on three-dimensional monte carlo modeling

Cited by 5 publications

References 12 publications

Remission spectrometry for blood vessel detection during stereotactic biopsy of brain tumors

Remission spectrometry for blood vessel detection during stereotactic biopsy of brain tumors

Multimodal measurement approach to identify individuals with mild cognitive impairment: study protocol for a cross-sectional trial

NIR light propagation in a digital head model for traumatic brain injury (TBI)

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