Journal of Neurology and Neurorehabilitation Research

All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.

Rapid Communication - Journal of Neurology and Neurorehabilitation Research (2022) Volume 7, Issue 3

Cerebral blood flow for evaluating laser speckle contrast imaging.

Janet Poole*

Department of Informatics and Neuroimaging Center (PennLINC), University of Pennsylvania, Richards Building, 5th Floor, Suite 5A, 3700 Hamilton Walk, Philadelphia, PA 19104, USA

*Corresponding Author:
Janet Poole
Department of Informatics and Neuroimaging Center (PennLINC)
University of Pennsylvania, Richards Building
5th Floor, Suite 5A, 3700 Hamilton Walk
Philadelphia, PA 19104, USA
E-mail: [email protected]

Received: 03-May-2022, Manuscript No. AAJNNR-22-65959; Editor assigned: 06-May-2022, Pre QC No. AAJNNR-22-65959(PQ); Reviewed: 20-May-2022, QC No. AAJNNR-22-65959; Revised: 23-May-2022, Manuscript No. AAJNNR-22-65959(R); Published: 26-May -2022, DOI: 10.35841/aajnnr-7.3.112

Citation: Poole J. Cerebral blood flow for evaluating laser speckle contrast imaging. J Neurol Neurorehab Res. 2022;7(3):112

Introduction

During neurosurgery, monitoring Cerebral Blood Flow (CBF) can offer crucial physiological information for a range of surgical operations. CBF measures are useful for determining if blood flow has restored to pre-surgery levels and measuring tissue viability after surgery. Existing intraoperative CBF surveillance methods depend on magnetic resonance imaging are costly and often impracticable, while procedures like indocyanine green angiography cannot give quantitative blood flow measurements. The optical technique of Laser Speckle Contrast Imaging (LSCI) has been widely employed to quantitatively image relative CBF in animal models in vivo. We used an existing neurosurgical operating microscope to collect LSCI pictures in people in real time for neurosurgical both laboratory condition and then after bipolar central venous catheters through a pilot human trials. Remains current ECG waves from the patients were used to create a filter that reduced measurement variances caused by motion artifacts. The findings show that employing LSCI to acquire blood circulation images during neurosurgeries is feasible, and that it is capable of producing whole field CBF image maps with great image resolution in real-time with no disturbance to the surgical procedure [1].

Postsurgical tissue viability

When a specimen is irradiated with coherently light source, the camera caught a scatter image while this laser beam hitting each pixel has travelled slightly different path lengths. Changes in the speckled time sequence reveal details on the mobility of a moving fluid inside the material. Whenever laser-illuminated photographs of perfused tissue are merged across periods comparable to motion dynamics, such as milliseconds of biologic tissues, a speckled pattern is captured, which results in noticeable blurring [2]. The ability to measure the hemodynamic response to functional challenges (i.e., electrical stimulation, hypercapnia, and cortical spreading depressions) and physiologic alterations (i.e., vascular occlusions, hyperoxia, and hypothermia) there in squirrel or cat cortical regions was tested during the first backscatter imaging techniques to CBF characterization. The LSCI studies' high sense to Collaborative filtering fluctuations has led to new applications in the study of neurovascular coupling and disease models. The spatial and temporal resolution of LSCI is frequently used in animals and introduces additional maps emerging with short - term erythema with and without resting-state CBF changes. Laser scanning techniques can be employed in previous research to investigate the relation among CBF with cerebral function, but the spatiotemporal advantages of wide field LSCI have facilitated regional mapping and monitoring [3].

Monitoring flow dynamic

Monitoring neuro-electric potentials with electrodes and blood oxygenation and volume with multispectral or intrinsic imaging have traditionally been used to support the temporary hyperemia seen with LSCI. More specifically, voltagesensitive dyes and intrinsic hemoglobin absorption imaging have been integrated with LSCI-based CBF imaging for a comprehensive optical evaluation of neural-electric processes and local hemodynamics. 48 Monitoring flow dynamics in parenchymal and particular cortex micro vessels as soon began to explore the pathological proved CSDs and neuron stimulation to the neuropathic signals in migraines [4].

This is a one-of-a-kind but expanding application of noncontact techniques to examine broad sections of intact cortex with the spatial and temporal resolution provided by wide field speckle imaging in combination with other optical microscopy techniques. LSCI has been applied to existing commercial and bespoke microscopes as a complementing approach in several of these implementations, with the picture optic often sharing the same.

Postoperative pain tissue

During a variety of surgical operations, monitoring Cerebral Blood Flow (CBF) is critical. CBF measurements is used to verify that cardiovascular system had already sustained to pre - surgical baseline values after surgeries along with aneurysm cutting or vascular bypass. CBF measurements can help determine postoperative pain tissue economic feasibility in experimental treatments, such as tumor resections. In methods that require functional localization, CBF values can be utilized to identify motor, sensory, and speech activation areas in the cortex. Although the relevance of imaging CBF during surgery is well understood, there are few approaches that can produce real-time CBF images while causing little surgical interference. As a matter of fact, in vivo blood flow measures throughout procedures are a surgical technique that is unattended [5].

We created a 20-gram, 3.1-cm-high tiny laser speckle imager for full-field high-resolution imaging of Cerebral Blood Flow (CBF) in freely moving animals. A multimode optical fiber bundle fixed to the imager's supporting frame illuminates the cortex with coherent laser light. A small microlams system collects the reflected light, which is subsequently photographed by a high-resolution CMOS camera at a tremendous speed (50 fps). We obtain high spatiotemporal resolution laser speckle contrast imaging of CBF in freely moving animals in real time using our small imager.

Laser Speckle Imaging (LSI) is a simple and reliable approach for imaging heterogeneity dynamics based upon speckled contrast analysis. Because of its excellent temporal resolution, LSI is extensively used for variation modeling of blood flow. However, for the usual situation of a speckle field created by both moving and localized scattered radiation such like red blood or bone or tissue, quantitative interpretation of the obtained data is just not straightforward. We offer a new processing approach, dLSI (dynamic laser speckle imaging), that may be utilized to appropriately extract the temporal correlation parameters from speckle contrast recorded in the presence of a static or slow-evolving backdrop [6].

References

  1. Ayata C, Shin HK, Salomone S, et al. Pronounced hypoperfusion during spreading depression in mouse cortex. J Cereb Blood Flow Metab. 2004;24(10):1172-82.
  2. Indexed at, Google Scholar, Cross Ref

  3. Bandyopadhyay R, Gittings AS, Suh SS,et al. Speckle-visibility spectroscopy: A tool to study time-varying dynamics. Rev Sci Instrum. 2005;76(9):093110.
  4. Indexed at, Google Scholar, Cross Ref

  5. Roe AW, editor. Imaging the brain with optical methods. Springerplus. 2009;11(11).
  6. Google Scholar, Cross Ref

  7. Kleinfeld D, Mitra PP, Helmchen F,et al. Fluctuations and stimulus-induced changes in blood flow observed in individual capillaries in layers 2 through 4 of rat neocortex. Proc Natl Acad Sci. 1998;95(26):15741-6.
  8. Indexed at, Google Scholar, Cross Ref

  9. Duncan DD, Lemaillet P, Ibrahim M, et al. Absolute blood velocity measured with a modified fundus camera. J Biomed Opt. 2010(5):056014.
  10. Indexed at, Google Scholar, Cross Ref

  11. Sutherland GR, Kaibara T, Wallace C, et al. Intraoperative assessment of aneurysm clipping using magnetic resonance angiography and diffusion-weighted imaging: technical case report. J Neurosurg. 2002;50(4):893-8.
  12. Indexed at, Google Scholar

Get the App