Assessing changes in regional cerebral hemodynamics in adults with a high-density full-head coverage time-resolved near-infrared spectroscopy device.

Significance: Cerebral oximeters have the potential to detect abnormal cerebral blood oxygenation to allow for early intervention. However, current commercial systems have two major limitations: (1) spatial coverage of only the frontal region, assuming that surgery-related hemodynamic effects are global and (2) susceptibility to extracerebral signal contamination inherent to continuous-wave near-infrared spectroscopy (NIRS). Aim: This work aimed to assess the feasibility of a high-density, time-resolved (tr) NIRS device (Kernel Flow) to monitor regional oxygenation changes across the cerebral cortex during surgery. Approach: The Flow system was assessed using two protocols. First, digital carotid compression was applied to healthy volunteers to cause a rapid oxygenation decrease across the ipsilateral hemisphere without affecting the contralateral side. Next, the system was used on patients undergoing shoulder surgery to provide continuous monitoring of cerebral oxygenation. In both protocols, the improved depth sensitivity of trNIRS was investigated by applying moment analysis. A dynamic wavelet filtering approach was also developed to remove observed temperature-induced signal drifts. Results: In the first protocol (28±5 years; five females, five males), hair significantly impacted regional sensitivity; however, the enhanced depth sensitivity of trNIRS was able to separate brain and scalp responses in the frontal region. Regional sensitivity was improved in the clinical study given the age-related reduction in hair density of the patients (65±15 years; 14 females, 13 males). In five patients who received phenylephrine to treat hypotension, different scalp and brain oxygenation responses were apparent, although no regional differences were observed. Conclusions: The Kernel Flow has promise as an intraoperative neuromonitoring device. Although regional sensitivity was affected by hair color and density, enhanced depth sensitivity of trNIRS was able to resolve differences in scalp and brain oxygenation responses in both protocols.

Validation of a handheld near-infrared spectrophotometer for measurement of chemical intramuscular fat in Australian lamb.

The objective of the study was to independently validate a calibrated commercial handheld near infrared (NIR) spectroscopic device and test its repeatability over time using phenotypically diverse populations of Australian lamb. Validation testing in eight separate data sub-groups (n = 1591 carcasses overall) demonstrated that the NIR device had moderate precision (R2 = 0.4-0.64, RMSEP = 0.70-1.22%) but fluctuated in accuracy between experimental site demonstrated by variable slopes (0.50-0.94) and biases (-0.86-0.02). The repeatability experiment (n = 10 carcasses) showed that time to scan post quartering affected NIR measurement from 0 to 24 h (P < 0.001). On average, NIR IMF% was 0.97% lower (P < 0.001) at 24 h (4.01% ± 0.166), compared to 0 h. There was no difference (P > 0.05) between Time 0 and 1 h or Time 0 and 4 h or between replicate scans within each time point. This study demonstrated the SOMA NIR device could predict lamb chemical IMF% with moderate precision and accuracy, however additional work is required to understand how loin preparation, blooming and surface hydration affect NIR measurement.

Near-Infrared-Driven Nanorocket for Rapid and Ultrasensitive Detection of MicroRNA.

Herein, by introducing gold nanostars (AuNSs) as fuel core, a near-infrared-driven nanorocket (NIDNR) with pretty fast walking was exploited for ultrasensitive miRNA detection. Compared with traditional nanomaterials-comprised nanomachines (NMs), the NIDNR possesses much better kinetic and thermodynamic performance owing to the extra photothermal driving force from localized surface plasmon (LSP). Impressively, the whole reaction time of NIDNR down to 15 min was realized, which is almost more than 8 times beyond those of conventional DNA-based NMs. This way, the inherent obstacle of traditional NMs, including long reaction time and low efficiency, could be easily addressed. As a proof of concept, the NIDNR was successfully applied to develop an electrochemical biosensing platform for rapid and sensitive detection of miRNA with an LOD down to 2.95 aM and achieved the real-time assay of real biological samples from human hepatocellular carcinoma cells (MHCC97L) and HeLa, thus providing an innovative insight to design more versatile DNA nanomachines for ultimate application in biosensing platform construction and clinical sample detection.

Non-invasively accuracy enhanced blood glucose sensor using shallow dense neural networks with NIR monitoring and medical features.

Non-invasive and accurate method for continuous blood glucose monitoring, the self-testing of blood glucose is in quest for better diagnosis, control and the management of diabetes mellitus (DM). Therefore, this study reports a multiple photonic band near-infrared (mbNIR) sensor augmented with personalized medical features (PMF) in Shallow Dense Neural Networks (SDNN) for the precise, inexpensive and pain free blood glucose determination. Datasets collected from 401 blood samples were randomized and trained with ten-fold validation. Additionally, a cohort of 234 individuals not included in the model training set were investigated to evaluate the performance of the model. The model achieved the accuracy of 97.8% along with 96.0% precision, 94.8% sensitivity and 98.7% specificity for DM classification based on a diagnosis threshold of 126 mg/dL for diabetes in fasting blood glucose. For non-invasive real-time blood glucose monitoring, the model exhibited ± 15% error with 95% confidence interval and the detection limit of 60-400 mg/dL, as validated with the standard hexokinase enzymatic method for glucose estimation. In conclusion, this proposed mbNIR based SDNN model with PMF is highly accurate and computationally cheaper compared to similar previous works using complex neural network. Some groups proposed using complicated mixed types of sensors to improve noninvasive glucose prediction accuracy; however, the accuracy gain over the complexity and costs of the systems harvested is still in questioned (Geng et al. in Sci Rep 7:12650, 2017). None of previous works report on accuracy enhancement of NIR/NN using PMF. Therefore, the proposed SDNN over PMF/mbNIR is an extremely promising candidate for the non-invasive real-time blood glucose monitoring with less complexity and pain-free.

Feasibility study of immersive virtual prism adaptation therapy with depth-sensing camera using functional near-infrared spectroscopy in healthy adults.

Prism Adaptation (PA) is used to alleviate spatial neglect. We combined immersive virtual reality with a depth-sensing camera to develop virtual prism adaptation therapy (VPAT), which block external visual cues and easily quantify and monitor errors than conventional PA. We conducted a feasibility study to investigate whether VPAT can induce behavioral adaptations by measuring after-effect and identifying which cortical areas were most significantly activated during VPAT using functional near-infrared spectroscopy (fNIRS). Fourteen healthy subjects participated in this study. The experiment consisted of four sequential phases (pre-VPAT, VPAT-10°, VPAT-20°, and post-VPAT). To compare the most significantly activated cortical areas during pointing in different phases against pointing during the pre-VPAT phase, we analyzed changes in oxyhemoglobin concentration using fNIRS during pointing. The pointing errors of the virtual hand deviated to the right-side during early pointing blocks in the VPAT-10° and VPAT-20° phases. There was a left-side deviation of the real hand to the target in the post-VPAT phase, demonstrating after-effect. The most significantly activated channels during pointing tasks were located in the right hemisphere, and possible corresponding cortical areas included the dorsolateral prefrontal cortex and frontal eye field. In conclusion, VPAT may induce behavioral adaptation with modulation of the dorsal attentional network.

Regional difference in prefrontal oxygenation before and during overground walking in humans: a wearable multichannel NIRS study.

Using wireless multichannel near-infrared spectroscopy, regional difference in cortical activity over the prefrontal cortex (PFC) was examined before and during overground walking and in response to changes in speed and cognitive demand. Oxygenated-hemoglobin concentration (Oxy-Hb) as index of cortical activity in ventrolateral PFC (VLPFC), dorsolateral PFC (DLPFC), and frontopolar cortex (FPC) was measured in 14 subjects, whereas heart rate was measured as estimation of exercise intensity in six subjects. The impact of mental imagery on prefrontal Oxy-Hb was also explored. On both sides, Oxy-Hb in VLPFC, DLPFC, and lateral FPC was increased before the onset of normal-speed walking, whereas Oxy-Hb in medial FPC did not respond before walking onset. During the walking, Oxy-Hb further increased in bilateral VLPFC, whereas Oxy-Hb was decreased in DLPFC and lateral and medial FPC. Increasing walking speed did not alter the increase in Oxy-Hb in VLPFC but counteracted the decrease in Oxy-Hb in DLPFC (but not in lateral and medial FPC). Treadmill running evoked a greater Oxy-Hb increase in DLPFC (n = 5 subjects). Furthermore, increasing cognitive demand during walking, by deprivation of visual feedback, counteracted the decrease in Oxy-Hb in DLPFC and lateral and medial FPC, but it did not affect the increase in Oxy-Hb in VLPFC. Taken together, the profound and localized Oxy-Hb increase is a unique response for the VLPFC. The regional heterogeneity of the prefrontal Oxy-Hb responses to natural overground walking was accentuated by increasing walking speed or cognitive demand, suggesting functional distinction within the PFC.

Broadband absorption spectroscopy of heterogeneous biological tissue.

Absorption spectra (∼600 to 1064 nm) of six tissues in three healthy volunteers were measured by combining dual-slope continuous-wave broadband spectroscopy with self-calibrated frequency-domain measurements of scattering at two wavelengths (690 and 830 nm). The spectral fit with a linear combination of oxy- and deoxyhemoglobin, water, and lipids extinction spectra is improved by a wavelength-independent absorption background. The need to introduce this background is assigned to the inhomogeneous distribution of absorbers in tissue. By using a two-layer model, the relationship between recovered concentrations and their two-layer values was investigated, and the implications for non-invasive tissue spectroscopy are discussed.

Nanoparticles for In Vivo Lifetime Multiplexed Imaging.

Lifetime multiplexed imaging refers to the simultaneous labeling of different structures with fluorescent probes that present identical photoluminescence spectra and distinct fluorescence lifetimes. This technique allows extracting quantitative information from multichannel in vivo fluorescence imaging. In vivo lifetime multiplexed imaging requires fluorophores with excitation and emission bands in the near-infrared (NIR) and tunable fluorescence lifetimes, plus an imaging system capable of time-resolved image acquisition and analysis.

Cost-Effectiveness of Vioptix versus Clinical Examination for Flap Monitoring of Autologous Free Tissue Breast Reconstruction.

BACKGROUND: Vioptix is a near-infrared spectroscopy tissue oximetry technology that allows for noninvasive monitoring of flap perfusion. Despite the reported benefits of Vioptix, the cost-effectiveness of this flap monitoring technology has not been compared to clinical examination alone. METHODS: A cost-effectiveness model, from the patient perspective, was constructed with two treatment arms: clinical examination versus clinical examination combined with Vioptix for flap monitoring after autologous, free flap breast reconstruction. Costs, utilities, and other model inputs were identified from the literature. One-way and probabilistic sensitivity analyses were performed. Gamma distributions were created for cost variables, and beta distributions were created for probability variables. An incremental cost-effectiveness ratio under $50,000 per quality-adjusted life-year (QALY) was considered cost-effective. All analyses were performed using TreeAge Pro (Williamstown, Mass.). RESULTS: Mean cost of autologous free tissue transfer breast reconstruction with clinical examination-based flap monitoring was found to be $37,561 with an effectiveness of 0.79, whereas the mean cost of clinical examination with Vioptix for flap monitoring was $39,361 with effectiveness of 0.82. This yielded an incremental cost-effectiveness ratio of $60,507 for clinical examination combined with Vioptix for flap monitoring. One-way sensitivity analysis revealed that clinical examination with Vioptix became cost-effective when the cost of Vioptix was less than $1487. Probabilistic sensitivity analysis found that clinical examination was cost-effective in 86.5 percent of cases. CONCLUSION: Although clinical examination combined with Vioptix is minimally more effective for flap monitoring after autologous, free flap breast reconstruction, clinical examination alone is the more cost-effective flap monitoring option.

Initial clinical experiences using the intraoperative probe-based parathyroid autofluorescence identification system-PTeye™ during thyroid and parathyroid procedures.

BACKGROUND AND OBJECTIVE: The Food and Drug Administration has cleared a probe-based near-infrared autofluorescence (NIRAF) detection system called PTeye™ as an adjunct tool for label-free intraoperative parathyroid gland (PG) identification. Since PTeye™ has been investigated only in a "blinded" manner to date, this study describes the preliminary impressions of PTeye™ when used by surgeons without being blinded to the device output. METHODS: Patients undergoing thyroid and parathyroid procedures were prospectively recruited. Target tissues were intraoperatively assessed with PTeye™. The surgeon's confidence in PG identification was recorded concomitantly with NIRAF parameters that were output in real-time from PTeye™. RESULTS: A retrospective review of prospectively collected data on 83 patients was performed. PTeye™ was used for interrogating 336 target tissues in 46 parathyroid and 37 thyroid procedures. PTeye™ yielded an overall accuracy of 94.3% with a positive predictive value of 93.0% and a negative predictive value of 100%. An increase in confidence for intraoperative PG identification with PTeye™ was observed by all three participating high-volume surgeons, irrespective of their level of accrued surgical experience. CONCLUSIONS: Probe-based NIRAF detection with PTeye™ can be a valuable adjunct device to intraoperatively identify PGs for surgeons of varied training and experience.

Bedside hyperspectral imaging indicates a microcirculatory sepsis pattern - an observational study.

INTRODUCTION: Microcirculatory alterations are key mechanisms in sepsis pathophysiology leading to tissue hypoxia, edema formation, and organ dysfunction. Hyperspectral imaging (HSI) is an emerging imaging technology that uses tissue-light interactions to evaluate biochemical tissue characteristics including tissue oxygenation, hemoglobin content and water content. Currently, clinical data for HSI technologies in critical ill patients are still limited. METHODS AND ANALYSIS: TIVITA® Tissue System was used to measure Tissue oxygenation (StO2), Tissue Hemoglobin Index (THI), Near Infrared Perfusion Index (NPI) and Tissue Water Index (TWI) in 25 healthy volunteers and 25 septic patients. HSI measurement sites were the palm, the fingertip, and a suprapatellar knee area. Septic patients were evaluated on admission to the ICU (E), 6 h afterwards (E+6) and three times a day (t3-t9) within a total observation period of 72 h. Primary outcome was the correlation of HSI results with daily SOFA-scores. RESULTS: Serial HSI at the three measurement sites in healthy volunteers showed a low mean variance expressing high retest reliability. HSI at E demonstrated significantly lower StO2 and NPI as well as higher TWI at the palm and fingertip in septic patients compared to healthy volunteers. StO2 and TWI showed corresponding results at the suprapatellar knee area. In septic patients, palm and fingertip THI identified survivors (E-t4) and revealed predictivity for 28-day mortality (E). Fingertip StO2 and THI correlated to SOFA-score on day 2. TWI was consistently increased in relation to the TWI range of healthy controls during the observation time. Palm TWI correlated positively with SOFA scores on day 3. DISCUSSION: HSI results in septic patients point to a distinctive microcirculatory pattern indicative of reduced skin oxygenation and perfusion quality combined with increased blood pooling and tissue water content. THI might possess risk-stratification properties and TWI could allow tissue edema evaluation in critically ill patients. CONCLUSION: HSI technologies could open new perspectives in microcirculatory monitoring by visualizing oxygenation and perfusion quality combined with tissue water content in critically ill patients - a prerequisite for future tissue perfusion guided therapy concepts in intensive care medicine.

Performance of different portable and hand-held near-infrared spectrometers for predicting beef composition and quality characteristics in the abattoir without meat sampling.

The availability of portable and handheld NIR instruments on the market opens up new possibilities in meat analysis. However, there is lack of research comparing different NIR instruments for evaluating beef characteristics from spectra obtained directly on the meat surface. Our aim, therefore, was to build and test calibration and prediction models for predicting beef characteristics, and to compare the performances of three NIR instruments differing in size and characteristics: a transportable visible-NIR spectrometer (Vis-NIRS), a portable (NIRS), and a hand-held Micro-NIRS. Spectra were collected from 178 beef samples (Longissimus thoracis muscle) from the meat surface in the abattoir. The spectra were subjected to different mathematical pretreatments then partial least square regressions. The results showed that all instruments predicted dry matter, protein and lipids with R2VAL 0.23 to 0.70; pH and cooking loss R2VAL 0.19 to 0.25; and color R2VAL 0.35 to 0.77. Overall, the prediction performances of the three instruments were similar, although Micro-NIRS performed better in some respects.

Rapid and real-time detection of black tea fermentation quality by using an inexpensive data fusion system.

Intelligent identification of black tea fermentation quality is becoming a bottleneck to industrial automation. This study presents at-line rapid detection of black tea fermentation quality at industrial scale based on low-cost micro-near-infrared spectroscopy (NIRS) and laboratory-made computer vision system (CVS). High-performance liquid chromatography and a spectrophotometer were used for determining the content of catechins and theaflavins, and the color of tea samples, respectively. Hierarchical cluster analysis combined with sensory evaluation was used to group samples through different fermentation degrees. A principal component analysis-support vector machine (SVM) model was developed to discriminate the black tea fermentation degree using color, spectral, and data fusion information; high accuracy (calibration = 95.89%, prediction = 89.19%) was achieved using mid-level data fusion. In addition, SVM model for theaflavins content prediction was established. The results indicated that the micro-NIRS combined with CVS proved a portable and low-cost tool for evaluating the black tea fermentation quality.

Ultrathin arrayed camera for high-contrast near-infrared imaging.

We report an ultrathin arrayed camera (UAC) for high-contrast near infrared (NIR) imaging by using microlens arrays with a multilayered light absorber. The UAC consists of a multilayered composite light absorber, inverted microlenses, gap-alumina spacers and a planar CMOS image sensor. The multilayered light absorber was fabricated through lift-off and repeated photolithography processes. The experimental results demonstrate that the image contrast is increased by 4.48 times and the MTF 50 is increased by 2.03 times by eliminating optical noise between microlenses through the light absorber. The NIR imaging of UAC successfully allows distinguishing the security strip of authentic bill and the blood vessel of finger. The ultrathin camera offers a new route for diverse applications in biometric, surveillance, and biomedical imaging.

SiPM-based gamma detector with a central GRIN lens for a visible/NIRF/gamma multi-modal laparoscope.

Intraoperative imaging has been studied using conventional devices such as near infrared (NIR) optical probes and gamma probes. However, these devices have limited depth penetration and spatial resolution. In a previous study, we realized a multi-modal endoscopic system. However, charge-coupled device (CCD)-based gamma imaging required long acquisition times and lacked gamma energy information. A silicon photomultiplier (SiPM)-based gamma detector is implemented in a multi-modal laparoscope herein. A gradient index (GRIN) lens and CCD are used to transfer and readout visible and NIR photons. The feasibility of in-vivo sentinel lymph node (SLN) mapping was successfully performed with the proposed system.

Two-dimensional moisture content and size measurement of pharmaceutical granules after fluid bed drying using near-infrared chemical imaging.

In pharmaceutical wet granulation, drying is a critical step in terms of energy and material consumption, whereas granule moisture content and size are important process outcomes that determine tabletting performance. The drying process is, however, very complex due to the multitude of interacting mechanisms on different scales. Building robust physical models of this process therefore requires detailed data. Current data collection methods only succeed in measuring the average moisture content of a size fraction of granules, whereas this property rather follows a distribution that, moreover, contains information on the drying patterns. Therefore, a measurement method is devised to simultaneously characterise the moisture content and size of individual pharmaceutical granules. A setup with near-infrared chemical imaging (NIR-CI) is used to capture an image of a number of granules, in which the absorbance spectra are used for deriving the moisture content of the material and the size of the granules is estimated based on the amount of pixels containing pharmaceutical material. The quantification of moisture content based on absorption spectra is performed with two different regression methods, Partial Least Squares regression (PLSR) and Elastic Net Regression (ENR). The method is validated with particle size data for size determination, loss-on-drying (LOD) data of average moisture contents of granule samples and, finally, batch fluid bed experiments in which the results are compared to the most detailed method to date. The individual granule moisture contents confirmed again that granule size is an important factor in the drying process. The measurement method can be used to gain more detailed experimental insight in different fluidisation and particulate processes, which will allow building of robust process models.

Effect of Formalin Fixation for Near-Infrared Fluorescence Imaging with an Antibody-Dye Conjugate in Head and Neck Cancer Patients.

PURPOSE: This study evaluated the effect of formalin fixation for near-infrared (NIR) fluorescence imaging of an antibody-dye complex (panitumumab-IRDye800CW) that was intravenously administered to patients with head and neck squamous cell carcinoma (HNSCC) scheduled to undergo surgery of curative intent. PROCEDURES: HNSCC patients were infused with 25 or 50 mg of panitumumab-IRDye800CW followed by surgery 1-5 days later. Following resection, primary tumor specimens were imaged in a closed-field fluorescence imaging device, before and after formalin fixation. The fluorescence images of formalin-fixed specimens were compared with images prior to formalin fixation. Regions of interest were drawn on the primary tumor and on the adjacent normal tissue on the fluorescence images. The mean fluorescence intensity (MFI) and tumor-to-background ratios (TBRs) of the fresh and formalin-fixed tissues were compared. RESULTS: Of the 30 enrolled patients, 20 tissue specimens were eligible for this study. Formalin fixation led to an average of 10 % shrinkage in tumor specimen size (p < 0.0001). Tumor MFI in formalin-fixed specimens was on average 10.9 % lower than that in the fresh specimens (p = 0.0002). However, no statistical difference was found between the TBRs of the fresh specimens and those of the formalin-fixed specimens (p = 0.85). CONCLUSIONS: Despite the 11 % decrease in MFI between fresh and formalin-fixed tissue specimens, the relative difference between tumor and normal tissue as measured in TBR remained unchanged. This data suggests that evaluation of formalin-fixed tissue for assessing the accuracy of fluorescence-guided surgery approaches could provide a valid, yet more flexible, alternative to fresh tissue analysis. TRIAL REGISTRATION: NCT02415881.

Frontal lobe oxyhemoglobin levels in patients with lower extremity burns assessed using a functional near-Infrared spectroscopy device during usual walking: a pilot study.

BACKGROUND: Understanding the mechanisms associated with locomotor networks may be of benefit for rehabilitation of burn victims with neurological locomotor deficits. A wearable functional near-infrared spectroscopy (fNIRS) device has been developed for studying cortical hemodynamics. OBJECTIVES: To investigate cortical brain activity during usual walking, we examined patterns of cortical activation using fNIRS device (NIRSIT®; OBELAB Inc., Seoul, Korea), in patients with neurological injury caused by lower extremity burns. METHODS: This cross-sectional study assessed 15 patients with lower extremity burns, 10 patients with upper extremity burns, and 11 healthy controls. We measured walking-related cortical activity using an fNIRS device at baseline and during usual walking. RESULTS: There was no significant difference between the burns groups in terms of age (43.50 ± 14.08 and 44.67 ± 6.92 years, P = 1.00), pain score of NRS (Numeric rating scale) (5.83 ± 1.19 and 6.67 ± 1.21, P = 0.18) or the mean time since injury (228.50 ± 83.43 and 199.33 ± 68.84 days, P = 0.78). Measures showed increased cortical activation in the prefrontal cortex in patients with lower extremity burns than in patients with healthy controls(P = 0.015). The measured HbO2 datas of the regions during usual walking in patients with lower extremity burn were insignificantly higher compared with the datas in patient with upper extremity burn (P = 0.302). CONCLUSIONS: The patients with neurological injury due to lower extremity burns significantly rely more on cognitive resources even when performing a usual walking task.

Tinnitus and auditory cortex: using adapted functional near-infrared spectroscopy to measure resting-state functional connectivity.

OBJECTIVE: Tinnitus, phantom sound perception, arises from aberrant brain activity within auditory cortex. In tinnitus animal models, auditory cortex neurons show increased spontaneous firing and neural synchrony. In humans, similar hyperactivation in auditory cortex has been displayed with functional near-infrared spectroscopy (fNIRS). Resting-state functional connectivity (RSFC) or increased connectivity between brain regions has also been shown in tinnitus using fNIRS. However, current fNIRS technology utilizes infrared (IR)-sources and IR-detectors placed on the scalp that restricts (~3 cm depth IR penetration) signal capture to outer cerebral cortex due to skin and skull bone. To overcome this limitation, in this proof of concept study, we adapted fNIRS probes to fit in the external auditory canal (EAC) to physically place IR-probes deeper within the skull thereby extracting neural signals from deeper auditory cortex. METHODS: Twenty adults with tinnitus and 20 nontinnitus controls listened to periods of silence and broadband noise before and after 5 min of silence to calculate RSFC. Concurrent scalp probes over auditory cortex and an adapted probe placed in the right EAC were utilized. RESULTS: For standard probes, left and right auditory cortex in tinnitus showed increased RSFC to each other and to other nonauditory cortices. Interestingly, adapted fNIRS probes showed trends toward increased RSFC. CONCLUSION: While many areas for the adapted probes did not reach significance, these data using a highly innovative and newly created probe adapting fNIRS technology to the EAC substantiates our previously published data in human tinnitus and concurrently validates this technology as a useful and expanded brain imaging modality.

Current state of intraoperative use of near infrared fluorescence for parathyroid identification and preservation.

BACKGROUND: Finding and preserving normal parathyroid glands or localizing and removing diseased parathyroid glands are crucial steps to successful thyroid and parathyroid operations. Using near-infrared fluorescence detection to identify parathyroid glands during thyroid and parathyroid operations has lately gained widespread recognition, with 2 Food and Drug Administration-cleared devices currently in the market. We aim to update the endocrine surgery community on how near-infrared fluorescence detection can be most optimally used for rapid intraoperative parathyroid gland identification or preservation. METHODS: A literature review was performed using the key terms: "parathyroid," "near infrared," and "fluorescence" in relevant search engines. Based on the reviewed literature and expert surgeons' opinions, recommendations were formulated for applying near-infrared fluorescence detection to identify or preserve parathyroid glands during cervical endocrine surgery. RESULTS: The scope of near-infrared fluorescence detection can be broadly categorized into (1) using near-infrared auto-fluorescence to identify or locate both healthy and diseased parathyroid glands, and (2) using contrast-enhanced near-infrared fluorescence to evaluate parathyroid gland perfusion. The benefits and pitfalls for both near-infrared-based approaches are described herein. CONCLUSION: Near-infrared fluorescence detection appears helpful for identification and likely preservation of parathyroid glands. We hope these recommendations will be valuable to the practicing endocrine surgeon as they consider incorporating these intraoperative adjuncts in their surgical practice.