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The purpose of this study is to explore the differences in the steroid metabolic network between hyperandrogenic and non-hyperandrogenic women with polycystic ovary syndrome (PCOS). A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) was employed for the quantification of 36 kinds of serum steroids in 80 PCOS women during their follicular phase. Compared with those in non-hyperandrogenemia PCOS women (NA-PCOS), the levels of 17-hydroprogesterone (P = 0.009), androstenedione (P 0.001), total testosterone (P 0.001), dihydrotestosterone (P = 0.025), estrone (P = 0.007), and estradiol (P 0.001) were increased in hyperandrogenemia PCOS (HA-PCOS) women. It was suggested that HA-PCOS may have increased activity of P450c17 (17-hydropregnenolone/pregnenolone, P = 0.008), 3βHSD2 (androstenedione/dehydroepiandrosterone, P = 0.004), and 17βHSD3 (testosterone/dehydroepiandrosterone, P = 0.01) and decreased activity of 5α reductase (dihydrotestosterone/testosterone, P = 0.008). Moreover, the ratio of luteinizing hormone (LH) to follicle stimulating hormone (FSH) was found to be related to these increased steroids and enzyme activities. In conclusion, the HA-PCOS and the NA-PCOS women showed different steroid profiles, and the different enzyme activities in steroidogenic pathway may be the main reason for the difference.

Gestational diabetes mellitus (GDM) is not only a threat to the health of pregnant women, but also has profound effects on the health of offspring. Studies have shown that the imbalance of estrogen metabolism is associated with an increased risk of GDM. In this study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established and validated for simultaneous quantification of thirteen estrogens in the urine of GDM women, including estrone (E1), estradiol (E2), estriol (E3), and their hydroxylated and methylated metabolites. The method was achieved on a Waters CORTECS C18 column (2.1 mm × 150 mm, 1.6 µm) within 8.5 min. The linear range of thirteen estrogens in urine was 2-1000 pg·mL

The advent of the metaverse age has gradually transformed digital survival from a fantasy in science fiction to a reality. Especially in recent years, the college students, as the objects of ideological and political education in universities, have been deeply embedded in their learning, social interaction, entertainment, and consumption behaviors, presenting new characteristics of the times. From the aspects of the background of intelligent technology on College Students’ network behavior, the types of College Students’ network behavior, the multiple effects of intelligent technology, the nature of College Students’ network behavior, etc., provide some basis for ideological and political education.

Tacrolimus has a narrow therapeutic index and large individual differences in pharmacokinetics. The distribution of tacrolimus in ascitic fluid and its influence on whole-blood tacrolimus were unclear. In this study, a sensitive ultra-performance liquid chromatography-tandem mass spectrometry method was established and validated for the quantification of tacrolimus in the ascitic fluid of liver transplant recipients. Chromatographic separation was achieved on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column (2.1 × 100 mm, 3.5 μm). Mass spectrometry was performed in multiple reaction monitoring conditions of transitions m/z 821.4→768.5 for tacrolimus. The concentrations of tacrolimus in the ascitic fluid range from 0.2 to 3.0 ng/mL, accounting for 1.19-31.87% of whole-blood tacrolimus concentrations. A linear mixed model showed a statistically significant positive correlation between the steady-state trough blood concentration of tacrolimus and the corresponding amount of tacrolimus excreted in the ascitic fluid for 24 consecutive hours, especially after normalization by daily dose per unit body weight. These data suggested that the distribution of tacrolimus in the ascitic fluid has great individual differences. The whole-blood tacrolimus concentration, dose per unit body weight, and other confounding factors may contribute to the excretion of tacrolimus in ascitic fluid, but the influence of tacrolimus excretion in drained ascitic fluid on the whole-blood tacrolimus concentration is negligible.

The embedded ratio of retaining structures and improved depth of ground at an excavation base are two key factors for the stability of deep excavation. For a collapsed excavation in soft cl...

Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir (TFV) that has been approved for the treatment of chronic hepatitis B virus (HBV) infection. It has greater plasma stability and more favorable renal safety than tenofovir disoproxil fumarate (TDF), the first approved oral prodrug of TFV. However, the distribution of TFV in the breast milk of mothers treated with TAF is still unclear. In this study, sixteen participants with chronic HBV infection were enrolled and received antiretroviral therapy with 25 mg of TAF or 300 mg of TDF daily from 24 to 28 weeks of gestation until the 4th week postpartum. For the first time, the distribution of TFV in the breast milk of mothers with chronic HBV infection treated with TAF and its difference from TDF were evaluated by using a sensitive UPLC–MS/MS method. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C18 column (1.7 µm 2.1 × 100 mm). Mass spectrometry analysis was performed in positive electrospray ionization mode and multiple reaction monitoring (MRM) conditions of transitions m/z 288.1→176.2 for TFV. This method was linear from 0.5 to 500 ng/ml. Surprisingly, on the third postpartum day, the median Cmax of TFV in the breast milk was much higher in the mothers treated with TAF (101.2 ng/ml) than TDF (21.6 ng/ml) at a similar Tmax of 4 h. Accordingly, the median AUC0-8 value was 755.6 ng h/mL in the mothers taking TAF, which was at a 5-fold higher level than TDF. The concentration of TFV in the breast milk of mothers in both groups decreased with increasing lactation time. These data indicated that there was a relatively higher exposure of TFV in the breast milk of mothers taking TAF, despite the lower dosage compared to TDF. This study provides support for further evaluating the safety of breastfeeding after the administration of TAF and TDF.

The aim of the present study was to investigate the effects and mechanism of oxymatrine (OMT) combined with compound yinchen granules (CYG) on the apoptosis of hepatocytes through the Akt/FoxO3a/Bim pathway in rats with acute liver failure. The rat model of acute liver failure was established using lipopolysaccharide/D-galactosamine (LPS/D-GalN). The expression of proteins in rat liver tissues was detected by western blot analysis. The mRNA expression of FoxO3a, Bim, Bax, Bcl-2, and caspase-3 in rat liver tissues was detected by RT-qPCR. The apoptosis rate of rat hepatocytes was determined by flow cytometry. Western blots showed that when compared with the normal group, the expression of p-Akt and p-FoxO3a in the model group was decreased ( P < 0.05 ), while the expression of Bim was increased ( P < 0.01 ). Compared with the model group, the expression of p-Akt and p-FoxO3a in the OMT group and the OMT combined with CYG groups was increased ( P < 0.05 or P < 0.01 ), while the expression of Bim was decreased ( P < 0.05 ). The Bax/Bcl-2 ratio and caspase-3 protein expression in the model group were significantly higher than those in the normal group ( P < 0.01 ). The Bax/Bcl-2 ratio and the expression of caspase-3 protein in the OMT group and the OMT combined with CYG groups were significantly lower than those in the model group ( P < 0.01 ). The results of RT-qPCR were consistent with those of western blot. The results of flow cytometry showed that the apoptosis rate of hepatocytes in the OMT group and the OMT combined with CYG groups was significantly lower than that in the model group ( P < 0.05 or P < 0.01 ). We concluded that LPS/D-GalN can induce apoptosis of hepatocytes in rats with acute liver failure through the Akt/FoxO3a/Bim pathway. OMT combined with CYG inhibits apoptosis of hepatocytes in rats with acute liver failure via the Akt/FoxO3a/Bim pathway.

Background Practical application of hemodynamic modification analysis based on computational fluid dynamics (CFD) in intracranial aneurysms is still under study. Purpose To determine the clinical applicability of virtual stenting of aneurysms by comparing the simulated results with clinical outcome of real stenting. Material and Methods Three-dimensional (3D) digital subtraction angiography (DSA) images were imported to a dedicated integrated prototypic CFD platform (Siemens Healthcare GmbH) which allows all necessary steps of 3D models for CFD analysis. The results of CFD simulation with virtual implantation of a stent can be visualized in the same platform for qualitative comparisons on a color-coded volume visualization window. Five small intracranial aneurysms with and without virtual stenting were analyzed and assessed on a qualitative level. Expert rating were performed for evaluating the simulated results, and comparing those to the long-term follow-up outcomes of real stenting. Results CFD simulation after virtual stenting was feasible in five differently located aneurysms and corresponded to the long-term changes of stented aneurysms by showing alteration in flow pattern. There was no significant difference ( P = 0.5) between the simulated hemodynamic changes after virtual stenting and the angiographic changes after stenting in four aneurysms except one. There was good agreement regarding the assessment of the changes by two raters (kappa = 0.657). Conclusion CFD analysis using patient-specific virtual stenting of the CFD platform may be used as a simple and less time-consuming test tool predicting the involution of aneurysms after stent placement by analyzing the vector visualization of the flow changes.

PURPOSE To identify differential changes in proteins and metabolites underlying "fast" type 1 (T1DC) and "slow" type 2 (T2DC) diabetic cataract (DC) formation in rat. METHODS Rat models of types 1 and 2 diabetes consisted of streptozotocin injection without and with high-fat diet, respectively. Cataract progression was examined weekly. At week 6, total protein changes were comparatively and quantitatively assessed by two-dimensional differential in-gel electrophoresis (2-D DIGE) coupled with mass spectrometry, and relevant metabolic changes were examined. Differences in high molecular weight (HMW) crystallin species between diabetic and control lenses were similarly identified. RESULTS Cataracts were morphologically different and progressed more slowly in T2DC versus T1DC. αA-crystallin, βB2-crystallin, and βA4-crystallin were significantly decreased in both DC types versus control. αB-crystallin was increased while βB1-crystallin was markedly decreased in T2DC. In T1DC, γB-crystallin and γS-crystallin fragmentation were increased. High-fat diet by itself had little impact, except for lowering γS-crystallin fragmentation. Despite significantly decreased opacity, a greater decrease in intermediate filaments (IFs) and more HMW crystallin species were observed in T2DC versus T1DC. However, aldose reductase expression and activity and sorbitol levels were increased to a greater extent in T1DC, while reduced glutathione (GSH) and reduced form of nicotinamide adenine dinucleotide phosphate (NADPH) levels were decreased to a greater extent and adenosine triphosphate (ATP) level was much lower in T1DC versus T2DC. CONCLUSIONS The results suggest that osmotic damage, GSH loss, and decreased ATP production might be important pathological mechanisms in T1DC formation, whereas crystallin modification and cross-linking/aggregation as well as IF degradation may play more crucial roles in T2DC formation.

The purpose of this study is to examine the impacts of ambidexterity of exploration/exploitation on long-term performance and the moderating effects of slack resources. The methodology adopted is panel data analysis of a sample dataset of 125 high technology firms in China. The finding of this study shows that a moderating role of organizational slack between ambidexterity and long-term performance is strongly supported. The research and practical implications of this paper are: (1) Exploration and exploitation can be mutually enhancing instead of being fundamentally contradictory; (2) Slack resources moderate the relationship between ambidexterity and performance. The originality and value of the paper is that it is one of the earliest studies that empirically examine the moderating effects of slack resources on ambidexterity-performance relationship.

Diffuse optical imaging (DOI) is a promising noninvasive and nonionizing method for breast imaging. Several research groups have developed hand-held-based optical imaging devices which are portable and patient-comfortable toward clinical translation of the technology. The different hand-held optical devices developed to date are reviewed herein with a focus on the clinical applications. The hand-held device developed at Florida International University is unique in its ability to perform 3-D tomography using DOI alone via self-coregistration facilities. Results demonstrate the ability of the device to perform 2-D imaging and 3-D tomography in human breast tissue.

Hand-held based optical imaging systems are a recent development towards diagnostic imaging of breast cancer. To date, all the hand-held based optical imagers are used to perform only surface mapping and target localization, but are not capable of demonstrating tomographic imaging. Herein, a novel hand-held probe based optical imager is developed towards three-dimensional (3-D) optical tomography studies. The unique features of this optical imager, which primarily consists of a hand-held probe and an intensified charge coupled device detector, are its ability to; (i) image large tissue areas ( 5 × 10 sq. cm ) in a single scan, (ii) perform simultaneous multiple point illumination and collection, thus reducing the overall imaging time; and (iii) adapt to varying tissue curvatures, from a flexible probe head design. Experimental studies are performed in the frequency domain on large slab phantoms ( ∼ 650 ml ) using fluorescence target(s) under perfect uptake (1:0) contrast ratios, and varying target depths ( 1 – 2 cm ) and X - Y locations. The effect of implementing simultaneous over sequential multiple point illumination towards 3-D tomography is experimentally demonstrated. The feasibility of 3-D optical tomography studies has been demonstrated for the first time using a hand-held based optical imager. Preliminary fluorescence-enhanced optical tomography studies are able to reconstruct 0.45 ml target(s) located at different target depths ( 1 – 2 cm ) . However, the depth recovery was limited as the actual target depth increased, since only reflectance measurements were acquired. Extensive tomography studies are currently carried out to determine the resolution and performance limits of the imager on flat and curved phantoms.

The relationship between ambidexterity and firm performance holds a prominent place in the literature. However, studies that examine the conditions under which ambidexterity leads to success are relatively scarce. Based on a sample of 226 firms in China, this study examines the moderating effects of organizational slack and organizational life cycle on the relationship between balance dimension of ambidexterity and combined dimension of ambidexterity and firm performance. The empirical results reveal that pursuing a high level of combined dimension of organizational ambidexterity is only beneficial to firms with a high level of organizational slack or firms in maturity stage, while pursuing a high level of balance dimension of organizational ambidexterity is only beneficial to firms in growth stage, but not to firms in maturity stage.

The aim of this work was to establish measurement conditions under which endogenous skin fluorescence ("auto-fluorescence") is relatively invariant, so that changes in exogenous agents can be accurately determined. Fluorescence emission was measured on the volar forearm of 36 subjects, chosen to be equally representative of all 6 Fitzpatrick skin types. All subjects were exposed to approximately 40 minutes of optical excitation at 450 and 500 nm with 4 irradiances between 0.3 and 9 mW/cm2. Both non-optically-induced (e.g. tissue settling and fluctuation) and optically-induced variations were observed in the measured fluorescence and mechanisms explaining these effects are proposed. The optically-induced auto-fluorescence decay was independent of skin type when excited at 450 nm, but significantly dependent on skin type when excited at 500 nm. Further, the extent of decay over time was linearly related to irradiance at 500 nm, but at 450 nm was non-linear, with the extent of decay rolling off between 2 and 9 mW/cm2. In order to maintain the auto-fluorescence signal within 95% of its original value over a 30 minute period, the excitation at 450 nm would need to be limited to 1.5 mW/cm2, while excitation at 500 nm should be limited to 5 mW/cm2.

Multi-beam technology is one of the key technologies in optical phased array systems for multi-object treatment and multi-task operation. A multi-beam forming and steering method was proposed. This method uses isosceles triangle multilevel phase grating (ITMPG) to form multiple beams simultaneously. Phase profile of the grating is a quantized isosceles triangle with stairs. By changing the phase difference corresponding to the triangle height, multiple beams can be steered symmetrically. It took 34 ms to calculate a set of parameters for one ITMPG, namely one steering. A liquid crystal spatial light modulator was used for the experiment, which formed 6 gratings. The distortion of which had been compensated with the accuracy of 0.0408 λ. Each grating included 16 phase elements with the same period. Steering angle corresponded to the triangle height, which is the phase difference. Relative diffraction efficiency for multiple beams was greater than 81%, intensity nonuniformity was less than 0.134, and the deflection resolution was 2.263 mrad. Experimental results demonstrate that the proposed method can be used to form and steer symmetrical multiple beams simultaneously with the same intensity and high diffraction efficiency in the far field, the deflection resolution is related to the reciprocal of grating period.

Near-infrared (NIR) optical imaging is a noninvasive and nonionizing modality that is emerging as a diagnostic tool for breast cancer. The handheld optical devices developed to date using the NIR technology are predominantly developed for spectroscopic applications. A novel handheld probe-based optical imaging device has been recently developed toward area imaging and tomography applications. The three-dimensional (3D) tomographic imaging capabilities of the device have been demonstrated from previous fluorescence studies on tissue phantoms. In the current work, fluorescence imaging studies are performed on tissue phantoms, in vitro, and in vivo tissue models to demonstrate the fast two-dimensional (2D) surface imaging capabilities of this flexible handheld-based optical imaging device, toward clinical breast imaging studies. Preliminary experiments were performed using target(s) of varying volume (0.23 and 0.45 cm(3)) and depth (1-2 cm), using indocyanine green as the fluorescence contrast agent in liquid phantom, in vitro, and in vivo tissue models. The feasibility of fast 2D surface imaging ( approximately 5 seconds) over large surface areas of 36 cm(2) was demonstrated from various tissue models. The surface images could differentiate the target(s) from the background, allowing a rough estimate of the target's location before extensive 3D tomographic analysis (future studies).

Several hand-held based optical imaging devices have been developed towards breast imaging, which are portable, patient-comfortable, and use non-ionizing radiation. The devices developed to date are limited in that they have flat probe faces and are incapable of real-time coregistration (as needed for 3-D tomographic imaging). A hand-held based optical imager has been developed in our lab, which has unique features of (i) simultaneous over sequential source illumination, which enables rapid data acquisition, (ii) a flexible probe face, which enables it to contour to any tissue curvature, and (iii) self coregistration facilities towards 3-D tomographic imaging. Real-time coregistration is demonstrated using the imager via fluorescence-enhanced studies in the continuous-wave mode, performed on slab phantoms (filled with 1% Liposyn solution) and in vitro samples (chicken breast). Additionally, preliminary studies were conducted using curved phantoms. In all cases, a 0.45-cc target filled with 1 μM Indocyanine green was used to represent a tumor. Real-time 2-D surface images of the phantom were obtained via multiple scans at different target depths. Preliminary surface imaging studies demonstrated that the summation of multiple scans distinctly differentiated the target from artifacts (up to 3 cm deep), which was not possible from individual scans.

Hand-held based optical imagers have become a new research interest for its maximum patient comfort, less bulky instrument and potential for clinical translation towards breast cancer diagnostics. However, its ability for optical tomography is either limited by depth recovery since only reflectance measurements were obtained using a hand-held design for imaging. In this study, we introduced a self-guided multi-projection technique, which can take advantage of potential portability of hand-held probe based system, towards improvement of target depth recovery during fluorescence optical tomography studies.

Hand-held probe based optical imager has become popular towards breast imaging for its potential portability and maximum patient comfort (no compression involved), but are currently limited on three-dimensional (3-D) tumor localization. A novel hand-held probe based optical imager with unique source and detector set-up was recently developed in our laboratory towards tomographic breast imaging. With 3-D fluorescence tomography feasibility of this novel optical imager demonstrated in previous studies, extensive phantom studies under various conditions were performed to assess current system limitation on 3-D tumor/target recovery. The phantom studies have been performed on slab geometries (650 ml) under different target depths (1-2.5 cm), target volumes (0.45, 0.23 and 0.10 cc), fluorescence absorption contrast ratios (1:0, 1000:1 to 5:1), and number of targets (up to 3), using Indocyanine Green (ICG) as the fluorescence contrast agent. The fluorescence optical measurements acquired on phantom surface were applied towards an Approximate Extended Kalman Filter (AEKF) algorithm for 3-D mapping of fluorescence absorption coefficient over entire phantom volume. In most cases, the target was successfully reconstructed. Currently, the limitations in terms of resolution, depth, and volume recovery of the embedded target are assessed. Upon further experimental validation based on in-vitro and in-vivo studies, the clinical translation of this technology is promising.

Hand-held based optical imaging devices are currently developed by researchers toward clinical translation of the technology. However, the devices developed to date are limited in that they are unable to contour to different tissue curvatures, and they are not capable of coregistration which is necessary for 3D tomography. A novel hand-held based optical imager has been developed in our Optical Imaging Laboratory and tested on homogeneous tissue phantoms. The unique features of the device include (i) flexibility to contour to different tissue curvatures, (ii) simultaneous illumination for rapid data acquisition, and (iii) real-time coregistration capabilities to enable 3D tomography. Herein, studies are performed to demonstrate the ability of the hand-held device to image in vitro samples designed to better mimic the heterogeneous nature of human breast tissue. A fluorescent target (0.45 cc) filled with 1 μM indocyanine green (ICG) was used to represent a tumor and placed at different depths up to 2.5 cm within a 10x10x10 cm3 acrylic cube filled with minced chicken breast and 1% Liposyn. The hand-held device was used to recover the target location from 2D surface contour plots of the fluorescent signal. Parallely, preliminary in vivo studies have been carried out on normal human subjects using a simulated fluorescent target (0.45cc), where the probe was placed on the tissue surface with gentle compression. These studies demonstrate the potential for clinical translation of our hand-held based optical imager for real-time tomographic imaging.

Near-infrared (NIR) optical imaging is an emerging noninvasive modality for breast cancer diagnosis. The currently available optical imaging systems towards tomography studies are limited either by instrument portability, patient comfort, or flexibility to image any given tissue volume. Hence, a novel hand-held probe based gain modulated intensified CCD camera imaging system is developed such that it can possibly overcome some of the above limitations. The unique features of this hand-held probe based optical imaging system are: (i) to perform simultaneous multiple point illumination and detection, thus decreasing the total imaging time and improving overall signal strength; (ii) to adapt to the tissue contours, thus decreasing the light leakage at contact surface; and (iii) to obtain trans-illumination measurements apart from reflectance measurements, thus improving the depth information. Phantom studies are performed to demonstrate the feasibility of performing fluorescence optical imaging under different target depths using cubical phantoms (10×6.5×10 cc). The effect of simultaneous multiple point illumination over sequential single point illumination is demonstrated from experimental phantom studies.

A novel hand-held probe-based optical imager with self co-registration facilities is developed towards breast cancer diagnosis. Initial experimental studies on slab tissue phantoms have demonstrated the feasibility of co-registered measurements towards future tomography studies.

A novel hand-held probe based optical imager is developed and used to demonstrate the feasibility of three-dimensional (3-D) tomography on slab phantoms. Fluorescence target localization in 3-D is also demonstrated without tomographic analysis.

Near-infrared optical imaging is an emerging noninvasive technology toward breast cancer diagnosis. The optical imaging systems available to date are limited either by flexibility to image any given breast volume, patient comfort, or instrument portability. Here, a hand-held optical probe is designed and developed, 1. employing a unique measurement scheme of simultaneous multiple point illumination and collection for rapid data acquisition and minimal patient discomfort, and 2. employing a curved probe head such that it allows flexible imaging of tissue curvatures. Simulation studies are carried out on homogeneous slab phantoms (5×10×8 cc) to determine an appropriate source-detector configuration for the probe head. These design features are implemented in the development of the probe, which consisted of six simultaneous illuminating and 165 simultaneous collecting fibers, spaced 0.5 cm apart on a 5×10 sq-cm probe head. Simulation studies on 3-D slab and curved phantoms demonstrate an increase in the total area of predicted fluorescence amplitude and overall signal strength on using simultaneous multiple point sources over a single point source. The probe is designed and developed such that on coupling with a detection system in the future, the hand-held probe based imager can be clinically assessed toward cancer diagnostic imaging.

Near-infrared (NIR) optical imaging is an emerging noninvasive modality for breast cancer diagnosis. However, the currently available optical imaging systems towards tomography studies are limited either by instrument portability, patient comfort, or flexibility to image any given tissue volume. Herein, a hand-held based optical imaging system is developed such that it can possibly overcome some of the above limitations. The unique features of the hand-held optical probe are: (i) to perform simultaneous multiple point illumination and detection, thus decreasing the total imaging time and improving the overall signal strength; (ii) to adapt to the contour of tissue surface, thus decreasing the leakage of excitation and emission signal at contact surface; and (iii) to obtain trans-illumination measurements apart from reflectance measurements, thus improving the depth information. The increased detected signal strength as well as total interrogated tissue volume is demonstrated by simulation studies (i.e. forward model) over a 5×10×10 cc slab phantom. The appropriate number and layout of the source and detection points on the probe head is determined and the hand-held optical probe is developed. A frequency-domain ICCD (intensified charge coupled device) detection system, which allows simultaneous multiple points detection, is developed and coupled to the hand-held probe in order to perform fluorescence-enhanced optical imaging of tissue phantoms. In the future, imaging of homogenous liquid phantoms will be used for the assessment of this hand-held system, followed by extensive imaging studies on different phantoms types under various experimental conditions.

A hand-held probe based optical optical imager has recently been developed towards three-dimensional tomography. In this study, the improvement of target depth recovery was demonstrated using a multi-projection technique on large slab phantoms using 0.45 cc fluorescing target(s) (with 1:0 contrast ratio) of 1.5 to 2.5 cm deep. Tomographic results using single- and multi (here dual) projection measurements (with and without a priori information of target location) were compared. In all experimental cases, the use of multi-projection measurements along with a priori information recovered target depth and location closer to its true values, demonstrating its applicability for clinical translation.

Near-infrared optical imaging holds a promise as a noninvasive technology toward cancer diagnostics and other tissue imaging applications. In recent years, hand-held based imagers are of great interest toward the clinical translation of the technology. However hand-held imagers developed to date are typically designed to obtain surface images and not tomography information due to lack of coregistration facilities. Herein, a recently developed hand-held probe-based optical imager in our Optical Imaging Laboratory has been implemented with novel coregistration facilities toward real-time and tomographic imaging of tissue phantoms. Continuous-wave fluorescence-enhanced optical imaging studies were performed using an intensified charge coupled device camera based imaging system in order to demonstrate the feasibility of automated coregistered imaging of flat phantom surfaces, using a flexible probe that can also contour to curvatures. Three-dimensional fluorescence tomographic reconstructions were also demonstrated using coregistered frequency-domain measurements obtained using the hand-held based optical imager. It was also observed from preliminary studies on cubical phantoms that multiple coregistered scans differentiated deeper targets (approximately 3 cm) from artifacts that were not feasible from a single coregistered scan, demonstrating the possibility of improved target depth detectability in the future.

Hand-held probe based optical imagers are popular towards breast imaging due to their potential portability and maximum patient comfort. Recently, a novel hand-held probe based optical imager has been developed and its feasibility for three-dimensional fluorescence tomographic imaging demonstrated. Herein, extensive tomography studies were performed on large slab phantoms (650 ml) in order to assess the performance limits of the hand-held imager. Experiments were performed using different target volumes (0.1–0.45 cc), target depths (1–3 cm), and fluorescence (Indocyanine Green) absorption contrast ratios in a non-fluorescing (1:0) and constant fluorescing backgrounds (1000:1-5:1). The estimated sensitivity and specificity of the hand-held imager is 43% and 95%, respectively.