Deep-learning approach to stratified reconstructions of tissue absorption and scattering in time-domain spatial frequency domain imaging.

Significance: The conventional optical properties (OPs) reconstruction in spatial frequency domain (SFD) imaging, like the lookup table (LUT) method, causes OPs aliasing and yields only average OPs without depth resolution. Integrating SFD imaging with time-resolved (TR) measurements enhances space-TR information, enabling improved reconstruction of absorption (µa) and reduced scattering (µs') coefficients at various depths. Aim: To achieve the stratified reconstruction of OPs and the separation between µa and µs', using deep learning workflow based on the temporal and spatial information provided by time-domain SFD imaging technique, while enhancing the reconstruction accuracy. Approach: Two data processing methods are employed for the OPs reconstruction with TR-SFD imaging, one is full TR data, and the other is the featured data extracted from the full TR data (E, continuous-wave component, ⟨t⟩, mean time of flight). We compared their performance using a series of simulation and phantom validations. Results: Compared to the LUT approach, utilizing full TR, E and ⟨t⟩ datasets yield high-resolution OPs reconstruction results. Among the three datasets employed, full TR demonstrates the optimal accuracy. Conclusions: Utilizing the data obtained from SFD and TR measurement techniques allows for achieving high-resolution separation reconstruction of µa and µs' at different depths within 5 mm.

Wide-field illumination diffuse optical tomography within a framework of single-pixel time-domain spatial frequency domain imaging.

We present a wide-field illumination time-domain (TD) diffusion optical tomography (DOT) for three-dimensional (3-D) reconstruction within a shallow region under the illuminated surface of the turbid medium. The methodological foundation is laid on the single-pixel spatial frequency domain (SFD) imaging that facilitates the adoption of the well-established time-correlated single-photon counting (TCSPC)-based TD detection and generalized pulse spectrum techniques (GPST)-based reconstruction. To ameliorate the defects of the conventional diffusion equation (DE) in the forward modeling of TD-SFD-DOT, mainly the low accuracy in the near-field region and in profiling early-photon migration, we propose a modified model employing the time-dependent δ-P1 approximation and verify its improved accuracy in comparison with both the Monte Carlo and DE-based ones. For a simplified inversion process, a modified GPST approach is extended to TD-SFD-DOT that enables the effective separation of the absorption and scattering coefficients using a steady-state equivalent strategy. Furthermore, we set up a single-pixel TD-SFD-DOT system that employs the TCSPC-based TD detection in the SFD imaging framework. For assessments of the reconstruction approach and the system performance, phantom experiments are performed for a series of scenarios. The results show the effectiveness of the proposed methodology for rapid 3-D reconstruction of the absorption and scattering coefficients within a depth range of about 5 mean free pathlengths.

Extended Kalman filtering for enhancing a cyclic pattern-updating scheme of single-pixel dynamic fluorescence spatial frequency domain imaging: publisher's note.

This publisher's note contains a correction to Opt. Lett.48, 5443 (2023)10.1364/OL.495099.

Extended Kalman filtering for enhancing a cyclic pattern-updating scheme of single-pixel dynamic fluorescence spatial frequency domain imaging.

A single-pixel imaging technique applied to fluorescence spatial frequency domain imaging (f-SFDI) brings many positive benefits, but its low frame rate will also lead to severe quantitative degradation when dynamically imaging a vibrant target. This work presents a novel, to the best of our knowledge, single-pixel imaging approach that combines the extended Kalman filtering (EKF) and a cyclic one-pattern updating for an enhanced dynamic f-SFDI. The cyclic one-pattern updating scheme enables the dynamic imaging at a high frame rate, and on this basis, the imaging process of an intensity temporally varying target (assuming no structure motion in the scene) is dynamically modelled, and accordingly, the surface intensities and images at each sampling time point simultaneously estimated via the EKF. Simulation and phantom validations demonstrate that the method can improve the quantitative accuracy of the results. An in vivo experiment performed on two mice for dynamic monitoring of photosensitizer doses in a photodynamic therapy further demonstrates the clinical feasibility of the proposed method.

Profile-based intensity and frequency corrections for single-snapshot spatial frequency domain imaging.

We have proposed the profile-based intensity and frequency corrections for single-snapshot spatial frequency domain (SFD) imaging to mitigate surface profile effects on the measured intensity and spatial frequency in extracting the optical properties. In the scheme, the spatially modulated frequency of the projected sinusoidal pattern is adaptively adjusted according to the sample surface profile, reducing distortions of the modulation amplitude in the single-snapshot demodulation and errors in the optical property extraction. The profile effects on both the measured intensities of light incident onto and reflected from the sample are then compensated using Minnaert's correction to obtain the true diffuse reflectance of the sample. We have validated the method by phantom experiments using a highly sensitive SFD imaging system based on the single-pixel photon-counting detection and assessed error reductions in extracting the absorption and reduced scattering coefficients by an average of 40% and 10%, respectively. Further, an in vivo topography experiment of the opisthenar vessels has demonstrated its clinical feasibility.

Multi-wavelength spatial frequency domain diffuse optical tomography using single-pixel imaging based on lock-in photon counting.

We present a spatial frequency domain (SFD) diffuse optical tomography for simultaneous acquisition of multi-wavelength tomographic images of turbid media. We propose a highly sensitive single-pixel SFD imaging system for simultaneously collecting multi-wavelength spatially modulated reflectance images, instead of using the expensive electron-multiplying charge-coupled device camera that requires switching between the multi-wavelength collections. The single-pixel SFD imaging system using three low-power light sources (455, 532 and 660 nm) that were intensity-modulated by square waves with three different frequencies for frequency encoding, and all the light sources were focused onto one digital micromirror device (DMD) for generating wide-field sinusoidal illumination patterns. Reflected light from the surface of the turbid media was modulated by the other DMD with many sampling patterns before being spatially integrated. Spatially integrated light signals were frequency decoded with a novel highly sensitive lock-in photon counting detection, then multi-wavelength spatially modulated reflectance images were recovered with the single-pixel imaging (SPI) method. We incorporated the two-dimensional discrete cosine transform (DCT) into the SPI method to reduce the number of sampling patterns, and, thereby, the proposed DCT-SPI scheme achieved a fast acquisition of SFD reflectance images that is desired for a dynamic SFD imaging application. Direct current (DC) and alternating current (AC) amplitudes at all the locations on the media surface were extracted from the recovered images. Multi-wavelength tomographic images were reconstructed with an inversion algorithm based on the first-order Rytov approximation of the diffusion equation, using both the extracted DC and AC amplitudes. We performed experiments using a series of tissue simulating phantoms to verify the performances of the proposed approach and compared the experimental results with those using a conventional camera-based SFD imaging system. The results demonstrate that our DCT-SPI based SFD-DOT approach is well suited for simultaneous reconstruction of multi-wavelength tomographic images to pave the way for many SFD imaging applications.

Sparsity-regularized approaches to directly reconstructing hemodynamic response in brain functional diffuse optical tomography.

In brain functional diffuse optical tomography, conventional indirect approaches first separately reconstruct the spatial changes in the absorption coefficients at every time point and then calculate the spatial excited levels in terms of hemodynamic models. Direct approaches combine the two steps necessary in the indirect approaches and obtain the spatial excited levels directly. Although reconstruction quality has been improved by the direct approaches to some extent, they still lack sharp edges and suffer from low spatial resolution because of the ill-posedness of the inverse problems. In this paper, a priori sparsity is introduced to obtain the sparse solutions and further improve reconstruction quality. Simulation experiments are conducted to illustrate the expected performance improvements of the proposed approaches.

Clinical value of monitoring serum C1q and CTRP1 levels in patients with coronary heart disease / 中华检验医学杂志

Objective@#To explore the relationship between serum complement 1q (C1q) and C1q/tumor necrosis factor-related protein 1 (CTRP1) levels in patients with coronary atherosclerotic heart disease (CHD) and their clinical value.@*Methods@#Case-control study.115 patients with CHD who were hospitalized in the Department of Cardiology of Ningxia Medical University General Hospital from January 2018 to November 2018 were selected as the case group, including 72 males and 43 females, aged 35-82 years, average (59.96±9.49) years old. There were three subgroups: stable angina group (SAP, n=12), unstable angina group (UA, n=69), and acute myocardial infarction group (AMI, n=34). The control group was selected from 43 healthy subjects in the same period, including 21 males and 22 females, aged 23-71 years, with an average of (45.00±10.66) years old. Serum C1q and CTRP1 levels were tested by immunoturbidimetry and ELISA, and other biochemical indicators such as triglyceride (TG) and total cholesterol (CHOL) were detected.Multiple linear regression was used to analyze the influence of various factors on C1q level. ROC curve and area under the curve (AUC) to explore the diagnostic value of C1q and CTRP1.@*Results@#The C1q level in the CHD group (184.06±31.05) mg/L was higher than that in the control group (122.22±28.18) mg/L (t=-11.405, P<0.001). The AMI group (192.80±34.08) mg/L was significantly higher than the SAP group (169.17±27.13) mg/L (t=-2.328, P=0.021).The CTRP1 level in the CHD group [241.85(79.38)] ng/ml was lower than that in healthy control group [292.7(67.64)] ng/ml (Z=-3.64, P<0.001). Group B with higher Gensini score (t=3.672, P<0.001) and group C (t=2.529, P=0.013) had higher C1q levels than group A.After adjusting for the effects of age, sex and other indicators, C1q levels were correlated with HDL-C (β=-0.582, P<0.001),CHOL (β=0.384,P<0.001) and systolic blood pressure (β=0.142,P=0.038). The ROC curve shows that when the CHD is diagnosed, the sensitivity of C1q level >150.82 mg/L is 87%,the specificity is 88.4%, and the AUC is 0.942. The corresponding sensitivity and specificity of CTRP1 <281.80 ng/ml are 76.5% and 60.5% respectively, and the AUC is 0.688. The AUC obtained by combined predictors was 0.944, and the sensitivity and specificity were 89.6% and 86.0% respectively. When AMI is diagnosed, C1q level >178.3 mg/L, corresponding sensitivity and specificity are 70.6% and 66.1%, the AUC is 0.726, CTRP1 has no diagnostic value.@*Conclusions@#Serum C1q levels in patients with CHD are elevated, and AMI patients are higher than SAP patients; C1q may be a potential marker reflecting the severity of coronary artery disease; there is no significant correlation between serum C1q and CTRP1 in CHD patients.

Clinical value of monitoring serum C1q and CTRP1 levels in patients with coronary heart disease / 中华检验医学杂志

Objective To explore the relationship between serum complement 1q (C1q) and C1q/tumor necrosis factor-related protein 1 (CTRP1) levels in patients with coronary atherosclerotic heart disease (CHD) and their clinical value.Methods Case-control study.115 patients with CHD who were hospitalized in the Department of Cardiology of Ningxia Medical University General Hospital from January 2018 to November 2018 were selected as the case group, including 72 males and 43 females, aged 35-82 years, average (59.96 ± 9.49) years old. There were three subgroups: stable angina group (SAP, n=12), unstable angina group (UA,n=69), and acute myocardial infarction group (AMI, n=34). The control group was selected from 43 healthy subjects in the same period, including 21 males and 22 females, aged 23-71 years, with an average of (45.00 ± 10.66) years old. Serum C1q and CTRP1 levels were tested by immunoturbidimetry and ELISA, and other biochemical indicators such as triglyceride (TG) and total cholesterol (CHOL) were detected.Multiple linear regression was used to analyze the influence of various factors on C1q level. ROC curve and area under the curve (AUC) to explore the diagnostic value of C1q and CTRP1. Results The C1q level in the CHD group (184.06±31.05) mg/L was higher than that in the control group (122.22±28.18) mg/L (t=-11.405, P<0.001). The AMI group (192.80 ± 34.08) mg/L was significantly higher than the SAP group (169.17 ± 27.13) mg/L (t=-2.328, P=0.021). The CTRP1 level in the CHD group [241.85(79.38)] ng/ml was lower than that in healthy control group [292.7(67.64)] ng/ml (Z=-3.64, P<0.001). Group B with higher Gensini score (t=3.672, P<0.001) and group C (t=2.529, P=0.013) had higher C1q levels than group A.After adjusting for the effects of age, sex and other indicators, C1q levels were correlated with HDL-C (β=-0.582, P<0.001),CHOL (β=0.384,P<0.001) and systolic blood pressure (β=0.142,P=0.038). The ROC curve shows that when the CHD is diagnosed,the sensitivity of C1q level>150.82 mg/L is 87％,the specificity is 88.4％, and the AUC is 0.942. The corresponding sensitivity and specificity of CTRP1<281.80 ng/ml are 76.5％and 60.5％ respectively, and the AUC is 0.688. The AUC obtained by combined predictors was 0.944, and the sensitivity and specificity were 89.6％ and 86.0％ respectively. When AMI is diagnosed, C1q level >178.3 mg/L, corresponding sensitivity and specificity are 70.6％ and 66.1％, the AUC is 0.726, CTRP1 has no diagnostic value. Conclusions Serum C1q levels in patients with CHD are elevated,and AMI patients are higher than SAP patients;C1q may be a potential marker reflecting the severity of coronary artery disease;there is no significant correlation between serum C1q and CTRP1 in CHD patients.

Surgical methods and efficacies for cervicothoracolumbar spinal schwannoma.

The aim of this study was to investigate the surgical methods and efficacies for cervicothoracolumbar spinal schwannoma (CSS). A total of 52 patients who had undergone treatment for schwannoma were retrospectively analyzed. Two methods were employed for the surgical resection of the thoracic and lumbar schwannomas: Type I (posterior midline approach semi-laminectomy with tumor resection and internal fixation with pedicle screws) was used in 24 cases, and type II (posterior midline approach laminectomy with tumor resection and internal fixation with pedicle screws) was used in 26 cases. Two cases of giant cervical schwannoma were treated via anterior-posterior combined surgery. Histopathological examination confirmed the diagnosis of schwannoma in all cases (n=52). The clinical status of the patients was evaluated pre- and postoperatively using the visual analog scale, Oswestry Disability Index and Japanese Orthopedic Association scale, and the scores associated with the two types of surgical method were compared. Within the follow-up period, which lasted between 6 months and 3 years, no recurrence was detected, and such preoperative symptoms as radicular pain and spinal dysfunction were improved significantly. The numbness and hyperesthesia were relieved to different extents. In conclusion, methods of exposing and surgically treating CSS should be selected according to the growth site of the schwannoma in order to reduce the blood loss and surgery duration and to improve the surgical safety.

Treatment of thoracolumbar deformity with transpedicular eggshell technique / 中国骨伤

<p><b>OBJECTIVE</b>To evaluate the clinical effects of transpedicular eggshell technique in treating thoracolumbar deformity.</p><p><b>METHODS</b>From December 2008 to December 2011,36 patients with thoracolumbar deformity were treated with transpedicular eggshell technique. There were 20 males and 16 females with an average age of 45 years old (ranged from 20 to 58). Among them, 5 cases were congenital hemivertebrae deformity, 12 cases were secondary to tuberculotic deformity, 14 cases were post-traumatic deformity with pain, 5 cases were ankylosing spondylitis. Low back pain, living ability, scoliotic Cobb angle were analyzed according to VAS scoring, Oswestry Disability Index (ODI), radiological examination.</p><p><b>RESULTS</b>Average operative time was 245 min and average bleeding was 1 900 ml in 36 patients. All patients were followed up more than 1 year and obtained bone fusion at 1 year after operation. Preoperative,postoperative at 1 week and 1 year, VAS scoring was 7.2 +/- 1.4, 2.5 +/- 1.0, 1.8 +/- 0.5, respectively; ODI was (72.50 +/- 10.80)%, (42.50 +/- 11.10)%, (22.50 +/- 7.90)%, respectively; kyphosis Cobb angle was (76.31 +/- 2.52) degrees, (23.66 +/- 1.16) degrees, (23.67 +/- 1.16) degrees, respectively; lumbar scoliosis Cobb angle was (71.86 +/- 4.02) degrees, (30.81 +/- 2.33) degrees, (30.82 +/- 2.32) degrees, respectively. Postoperative at 1 week and 1 year,above data had obviously improved than that of preoperative (P < 0.05); and there was no significant difference in Cobb angle between postoperative at 1 week and postoperative at 1 year (P > 0.05).</p><p><b>CONCLUSION</b>Treatment of thoracolumbar deformity with transpedicular eggshell technique could obtain effective correcting and clinical results.</p>

Pathological observation of lung injury in experimental animals induced by non-ferrous metal (tin) dusts / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To explore the characters of lung injury induced by tin dusts and to provide the diagnosis evidence of tin pneumoconiosis.</p><p><b>METHODS</b>Forty SD rats were randomly divided into four groups: the group exposed to tin dusts from smelting workshop, the group exposed to tin dusts from tin refining workshop, the positive control group exposed to standard quartz dusts and the negative control group exposed to saline. The pathological changes of rat lungs were observed dynamically.</p><p><b>RESULTS</b>In rats exposed to tin dusts, on the 30th day after exposure to tin dusts, the scattered hoar tip size of the spots in surface and section of the lungs were observed, the scattered focal granulomatous inflammation around the small bronchi and dust particles in lung tissue were observed under microscope; on the 90th day after exposure to tin dusts, the granulomatous inflammation increase, the fibroblasts proliferation, collagen fibers formation and positive VG staining were found. There were significant differences, as compared with positive or negative controls (P < 0.05). These pathological changes were basically the characters of specific pathological changes in early tin pneumoconiosis.</p><p><b>CONCLUSION</b>Non-ferrous metal tin dusts can induce the specific lung injury (granuloma formation) in lung tissue of rats exposed to tin dusts, which fulfilled the diagnostic criteria of specific pathological changes in early tin pneumoconiosis.</p>

Continuous in situ monitoring of the dissolution rate of solid pharmaceutical preparations using a multiple channel fiber-optic chemical sensor / 药学学报

<p><b>AIM</b>To study the dissolution rate of solid pharmaceutical preparation on-line, a multiple channel fiber-optic chemical sensor based on fluorescence multiple quenching (FOCSMQ) without filtering and sampling was made.</p><p><b>METHODS</b>Using the multiple channel FOCSMQ linked with computer, the dissolution rates of ofloxacin tablets, metronidazole tablets and nitrofurantoin tablets were monitored continuously on-line. The instrument can give the sample data, display the real time curve and calculate the T1/2 and td automatically. A computer was used to select the best function from five common fitting models to fit the dissolution curve.</p><p><b>RESULTS</b>The average recoveries of the FOCSMQ method were 97.4%-104.4%, 97.4%-103.8% and 96.6%-102.1%. The RSDs (n = 6) of within-day and between-day were less than 5%. The parameters of the dissolution and all results of measurement using the instrument have no significant difference compared with the Chinese Pharmacopoeia (ChP) (2000) method and the United States Pharmacopoeia (USP) (23) method (P > 0.05). It does not need sampling and dilution, and never contaminate sample. It can shorten time of the experiment.</p><p><b>CONCLUSION</b>The method is simple, rapid and reliable.</p>