Demonstration Study of Reflector-Based Volumetric Speed-of-Sound Imaging With Linear Ultrasound Arrays.

Conventional B-mode ultrasound imaging has difficulty in delineating homogeneous soft tissues with similar acoustic impedances, as the reflectivity depends on the acoustic impedance at the interface. As a quantitative imaging biomarker sensitive to alteration of biomechanical properties, speed-of-sound (SoS) holds promising potential for tissue and disease differentiation such as delineation of different breast tissue types with similar acoustic impedance. Compared to two-dimensional (2D) SoS images, three-dimensional (3D) volumetric SoS images achieved through a full-angle ultrasound scan can reveal more intricate morphological structures of tissues; however, they generally require a ring transducer. In this study, we introduce a 3D SoS reconstruction system that utilizes hand-held linear arrays instead. This system employs a passive reflector positioned opposite the linear arrays, serving as an echogenic reference for time-of-flight (ToF) measurements, and a high-definition camera to track the location corresponding to each group of transmit-receive data. To merge these two streams of ToF measurements and location tracking, a voxel-based reconstruction algorithm is implemented. Experimental results with gelatin phantom and ex vivo tissue have demonstrated the stability of our proposed method. Moreover, the results underscore the potential of this system as a complementary diagnostic modality, particularly in the context of diseases such as breast cancer.

Short-Term Changes in Weight, Body Composition, and Metabolic Biomarkers After Laparoscopic Sleeve Gastrectomy in Patients with Obesity: A Comparative Prospective Study.

PURPOSE: To investigate the changes in weight, body composition, and metabolic biomarkers in patients with obesity after laparoscopic sleeve gastrectomy (LSG) and compare those changes between patients with and without metabolic syndrome (MS). MATERIALS AND METHODS: This retrospective longitudinal study included 76 patients who underwent LSG, among whom 32 had complete 1-year postoperative body composition and metabolic biomarkers. Body composition was measured by quantitative CT. Weight changes were compared between the MS and non-MS groups at 1-, 3-, 6-, and 12-month post-LSG in all patients; changes in body compositions and metabolic biomarkers from one day pre-LSG to 12-month post-LSG were also compared in those 32 patients. RESULTS: MS occurred in 46% (35/76) of all patients and 44% (14/32) of patients with complete follow-up data. Excess weight loss was lower in the MS group than that in the non-MS group at 1-, 3-, 6-, and 12-month post-LSG; the 12-month difference was significant (MS vs. non-MS: 0.91 ± 0.22 vs. 1.07 ± 0.42, P = 0.04). The greatest rate of visceral fat area (VFA) change occurred 12-month post-LSG in both the non-MS [0.62(0.55,0.7)] and MS [0.6(0.51,0.63)] groups. The most significant reduction in ectopic fat occurred in liver fat (LF) [non-MS, 0.45(0.22,0.58); MS, 0.39(0.23,0.58)]. CONCLUSION: LGS significantly improves weight, body composition, and metabolic biomarkers in populations with obesity, regardless of whether they have MS. Among the body composition, VFA and LF were the most significantly improved body composition measurements.

Intradural fat graft packing is not indispensable in preventing postoperative cerebrospinal fluid leakage in endoscopic endonasal pituitary adenoma surgeries.

Objectives: Is intradural fat graft packing indispensable in preventing postoperative cerebrospinal fluid leakage in endoscopic endonasal pituitary adenoma surgeries? This study aimed to review the methods and outcomes of our graded sellar floor reconstruction strategy without fat graft packing in endoscopic endonasal pituitary adenoma surgeries. Methods: From March 2018 to December 2022, 200 patients underwent endoscopic endonasal pituitary adenoma resection by a single author in our institute. We applied different graded skull base reconstruction strategies in different periods. Intradural fat graft packing was used to reconstruct the skull base in the early period, from March 2018 to June 2019, but fat graft was not used in the late period, from January 2020 to December 2022. The effect of these different graded skull base reconstruction strategies and whether intradural fat graft packing is necessary were evaluated by observing the incidence of postoperative cerebrospinal fluid leak. Results: In the early period, fat graft was used to reconstruct skull base when the intraoperative cerebrospinal fluid (CSF) leakage existed. There were two patients who suffered from postoperative cerebrospinal fluid leak in this group. In the late period, fat graft was not used to reconstruct the skull base, and no patient suffered from postoperative cerebrospinal fluid leakage in this group. Conclusions: Intradural fat graft packing is unnecessary in the endoscopic endonasal pituitary adenoma resection. The outcome of our graded sellar floor reconstruction strategy is satisfactory.

Diffusion-relaxation correlation spectrum imaging for predicting tumor consistency and gross total resection in patients with pituitary adenomas: a preliminary study.

OBJECTIVE: To evaluate the ability of diffusion-relaxation correlation spectrum imaging (DR-CSI) to predict the consistency and extent of resection (EOR) of pituitary adenomas (PAs). METHODS: Forty-four patients with PAs were prospectively enrolled. Tumor consistency was evaluated at surgery as either soft or hard, followed by histological assessment. In vivo DR-CSI was performed and spectra were segmented following to a peak-based strategy into four compartments, designated A (low ADC), B (mediate ADC, short T2), C (mediate ADC, long T2), and D (high ADC). The corresponding volume fractions ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]) along with the ADC and T2 values were calculated and assessed using univariable analysis for discrimination between hard and soft PAs. Predictors of EOR > 95% were analyzed using logistic regression model and receiver-operating-characteristic analysis. RESULTS: Tumor consistency was classified as soft (n = 28) or hard (n = 16). Hard PAs presented higher [Formula: see text] (p = 0.001) and lower [Formula: see text] (p = 0.013) than soft PAs, while no significant difference was found in other parameters. [Formula: see text] significantly correlated with the level of collagen content (r = 0.448, p = 0.002). Knosp grade (odds ratio [OR], 0.299; 95% confidence interval [CI], 0.124-0.716; p = 0.007) and [Formula: see text] (OR, 0.834, per 1% increase; 95% CI, 0.731-0.951; p = 0.007) were independently associated with EOR > 95%. A prediction model based on these variables yielded an AUC of 0.934 (sensitivity, 90.9%; specificity, 90.9%), outperforming the Knosp grade alone (AUC, 0.785; p < 0.05). CONCLUSION: DR-CSI may serve as a promising tool to predict the consistency and EOR of PAs. CLINICAL RELEVANCE STATEMENT: DR-CSI provides an imaging dimension for characterizing tissue microstructure of PAs and may serve as a promising tool to predict the tumor consistency and extent of resection in patients with PAs. KEY POINTS: • DR-CSI provides an imaging dimension for characterizing tissue microstructure of PAs by visualizing the volume fraction and corresponding spatial distribution of four compartments ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]). • [Formula: see text] correlated with the level of collagen content and may be the best DR-CSI parameter for discrimination between hard and soft PAs. • The combination of Knosp grade and [Formula: see text] achieved an AUC of 0.934 for predicting the total or near-total resection, outperforming the Knosp grade alone (AUC, 0.785).

An Instant Underwater Tissue Adhesive Composed of Catechin-Chondroitin Sulfate and Cholesterol-Polyethyleneimine.

Due to the safety issue and poor underwater adhesion of current commercially available bioadhesives, they are hard to apply to in vivo physiological environments and more diverse medical use conditions. In this study, a novel and facile bioadhesive for underwater medical applications are designed based on the coacervation of electrostatic interactions and hydrophobic interactions, with the introduction of catechin as a provider of catechol moieties for adhesion to surrounding tissues. The orange-colored bio-adhesive, named PcC, is generated within seconds by mixing catechin-modified chondroitin sulfate and cholesterol chloroformate-modified polyethyleneimine with agitation. In vitro mechanical measurements prove that this novel PcC bio-adhesive is superior in underwater adhesion performance when applied to cartilage. Animal experiments in a rat mastectomy model and rat cartilage graft implantation model demonstrate its potential for diverse medical purposes, such as closing surgical incisions, reducing the formation of seroma, and tissue adhesive applied in orthopedic or cartilage surgery.

Engineering strategies to achieve efficient in vitro expansion of haematopoietic stem cells: development and improvement.

Haematopoietic stem cells are the basis for building and maintaining lifelong haematopoietic mechanisms and an important resource for the treatment of blood disorders. Haematopoietic niches are a microenvironment in the body where stem cells tend to accumulate, with some nurse cells protecting and regulating stem cells. On the basis of biology, materials science, and engineering, researchers have constructed stem cell niches to address the current clinical shortage of stem cells and to explore stem cell behaviour for biomedical research. Herein, three main resource categories involved in haematopoietic stem cell niche engineering are reviewed: first, the basic approach to construct bionic cell culture environments is to use cytokines, nurse cells or extracellular matrix; second, microscale technologies are applied to mimic the properties of natural stem cell niches; and finally, biomaterials are used to construct the three-dimensional extracellular matrix-like culture environment.

Early outcomes of endoscopic endonasal approach pituitary adenomas resection with minimal nasal injury.

ABSTRACT: To report the results of a consecutive series of pituitary adenomas resected through endoscopic endonasal approach (EEA) with minimal nasal injury.Retrospectively review tumor characteristics and surgical outcomes of a consecutive series of EEA pituitary adenomas resection performed mainly by a single author between March 2018 and June 2019.A total of 75 endoscopic endonasal approach pituitary adenoma resections were performed by the authors' team. Of the 75 patients, 28 through mononostril EEA, 47 through Binonostril EEA. Hadad-Bassagasteguy vascularized nasoseptal flap was harvested in only 4 (5.3%) patients with a high risk of postoperative cerebrospinal fluid leak, and one side middle turbinate only been resected in 2 (2.7%) patients, other patients preserved bilateral middle turbinate. Of the 75 patients, gross total resection is 74.7%, near-total resection is 16.0%. Endocrinological remission was achieved in 76.9% of GH-secreting adenomas, 61.5% of prolactin-secreting adenomas. The postoperative cerebrospinal fluid leak rate was 2.7%. Two patients had suprasellar hemorrhage, 1 patient had perioperative stroke, 2 patients had permanent diabetes insipidus, no cranial nerve deficits, internal carotid artery injury, anosmia, and death. The sino-nasal function was measured with the Sino-Nasal Outcome Test-22 and visual analog scale for olfaction preoperatively and postoperatively, and there was no statistically significant difference.The EEA is an effective approach to resect pituitary adenomas, the gross total resection and near-total resection rate and endocrinological remission rate are satisfactory. The EEA is a safe approach, as the complication rate is acceptable compared with those reported in the previous series of microscopic and endoscopic approaches. These results can be achieved with minimal nasal injury.

Multispectral photoacoustic holography of elastomers from a bright background.

Photoacoustic imaging of elastomers has important biomedical value. However, a bright background, e.g., blood vessels in living tissue, brings a challenge for photoacoustic elastography. In this study, we predicted that the spectrum of photoacoustic signals from elastomers with high elasticity could appear as narrow peaks at the eigen-frequencies of elastomers, but the signals from a bright background, e.g., blood vessel, show flat broadband spectrum for their low-quality factor. Even when the two kinds of signals are mixed together, the signals from elastomers can be identified from the spectrum since they present as convex narrow peaks on a wide base. Based on this factor, we propose a multispectral photoacoustic holography to realize selective imaging of tiny elastomers. This method recovers the image only using several frequency components in photoacoustic signals, instead of the whole-band signal. Since these narrow peaks in the spectrum correspond to the eigen-vibration of elastomers, the proposed method can highlight the elastomers with high elasticity from a bright background with low elasticity. The method was validated by experiments. This study might be helpful to localize elastic anomalous areas in the tissue, such as calcification in the vascular network, microcalcification in a tumor, and implants.

Trileaflet Aortic Valve Reconstruction Using Bovine Pericardium.

AIM: For several years now, trileaflet aortic valve reconstruction has been performed in patients with various aortic valve diseases. This study aimed to explore the feasibility and durability of trileaflet aortic valve reconstruction with bovine pericardium. METHOD: Trileaflet aortic valve reconstruction with bovine pericardium was performed in 519 patients with various aortic valve diseases from April 2008 to December 2019. The results for all 519 patients were reviewed retrospectively. Mean age was 48.04±19.08 years (range, 13-80 years), and 40 patients were younger than 18 years of age. Thirty-four (34) patients had aortic stenosis, 344 patients had aortic regurgitation, and 141 patients had both aortic stenosis and regurgitation. One hundred and fifty-four (154) patients had bicuspid aortic valves, and three patients had quadricuspid aortic valves. The size of the pericardial leaflets was designed to be individually proportional to the size of the aortic root. RESULTS: Mean length of follow-up was 41.97±22.68 years (range, 1-127 months). In total, 448 patients were reviewed, and the follow-up rate was 86.4%. All procedures were successful without conversion to prosthetic valve replacement during the procedure. Six (6) patients died after the procedure (in-hospital mortality, 1.2%). All-cause mortality occurred in 11 patients during the follow-up period. The 10-year cumulative survival rate was 94.7%±2.9%. Redo aortic valve surgery was performed in 11 patients after the procedure. The actuarial freedom from redo aortic valve surgery after the procedure was 88.2%±5.2%. At the end of the follow-up, the mean peak was 29.1±9.6 mmHg and mean gradient was 15.6±6.2 mmHg. CONCLUSIONS: The mid- and long-term outcomes in patients with various aortic valve diseases undergoing trileaflet aortic valve reconstruction with bovine pericardium are encouraging. The engineered pericardial leaflets should be individually proportional to the size of the aortic root.

Circ0120816 acts as an oncogene of esophageal squamous cell carcinoma by inhibiting miR-1305 and releasing TXNRD1.

BACKGROUND: Circular RNAs (circRNAs) have been discovered to participate in the carcinogenesis of multiple cancers. However, the role of circRNAs in esophageal squamous cell carcinoma (ESCC) progression is yet to be properly understood. This research aimed to investigate and understand the mechanism used by circRNAs to regulate ESCC progression. METHODS: Bioinformatics analysis was first performed to screen dysregulated circRNAs and differentially expressed genes in ESCC. The ESCC tissue samples and adjacent normal tissue samples utilized in this study were obtained from 36 ESCC patients. All the samples were subjected to qRT-PCR analysis to identify the expression of TXNRD1, circRNAs, and miR-1305. Luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay were later conducted to verify the existing relationship among circ0120816, miR-1305 and TXNRD1. CCK-8, BrdU, cell adhesion, cell cycle, western blot and caspase 3 activity assays were also employed to evaluate the regulation of these three biological molecules in ESCC carcinogenesis. To evaluate the effect of circ0120816 on ESCC tumor growth and metastasis, the xenograft mice model was constructed. RESULTS: Experimental investigations revealed that circ0120816 was the highest upregulated circRNA in ESCC tissues and that this non-coding RNA acted as a miR-1305 sponge in enhancing cell viability, cell proliferation, and cell adhesion as well as repressing cell apoptosis in ESCC cell lines. Moreover, miR-1305 was observed to exert a tumor-suppressive effect in ESCC cells by directly targeting and repressing TXNRD1. It was also noticed that TXNRD1 could regulate cyclin, cell adhesion molecule, and apoptosis-related proteins. Furthermore, silencing circ0120816 was found to repress ESCC tumor growth and metastasis in vivo. CONCLUSIONS: This research confirmed that circ0120816 played an active role in promoting ESCC development by targeting miR-1305 and upregulating oncogene TXNRD1.

Autologous cell membrane coatings on tissue engineering xenografts for suppression and alleviation of acute host immune responses.

Xenogeneic extracellular matrix (ECM) based tissue engineering graft is one of the most promising products for transplantation therapies, which could alleviate the pain of patients and reduce surgery cost. However, in order to put ECM based xenografts into clinical use, the induced inflammatory and immune responses have yet to be resolved. Cell membrane is embedded with membrane proteins for regulation of cell interactions including self-recognition and potent in reducing foreign body rejections. In this study, a novel and facile method for evasion from immune system was developed by coating autologous red blood cell membrane as a disguise on xenogeneic ECM based tissue engineering graft surface. Porcine source Living Hyaline Cartilage Graft (LhCG) and decellularized LhCG (dLhCG) established by our group for cartilage tissue engineering were chosen as model grafts. The cell membrane coating was quite stable on xenografts with no obvious decrease in amount for 4 weeks. The autologous cell membrane coated xenograft has been proved to be recognized as "self" by immune system on cell, protein and gene levels according to the 14-day lasting in vivo study on rats with less inflammatory cells infiltrated and low inflammation-related cytokines gene expression, showing alleviated acute immune and inflammatory responses.

Multiple information extracted from photoacoustic radio-frequency signal and the application on tissue classification.

Photoacoustic imaging is a hybrid biomedical imaging technique, combining rich optical contrasts and good acoustic resolution in deep tissues. As a noninvasive and nonionized imaging method, photoacoustic imaging has shown great potentials in biomedicine in the past decade. In this review, we give a brief introduction of the physical principle and three major implementations of photoacoustic imaging. Then, we present pictures of some recent progress about the extraction of new imaging parameters from photoacoustic radio-frequency signals. These parameters are highly associated with the tissue microstructure characteristics, including characteristic size, number density, and elasticity. This information could give us insight into various properties of tissue in-depth and be applied to tissue classification for basic research and clinical settings.

''Chimney'' Bentall Procedure in the Small Aortic Root After Prior Aortic Valve Operations.

The ''Chimney'' Bentall procedure using a self-assembled valve composite graft has been performed in 24 patients with a small aortic root or annulus after previous valve replacement in our center. The mean diameter of the aortic annulus was 19.58 ± 1.8 mm. During the procedure, the mean size of the implanted aortic valve prosthesis was 22.75 ± 1.78 mm. The mean gradient across the aortic valve prosthesis was 11.17 ± 2.24 mm Hg. This technique allows for the implantation of a larger prosthesis in patients with a small aortic annulus or root after previous aortic valve operation and results in good postoperative hemodynamic characteristics and early clinical results.

Multisource spectral-integrated estimation of cadmium concentrations in soil using a direct standardization and Spiking algorithm.

Benefiting from the advantages of a wide spatial sampling range and strong continuity, hyperspectral analysis provides a potential way to detect heavy metals in soil. However, it is still a great challenge to identify the spectral response characteristics of heavy metals from naturally polluted soil samples. This paper innovatively produces near standard soil samples for exploring the exact spectral response of cadmium (Cd) in soil and presents a novel method by combining the direct standardization (DS) and Spiking algorithms for integrating multisource spectra to improve the accuracy of Cd concentration estimation. A total of 46 naturally polluted soil samples were collected from a known Cd-contaminated mining area in Xiangjiang River Basin, China. The soil spectra of the naturally polluted soil samples were synchronously measured in the field. Moreover, clean soils with low heavy metal contaminants were collected to produce 65 near standard soil samples with known Cd levels. Then, the spectra and Cd concentrations of all 111 soil samples were measured under laboratory conditions. The principle component stepwise regression (PCSR) analysis results illustrated that the reflectance at all the wavelengths (380-2460 nm) is indicative of the differences in the soil Cd concentrations. Among these, the sensitivity of the spectral reflectance is the strongest at approximately 400 nm, 1000 nm and above 2300 nm. Additionally, the integrated multisource spectra significantly improved the accuracy of soil Cd concentration estimation (coefficient of determination, R2 = 0.96; root mean square error, RMSE = 0.29; ratio of prediction to deviation, RPD = 1.21) when 30 transfer samples and 15 training samples were simultaneously implemented in the combined DS and Spiking algorithm. This will provide a feasible scheme for exploration of spectral response characteristics of multiple soil heavy metals, and highlight the potential of developing low-level and satellite remote sensing on a large scale.

New one-step model of breast tumor locating based on deep learning.

BACKGROUND: Breast cancer has the highest cancer prevalence rate among the women worldwide. Early detection of breast cancer is crucial for successful treatment and reducing cancer mortality rate. However, tumor detection of breast ultrasound (US) image is still a challenging work in computer-aided diagnosis (CAD). OBJECTIVE: This study aims to develop a novel automated algorithm for breast tumor detection based on deep learning. METHODS: We proposed a new deep learning network named One-step model which have one input and two outputs, the first one was the segmentation result and the other one was used for false-positive reduction. The proposed One-step model includes three key components: Base-net, Seg-net, and Cls-net based on Anchor Box. The model chose DenseNet to construct Base-net, the decoder part of RefineNet as Seg-net, and connected several middle layers of Base-net and Seg-net to Cls-net. From the first output acquired by Base-net and Seg-net, the model detected a series of suspicious lesion regions. Then the second output from the Cls-net was used to recognize and reduce the false-positive regions. RESULTS: Experimental results showed that the new model achieved competitive detection result with 90.78% F1 score, which was 8.55% higher than Single Shot MultiBox Detector (SSD) method. In addition, running new model is also computational efficient and has comparative cost effect as SSD. CONCLUSIONS: We established a novel One-step model which improves location accuracy by generating more precise bounding box via Seg-net and removing false targets by another object detection network (Cls-net). On the other hand, a real-time detection of tumor is achieved by sharing the common Base-net. The experimental results showed that the new model performed well on various irregular and blurred ultrasound images. As a result, this study demonstrated feasibility of applying deep learning scheme to detect breast lesions depicting on US image.

Albumin conjugates and assemblies as versatile bio-functional additives and carriers for biomedical applications.

As the most abundant plasma protein, serum albumin has been extensively studied and employed for therapeutic applications. Despite its direct clinical use for the maintenance of blood homeostasis in various medical conditions, this review exclusively summarizes and discusses albumin-based bio-conjugates and assemblies as versatile bio-functional additives and carriers in biomedical applications. As one of the smallest-sized proteins in the human body, albumin is physiochemically stable and biochemically inert. Moreover, albumin is also endowed with abundant specific binding sites for numerous therapeutic compounds, which also endow it with superior bioactivities. Firstly, due to its small size and binding specificity, albumin alone or its derived assemblies can be utilized as competent drug carriers, which can deliver drugs through the enhanced permeability and retention (EPR) effect or actively target lesion sites through binding with gp60 and secreted protein acidic and rich in cysteine (SPARC) in tumor sites. Furthermore, its biochemical stability and inertness make it a safe and biocompatible coating material for use in biomedical applications. Albumin-based surface modifying additives can be used to functionalize both macro substrates (e.g. surfaces of medical devices or implants) and nanoparticle surfaces (e.g. drug carriers and imaging contrast agents). In this review, we elaborate on the synthesis and applications of albumin-based bio-functional coatings and drug carriers, respectively.

The Evolution of the Minimally Invasive Approach and Conventional Median Sternotomy for Coronary Artery Fistula Correction.

BACKGROUND: Minimally invasive cardiac surgery has become a safe and cosmetic alternative to standard median sternotomy. This retrospective study reviews our results and experience with the minimally invasive approach for congenital coronary artery fistula correction, compared with conventional approach. METHODS: From February 2001 to June 2016, 110 patients with isolated coronary artery fistula (CAF) in our centre underwent correction through minimally invasive approach (MIA) (n=65) or standard median sternotomy (SMS) (n=45). Cardiopulmonary bypass (CPB) was used in 16 patients in the SMS group, and all the other patients underwent the procedure without CPB through a standard median sternotomy or minimally invasive approach. RESULTS: There was no in-hospital mortality and no patients reverted to a median sternotomy in the MIA group. Subxiphoid incision (32 cases) and parasternal incision (28 cases) were the most common approaches used for the procedure. The operative time was 67.82±14.4minutes in MIA group and 107.04±27.91minutes (p=0.0001) in the SMS group. The intubation time was 3.58±2.33hours in the MIA group and 6.1±3.26hours in the SMS group (p=0.0001); the intensive care unit (ICU) stay was 10.04±7.95hours in the MIA group and 19.74±7.81hours in the SMS group (p=0.0001). Three patients (two in MIA Group vs one in SMS Group, p=0.787) were identified with a trivial residual shunt during the procedure, which had disappeared by discharge. CONCLUSIONS: Minimally invasive approach can provide an excellent surgical exposure for CAF ligation in selective patients compared with SMS. It is a safe and cosmetic alternative to conventional treatment and minimised the length of stay.

High resolution Physio-chemical Tissue Analysis: Towards Non-invasive In Vivo Biopsy.

Conventional gold standard histopathologic diagnosis requires information of both high resolution structural and chemical changes in tissue. Providing optical information at ultrasonic resolution, photoacoustic (PA) technique could provide highly sensitive and highly accurate tissue characterization noninvasively in the authentic in vivo environment, offering a replacement for histopathology. A two-dimensional (2D) physio-chemical spectrogram (PCS) combining micrometer to centimeter morphology and chemical composition simultaneously can be generated for each biological sample with PA measurements at multiple optical wavelengths. This spectrogram presents a unique 2D "physio-chemical signature" for any specific type of tissue. Comprehensive analysis of PCS, termed PA physio-chemical analysis (PAPCA), can lead to very rich diagnostic information, including the contents of all relevant molecular and chemical components along with their corresponding histological microfeatures, comparable to those accessible by conventional histology. PAPCA could contribute to the diagnosis of many diseases involving diffusive patterns such as fatty liver.

Evaluation of bladder microvasculature with high-resolution photoacoustic imaging.

We explored the potential of an emerging laser-based technology, photoacoustic imaging (PAI), for bladder cancer diagnosis through high-resolution imaging of microvasculature in the bladder tissues. Imaging results from ex vivo canine bladders demonstrated the excellent ability of PAI in mapping three-dimensional microvasculature in optically scattering bladder tissues. By comparing the results from human bladder specimens affected by cancer to those from the normal control, the feasibility of PAI to differentiate malignant from benign bladder tissues was also explored. The distinctive morphometric characteristics of tumor microvasculature can be seen in the images from cancer samples, suggesting that PAI may allow in vivo assessment of neoangiogenesis that is closely associated with bladder cancer generation and progression. By presenting subsurface morphological and physiological information in bladder tissues, PAI, when performed in a similar way as in conventional endoscopy, provides an opportunity for improved diagnosis, staging, and treatment guidance of bladder cancer.