Urology

Histopathological Analysis of Renal Biopsies With Dynamic Full-field Optical Coherence Tomography, a Comparison to Conventional Histopathological Findings in Kidney Transplant Recipients (HARBOR)

Banff classification stands as gold standard and international consensus for the identification, diagnosis and categorization of renal allograft pathology. In addition to multiple revision dedicated to the clarification and refinement of these diagnostic categories, a special attention is now dedicated to the development of automated protocols serving the use of artificial intelligence in digital pathology. To be integrated in the actual early post-transplant monitoring procedure, such original approach is considered to match various growing expectations of clinicians and pathologists regarding the future of transplant nephropathology : decrease inter-observer variability, reduce human errors and limit time-consuming analysis of kidney biopsy. Among these, an accelerated reading and access to Banff diagnostic criteria could help initiating both appropriate and immediate treatment to improve graft survival in kidney transplant recipients. Yet conventional histopathology still require...

Researchers Use Optical Imaging Technology to Evaluate Transplant Viability of Donor Kidneys

Each year more than 8,000 people die while waiting to receive a kidney transplant, many of whom have spent four or more years on donor waitlists, hoping for a miracle to arrive. These deaths occur due to a worldwide shortage of kidneys for transplantation because there is currently no reliable means to quickly and efficiently determine the viability of enough donor kidneys to meet the demand. A team of researchers from the University of Oklahoma and the OU Health Sciences Center, with assistance from LifeShare of Oklahoma, as well as researchers and clinicians from the University of Massachusetts Amherst, Worchester Polytechnic Institute and Georgetown Medical Center will collaborate to investigate the use of optical coherence tomography to evaluate donor kidneys and develop new scanning methods and machine learning algorithms to reduce the evaluation time of donor kidneys while substantially increasing the information about the viability of these organs for transplant surgeons a...

University of Massachusetts, Amherst Receives NIH Grant for Automatic Wide-Field Optical Coherence Tomography for Assessment of Transplant Kidney Viability

University of Massachusetts, Amherst Received a 2022 NIH Grant for $671,945 for Automatic Wide-Field Optical Coherence Tomography for Assessment of Transplant Kidney Viability. The principal investigator is Yu Chen. Below is a summary of the proposed study. There is a worldwide shortage of kidneys for transplantation due mainly to the fact that there is no reliable means to determine the viability of kidneys available for transplant. There are unmet clinical needs to reduce the >8,000 deaths that occur each year from failures of finding viable kidney matches for transplant, to reduce the nearly 4- year time on donor waitlists, and to reduce the number of failed transplants. The current process for screening deceased donor kidneys uses two methods: 1) pathological scores based on anatomical features from a biopsy (tubules, glomeruli, etc.) and 2) the Kidney Donor Profile Index (KDPI) derived from the donor’s medical history (hypertension, diabetes, weight, etc.). However, cl...

Optical coherence tomography and convolutional neural networks can differentiate colorectal liver metastases from liver parenchyma ex vivo

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Purpose: Optical coherence tomography (OCT) is an imaging technology based on low-coherence interferometry, which provides non-invasive, high-resolution cross-sectional images of biological tissues. A potential clinical application is the intraoperative examination of resection margins, as a real-time adjunct to histological examination. In this ex vivo study, we investigated the ability of OCT to differentiate colorectal liver metastases (CRLM) from healthy liver parenchyma, when combined with convolutional neural networks (CNN). Methods: Between June and August 2020, consecutive adult patients undergoing elective liver resections for CRLM were included in this study. Fresh resection specimens were scanned ex vivo, before fixation in formalin, using a table-top OCT device at 1310 nm wavelength. Scanned areas were marked and histologically examined. A pre-trained CNN (Xception) was used to match OCT scans to their corresponding histological diagnoses. To validate the results, a stra...

Assessment of microvascular involvement in lupus nephritis patients by retinal OCT-angiography and kidney biopsies

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Objectives: Ocular and renal microvascular damage in lupus nephritis (LN) share similar physiopathological pathways that have investigated using traditional fundus examination and high-resolution colour electroretinography. Optical coherence tomography angiography (OCTA) is a recent, non-invasive technique for imaging the microvasculature of retina and choroid. Aim of the study was to investigate through OCTA analysis the relationship between retinal microvascular alterations and renal functional and histologic features. Methods: Systemic lupus erythematosus (SLE) patients with LN, SLE without renal involvement and healthy controls were recruited and accomplished an ophthalmological evaluation, including OCTA. SLE-LN patients underwent a rheumatological evaluation, including disease-related clinical and laboratory features collection and kidney biopsy examination. Results: This cross-sectional study enrolled forty-six eyes of 23 LN patients, thirty-two eyes of 16 SLE patients and fo...

Dynamic volumetric imaging and cilia beat mapping in the mouse male reproductive tract with optical coherence tomography

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Spermatozoa transport within the male reproductive tract is a highly dynamic and biologically important reproductive event. However, due to the lack of live volumetric imaging technologies and quantitative measurements, there is little information on the dynamic aspect and regulation of this process. Here, we presented ex vivo dynamic volumetric imaging of the mouse testis, efferent duct, epididymis, and vas deferens at a micro-scale spatial resolution with optical coherence tomography (OCT). Micro computed tomography imaging is presented as a reference for the proposed OCT imaging. Application of functional OCT analysis allowed for 3D mapping of the cilia beat frequency in the efferent duct, which volumetrically visualized the spatial distribution of the ciliated cells and corresponding ciliary activities. Potentially these analyses could be expanded to in vivo settings through intravital approach. In summary, this study demonstrated that OCT has a great potential to investigate th...

Feasibility of the soft attention-based models for automatic segmentation of OCT kidney images

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Clinically, optical coherence tomography (OCT) has been utilized to obtain the images of the kidney's proximal convoluted tubules (PCTs), which can be used to quantify the morphometric parameters such as tubular density and diameter. Such parameters are useful for evaluating the status of the donor kidney for transplant. Quantifying PCTs from OCT images by human readers is a time-consuming and tedious process. Despite the fact that conventional deep learning models such as conventional neural networks (CNNs) have achieved great success in the automatic segmentation of kidney OCT images, gaps remain regarding the segmentation accuracy and reliability. Attention-based deep learning model has benefits over regular CNNs as it is intended to focus on the relevant part of the image and extract features for those regions. This paper aims at developing an Attention-based UNET model for automatic image analysis, pattern recognition, and segmentation of kidney OCT images. We evaluated five me...

Ex-vivo evaluation of miniaturized probes for endoscopic optical coherence tomography in urothelial cancer diagnostics

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Background: The gold standard for detecting bladder cancer is white light cystoscopy (WLC) and resection of suspicious lesions. In this study, we evaluate two miniaturized Optical Coherence Tomography (OCT) probes for endoscopic use, regarding their applicability in diagnosing urothelial cancer. Materials and methods: In total, 33 patients who underwent a radical cystectomy were included. Preoperative oncological staging and determining the indication for the surgical intervention were done following the latest European Association of Urology (EAU) guidelines. Samples were taken from bladder tissue after bladder removal and prepared for OCT measurement. Additionally, porcine bladder samples were used as reference tissue. We took measurements using two miniaturized probes: a bimodal probe and a single modality OCT probe. A non-miniaturized standard OCT scanner was used as a reference. Results: Histopathological examination revealed urothelial cancer in all but three patients. Measure...

Scinvivo Closes an Investment Round of 1 Million Euro from NextStage Early Stage Fund

Financing secured towards in human clinical trials & CE Scinvivo, a MedTech startup based in Eindhoven, has closed an investment round of 1 Million Euro from NextStage Early Stage Fund (NSESF), Innovatiefonds Noord-Holland and current shareholders. With this investment Scinvivo has secured the development of in human clinical trials and CE certification. Scinvivo is on a mission to make cancer diagnostics faster and more accurate, enabling reduction of unnecessary surgeries and improving the quality of patients' lives. Scinvivo develops an imaging platform based on a forward looking OCT catheter to visualise the human morphological tissue structure a few mm’s deep with a high resolution.This approach fills the gap of the current image modalities and enables more precieze minimal invasive surgeries and will significantly improve the diagnosis of cancer resulting in a precise personalised treatment. Bladder cancer is chosen as the first field for the imaging platform. The...

Label-free functional and structural imaging of liver microvascular complex in mice by Jones matrix optical coherence tomography

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We demonstrate label-free imaging of the functional and structural properties of microvascular complex in mice liver. The imaging was performed by a custom-built Jones-matrix based polarization sensitive optical coherence tomography (JM-OCT), which is capable of measuring tissue's attenuation coefficient, birefringence, and tiny tissue dynamics. Two longitudinal studies comprising a healthy liver and an early fibrotic liver model were performed. In the healthy liver, we observed distinctive high dynamics beneath the vessel at the initial time point (0 h) and reappearance of high dynamics at 32-h time point. In the early fibrotic liver model, we observed high dynamics signal that reveals a clear network vascular structure by volume rendering. Longitudinal time-course imaging showed that these high dynamics signals faded and decreased over time. ( Read Full Article )

Optical Coherence Tomography Angiography of Early Stage 1a Retinal Hemangioblastoma in Von-Hippel-Lindau

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Von-Hippel-Lindau (VHL) syndrome is characterized by focal vasoproliferative tumors of retinal capillaries called retinal capillary hemangioblastomas (RCH). These tumors are initially small and can be easily missed if not looked for carefully. As they grow, these tumors are more demanding to treat and hence the importance of detecting them early and treating them. Herein, we describe and review the optical coherence tomography angiography (OCTA) of the early- stage lesion, which suggested the involvement of superficial and a deeper retinal capillary plexus. In addition, to helping us detect these lesions earlier, OCTA may also help to understand the in vivo changes occurring at an earlier phase. ( Read Full Article )

Optical coherence microangiography of the mouse kidney for diagnosis of circulatory disorders

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Optical coherence tomography (OCT) has become widespread in clinical applications in which precise three-dimensional functional imaging of living organs is required. Nevertheless, the kidney is inaccessible for the high resolution OCT imaging due to a high light attenuation coefficient of skin and soft tissues that significantly limits the penetration depth of the probing laser beam. Here, we introduce a surgical protocol and fixation scheme that enables functional visualization of kidney's peritubular capillaries via OCT microangiography. The model of reversible/irreversible glomerulus embolization using drug microcarriers confirms the ability of OCT to detect circulatory disorders. This approach can be used for choosing optimal carriers, their dosages and diagnosis of other blood flow pathologies. ( Read Full Article )

Evaluation Through the Optical Coherence Tomography Analysis of the Influence of Non-Alcoholic Fatty Liver Disease on the Gingival Inflammation in Periodontal Patients

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Purpose: The purpose of this ex vivo study is to exhibit the inflammatory changes that occur within the gingival tissue by using optical coherence tomography (OCT) in periodontal patients with non-alcoholic fatty liver disease (NAFLD) and if NAFLD could influence the local periodontal inflammation. Patients and Methods: Gingival tissue samples obtained from patients were divided into three groups – P (periodontitis), NAFLD+P (NAFLD+periodontitis) and H (healthy) groups - and were scanned using an OCT light beam, in order to perform a qualitative and quantitative analysis of images. The value of average pixel density has been associated with the degree of inflammation. Results: The highest average pixel density was found in patients from the H group, while the lowest value of average pixel density was recorded in gingival tissue samples collected from patients with NAFLD+P. The image assessments from NAFLD+P group delivered lower values of average pixel density than those of P ...

Phase II multi-center trial of optical coherence tomography as an adjunct to white light cystoscopy for intravesical real time imaging and staging of bladder cancer

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Background: Optical coherence tomography (OCT) is a novel imaging modality that provides microstructural information of different tissue layers using near-infrared light. This prospective, multicenter phase II trial aimed to assess the accuracy of OCT-assisted cystoscopy for bladder tumor staging. Methods: Patients with primary or recurrent bladder tumors (Ta,T1) identified by outpatient cystoscopy were included. The primary objective was to assess the accuracy and positive predictive value of for determining tumor stage ≥T1 correlated by histopathology. 72 suspicious lesions from 63 patients were eligible to analyze in the study. All suspected lesions were evaluated with conventional cystoscopy, interpreted in real-time using OCT, and then resected. All results were compared to pathology. A total of 363 OCT images of tumor and normal mucosa in 25 patients were obtained to evaluate diagnostic efficacy of the computer-aided texture analysis algorithm. Results: Sensitivity and spec...

Low-molecular-weight dextran for optical coherence tomography may not be protective against kidney injury in patients with renal insufficiency

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Background: Low-molecular-weight dextran (LMWD) is considered a safe alternative to contrast media for blood displacement during optical coherence tomography (OCT) imaging. Aim: To investigate whether the use of LMWD for OCT is protective against kidney injury in patients with advanced renal insufficiency. Methods: In this retrospective cohort study, we identified 421 patients with advanced renal insufficiency (estimated glomerular filtration rate < 45 mL/min/1.73 m 2 ) who underwent coronary angiography or percutaneous coronary intervention; 79 patients who used additional LMWD for OCT imaging (LMWD group) and 342 patients who used contrast medium exclusively (control group). We evaluated the differences between these two groups and performed a propensity score-matched subgroup comparison. Results: The median total volume of contrast medium was 133.0 mL in the control group vs 140.0 mL in the LMWD group. Although baseline renal function was not statistically different between th...

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