High-resolution Real-time Imaging Research Articles

Single-shot quantitative phase imaging with phase modulation of a liquid crystal spatial light modulator (LC-SLM) under white light illumination.

We propose a novel, to the best of our knowledge, single-shot quantitative phase imaging (QPI) technique with the phase modulation of a liquid crystal spatial light modulator (LC-SLM) under white light illumination. By studying the phase modulation characteristics of an LC-SLM under white light illumination, images captured at different wavelengths are equivalent to those captured at different defocus distances when loading a Fresnel lens pattern on the LC-SLM. Consequently, a color camera is able to simultaneously acquire multi-intensity images at different defocus distances. Finally, the phase is retrieved from a single-shot color image using the transport of intensity equation. To demonstrate the flexibility and accuracy of our method, a photoetched phase object and human red blood cells are quantitatively measured. An investigation of living yeast cells is conducted to verify the dynamic measurement capability. The proposed method provides a simple, efficient, and flexible means to accomplish real-time high-resolution quantitative phase imaging without sacrificing the field of view (FOV), which can be further integrated into a conventional microscope to achieve real-time microscopic QPI.

Technical note: Rapid and high-resolution deep learning-based radiopharmaceutical imaging with 3D-CZT Compton camera and sparse projection data.

The Compton camera (CC) has great potential in nuclear medicine imaging due to the high detection efficiency and the ability to simultaneously detect multi-energy radioactive sources. However, the finite resolution of the detectors will degrade the images that the real-world CC can obtain. Besides, the CC sometimes can be limited by the detection efficiency, leading to difficulty in using sparse projection data to realize high-resolution reconstruction with short-time measurement, which limits its clinical application for real-time or rapid radiopharmaceutical imaging. To overcome the difficulty and promote the usage of the CC in radiopharmaceutical imaging, we present a deep learning (DL)-based CC reconstruction method to realize rapid and high-resolution imaging with short-time measurement. We developed a DL-based algorithm MCBP-CCnet via Monte Carlo sampling-based back projection and a dedicated convolutional neural network, called CC-Net, to realize the rapid and high-resolution reconstruction with sparse projection data. A CC prototype based on a single three-dimensional position-sensitive CdZnTe (3D-CZT) detector was used to demonstrate the feasibility of our proposed method. The simulations and experiments of radiopharmaceutical imaging used the 3D-CZT CC and [18 F]NaF. A 3D-printing mouse phantom was also further used to evaluate the performance of the proposed method in animal molecular imaging. The simulation and experimental results showed that the proposed method could realize the images reconstruction within 5s for list-mode projection data and realized a rapid reconstruction within 35s for experimental radiopharmaceutical imaging based on the 3D-printing mouse phantom, as well as realized the high-resolution imaging with an accuracy of within 0.78mm in terms of the sparse projection data that only contained hundreds of events. Besides, the deviations between the reconstructed radiative activities and the exact values were less than 1.51%. The results demonstrated that the proposed method could realize the rapid and high-resolution CC reconstruction with sparse projection data obtained by the 3D-CZT CC and realize the high-resolution radiopharmaceutical imaging. The study in this paper also demonstrated the potential and feasibility of future applications of a 3D-CZT CC for real-time high-resolution radiopharmaceutical imaging with short-time measurement.

Identification of a quasi-liquid phase at solid–liquid interface

An understanding of solid–liquid interfaces is of great importance for fundamental research as well as industrial applications. However, it has been very challenging to directly image solid–liquid interfaces with high resolution, thus their structure and properties are often unknown. Here, we report a quasi-liquid phase between metal (In, Sn) nanoparticle surfaces and an aqueous solution observed using liquid cell transmission electron microscopy. Our real-time high-resolution imaging reveals a thin layer of liquid-like materials at the interfaces with the frequent appearance of small In nanoclusters. Such a quasi-liquid phase serves as an intermediate for the mass transport from the metal nanoparticle to the liquid. Density functional theory-molecular dynamics simulations demonstrate that the positive charges of In ions greatly contribute to the stabilization of the quasi-liquid phase on the metal surface.

Imaging of the skin microvascularization using spatially depolarized dynamic speckle.

.SignificanceWe propose a technique devoted to real-time high-resolution imaging of skin microvascularization.AimThe process utilizes the temporal variation of the spatially depolarized optical speckle field generated by moving red blood cells when illuminated with fully polarized coherent light.ApproachPolarimetric filtering prevents the contribution of surface scattering from reaching the camera and thus favors the detection of multiscattered photons from the deeper layers of the skin.ResultsFull-field images reveal the microvasculature with a spatial resolution of . The acquisition speed allows for real-time applications.ConclusionsWe demonstrate the ability of this method to determine in 1 s a stable and reliable microvascular activity, enabling numerous clinical applications that require quantitative measurements.

Real-time high-resolution millimeter-wave imaging for in-vivo skin cancer diagnosis

High-resolution millimeter-wave imaging (HR-MMWI), with its high discrimination contrast and sufficient penetration depth, can potentially provide affordable tissue diagnostic information noninvasively. In this study, we evaluate the application of a real-time system of HR-MMWI for in-vivo skin cancer diagnosis. 136 benign and malignant skin lesions from 71 patients, including melanoma, basal cell carcinoma, squamous cell carcinoma, actinic keratosis, melanocytic nevi, angiokeratoma, dermatofibroma, solar lentigo, and seborrheic keratosis were measured. Lesions were classified using a 3-D principal component analysis followed by five classifiers including linear discriminant analysis (LDA), K-nearest neighbor (KNN) with different K-values, linear and Gaussian support vector machine (LSVM and GSVM) with different margin factors, and multilayer perception (MLP). Our results suggested that the best classification was achieved by using five PCA components followed by MLP with 97% sensitivity and 98% specificity. Our findings establish that real-time millimeter-wave imaging can be used to distinguish malignant tissues from benign skin lesions with high diagnostic accuracy comparable with clinical examination and other methods.

OCT-Guided Surgery for Gliomas: Current Concept and Future Perspectives.

Optical coherence tomography (OCT) has been recently suggested as a promising method to obtain in vivo and real-time high-resolution images of tissue structure in brain tumor surgery. This review focuses on the basics of OCT imaging, types of OCT images and currently suggested OCT scanner devices and the results of their application in neurosurgery. OCT can assist in achieving intraoperative precision identification of tumor infiltration within surrounding brain parenchyma by using qualitative or quantitative OCT image analysis of scanned tissue. OCT is able to identify tumorous tissue and blood vessels detection during stereotactic biopsy procedures. The combination of OCT with traditional imaging such as MRI, ultrasound and 5-ALA fluorescence has the potential to increase the safety and accuracy of the resection. OCT can improve the extent of resection by offering the direct visualization of tumor with cellular resolution when using microscopic OCT contact probes. The theranostic implementation of OCT as a part of intelligent optical diagnosis and automated lesion localization and ablation could achieve high precision, automation and intelligence in brain tumor surgery. We present this review for the increase of knowledge and formation of critical opinion in the field of OCT implementation in brain tumor surgery.

High-Resolution Real-Time Imaging Processing for Spaceborne Spotlight SAR With Curved Orbit via Subaperture Coherent Superposition in Image Domain

With the increasing of application requirements, the high-resolution real-time imaging processing of the spaceborne spotlight synthetic aperture radar (SAR) has been developed. Since the traditional real-time imaging algorithms have the problems that the range model has errors and the two-dimensional (2-D) space-variance of the equivalent velocity caused by the curved orbit cannot be effectively eliminated. Thus, this article proposes a high-resolution real-time imaging algorithm for spaceborne spotlight SAR with curved orbit via subaperture coherent superposition in image domain. In this article, the echo data are first divided into subapertures to avoid the azimuth spectrum aliasing. After that, the 2-D space-variance of the equivalent velocity caused by the curved orbit can be eliminated by the method of azimuth time scale transformation, higher order phase compensation, and introducing phase transition function. Then, the dechirp function is applied for the subaperture signals to obtain the partial-resolution subaperture images. Finally, these partial-resolution subaperture images are coherently superposed in the image domain to obtain the final full-resolution image of the whole echo data. Moreover, the proposed algorithm improves the real-time performance by adopting the idea that the subaperture data recording and subaperture real-time imaging processing are synchronized, which greatly accelerates the acquisition of the final full-resolution imaging result. At the end of this article, the simulations and the real-time performance analysis are performed to validate the proposed algorithm.

Eye MG 3D Application - A comprehensive ocular anatomy and pathophysiology 3D atlas with real-time true color confocal images to enhance ophthalmology education and e-Counseling.

Concepts pertaining to ophthalmology have lots of theoretical frameworks. Neophyte residents and novice surgeons may have to mentally visualize these concepts during the initial days of training. Only a powerful cognitive tool such as a three-dimensional (3D) eyeball model, with real-time TrueColor confocal images (and not animated images or models), can fill in these intellective mental gaps. Giving the users (i.e., residents and students) the power to choose and visualize various parts of the eye, with multiple magnitudes of zoom, is mandatory for optimal e-learning. To make ophthalmic concept learning better, we have developed a 3D app Eye MG 3D (patent pending) comprising ocular anatomy and pathophysiological 3D models, built on an advanced interactive 3D touch interface, by using patient’s real-time confocal images to serve as a new-age pedagogical tool and e-counseling. According to our knowledge, there are no applications to date that incorporate real-time high-resolution multimodal confocal fundus images and photoreal visuals for interactive and immersive 3D learning.

Research on terahertz real-time near-field spectral imaging

In this paper, a real-time near-field high-resolution THz (terahertz, THz) spectral imaging system is designed and built by using optical rectification and wave-front tilting to generate strong-field terahertz signals and based on electro-optical detection. The system can switch between large beam THz imaging and tight-focusing THz imaging, which provides a method for implementing the integrated application of the system. Since the imaging is based on the traditional THz time-domain spectroscopy method, the spectral amplitude and phase information of the sample can be obtained simultaneously. The spectral resolution is about 15 GHz. A series of micromachining samples is measured and studied by using the system, and the performance of the imaging system is analyzed by using the micron structure. The results show the superiority of the real-time high-resolution terahertz spectral imaging system in terms of spatial resolution and imaging speed. The real-time imaging frame rate is up to 20 f/s (1200 frames/min) at 1024 pixel × 512 pixel. In the large-field THz imaging, the optimal spatial resolution reaches <i>λ</i>/4 at 1.5 THz. In the tightly focused THz imaging, the optimal spatial resolution reaches λ/12 at 0.82 THz. These properties make the system suitable for the applications in biomedical imaging, bbological effects and other areas .

Single shot real-time high-resolution imaging through dynamic turbid media based on deep learning

Low signal-to-noise ratio (SNR) measurement is conceivable the primary obstruction to real-time, high-resolution through dynamic turbid media optical imaging. To break this restriction, by individualizing and employing these low SNR measurement data, the spectrum estimation theory is procured a noise model for scatter imaging. The noise model proposed is exploited to synthesize data set training to settle the related problems of noise phase without knowing the experimental scenes. We verify the robustness of the resulting deep correlography method to noise, outdistance the capabilities of the existing Fourier-domain shower-curtain effect (FDSE) system in terms of spatial resolution and total acquisition time, in addition, the targets can be reconstructed from a standard sCMOS detector with a 150 ms exposure.

Ultra-thin temperature controllable microwell array chip for continuous real-time high-resolution imaging of living single cells

Single-cell imaging, a powerful analytical method to study single-cell behavior, such as gene expression and protein profiling, provides an essential basis for modern medical diagnosis. The coding and localization function of microfluidic chips has been developed and applied in living single-cell imaging in recent years. Simultaneously, chip-based living single-cell imaging is also limited by complicated trapping steps, low cell utilization, and difficult high-resolution imaging. To solve these problems, an ultra-thin temperature-controllable microwell array chip (UTCMA chip) was designed to develop a living single-cell workstation in this study for continuous on-chip culture and real-time high-resolution imaging of living single cells. The chip-based on ultra-thin ITO glass is highly matched with an inverted microscope (or confocal microscope) with a high magnification objective (100 × oil lens), and the temperature of the chip can be controlled by combining it with a home-made temperature control device. High-throughput single-cell patterning is realized in one step when the microwell array on the chip uses hydrophilic glass as the substrate and hydrophobic SU-8 photoresist as the wall. The cell utilization rate, single-cell capture rate, and microwell occupancy rate are all close to 100% in the microwell array. This method will be useful in rare single-cell research, extending its application in the biological and medical-related fields, such as early diagnosis of disease, personalized therapy, and research-based on single-cell analysis.

Zebrafish Cancer Predisposition Models.

Cancer predisposition syndromes are rare, typically monogenic disorders that result from germline mutations that increase the likelihood of developing cancer. Although these disorders are individually rare, resulting cancers collectively represent 5–10% of all malignancies. In addition to a greater incidence of cancer, affected individuals have an earlier tumor onset and are frequently subjected to long-term multi-modal cancer screening protocols for earlier detection and initiation of treatment. In vivo models are needed to better understand tumor-driving mechanisms, tailor patient screening approaches and develop targeted therapies to improve patient care and disease prognosis. The zebrafish (Danio rerio) has emerged as a robust model for cancer research due to its high fecundity, time- and cost-efficient genetic manipulation and real-time high-resolution imaging. Tumors developing in zebrafish cancer models are histologically and molecularly similar to their human counterparts, confirming the validity of these models. The zebrafish platform supports both large-scale random mutagenesis screens to identify potential candidate/modifier genes and recently optimized genome editing strategies. These techniques have greatly increased our ability to investigate the impact of certain mutations and how these lesions impact tumorigenesis and disease phenotype. These unique characteristics position the zebrafish as a powerful in vivo tool to model cancer predisposition syndromes and as such, several have already been created, including those recapitulating Li-Fraumeni syndrome, familial adenomatous polyposis, RASopathies, inherited bone marrow failure syndromes, and several other pathogenic mutations in cancer predisposition genes. In addition, the zebrafish platform supports medium- to high-throughput preclinical drug screening to identify compounds that may represent novel treatment paradigms or even prevent cancer evolution. This review will highlight and synthesize the findings from zebrafish cancer predisposition models created to date. We will discuss emerging trends in how these zebrafish cancer models can improve our understanding of the genetic mechanisms driving cancer predisposition and their potential to discover therapeutic and/or preventative compounds that change the natural history of disease for these vulnerable children, youth and adults.

실시간 고해상도 컬러 영상 워핑을 위한 FPGA 기반 하드웨어 설계

본 논문에서는 고해상도 컬러 영상 워핑의 실시간 처리를 위한 FPGA 기반 하드웨어를 설계한다. 영상 워핑은 입력 영상에 2D 좌표 변환을 적용하는 영상 처리 알고리즘으로 실시간 영상 워핑 구현을 위해서는 좌표 변환 연산, 픽셀 데이터 보간 연산, 그리고 고속 영상 버퍼 메모리 구조 등 3가지 문제에서 실시간 성능 및 정확성을 확보하여야 한다. 본 논문에서는 CFA 컬러 영상 워핑을 활용한 연산량 감소, 오프라인 캐시 스케줄링 및 캐시 메모리 분할 구조를 적용한 영상 데이터 캐시, 그리고 연산의 선후 관계 및 타이밍 조건을 고려한 병렬 처리 및 파이프라인 구조 등을 통하여 실시간 동작 성능을 확보한다. Full HD 해상도의 컬러 영상 입력에 대한 구현된 시스템의 동작 정확성을 PC 소프트웨어의 처리 결과와 비교/확인하고, 실시간 렌즈 왜곡 보정에 적용하여 구현된 시스템의 타당성을 검증한다.

Diagnostic Accuracy of B-scan Ultrasonography for Posterior Segment Eye Disorders- A Cross-sectional Study

Introduction: Ophthalmic Ultrasound (USG) produces real time high resolution images of the eye and orbit. It can categorise, predict location and diagnose posterior segment pathology of the eye very well and is usually used in preoperative evaluation. However, the diagnostic accuracy, in terms of predicting probability of Posterior Segment Disease (PSD) post-USG, has usually not been studied, that too in Indian set-up. Hence, this study was conducted. Aim: To find out the prevalence and pattern of PSD among patients referred to radiology department using B-scan USG, and to find out the diagnostic accuracy of B-scan USG in such cases. Materials and Methods: The study was cross-sectional in nature conducted over a period of two years (2007-09) and conducted in the Department of Radiodiagnosis and Ophthalmology of a tertiary care centre of Eastern India. Patients were referred to the Radiology department for ruling out intraocular pathology using B-scan ophthalmic USG were included in the study, irrespective of any age and gender. Data were captured on an excel sheet and analysed using Stata 12.1. Prevalence and pattern of PSDs were established from the data while diagnostic accuracy was calculated in terms of sensitivity, specificity, predictive values and log Likelihood Ratios (LR). Accuracy of B-scan USG was also estimated and adjusted for verification bias. Results: The mean age of 84 study participants was 37.4±19.5 years, with maximum in between 41-50 years. Males predominated (72.6%). A 50% presented with low vision, and most commonly associated with cataract 45 cases (54%). Prevalence of posterior segment eye disorders was 13.1%. Adjusted sensitivity, adjusted specificity and Negative Predictive Values (NPV) were 100%. Positive Predictive Value (PPV) was 45.33%. Post-test probability was 46.6%, while after adjustment it was infinite. Adjusted accuracy was 100%. Conclusion: Prevalence of posterior segment eye disorders was 13.1% for cases referred to radiology department. The most common PSD that was found was retinal mass. Using B-scan USG for preoperative assessment and confirmation of diagnosis increases the probability of detecting presence or absence of posterior segment pathology. Absence of PSD using this is also very helpful in ruling out disease entirely. It also has a very high sensitivity and hence has a scope to be used even in rural health centres.

Multispectral optoacoustic tomography might be a helpful tool for noninvasive early diagnosis of psoriatic arthritis

Currently used imaging methods for diagnosis of psoriatic arthritis (PsA) frequently come along with exposure to radiation and can often only show long-term effects of the disease. The aim of the study was to check the feasibility of a new optoacoustic imaging method to identify PsA. 22 psoriasis patients and 19 healthy volunteers underwent examination using multispectral optoacoustic tomography (MSOT). The presence of arthritis was assessed via quantification of optoacoustic signal intensity of the endogenous chromophores oxy- and deoxyhemoglobin. We conducted high-resolution real-time ultrasound images of the finger joints. The semi quantitative analysis of the optoacoustic signals for both hemoglobin species showed a significant higher blood content and oxygenation in PsA patients compared to healthy controls.Our results indicate that MSOT might allow detection of inflammation in an early stage. If the data is further confirmed, this technique might be a suitable tool to avoid delay of diagnosis of PsA.

Increased peak end-expiratory pressure in ventilated preterm lambs changes cerebral microvascular perfusion: direct synchrotron microangiography assessment.

Positive end-expiratory pressure (PEEP) improves oxygenation in mechanically ventilated preterm neonates by preventing lung collapse. However, high PEEP may alter cerebral blood flow secondarily to the increased intrathoracic pressure, predisposing to brain injury. The precise effects of high PEEP on cerebral hemodynamics in the preterm brain are unknown. We aimed to assess the effect of PEEP on microvessels in the preterm brain by using synchrotron radiation (SR) microangiography, which enables in vivo real-time high-resolution imaging of the cerebral vasculature. Preterm lambs (0.8 gestation, n = 4) were delivered via caesarean section, anesthetized, and ventilated. SR microangiography of the right cerebral hemisphere was performed with iodine contrast administered into the right carotid artery during PEEP ventilation of 5 and 10 cmH2O. Carotid blood flow was measured using an ultrasonic flow probe placed around the left carotid artery. An increase of PEEP from 5 to 10 cmH2O increased the diameter of small cerebral vessels (<150 µm) but decreased the diameter of larger cerebral vessels (>500 µm) in all four lambs. Additionally, the higher PEEP increased the cerebral contrast transit time in three of the four lambs. Carotid blood flow increased in two lambs, which also had increased carbon dioxide levels during PEEP 10. Our results suggest that PEEP of 10 cmH2O alters the preterm cerebral hemodynamics, with prolonged cerebral blood flow transit and engorgement of small cerebral microvessels likely due to the increased intrathoracic pressure. These microvascular changes are generally not reflected in global assessment of cerebral blood flow or oxygenation.NEW & NOTEWORTHY An increase of positive end-expiratory pressure (PEEP) from 5 to 10 cmH2O increased the diameter of small cerebral vessels (<150 µm) but decreased the diameter of larger cerebral vessels (>500 µm). This suggests increased intrathoracic pressure due to high PEEP can drive microvessel engorgement in the preterm brain, which may play a role in cerebrovascular injury.

Modeling Immune Checkpoint Inhibitor Efficacy in Syngeneic Mouse Tumors in an Ex Vivo Immuno-Oncology Dynamic Environment.

The immune checkpoint blockade represents a revolution in cancer therapy, with the potential to increase survival for many patients for whom current treatments are not effective. However, response rates to current immune checkpoint inhibitors vary widely between patients and different types of cancer, and the mechanisms underlying these varied responses are poorly understood. Insights into the antitumor activities of checkpoint inhibitors are often obtained using syngeneic mouse models, which provide an in vivo preclinical basis for predicting efficacy in human clinical trials. Efforts to establish in vitro syngeneic mouse equivalents, which could increase throughput and permit real-time evaluation of lymphocyte infiltration and tumor killing, have been hampered by difficulties in recapitulating the tumor microenvironment in laboratory systems. Here, we describe a multiplex in vitro system that overcomes many of the deficiencies seen in current static histocultures, which we applied to the evaluation of checkpoint blockade in tumors derived from syngeneic mouse models. Our system enables both precision-controlled perfusion across biopsied tumor fragments and the introduction of checkpoint-inhibited tumor-infiltrating lymphocytes in a single experiment. Through real-time high-resolution confocal imaging and analytics, we demonstrated excellent correlations between in vivo syngeneic mouse and in vitro tumor biopsy responses to checkpoint inhibitors, suggesting the use of this platform for higher throughput evaluation of checkpoint efficacy as a tool for drug development.

Abstract 2785: 13C-MRI detects increased lactate flux in HCC following hepatic thermal A\ablation and correlates with PFKFB3 Expression

Abstract Thermal ablation (TA) is an accepted therapy for early HCC and hepatic metastases from colorectal and breast cancers. However, suboptimal TA is a risk factor for early HCC recurrence and has been associated with a reduction in overall survival. This effect has been attributed to hypoxic response in periablative tissue mediated by HIF-1. Malignant transformation leads to increased anaerobic glycolysis even under normoxic conditions. This process is detectable by hyperpolarized 13C MRI (h13C MRI), which enables real-time high-resolution imaging of the conversion from pyruvate to lactate and may be used as a potential predictor for therapeutic response in HCC. We have identified two potential metabolic regulators and therapeutic targets with a direct link to lactate flux which may be monitored with h13C MRI. PFKFB3 has been identified as a crucial metabolic factor in several cancer types, encoding for inducible 6-phosphofructo-2-kinase and enhancing production of F2,6P2, consequently activating PK1 and glycolysis. Expression levels of PFKFB3 have been found to be higher in malignancies than in normal tissues, attributed to loss of glycolytic control and accelerating neoplastic activity. Hexokinase 3 (HK3), a key catalyst in the first committed steps in glucose metabolism, is also a key promoter involved in epithelial-mesenchymal transition. When we exposed an HCC rat cell line, N1S1, to heat stress, simulating the marginal zone of TA therapy, 20%-90% of cells survived at 40°C-50°C and there was no survival by 55°C. 5-8 days following this treatment, cell proliferation and mRNA expression of glycolysis-related genes were analyzed. Cellular proliferation rate was significantly higher in the heat-treated groups. mRNA expression of PFKFB3 was increased after thermal treatment, while HK3 expression was significantly decreased. We then developed an in vivo orthotopic rat model of a solitary N1S1 HCC and used h13C MRI to measure in vivo tumor lactate flux in response to radiofrequency ablation (RFA), a type of thermal ablation, of adjacent normal hepatic tissue, simulating local treatment of a distant lesion. h13C MRI demonstrated significantly increased tumor 13C lactate flux in the RFA arm relative to the control group (change in lactate-to-pyruvate ratio of 0.236±0.278 vs -0.035±0.107, p=0.0465, n=6), while background liver lactate flux was unchanged. We found that this correlated with mRNA expression of PFKFB3 and HK3, which was statistically significantly greater within tumors from the RFA group compared to control tumors (PFKFB3, 1.052±0.091 vs 0.655±0.294, p=0.0004, n=6; HK3, 0.751±0.130 vs 0.501±0.163, p=0.0036, n=6). The PFKFB3 expression patterns were concordant between in vitro and in vivo experiments. Our data shows that PFKFB3 may be an attractive treatment target for HCC, and h13C MRI may be a noninvasive technique well-suited to monitor treatment response. Citation Format: Qianhui Dou, Aaron K. Grant, Cody Callahan, David Mwin, Muneeb Ahmed, Leo L. Tsai. 13C-MRI detects increased lactate flux in HCC following hepatic thermal A\ablation and correlates with PFKFB3 Expression [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2785.

The Role of Intraoperative Microscope-Integrated OCT in Retinal Surgery. Part 1: Pro

Novel microscope-integrated OCT now allows targeted intraoperative high-resolution real-time imaging. In comparison to conventional surgical microscopes, intraoperative real-time OCT visualisation of retinal layers and vitreous body provides valuable information for surgical decision-making. In addition, simultaneous OCT imaging of retinal structures displayed within the funduscopic view through the eye-piece of the microscope allows direct guidance of instrument-tissue interaction and surgical manoeuvres. As a result, targeted iOCT imaging enables enhanced precision and the development of real-time guided surgical techniques at micron level.

Ultrafast Ultrasound Imaging for Super-Resolution Preclinical Cardiac PET

PurposePhysiological motion and partial volume effect (PVE) significantly degrade the quality of cardiac positron emission tomography (PET) images in the fast-beating hearts of rodents. Several Super-resolution (SR) techniques using a priori anatomical information have been proposed to correct motion and PVE in PET images. Ultrasound is ideally suited to capture real-time high-resolution cine images of rodent hearts. Here, we evaluated an ultrasound-based SR method using simultaneously acquired and co-registered PET-CT-Ultrafast Ultrasound Imaging (UUI) of the beating heart in closed-chest rodents.ProceduresThe method was tested with numerical and animal data (n = 2) acquired with the non-invasive hybrid imaging system PETRUS that acquires simultaneously PET, CT, and UUI.ResultsWe showed that ultrasound-based SR drastically enhances the quality of PET images of the beating rodent heart. For the simulations, the deviations between expected and mean reconstructed values were 2 % after applying SR. For the experimental data, when using Ultrasound-based SR correction, contrast was improved by a factor of two, signal-to-noise ratio by 11 %, and spatial resolution by 56 % (~ 0.88 mm) with respect to static PET. As a consequence, the metabolic defect following an acute cardiac ischemia was delineated with much higher anatomical precision.ConclusionsOur results provided a proof-of-concept that image quality of cardiac PET in fast-beating rodent hearts can be significantly improved by ultrasound-based SR, a portable low-cost technique. Improved PET imaging of the rodent heart may allow new explorations of physiological and pathological situations related with cardiac metabolism.