Scattering integral equation formulation for intravascular inclusion biosensing.

A dielectric waveguide, inserted into blood vessels, supports its basic mode that is being scattered by a near-field intravascular inclusion. A rigorous integral equation formulation is performed and the electromagnetic response from that inhomogeneity is semi-analytically evaluated. The detectability of the formation, based on spatial distribution of the recorded signal, is estimated by considering various inclusion sizes, locations and textural contrasts. The proposed technique, with its variants and generalizations, provides a generic versatile toolbox to efficiently model biosensor layouts involved in healthcare monitoring and disease screening.

Prediction of lymph node metastasis in T1 colorectal cancer based on combination of body composition and vascular invasion.

OBJECTIVES: Lymph node metastasis (LNM) in colorectal cancer (CRC) patients is not only associated with the tumor's local pathological characteristics but also with systemic factors. This study aims to assess the feasibility of using body composition and pathological features to predict LNM in early stage colorectal cancer (eCRC) patients. METHODS: A total of 192 patients with T1 CRC who underwent CT scans and surgical resection were retrospectively included in the study. The cross-sectional areas of skeletal muscle, subcutaneous fat, and visceral fat at the L3 vertebral body level in CT scans were measured using Image J software. Logistic regression analysis were conducted to identify the risk factors for LNM. The predictive accuracy and discriminative ability of the indicators were evaluated using receiver operating characteristic (ROC) curves. Delong test was applied to compare area under different ROC curves. RESULTS: LNM was observed in 32 out of 192 (16.7%) patients with eCRC. Multivariate analysis revealed that the ratio of skeletal muscle area to visceral fat area (SMA/VFA) (OR = 0.021, p = 0.007) and pathological indicators of vascular invasion (OR = 4.074, p = 0.020) were independent risk factors for LNM in eCRC patients. The AUROC for SMA/VFA was determined to be 0.740 (p < 0.001), while for vascular invasion, it was 0.641 (p = 0.012). Integrating both factors into a proposed predictive model resulted in an AUROC of 0.789 (p < 0.001), indicating a substantial improvement in predictive performance compared to relying on a single pathological indicator. CONCLUSION: The combination of the SMA/VFA ratio and vascular invasion provides better prediction of LNM in eCRC.

Visualization of intradermal blood vessel structures by dual-wavelength photoacoustic microscopy and characterization of three-dimensional construction of livedo-racemosa in cutaneous polyarteritis nodosa.

BACKGROUND: Photoacoustic microscopy is expected to have clinical applications as a noninvasive and three-dimensional (3D) method of observing intradermal structures. OBJECTIVE: Investigate the applicability of a photoacoustic microscope equipped with two types of pulsed lasers that can simultaneously recognize hemoglobin and melanin. METHODS: 16 skin lesions including erythema, pigmented lesions, vitiligo and purpura, were analyzed to visualize 3D structure of melanin granule distribution and dermal blood vessels. 13 cases of livedo racemosa in cutaneous polyarteritis nodosa (cPN) were further analyzed to visualize the 3D structure of dermal blood vessels in detail. Vascular structure was also analyzed in the biopsy specimens obtained from tender indurated erythema of cPN by CD34 immunostaining. RESULTS: Hemoglobin-recognition signal clearly visualized the 3D structure of dermal blood vessels and melanin-recognition signal was consistently reduced in vitiligo. In livedo racemosa, the hemoglobin-recognition signal revealed a relatively thick and large reticular structure in the deeper layers that became denser and finer toward the upper layers. The numerical analysis revealed that the number of dermal blood vessels was 1.29-fold higher (p<0.05) in the deeper region of the lesion than that of normal skin. The CD34 immunohistochemical analysis in tender indurated erythema revealed an increased number of dermal vessels compared with normal skin in 88.9% (8/9) of the cases, suggesting that vascular network remodeling had occurred in cPN. CONCLUSION: The photoacoustic system has an advantage in noninvasively detecting dermal blood vessel structures that are difficult to recognize by two-dimensional histopathology specimen examination and is worth evaluating in various skin diseases.

Virtual Shape-Editing of Patient-Specific Vascular Models Using Regularized Kelvinlets.

OBJECTIVE: Cardiovascular diseases, and the interventions performed to treat them, can lead to changes in the shape of patient vasculatures and their hemodynamics. Computational modeling and simulations of patient-specific vascular networks are increasingly used to quantify these hemodynamic changes, but they require modifying the shapes of the models. Existing methods to modify these shapes include editing 2D lumen contours prescribed along vessel centerlines and deforming meshes with geometry-based approaches. However, these methods can require extensive by-hand prescription of the desired shapes and often do not work robustly across a range of vascular anatomies. To overcome these limitations, we develop techniques to modify vascular models using physics-based principles that can automatically generate smooth deformations and readily apply them across different vascular anatomies. METHODS: We adapt Regularized Kelvinlets, analytical solutions to linear elastostatics, to perform elastic shape-editing of vascular models. The Kelvinlets are packaged into three methods that allow us to artificially create aneurysms, stenoses, and tortuosity. RESULTS: Our methods are able to generate such geometric changes across a wide range of vascular anatomies. We demonstrate their capabilities by creating sets of aneurysms, stenoses, and tortuosities with varying shapes and sizes on multiple patient-specific models. CONCLUSION: Our Kelvinlet-based deformers allow us to edit the shape of vascular models, regardless of their anatomical locations, and parametrically vary the size of the geometric changes. SIGNIFICANCE: These methods will enable researchers to more easily perform virtual-surgery-like deformations, computationally explore the impact of vascular shape on patient hemodynamics, and generate synthetic geometries for data-driven research.

An optical system for noninvasive microscopy of psoriatic mice in vivo.

Psoriasis is a chronic inflammatory skin disease involved with both complex morphological changes of skin and immune processes. The clinical diagnostics and research of psoriasis often require invasive biopsy which lacks their real-time dynamics in vivo. Here we report a noninvasive microscopic system developed by combining in vivo fluorescent microscopy, optical clearing, and immunolabeling to enable real-time imaging of immune cells and cytokines in blood flow in psoriatic animal models. The vascular morphology and time-lapse kinetics of interleukin (IL)-23, IL-17, tumor necrosis factor-α, and CD4+ cells in blood are captured at submicron resolution through the thickening epidermis and opaque scales during the development of psoriasis in vivo. Our data suggest IL-23 recruits CD4+ cells to release IL-17 in blood that further leaks out in the psoriatic skin area. This optical system enables noninvasive and real-time assessment of immune molecules and cells in vivo, providing good potential for medical researches on psoriasis.

Deconvolution-Based Partial Volume Correction for Volumetric Blood Flow Measurement.

Ultrasound-based blood flow (BF) monitoring is vital in the diagnosis and treatment of a variety of cardiovascular and neurologic conditions. Finite spatial resolution of clinical color flow (CF) systems, however, has hampered measurement of vessel cross Section areas. We propose a resolution enhancement technique that allows reliable determination of BF in small vessels. We leverage sparsity in the spatial distribution of the frequency spectrum of routinely collected CF data to blindly determine the point spread function (PSF) of the imaging system in a robust manner. The CF data are then deconvolved with the PSF, and the volumetric flow is computed using the resulting velocity profiles. Data were collected from phantom blood vessels with diameters between 2 and 6 mm using a clinical ultrasound system at 2 MHz insonation frequency. The proposed method yielded a flow estimation bias of 0 mL/min, standard deviation of error (SDE) of 22 mL/min, and a root-mean-square error (RMSE) of 22 mL/min over a 150 mL/min range of mean flows. Recordings were also obtained in low signal-to-noise ratio (SNR) conditions using a skull mimicking element, resulting in an estimation bias of -13 mL/min, SDE of 23 mL/min, and an RMSE of 26 mL/min. The effect of insonation frequency was also investigated by obtaining recordings at 4.3 MHz, yielding an estimation bias of -16 mL/min, SDE of 16 mL/min, and an RMSE of 22 mL/min. The results indicate that our technique can lead to clinically acceptable flow measurements across a range of vessel diameters in high and low SNR regimes.

Improvement of spatial resolution in photoacoustic microscopy using transmissive adaptive optics with a low-frequency ultrasound transducer.

Maintaining a high spatial resolution in photoacoustic microscopy (PAM) of deep tissues is difficult due to large aberration in an objective lens with high numerical aperture and photoacoustic wave attenuation. To address the issue, we integrate transmission-type adaptive optics (AO) in high-resolution PAM with a low-frequency ultrasound transducer (UT), which increases the photoacoustic wave detection efficiency. AO improves lateral resolution and depth discrimination in PAM, even for low-frequency ultrasound waves by focusing a beam spot in deep tissues. Using the proposed PAM, we increased the lateral resolution and depth discrimination for blood vessels in mouse ears.

Roles of DWI and T2-weighted MRI volumetry in the evaluation of lymph node metastasis and lymphovascular invasion of stage IB-IIA cervical cancer.

AIM: To determine whether magnetic resonance imaging volumetry on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) could be used to assess lymph node metastases (LNM) and lymphovascular invasion (LVSI) in resectable cervical cancer. MATERIAL AND METHODS: Sixty-five consecutive patients with cervical cancer were enrolled retrospectively. Tumour size, including maximum transverse diameter, tumour length, and gross tumour volume (GTV), was evaluated on DWI and T2WI. Apparent diffusion coefficient (ADC) values were measured. Univariate, multivariate, and receiver operating characteristic (ROC) curve analyses were performed to determine whether tumour size and ADC could be used to assess LNM and LVSI. RESULTS: Tumour length on both T2WI and DWI, and T2WI-based and DWI-based GTVs could be used to assess LNM (p=0.002, 0.004, 0.001, and <0.001, respectively). Tumour length on T2WI, T2WI-based GTV, DWI-based GTV, and ADC value could be used assess LVSI (p=0.039, 0.038, 0.012, 0.039, respectively). Multivariate analyses showed both T2WI-based GTV (odds ratio [OR] = 1.044; p=0.008) and DWI-based GTV (OR=1.941; p=0.019) were independent risk factors for LNM. T2WI-based GTV (OR=1.023, p=0.038) and DWI-based GTV (OR=3.275, p=0.008) were independent risk factors for LVSI. No statistically significant difference was identified between the area under the ROC curve (AUC) of the DWI-based GTV and the T2WI-based GTV (0.790 versus 0.775, p=0.113), or the tumour length on both T2WI (0.790 versus 0.734, p=0.185) and DWI (0.790 versus 0.737, p=0.333) for LNM. For LVSI, the AUC of DWI-based GTV was higher than T2WI-based GTV (0.720 versus 0.682, p=0.006). CONCLUSION: GTV on both T2WI and DWI could be used assess LNM and LVSI. DWI-based GTV might show the greatest potential for assessing LNM and LVSI in resectable cervical cancer.

Utility of shear wave elastography and high-definition color for diagnosing carpal tunnel syndrome.

OBJECTIVE: The diagnostic values of measuring median nerve (MN) stiffness and vascularity with shear wave elastography (SWE) and high-definition (HD) color were investigated in carpal tunnel syndrome (CTS). METHODS: Seventy patients (123 wrists) with CTS and thirty-five healthy volunteers (70 wrists) were enrolled. Based on nerve conduction studies (NCS), the patients were subdivided into NCS-negative, mild-to-moderate, and severe CTS groups. MN and abductor pollicis brevis (APB) SWE and MN HD color were performed on a longitudinal plane. RESULTS: The mild-to-moderate and severe CTS groups showed increased MN stiffness at the wrist and MN stiffness ratio (wrist-to forearm) compared with the control (p < 0.001). The NCS-negative CTS group showed increased MN stiffness at the wrist (p = 0.022) and MN stiffness ratio (p = 0.032) compared with the control. The severe CTS group showed increased MN stiffness at the wrist compared with the mild-to-moderate CTS group (p = 0.034). The cutoff-values in diagnosing NCS-confirmed CTS were 50.12 kPa for MN stiffness at the wrist, 1.91 for MN stiffness ratio, and grade 1 for HD color. CONCLUSIONS: SWE and HD color are good supportive tools in diagnosing and assessing severity in CTS. SIGNIFICANCE: SWE and HD color demonstrated that MN in CTS was associated with increased stiffness and hypervascularity.

RELATIONSHIP BETWEEN MYOPIC CHOROIDAL NEOVASCULARIZATION ACTIVITY AND PERFORATING SCLERAL VESSELS IN HIGH MYOPIA.

PURPOSE: To study perforating scleral vessels (PSVs) in patients with high myopia using swept-source optical coherence tomography and to determine their relationship with myopic choroidal neovascularization (mCNV) and its activity. METHODS: Retrospective analysis of patients with high myopia (≥-6 D or ≥26 mm of axial length) using multimodal imaging. The presence of PSVs and mCNV was assessed using swept-source optical coherence tomography images (TRITON; Topcon Corporation, Japan). RESULTS: Five hundred sixty-four eyes from 297 highly myopic patients were studied. One hundred fifty-five eyes (27.5%) showed signs of mCNV while PSVs were found in 500 eyes (88.6%). Perforating scleral vessels were found in 93.5% (145/155) of eyes with mCNV, and they were under or in contact with the mCNV in 80.6% (117/145). The mean number of intravitreal injections received by patients with mCNV was 4.06 ± 4.17 along 66.9 ± 4.1 months of follow-up. The number of injections per year was 1.32 ± 1.56, the mean number of relapses was 1.11 ± 1.83, and the mean number of relapses per year was 0.25 ± 0.41. CONCLUSION: Perforating scleral vessels are more common among highly myopic patients suffering from neovascular complications. Myopic CNV complexes that are coincident with PSVs on optical coherence tomography show higher rates of activity, needing more injections to control them and being more prone to relapses.

Imaging spectrum of extracranial arterial vascular pathology: pearls for the radiologist.

Non-invasive imaging plays an increasingly important role in assessing the extracranial vasculature. The applications of computed tomography angiography (CTA) and magnetic resonance angiography (MRA) continue to expand with growing demand for stroke imaging and anatomical assessment preceding vascular intervention. Imaging of the neck is performed for a variety of clinical indications with different imaging protocols. Even on non-dedicated vascular imaging, such as soft-tissue studies, the neck vessels and the proximal aortic arch are readily evaluable, providing an opportunity to promptly identify critical vascular abnormalities with significant therapeutic implications. Vascular abnormalities can have non-specific clinical signs and symptoms resulting in delays in both diagnosis and treatment. Understanding the common locations and appearances of vascular pathologies will help the radiologist to develop a systematic search strategy for evaluating neck imaging. Not only is identifying the pathology of paramount importance but also understanding how imaging further prognosticates and determines treatment options. As imaging techniques advance, further vascular radiological features are recognised with therapeutic implications, particularly for stroke. Such features include plaque morphology and vulnerability with imaging helping to identify those at high risk of stroke and recurrent strokes. Using clinical cases from a quaternary care academic medical centre a spectrum of clinically relevant arterial pathologies and associated features that could add further benefit to the radiology report are illustrated. A suggested systematic approach to evaluating the vasculature on neck imaging is also presented.

Learning from mistakes when reporting urgent and emergency vascular studies.

The majority of out-of-hours cases relate to neurological, chest, and gastrointestinal pathologies with acute vascular cases being encountered less commonly. Trainees and exposure of non-vascular/interventional radiology (IR) consultants to angiographic imaging is often limited in working hours and this may lead to reporting on-call cases outside of normal daytime practice. In a recent local review, a number on-call vascular studies were found to contain a number of vascular-related discrepancies. Vascular reporting is a complex subspecialty, which comprises many clear diagnoses (large vessel occlusions, large vessel aneurysms, or dissections); however, also several subtle and complex abnormalities. These more subtle abnormalities, at times, require dedicated vascular specialist review to ensure subtle findings are communicated appropriately to the clinical team. The recent increased complexity of endovascular treatments and their complications has also provided further challenge for the non-specialist reporter. Similarly, improved imaging techniques have allowed for non-obvious but significant findings that may require urgent management, such as small aneurysms and dissection flaps. We will review a range of key vascular findings that demonstrate learning opportunities, particularly within the acute and on-call settings. These will include gastrointestinal haemorrhage, subtle aortic pathologies, head and neck vascular emergencies, small to mid-sized vessel injuries and imaging of post-procedural complications. Educational hints and tips will be provided to enable learning from mistakes encountered by trainees and non-vascular specialist radiologists in the on-call or urgent reporting settings, and these will be reviewed with reference to the literature.

Impact of image averaging on vessel detection using optical coherence tomography angiography in eyes with macular oedema and in healthy eyes.

PURPOSE: To assess the repeatability of multiple automatic vessel density (VD) measurements and the effect of image averaging on vessel detection by optical coherence tomography angiography (OCTA). METHODS: An observational study was conducted in a series of healthy volunteers and patients with macular oedema. Five sequential OCTA images were acquired for each eye using the OptoVue HD device. The effect of the averaging of the 5 acquisitions on vessel detection was analysed quantitatively using a pixel-by-pixel automated analysis. In addition, two independent retina experts qualitatively assessed the change in vessel detection in averaged images segmented in 9 boxes and compared to the first non-averaged image. RESULTS: The automatic VD measurement in OCTA images showed a good repeatability with an overall mean intra-class correlation coefficient (ICC) of 0.924. The mean ICC was higher in healthy eyes compared to eyes with macular oedema (0.877 versus 0.960; p < 0.001) and in the superficial vascular plexus versus the deep vascular complex (0.967 versus 0.888; p = 0.001). The quantitative analysis of the effect of the averaging showed that averaged images had a mean gain of 790.4 pixels/box, located around or completing interruptions in the vessel walls, and a mean loss of 727.2 pixels/box. The qualitative analysis of the averaged images showed that 99.6% of boxes in the averaged images had a gain in vessel detection (i.e., vessels detected in the averaged image but not in the non-averaged image). The loss of pixels was due to a reduction in background noise and motion artifacts in all cases and no case of loss of vessel detection was observed. CONCLUSION: The automatic VD measurement using the OptoVue HD device showed a good repeatability in 5 acquisitions in a row setting. Averaging images increased vessel detection, and in about a third of boxes, decreased the background noise, both in healthy eyes and, in a greater proportion, in eyes with macular oedema.

Rationale and design of the application value of Beijing Vascular Health Stratification (BVHS): predictive value of combined assessment of vascular structure and function for cardiovascular events in general Chinese population.

BACKGROUND: Vascular endothelial dysfunction, arteriosclerosis and atherosclerotic plaque are well-known risk factors for cardiovascular disease (CVD). Studies on vascular health markers have been well-established, however, there is still a lack of related research on combined vascular structure and function indicators. METHOD: Beijing vascular health stratification (BVHS) is an evaluation system aiming at vascular health, combined the endothelial function, arteriosclerosis, atherosclerotic plaque and vascular lumen stenosis to comprehensively assess the vascular health and grade it. This study will explore the predictive value of the combined evaluation of vascular structure and function for cardiovascular events and assess the predictive value of BVHS and compare it with the existing risk assessment systems. A total of 1500 subjects will be enrolled into the prospective cohort study from a community and will be followed up for at least 3 years from July 1, 2020 to June 30, 2023. Subjects aged 40 or above, without coronary heart disease, stroke or peripheral artery disease, with written informed consent will be included; subjects with end-stage hepatorenal diseases (uremia, renal failure, cirrhosis, liver failure), mental disorders or cognitive disorders, with any other factors that the researcher thinks are not suitable for the study will be excluded. Traditional cardiovascular risk factors will be collected as adjusted confounders. DISCUSSION: BVHS is a potential and scientific vascular health evaluation system. The study will be the first to grade vascular health by combing various vascular indicators and explore the prediction value and compare with other risk prediction system in general Chinese population. TRIAL REGISTRATION: The trial is registered on http://www.chictr.org.cn/ (ChiCTR2000034085).

Navigation of Microrobots by MRI: Impact of Gravitational, Friction and Thrust Forces on Steering Success.

INTRODUCTION: Magnetic resonance navigation (MRN) uses MRI gradients to steer magnetic drug-eluting beads (MDEBs) across vascular bifurcations. We aim to experimentally verify our theoretical forces balance model (gravitational, thrust, friction, buoyant and gradient steering forces) to improve the MRN targeted success rate. METHOD: A single-bifurcation phantom (3 mm inner diameter) made of poly-vinyl alcohol was connected to a cardiac pump at 0.8 mL/s, 60 beats/minutes with a glycerol solution to reproduce the viscosity of blood. MDEB aggregates (25 ± 6 particles, 200 [Formula: see text]) were released into the main branch through a 5F catheter. The phantom was tilted horizontally from - 10° to +25° to evaluate the MRN performance. RESULTS: The gravitational force was equivalent to 71.85 mT/m in a 3T MRI. The gradient duration and amplitude had a power relationship (amplitude=78.717 [Formula: see text]). It was possible, in 15° elevated vascular branches, to steer 87% of injected aggregates if two MRI gradients are simultaneously activated ([Formula: see text] = +26.5 mT/m, [Formula: see text]= +18 mT/m for 57% duty cycle), the flow velocity was minimized to 8 cm/s and a residual pulsatile flow to minimize the force of friction. CONCLUSION: Our experimental model can determine the maximum elevation angle MRN can perform in a single-bifurcation phantom simulating in vivo conditions.

Assessment of flow within developing chicken vasculature and biofabricated vascularized tissues using multimodal imaging techniques.

Fluid flow shear stresses are strong regulators for directing the organization of vascular networks. Knowledge of structural and flow dynamics information within complex vasculature is essential for tuning the vascular organization within engineered tissues, by manipulating flows. However, reported investigations of vascular organization and their associated flow dynamics within complex vasculature over time are limited, due to limitations in the available physiological pre-clinical models, and the optical inaccessibility and aseptic nature of these models. Here, we developed laser speckle contrast imaging (LSCI) and side-stream dark field microscopy (SDF) systems to map the vascular organization, spatio-temporal blood flow fluctuations as well as erythrocytes movements within individual blood vessels of developing chick embryo, cultured within an artificial eggshell system. By combining imaging data and computational simulations, we estimated fluid flow shear stresses within multiscale vasculature of varying complexity. Furthermore, we demonstrated the LSCI compatibility with bioengineered perfusable muscle tissue constructs, fabricated via molding techniques. The presented application of LSCI and SDF on perfusable tissues enables us to study the flow perfusion effects in a non-invasive fashion. The gained knowledge can help to use fluid perfusion in order to tune and control multiscale vascular organization within engineered tissues.

Functionalizing Collagen with Vessel-Penetrating Two-Photon Phosphorescence Probes: A New In Vivo Strategy to Map Oxygen Concentration in Tumor Microenvironment and Tissue Ischemia.

The encapsulation and/or surface modification can stabilize and protect the phosphorescence bio-probes but impede their intravenous delivery across biological barriers. Here, a new class of biocompatible rhenium (ReI ) diimine carbonyl complexes is developed, which can efficaciously permeate normal vessel walls and then functionalize the extravascular collagen matrixes as in situ oxygen sensor. Without protective agents, ReI -diimine complex already exhibits excellent emission yield (34%, λem   = 583 nm) and large two-photon absorption cross-sections (σ2   = 300 GM @ 800 nm) in water (pH 7.4). After extravasation, remarkably, the collagen-bound probes further enhanced their excitation efficiency by increasing the deoxygenated lifetime from 4.0 to 7.5 µs, paving a way to visualize tumor hypoxia and tissue ischemia in vivo. The post-extravasation functionalization of extracellular matrixes demonstrates a new methodology for biomaterial-empowered phosphorescence sensing and imaging.

Tissue Clearing and 3-D Visualization of Vasculature with the PEGASOS Method.

Tissue clearing techniques turn tissue transparent through a series of chemical and physical treatments. They have provided a useful tool for three-dimensional (3-D) imaging to study tissue spatial organization and interactions. Many tissue clearing methods have been developed in recent years. Each method has its own application range depending on the purposes of the study. Three criteria for selecting an appropriate clearing method include clearing transparency, fluorescence preservation, and broad tissue applicability. PEG-associated solvent system (PEGASOS) emerged recently as a solvent-based tissue clearing method capable of rendering diverse tissues highly transparent while preserving fluorescence. Combined with vascular labeling techniques, PEGASOS method enables 3-D visualization of vasculature in whole tissues at subcellular resolution. Here, we describe the standard PEGASOS passive immersion protocol and several compatible vascular labeling techniques. Methods of 3-D imaging, data processing, and annotations are also briefly introduced.

Detecting Three-Dimensional Vascular Networks in the Mouse Embryonic Hindbrain.

Blood vessel formation is a fine-regulated process and interfering with blood vessel formation causes embryonic lethality as well as associated with many diseases in the adult, including inflammatory, ischemic, and cancer metastatic diseases. Brain contains abundant blood vessels and has some unique physiological functions, such as blood-brain barrier. Due to the thickness and opaque characters of the tissues, it is a challenge to visualize the three-dimensional structures of the brain blood vessels in the mouse. Therefore, establishing a protocol to display the three-dimensional structures in the brain is required for exploring the regulatory molecular mechanisms in brain blood vessel formation. In this manuscript, we introduced a whole-mount and a vibratome thick section of mouse embryonic hindbrain to display the three-dimensional structures of brain vascular system.