Characterization of Vortex Vein Drainage System in Healthy Individuals Imaged by Ultra-Widefield Optical Coherence Tomography Angiography.

Purpose: The purpose of this study was to investigate the choroidal characteristics of vortex vein (VV) drainage systems in healthy individuals using ultra-widefield optical coherence tomography angiography. Methods: The mean choroidal thickness (ChT) and choroidal vascularity index (CVI) of each VV quadrant (24 × 20 mm2 scan mode; superotemporal [ST], superonasal [SN], inferonasal [IN], and inferotemporal [IT] quadrants) were calculated. Furthermore, intervortex venous anastomosis (IVA) was classified into temporal, superior, inferior, and nasal types. Results: A total of 207 healthy eyes were analyzed to find that the ST quadrant had the thickest choroidal layer and highest CVI (all P < 0.05). Among the four VV drainage quadrants, the mean ChT and CVI decreased in the sequence of ST, SN, IT, and IN (all P < 0.05). Moreover, men had a higher CVI than women in all VV quadrants (all P < 0.05). IVA was observed in all VV quadrants of 91 eyes (43.96%), and in the macular region of 33 eyes (15.94%). Conclusions: The ST drainage system was identified as the preferred VV drainage route in healthy eyes. Among the four VV drainage quadrants, the drainage system adhered to the ST-SN-IT-IN order of descending perfusion. Furthermore, age- and sex-related differences were noted in the choroidal VV drainage systems of healthy eyes. Additionally, almost half of the healthy eyes had IVA in their choroidal vessel networks. Translational Relevance: The VV drainage system may be considered a novel imaging biomarker for ocular diseases.

Visual Feature-Guided Diamond Convolutional Network for Finger Vein Recognition.

Finger vein (FV) biometrics have garnered considerable attention due to their inherent non-contact nature and high security, exhibiting tremendous potential in identity authentication and beyond. Nevertheless, challenges pertaining to the scarcity of training data and inconsistent image quality continue to impede the effectiveness of finger vein recognition (FVR) systems. To tackle these challenges, we introduce the visual feature-guided diamond convolutional network (dubbed 'VF-DCN'), a uniquely configured multi-scale and multi-orientation convolutional neural network. The VF-DCN showcases three pivotal innovations: Firstly, it meticulously tunes the convolutional kernels through multi-scale Log-Gabor filters. Secondly, it implements a distinctive diamond-shaped convolutional kernel architecture inspired by human visual perception. This design intelligently allocates more orientational filters to medium scales, which inherently carry richer information. In contrast, at extreme scales, the use of orientational filters is minimized to simulate the natural blurring of objects at extreme focal lengths. Thirdly, the network boasts a deliberate three-layer configuration and fully unsupervised training process, prioritizing simplicity and optimal performance. Extensive experiments are conducted on four FV databases, including MMCBNU_6000, FV_USM, HKPU, and ZSC_FV. The experimental results reveal that VF-DCN achieves remarkable improvement with equal error rates (EERs) of 0.17%, 0.19%, 2.11%, and 0.65%, respectively, and Accuracy Rates (ACC) of 100%, 99.97%, 98.92%, and 99.36%, respectively. These results indicate that, compared with some existing FVR approaches, the proposed VF-DCN not only achieves notable recognition accuracy but also shows fewer number of parameters and lower model complexity. Moreover, VF-DCN exhibits superior robustness across diverse FV databases.

Agonist antibody to guanylate cyclase receptor NPR1 regulates vascular tone.

Heart failure is a leading cause of morbidity and mortality1,2. Elevated intracardiac pressures and myocyte stretch in heart failure trigger the release of counter-regulatory natriuretic peptides, which act through their receptor (NPR1) to affect vasodilation, diuresis and natriuresis, lowering venous pressures and relieving venous congestion3-8. Recombinant natriuretic peptide infusions were developed to treat heart failure but have been limited by a short duration of effect9,10. Here we report that in a human genetic analysis of over 700,000 individuals, lifelong exposure to coding variants of the NPR1 gene is associated with changes in blood pressure and risk of heart failure. We describe the development of REGN5381, an investigational monoclonal agonist antibody that targets the membrane-bound guanylate cyclase receptor NPR1. REGN5381, an allosteric agonist of NPR1, induces an active-like receptor conformation that results in haemodynamic effects preferentially on venous vasculature, including reductions in systolic blood pressure and venous pressure in animal models. In healthy human volunteers, REGN5381 produced the expected haemodynamic effects, reflecting reductions in venous pressures, without obvious changes in diuresis and natriuresis. These data support the development of REGN5381 for long-lasting and selective lowering of venous pressures that drive symptomatology in patients with heart failure.

Clinical study on the establishment of radio-cephalic autogenous arteriovenous fistulas in small blood vessels by multi-segment balloon dilation technique.

BACKGROUND: To investigate the effect of dilating small blood vessels using a balloon dilation (BD) technique on the occurrence of radio-cephalic autogenous arteriovenous fistulas in terms of patency, blood flow, and vein diameter (VD). METHODS: The subjects included in this study were all patients with chronic renal failure and required radio-cephalic arteriovenous fistula surgery for the first time and had not received dialysis before. Patients with VDs <2 mm were included as study subjects. They were either assigned treatment using a BD group or a control group that received hydrostatic dilation. The differences between the 2 groups were analyzed in terms of patency, blood flow, and VD. RESULTS: A total of 22 patients were enrolled in the balloon dilatation group and 20 patients in the control group. The diameters of cephalic veins (mm) of the experimental and control group were compared at various time points: immediately postoperation, 2.89 ±â€…0.42 versus 1.99 ±â€…0.28 (P < .001); 1 week later, 3.16 ±â€…0.59 versus 2.66 ±â€…0.60 (P = .022); 1 month later, 3.76 ±â€…0.91 versus 3.18 ±â€…0.83 (P = .087); and 2 months later, 4.08 ±â€…1.15 versus 3.38 ±â€…1.13 (P = .169). Brachial artery flows (mL/min) of the 2 groups at various time points were given as follows: immediately postoperation, 413.49 ±â€…145.09 versus 235.61 ±â€…87.77 (P < .001); 1 week later, 563.26 ±â€…206.83 versus 331.30 ±â€…126.78 (P < .001); 1 month later, 679.34 ±â€…218.56 versus 376.79 ±â€…156.25 (P < .001); and 2 months later, 736.31 ±â€…202.61 versus 394.60 ±â€…161.96 (P < .001). The primary patency at 1 year for the experimental group was 61.9% compared to 11.1% for the control group (P = .045). Similarly, the secondary patency rates at 1 year were 90.5% for the experimental group and 55.6% for the control group (P = .030). The results showed that the functional primary patency rate within 1 year was 57.1% versus 16.7% (P = .032), and the functional secondary patency rate within 1 year was 85.7% versus 50.0% (P = .038). CONCLUSION SUBSECTIONS: BD has obvious advantages over hydrostatic dilation for chronic renal failure patients with small veins in establishing arteriovenous fistula in terms of patency and blood flow.

Grade III Varicocele Surgical Treatment using Spermatic Vein-Superficial Abdominal Vein Shunt.

Microsurgical varicocelectomy is the most commonly used method for the treatment of varicocele (VC) in recent years. However, it is technically demanding with the risk of damaging the normal anatomical structure of the spermatic cord, such as the cremaster muscle, testicular artery, and vas deferens during the pampiniform plexus ligation. Also, traditional varicocelectomy hinders the drainage of the stagnant venous blood of the affected testicle, resulting in a persistent scrotal appearance of varicose veins and slower remission of swelling sensation in postoperative patients with grade III VC. Therefore, we developed a retroperitoneal varicocelectomy with a microscopical spermatic venous-superficial vein of the abdominal wall bypass procedure. The spermatic vein was transected and ligated proximally through the retroperitoneal space. Then, the distal spermatic vein was freed and passed through the internal ring; under the skin of the groin, a microscopic vascular anastomosis was performed to build the bypass of the distal spermatic vein and proximal inferior epigastric vein. The high ligation facilitates the protection of the normal anatomy of the spermatic cord, and the venous bypass allows rapid testicular blood drainage, which can effectively improve the degree of varicocele, testicular pain, and even spermatogenic function. In conclusion, the present protocol describes a promising way to reconstruct the spermatic return through high retroperitoneal ligation of the spermatic vein and anastomosis of the spermatic vein-inferior epigastric vein, which resulted in faster and more obvious improvement in symptoms and better prognosis of grade III VC.

Potential of the Thoracoepigastric Vein as a Drainage Vein in Breast Reconstruction With a Free Flap: An Anatomical Study Using Computed Tomography.

BACKGROUND: The recipient vessel choice is very important when performing free-flap breast reconstructions. Usually, the concomitant vein of the recipient artery is anastomosed, and mismatches in the diameter are occasionally observed. We consider the thoracoepigastric vein (TEV) as a potential useful recipient vein. The use of the TEV is not a novel technique. It has been used by surgeons for free-flap anastomoses in the axillary region, but usually as an anastomotic site for the second vein. However, anatomical findings such as TEV diameter, its deficiency rate, and influence on mastectomy are not clear. In this study, computed tomography (CT) was performed to evaluate the use of the TEV as a recipient vein for breast reconstruction. METHODS: The medical records of patients who underwent breast reconstruction with free-flap transfer were retrospectively evaluated. In most cases, CT was performed using a tissue expander inserted after mastectomy. The TEV was considered suitable if its diameter on the mastectomy side was >1 mm and the vertical distance from the most distal slice level where the TEV could be seen at the third costal cartilage height of the parasternal region was <50 mm. RESULTS: Sixty-six sides of 33 patients were evaluated. The mean age of the patients was 49.3 ± 5.1 years. The TEV was used in five flaps. TEV diameters were not significantly different between the left and right sides (1.85 ± 0.53 vs. 1.82 ± 0.6, respectively, p = 0.836). On the mastectomy side, eight (25%) TEVs were injured, but only three (8.6%) were considered unavailable. On the healthy side, 96.4% TEVs were available. CONCLUSIONS: TEVs may be a good choice as vein anastomosis targets for breast reconstruction with a free flap because of their relatively large vessel diameter. TRIAL REGISTRATION: UMIN-CTR: R000061573.

Anatomical Feasibility of Percutaneous Arteriovenous Fistula Formation in Korea.

INTRODUCTION: Currently, there are two types of percutaneous arteriovenous fistula (pAVF) formation systems approved by the FDA: Ellipsys and WavelinQ. Although these systems are already in use in Europe or the United States, they have not been approved for use in Korea yet. For this reason, this study aimed to check anatomical feasibility of these systems for Korean population prior to their actual use. METHODS: Consecutive patients who received ultrasound vein mapping for arteriovenous fistula formation from June 2021 to June 2022 were included. The anatomical feasibility of each system was confirmed according to the manufacturer's instructions for use (IFU). RESULTS: Upper extremity ultrasonography was performed for a total of 83 patients to determine their feasibility for pAVF formation. Of these patients, 65.1% were feasible for pAVF formation with appropriate deep communicating vein (DCV) and outflow. Among them, 57.8% were feasible for the Ellipsys system and 54.2% were feasible for the WavelinQ system. Most patients who were infeasible for pAVF formation had a DCV of small size. Ulnar vessels were more suitable than radial vessel for WavelinQ (54.2% vs 33.7%, P-value = .012). The most common reason for not meeting the criteria was a small vein size at the access site. CONCLUSIONS: More than half of all patients were feasible for pAVF formation in this study. Ellipsys had a higher feasibility than WavelinQ, although they showed no significant difference in the feasibility. If these devices are imported into Korea, it will be a good opportunity for many patients to reduce the surgical burden and create AVFs more easily through these procedures.

Duplicated and dilated ovarian vein with coexistence of persistent mesonephric artery.

During standard cadaveric dissection we encountered multiple vascular variations in the retroperitoneum: duplicated and dilated left ovarian vein with the coexistence of a persistent right mesonephric artery.

Fluid dynamics and venous hemodynamics in the lower extremities.

Chronic venous disease is a vascular disorder characterized by impaired venous return and a progressive dysfunction of the venous system. Pathological reflux can occur due to abnormal dilation and weakening of the vein wall. The circulatory system is a natural structure in which physical laws, such as the law of closed containers and gravity, operate. The malfunctions in the system also adhere to these laws of nature. This article explains how the principles of fluid dynamics apply to the flow of blood in the veins of the legs. I am discussing the principles of Pascal's law, Torricelli's law, Bernoulli's law, and Poiseuille's law, and how they are relating to the anatomy and physiology of the venous system.

Arterial and venous supply of the Harderian gland in hens.

Background: The Harderian gland in domestic birds is a major paraocular excretory gland that has an important role in tear production as well as in the immune protection of the conjunctiva surface. Aim: The aim of this research was to investigate the arterial and venous supply of the gland in hens and provide valuable and useful information for future research. Methods: The research was conducted on 26 adult hens, provenience of Lohmann Brown. For the identification and determination of blood vessels, we used the vascular corrosion cast technique in conjunction with the transmission electron microscope (TEM). Results: The casts showed that the gland receives the arterial supply via branches of a. ophthalmotemporalis and a. nasalis communis and these arteries are accompanied by the corresponding veins. Ultrastructural analyses showed the presence of fenestrated capillaries, which indicates the possibility for permeability of larger molecules. Conclusion: The present research gives important and detailed information about the arterial and venous supply of the Harderian gland in hens that may serve as guidelines for future vascular and morphological investigations.

Percutaneous Sclerotherapy of Venous Malformations.

Venous malformation (VM) stands as the most prevalent form of vascular malformation, characterized by its diverse morphology. These lesions can manifest in any part of the body, affecting different tissue planes and giving rise to symptoms such as pain, swelling, or physical dysfunction. In the realm of treatment, direct puncture VM sclerotherapy holds its place as the primary approach. This technique involves the administration of a sclerosing agent into the VM channels during contrast phlebography while simultaneously managing the outflow veins through different methods. The process of VM sclerotherapy induces endothelial damage, thrombosis, and fibrosis, resulting in symptom relief through lesion shrinkage. It is crucial to exercise caution techniques and sclerosing agents during VM sclerotherapy to minimize procedural complications, enhance clinical outcomes, and ultimately improve the patient's overall quality of life.

Venous Anomalies in Overgrowth Syndromes.

Overgrowth syndromes, particularly within the PIK3CA-related overgrowth syndrome (PROS) spectrum, are commonly associated with venous anomalies. The anomalies include spongiform venous malformations and persistent embryonic veins, such as the lateral marginal vein (of Servelle). The anomalous veins pose a significant risk of thromboembolic disease and should be occluded, preferably earlier in life. A thorough understanding of the conditions, anatomy, and interdisciplinary treatment of these complex anomalies is essential for optimal management. This review explores the clinical and imaging diagnosis of overgrowth syndromes and techniques for assessing and treating associated venous anomalies, particularly the endovenous closure of anomalous veins.

Wing vein abnormality analysis in honeybee (Apis mellifera L. 1758) populations from Iran.

The insect wing is one of the most important characteristics that allowed insects to occupy most of the habitats on the planet. Honeybee wings has been the subject of studies on the venation abnormalities. A total of 424 honeybees from 14 locations were collected and all four wings were removed and examined for 19 abnormalities on the forewings and 6 abnormalities on the hindwings. In general, supernumerary veins were the most common abnormalities seen and abnormalities no. 23, 2, 6, 1, 5, 21, 10, 13 had the highest and abnormalities no. 11, 17, 18, 19, 20, and 25 had the lowest frequencies. All of the abnormalities had similar frequencies in the right and left wings in the population. In terms of correlation between 25 abnormalities, abnormality pairs AB3-AB13, AB6-AB7, AB7-AB8, AB10-AB12, AB16-AB17 on the forewing and AB2-AB23, AB12-AB20, AB12-AB24, AB13-AB21, AB16-AB25, and AB17-AB25 between the forewing and hindwing show significant positive correlations and abnormality pairs AB4-AB5, AB7-AB15 and AB8-AB9 on the forewing show significant negative correlations with each other. In terms of the differential occurrence of abnormalities , a few locations differed significantly from other locations. This study provides some insights into the nature of these abnormalities on the honeybee wings.

Utility of Adrenal Vein Sampling With and Without Ultra-Low Dose ACTH Infusion in the Diagnostic Evaluation of Primary Aldosteronism.

BACKGROUND: Adrenal vein sampling (AVS), integral to identifying surgically remediable unilateral primary aldosteronism (PA), is technically challenging and subject to fluctuations in cortisol and aldosterone secretion. Intra-procedural adrenocorticotropic hormone (ACTH), conventionally administered as a 250-µg bolus and/or 50 µg per hour infusion, increases cortisol and aldosterone secretion and can improve AVS success, but may cause discordant lateralisation compared to unstimulated AVS. AIMS: To assess if AVS performed with ultra-low dose ACTH infusion causes discordant lateralisation. METHODS: Here, we describe our preliminary experience using an ultra-low dose ACTH infusion AVS protocol. We retrospectively reviewed the results of consecutive AVS procedures (n = 37) performed with and without ultra-low dose ACTH (1-µg bolus followed by 1.25 µg per hour infusion). RESULTS: Bilateral AV cannulation was successful in 70% of procedures pre-ACTH and 89% post-ACTH (p < 0.01). Sixty-nine percent of studies lateralised pre-ACTH and 55% post-ACTH, improving to 79% when both groups were combined. Lateralisation was discordant in 11 cases, including eight in which lateralisation was present only on basal sampling, and three in which lateralisation occurred only with ACTH stimulation. DISCUSSION: Overall, the decrease in lateralisation rates with ACTH was higher than previously reported for some protocols utilising conventional doses of ACTH. Our results suggest that AVS performed with ultra-low dose ACTH can cause discordant lateralisation similar to AVS performed with conventional doses of ACTH. CONCLUSION: Prospective studies directly comparing low and conventional dose ACTH AVS protocols and long-term patient outcomes are needed to help define the optimal ACTH dose for accurate PA subtyping.

[Evaluation of the anatomical morphology of the adrenal veins in patients with primary aldosteronism by adrenal venous sampling].

Objective: To analyze the anatomical characteristics of the adrenal veins through adrenal venography to improve the success rate of adrenal venography (AVS). Methods: This study was a cross-sectional study. Patients who were diagnosed with primary aldosteronism and underwent AVS from January 2019 to October 2023 at the First Affiliated Hospital of Dalian Medical University were included. Adrenal vein imaging was collected from the enrolled patients. We performed statistical analysis on the adrenal vein orifice position, inflow angle, and adrenal venography morphology. The adrenal venous orifice was defined as the location where the catheter was placed at the end of the calm inhalation. Spearman correlation analysis was used to explore the relationship between the positions of bilateral adrenal vein orifices and body mass index (BMI). Results: A total of 282 patients with successful bilateral AVS and complete bilateral adrenal vein imaging were enrolled, of whom 57.1% (161/282) were male and the age was (53.3±10.7) years old. The orifice of the left adrenal vein was located between the middle segment of the 11th thoracic vertebra and the upper segment of the 2nd lumbar vertebra. The inflow angle relative to the position of the orifice was all leftward and upward. The orifice of the right adrenal vein was located between the upper segment of the 11th thoracic vertebra and the lower segment of the 1st lumbar vertebra, and 91.1% (257/282) had a rightward and downward angle of inflow relative to the position of the orifice. The position of the adrenal vein orifices on both the left (r=0.211, P<0.001) and right (r=0.196, P=0.001) showed positive correlation with BMI. The position of the right adrenal vein orifice also increased with the position of the left adrenal orifice (r=0.530, P<0.001). The most common adrenal venography morphology on the right side was triangular (36.5%, 103/282), while the most common venography morphology on the left side was glandular (66.3%, 187/282). Conclusions: The anatomical morphology of adrenal veins are diverse. Being familiar with the morphological characteristics of the adrenal vein and identifying the adrenal vein accurately during surgery has important clinical value in improving the success rate of AVS.

Trigeminal neuralgia caused by venous compression: a comprehensive literature review.

Trigeminal neuralgia (TN), a severe facial pain condition, is often treated with microvascular decompression (MVD). While MVD is effective for arterial neurovascular compression, its efficacy in cases of venous compression and the intraoperative management of such cases remain areas of debate. This review aimed to analyze the intraoperative management strategies for offending veins during MVD and evaluate the outcomes of these procedures in cases of TN with purely venous compression. An extensive review of studies reporting on the intraoperative handling of veins and the surgical outcomes of MVD in purely venous compression cases was conducted. Fifteen full-text studies were included, encompassing a total of 600 patients. Notably, 82.33% of these patients achieved a Barrow Neurological Institute (BNI) I pain score, with follow-up periods ranging from 3 months to 12 years. MVD is a viable and effective treatment option for TN in cases of venous compression, with a significant proportion of patients experiencing substantial pain relief.

DDP-FedFV: A Dual-Decoupling Personalized Federated Learning Framework for Finger Vein Recognition.

Finger vein recognition methods, as emerging biometric technologies, have attracted increasing attention in identity verification due to their high accuracy and live detection capabilities. However, as privacy protection awareness increases, traditional centralized finger vein recognition algorithms face privacy and security issues. Federated learning, a distributed training method that protects data privacy without sharing data across endpoints, is gradually being promoted and applied. Nevertheless, its performance is severely limited by heterogeneity among datasets. To address these issues, this paper proposes a dual-decoupling personalized federated learning framework for finger vein recognition (DDP-FedFV). The DDP-FedFV method combines generalization and personalization. In the first stage, the DDP-FedFV method implements a dual-decoupling mechanism involving model and feature decoupling to optimize feature representations and enhance the generalizability of the global model. In the second stage, the DDP-FedFV method implements a personalized weight aggregation method, federated personalization weight ratio reduction (FedPWRR), to optimize the parameter aggregation process based on data distribution information, thereby enhancing the personalization of the client models. To evaluate the performance of the DDP-FedFV method, theoretical analyses and experiments were conducted based on six public finger vein datasets. The experimental results indicate that the proposed algorithm outperforms centralized training models without increasing communication costs or privacy leakage risks.

Effects of Venoactive Drug Therapy and Ovarian Vein Interventions on Vasoactive Neuropeptide and Cytokine Levels in Patients with Pelvic Venous Disorders.

BACKGROUND: To study and compare the effects of venoactive drug (VAD) therapy and ovarian vein embolization or resection (OVE or OVR, accordingly) on the levels of vasoactive peptides and cytokines in patients with pelvic venous disorders (PeVDs). METHODS: The study included 70 consecutive female patients with PeVD symptoms, such as chronic pelvic pain (CPP), dyspareunia, dysuria, and vulvar varicosities. Based on the results of clinical examination and duplex ultrasound of the pelvic veins, the patients were allocated to the VAD therapy (n = 38) or OVE/OVR (n = 32). Additionally, the enzyme-linked immunosorbent assay tests were performed to determine levels of calcitonin gene-related peptide (CGRP), substance P (SP), interleukins 6 and 8 (IL-6, IL-8) and monocyte chemotactic protein-1 (MCP-1) after a 2-month course of VAD therapy and at 3 months after OVE/OVR. RESULTS: The VAD therapy was associated with a significant decrease in CPP in 84% of patients with PeVD and isolated lesions of the parametrial veins (PVs) and uterine veins (UVs). VAD had no significant effect on the pelvic venous reflux. No changes in the CGRP, SP, IL-6, IL-8, and MCP-1 levels were detected after treatment. At 3 months after OVE or OVR, all patients with PeVD and combined lesions of the ovarian veins (OVs), PVs and UVs reported almost complete relief of CPP. Along with elimination of reflux in ovarian veins, the disappearance of reflux in PVs and UVs was noted. A decrease in the CGRP and SP levels was observed (0.7 ± 0.1 ng/mL and 0.12 ± 0.02 ng/mL before treatment; 0.5 ± 0.12 ng/mL and 0.09 ± 0.06 ng/mL after treatment, respectively; all P < 0.05). No changes in cytokine levels were revealed. CONCLUSIONS: Treatment with VAD is associated with the CPP relief, but has no significant effect on the CGRP, SP, IL-6, IL-8, and MCP-1 levels. OVE/OVR results in the CPP relief, elimination of the pelvic venous reflux and a significant decrease in the CGRP and SP levels, but does not change cytokine levels.

Venous malformations in children: comparison between magnetic resonance imaging and histopathological findings.

BACKGROUND: Among low-flow vascular malformations, venous malformations are relatively frequent. The pathological patterns vary in severity and are generally characterized by dilated vessels and low-flow blood that over time can organize into phleboliths. Sometimes small capillary and/or lymphatic vessels may be associated, micro- and/or macro-shunts may form alone or in different combinations, and finally adipose tissue may be interposed between the malformed vessels. Magnetic resonance imaging (MRI) is a crucial examination for confirming venous malformations because it can accurately identify different features of the lesions. OBJECTIVE: The aim of our study was to compare MRI and histopathological findings of venous malformations in children to assess the possibilities and limitations of MRI. MATERIALS AND METHODS: In a retrospective study, two observers independently evaluated the contrast-enhanced MRI of 26 children with venous malformations. Several radiological parameters were considered and compared with histopathological findings. The agreement between the interobserver radiological evaluation and between histopathological and radiological diagnosis was verified using Cohen's kappa. RESULTS: MRI interobserver agreement was excellent for micro-shunts and good for the remaining findings. The radiological-pathological agreement was perfect for the presence/absence of phleboliths and of macro-shunts and almost perfect for the presence of intralesional adipose tissue, lymphatic component, and micro-shunts. CONCLUSION: MRI in venous malformations can detect the presence of phleboliths, adipose tissue, and lymphatic components with excellent accuracy and good to excellent interobserver agreement. Furthermore, MR angiography can detect micro-shunts in simple and combined venous malformations with substantial agreement with histopathological findings.