Advanced imaging in acute and chronic deep vein thrombosis

Harnessing the power of bioprinting for the development of next-generation models of thrombosis

Thrombosis, a leading cause of cardiovascular morbidity and mortality, involves the formation of blood clots within blood vessels. Current animal models and in vitro systems have limitations in recapitulating the complex human vasculature and hemodynamic conditions, limiting the research in understanding the mechanisms of thrombosis. Bioprinting has emerged as a promising approach to construct biomimetic vascular models that closely mimic the structural and mechanical properties of native blood vessels. This review discusses the key considerations for designing bioprinted vascular conduits for thrombosis studies, including the incorporation of key structural, biochemical and mechanical features, the selection of appropriate biomaterials and cell sources, and the challenges and future directions in the field. The advancements in bioprinting techniques, such as multi-material bioprinting and microfluidic integration, have enabled the development of physiologically relevant models of thrombosis. The future of bioprinted models of thrombosis lies in the integration of patient-specific data, real-time monitoring technologies, and advanced microfluidic platforms, paving the way for personalized medicine and targeted interventions. As the field of bioprinting continues to evolve, these advanced vascular models are expected to play an increasingly important role in unraveling the complexities of thrombosis and improving patient outcomes. The continued advancements in bioprinting technologies and the collaboration between researchers from various disciplines hold great promise for revolutionizing the field of thrombosis research.

Venous Thromboembolism: Current Insights and Future Directions

Venous thromboembolism (VTE) is the third most common cause of death worldwide even though incidence rates differ globally. Western nations report 1 to 2 cases per 1,000 person-years, while Eastern countries exhibit lower rates (<1 per 1,000 person-years). This comprehensive review delves into diverse VTE risk factors including gender, diabetes, obesity, smoking, genetic mutations, hormonal influences, travel, infections, trauma, and cancer. Notably, VTE incidence is highest in certain cancers (such as pancreatic, liver, and non-small-cell lung cancers) and lowest in others (such as breast, melanoma, and prostate cancers). The extensive review provides essential information about prevalent factors and explores potential molecular mechanism contributing to VTE.

Magnetic resonance (MR) evaluation of deep venous thrombosis of 338 discharged viral pneumonia patients

Background

Viral pneumonia (VP) often leads to the development of deep vein thrombosis (DVT) in hospitalized patients. The aim of the study was to investigate the incidence of DVT in discharged patients with VP, and whether new and old DVT differ in transverse relaxation time.

Methods

In this prospective cohort study in Wuhan, China, 338 consecutive discharged VP patients from February 2021 to March 2023 who underwent T2 weighted Sampling Perfection with Application Optimized Contrast Evolution (SPACE) were recruited to detect DVT. T2 mapping and T2* mapping were performed for the patients with DVT detected by magnetic resonance imaging (MRI). The minimum, maximum, mean of T2 time and T2* time of DVT were recorded as T2min, T2max, T2mean, T2*min, T2*max, and T2*mean, respectively. Clinical data and laboratory findings were compared between new and old DVT cases, which were defined based on the examination results before and after discharge. A Mann-Whitney test was used to compare transverse relaxation time parameters between new and old DVT.

Results

Twelve percent of VP patients (40/338) developed new DVT after discharge. Thirty-three out of 104 DVTs did not resolve after discharge. Compared with patients with new DVT, patients with old DVT were older (67 vs. 59 years, P=0.003); and had a higher proportion of bedridden time >72 hours (72.7% vs. 37.0%, P<0.001). Patients with old DVT had a lower lymphocyte count (0.67×109/L vs. 0.97×109/L, P=0.01), higher C-reactive protein (59 vs. 35 mg/L, P=0.019), and higher levels of D-dimer (6.7 vs. 0.9 µg/mL, P<0.001) than patients with new DVT. Patients with old DVT received more invasive mechanical ventilation (30.3% vs. 7.4%, P<0.001) and had a higher proportion of acute respiratory distress syndrome (75.8% vs. 51.9%, P<0.001), and a higher proportion of cardiac injury (39.4% vs. 14.8%, P=0.033) than patients with new DVT. T2min, T2max, T2mean, and T2*max of new DVT were significantly greater than old DVT (17.6±10.4 vs. 13.2±5.9 ms, 94.9±44.9 vs. 42.3±23.6 ms, 46.8±24.0 vs. 25.0±12.6 ms, 22.5±12.4 vs. 10.7±3.5 ms, P<0.05 for all). There was no significant difference in T2*min or T2*mean between new and old DVT (3.2±0.4 vs. 3.1±0.4 ms, 8.2±4.9 vs. 5.5±1.5 ms, P>0.05 for both).

Conclusions

T2 weighted SPACE magnetic resonance (MR) is valuable in the follow-up of thrombosis of discharged VP patients. T2 mapping distinguishes between new and old DVT.

Epidemiology of clinically unsuspected venous thromboembolism in children with cancer: A population-based study from Maritimes, Canada

Inconsistencies in the definition of clinically unsuspected venous thromboembolism (VTE) in pediatric patients recently led to the recommendation of standardizing this terminology. Clinically unsuspected VTE (cuVTE) is defined as the presence of VTE on diagnostic imaging performed for indications unrelated to VTE in a patient without symptoms or clinical history of VTE. The prevalence of cuVTE in pediatric cancer patients is unclear. Therefore, the main objective of our study was to determine the prevalence of cuVTE in pediatric cancer patients. All patients 0-18 years old, treated at the IWK in Halifax, Nova Scotia, from August 2005 through December 2019 with a known cancer diagnosis and at least one imaging study were eligible (n = 743). All radiology reports available for these patients were reviewed (n = 18,120). The VTE event was labeled a priori as cuVTE event for radiology reports that included descriptive texts indicating a diagnosis of thrombosis including thrombus, central venous catheter-related, thrombosed aneurysm, tumor thrombosis, non-occlusive thrombus, intraluminal filling defect, or small fragment clot for patients without documentation of clinical history and or signs of VTE. A total of 18,120 radiology reports were included in the review. The prevalence of cuVTE was 5.5% (41/743). Echocardiography and computed tomography had the highest rate of cuVTE detection, and the most common terminologies used to diagnose cuVTE were thrombus and non-occlusive thrombus. The diagnosis of cuVTE was not associated with age, sex, and type of cancer. Future efforts should focus on streamlining radiology reports to characterize thrombi. The clinical significance of these cuVTE findings and their application to management, post-thrombotic syndrome, and survival compared to cases with symptomatic VTE and patients without VTE should be further studied.

Venous recanalisation in the setting of post-thrombotic syndrome: An expert consensus from the French Society of Vascular Medicine (SFMV) and the French Society of Cardiovascular Imaging and Interventional Radiology (SFICV)

Several aspects of the management of post-thrombotic syndrome (PTS) are still a matter of debate, or not yet addressed in international guidelines. The objective of this expert consensus from the French Society of Vascular Medicine (SFMV) and the French Society of Cardiovascular Imaging (SFICV) was to define the main elements of diagnosis and treatment of this syndrome, and to develop a proposal for its preoperative, procedural and follow-up management. In this consensus, the following issues were addressed: clinical and ultrasound diagnosis; pre-procedural workup; indications and contraindications to venous recanalisation; procedures; clinical and duplex ultrasound reports; follow-up; long-term treatment; management of great saphenous vein incompetency; anticoagulant and antiplatelet therapy after venous stenting.

Independent Risk Factors Associated With Venous Thromboembolism After Knee Arthroscopy: A Retrospective Study of 222 Patients

Background

A serious complication after knee arthroscopy is venous thromboembolism (VTE), which includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). However, asymptomatic VTE is frequently undetected.

Purpose

To (1) report the incidence of VTE after knee arthroscopy using ultrasound examination and computed tomography pulmonary angiography (CTPA) and (2) discover the independent risk factors of VTE after knee arthroscopy and determine the corresponding cutoff values of these indicators.

Study Design

Case-control study; Level of evidence, 3.

Methods

Included were 222 patients (115 male) who underwent arthroscopic knee procedures between October 2022 and January 2023. Baseline characteristics, blood test results, and VTE assessments were collected. During the 2-week follow-up, routine lower extremity vascular ultrasound was applied for DVT measurement, with CTPA evaluation for suspected PE. Patients were allocated into VTE and no-VTE groups, and descriptive statistics were used to analyze baseline data. Logistic regression analysis was used to determine the correlation between binary variables and the presence of postoperative VTE. Multivariate logistic regression analysis was further performed to determine the independent risk factors of VTE.

Results

Of the 222 patients, 37 (16.7%) had DVT and 1 (0.5%) had both DVT and PE. Compared to the no-VTE group, the VTE group was significantly older, with more female patients; higher body mass index (BMI) and postoperative D-dimer level; and higher rates of hypertension, hyperlipidemia, varicose veins of the lower extremity, and abnormal postoperative fibrin degradation product level (P≤ .043 for all). Notably, operative time >20 minutes was not significantly associated with postoperative VTE (P = .513). The independent risk factors for VTE included age >32 years (odds ratio [OR], 20.71 [95% CI, 4.40-97.47]; P < .001), BMI >23 kg/m2 (OR, 3.52 [95% CI, 1.11-11.14]; P = .032), hyperlipidemia (OR, 6.81 [95% CI, 1.86-24.88]; P = .004), and postoperative D-dimer level >0.63 mg/L (OR, 34.01 [95% CI, 7.36-157.07]; P < .001).

Conclusion

The incidence of VTE after knee arthroscopy was 16.7% at the 2-week follow-up. Age >32 years, BMI >23 kg/m2, hyperlipidemia, and postoperative D-dimer >0.63 mg/L were independent risk factors of postoperative VTE within 2 weeks after knee arthroscopy. For patients with knee arthroscopy, the cutoff value of postoperative D-dimer for VTE was found to be 0.63 mg/L for timely intervention.

Machine learning in cancer-associated thrombosis: hype or hope in untangling the clot

The goal of machine learning (ML) is to create informative signals and useful tasks by leveraging large datasets to derive computational algorithms. ML has the potential to revolutionize the healthcare industry by boosting productivity, enhancing safe and effective patient care, and lightening the load on clinicians. In addition to gaining mechanistic insights into cancer-associated thrombosis (CAT), ML can be used to improve patient outcomes, streamline healthcare delivery, and spur innovation. Our review paper delves into the present and potential applications of this cutting-edge technology, encompassing three areas: i) computer vision-assisted diagnosis of thromboembolism from radiology data; ii) case detection from electronic health records using natural language processing; iii) algorithms for CAT prediction and risk stratification. The availability of large, well-annotated, high-quality datasets, overfitting, limited generalizability, the risk of propagating inherent bias, and a lack of transparency among patients and clinicians are among the challenges that must be overcome in order to effectively develop ML in the health sector. To guarantee that this powerful instrument can be utilized to maximize innovation in CAT, clinicians can collaborate with stakeholders such as computer scientists, regulatory bodies, and patient groups.

Quality of referrals for lower extremity ultrasonography and computed tomography pulmonary angiography and associations with positive findings of venous thromboembolism

INTRODUCTION

The referral is the basis for radiologists' assessment of modality, protocol and urgency, and insufficient information may threaten patient safety. The aim of this study was to assess the completeness of referrals for lower extremity venous duplex ultrasonography (LEVDUS) and computed tomography pulmonary angiography (CTPA), and to investigate associations between the provided clinical information including risk factors, symptoms and lab results in the referrals and positive findings of deep vein thrombosis (DVT) and pulmonary embolism (PE), respectively.

METHODS

Referrals for LEVDUS (801) and CTPA (800) performed from 2016 to 2019 were obtained. Three categories of clinical information from the referrals were recorded: symptoms, risk factors and laboratory results, as well as positive imaging findings of venous thromboembolism (VTE). Referral completeness was rated from zero to three according to how many categories of clinical information the referral provided.

RESULTS

Information from all three clinical information categories was provided in 15% and 25% of referrals for LEVDUS and CTPA, respectively, while 2% and 10% of referrals did not contain any clinical information. Symptoms were provided most often (85% for LEVDUS and 94% for CTPA). Provided information about risk factors was significantly associated with positive findings for LEVDUS, (p = 0.02) and CTPA (p < 0.001).

CONCLUSION

A great majority of referrals failed to provide one or more categories of clinical information. Risk factors were associated with a positive finding of VTE on LEVDUS and CTPA.

IMPLICATIONS FOR PRACTICE

Improving clinical information in referrals may improve justification, patient safety and quality of radiology services.

Imaging of Visceral Vessels

The visceral vasculature is inextricably intertwined with abdominopelvic disease staging, spread, and management in routine and emergent cases. Comprehensive evaluation requires specialized imaging techniques for abnormality detection and characterization. Vascular pathology is often encountered on nondedicated routine imaging examinations, which may obscure, mimic, or confound many vascular diagnoses. This review highlights normal arterial, portal venous, and systemic venous anatomy and clinically relevant variants; diagnostic pitfalls related to image-acquisition technique and disease mimics; and characteristics of common and rare vascular diseases to empower radiologists to confidently interpret the vascular findings and avoid misdiagnosis.

Renal vein thrombosis in a patient secondary to high-grade rhabdoid renal cell carcinoma: a case report and review of literature

Introduction

Renal cell carcinoma, a common kidney tumour which is often incidentally discovered on imaging, can manifest with atypical symptoms. Renal cell carcinoma with rhabdoid features is a rare occurrence and even rarer in case of adults. Renal cell carcinoma has the tendency to form thrombus that can migrate to renal vein, inferior vena cava and even right atrium.

Case presentation

The authors report a case of an 81-year-old male with rhabdoid renal cell carcinoma presenting with persistent cough for 6-7 months. with tumour thrombus extending into the renal vein and hepatic inferior vena cava. The patient was found feeble for the surgery and hence was treated on anticancer drugs pembrolizumab and axitinib.

Conclusion

Renal cell carcinoma has the tendency to form tumour thrombus in renal vein and inferior vena cava. Prognosis without surgical intervention in these conditions is very poor.

Light on Alzheimer's disease: from basic insights to preclinical studies

Alzheimer's disease (AD), referring to a gradual deterioration in cognitive function, including memory loss and impaired thinking skills, has emerged as a substantial worldwide challenge with profound social and economic implications. As the prevalence of AD continues to rise and the population ages, there is an imperative demand for innovative imaging techniques to help improve our understanding of these complex conditions. Photoacoustic (PA) imaging forms a hybrid imaging modality by integrating the high-contrast of optical imaging and deep-penetration of ultrasound imaging. PA imaging enables the visualization and characterization of tissue structures and multifunctional information at high resolution and, has demonstrated promising preliminary results in the study and diagnosis of AD. This review endeavors to offer a thorough overview of the current applications and potential of PA imaging on AD diagnosis and treatment. Firstly, the structural, functional, molecular parameter changes associated with AD-related brain imaging captured by PA imaging will be summarized, shaping the diagnostic standpoint of this review. Then, the therapeutic methods aimed at AD is discussed further. Lastly, the potential solutions and clinical applications to expand the extent of PA imaging into deeper AD scenarios is proposed. While certain aspects might not be fully covered, this mini-review provides valuable insights into AD diagnosis and treatment through the utilization of innovative tissue photothermal effects. We hope that it will spark further exploration in this field, fostering improved and earlier theranostics for AD.

Chemical prophylaxis and venous thromboembolism following elective spinal surgery: A systematic review and meta-analysis

Background

Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a potentially devastating complication after surgery. Spine surgery is associated with an increased risk of postoperative bleeding, such as spinal epidural hematomas (SEH), which complicates the use of anticoagulation. Despite this dilemma, there is a lack of consensus around perioperative VTE prophylaxis. This systematic review investigates the relationship between chemoprophylaxis and the incidence rates of VTE and SEH in the elective spine surgical population.

Methods

A comprehensive literature search was performed using PubMed, Embase, and Cochrane databases to identify studies published after 2,000 that compared VTE chemoprophylaxis use in elective spine surgery. Studies involving patients aged < 18 years or with known trauma, cancer, or spinal cord injuries were excluded. Pooled incidence rates of VTE and SEH were calculated for all eligible studies, and meta-analyses were performed to assess the relationship between chemoprophylaxis and the incidences of VTE and SEH.

Results

Nineteen studies met our eligibility criteria, comprising a total of 220,932 patients. The overall pooled incidence of VTE was 3.2%, including 3.3% for DVT and 0.4% for PE. A comparison of VTE incidence between patients that did and did not receive chemoprophylaxis was not statistically significant (OR 0.97, p=.95, 95% CI 0.43-2.19). The overall pooled incidence of SEH was 0.4%, and there was also no significant difference between patients that did and did not receive chemoprophylaxis (OR 1.57, p=.06, 95% CI 0.99-2.50).

Conclusions

The use of perioperative chemoprophylaxis may not significantly alter rates of VTE or SEH in the elective spine surgery population. This review highlights the need for additional randomized controlled trials to better define the risks and benefits of specific chemoprophylactic protocols in various subpopulations of elective spine surgery.

Mechanical thromboprophylaxis for hip fractures in elderly patients: a prospective randomized controlled study

BACKGROUND

Hip fractures, most common in the geriatric age group, can develop proximal deep vein thrombosis (DVT). There is no consensus regarding the ideal method or duration of prophylaxis, particularly in a trauma patient. This study bridges this lacuna in data by making a random comparison between mechanical prophylaxis alone vis-a-vis combined with mechanical and Enoxaparin-based chemoprophylaxis.

MATERIALS AND METHODS

75 Elderly hip trauma patients from January 2019 to October 2020 at a single tertiary care center were randomly allocated into two groups using the sequentially numbered opaque sealed envelope method (SNOSE): one (n=44) receiving Enoxaparin and Mechanical prophylaxis and another (n=31) receiving Mechanical prophylaxis alone. All patients underwent CT (computed tomography) venography to screen for proximal DVT between days 5 to 10 of injury. The primary outcomes were the incidence of proximal DVT and pulmonary embolism (PE), and safety outcomes (wound complications and adverse systemic events) were recorded during the treatment.

RESULTS

No symptomatic or asymptomatic proximal DVT and death incidence was reported in either group. One case of pulmonary embolism was seen in the combined prophylaxis group. There was no significant difference between the groups regarding the above-mentioned parameters mentioned.

CONCLUSIONS

There is no significant difference in the incidence of proximal DVT between mechanical alone and combined chemical-mechanical prophylaxis in elderly patients sustaining hip trauma. The incidence of proximal DVT can be reduced by mechanical prophylaxis alone. It was efficacious and safer than combined mechanical and enoxaparin prophylaxis in preventing venous thromboembolism in elderly hip trauma patients.

Development and characterization of transfontanelle photoacoustic imaging system for detection of intracranial hemorrhages and measurement of brain oxygenation: Ex-vivo

We have developed and optimized an imaging system to study and improve the detection of brain hemorrhage and to quantify oxygenation. Since this system is intended to be used for brain imaging in neonates through the skull opening, i.e., fontanelle, we called it, Transfontanelle Photoacoustic Imaging (TFPAI) system. The system is optimized in terms of optical and acoustic designs, thermal safety, and mechanical stability. The lower limit of quantification of TFPAI to detect the location of hemorrhage and its size is evaluated using in-vitro and ex-vivo experiments. The capability of TFPAI in measuring the tissue oxygenation and detection of vasogenic edema due to brain blood barrier disruption are demonstrated. The results obtained from our experimental evaluations strongly suggest the potential utility of TFPAI, as a portable imaging modality in the neonatal intensive care unit. Confirmation of these findings in-vivo could facilitate the translation of this promising technology to the clinic.

Combined Management of Wound Ulcers With Focus on Interventional Techniques

This review provides a summary of current practice patterns in managing venous ulcers. The authors will describe the workup for venous ulcers, including differentiation of symptoms, physical examination, and imaging to guide the most effective treatment course for each patient. An overview of conservative management and minimally invasive treatment options for venous ulcers will be provided with a specific focus on periulcer foam sclerotherapy to aid in preventing ulcer recurrence and promoting healing. We will give interventional troubleshooting techniques for challenging patient presentations.

Lessons Learned With Venous Stenting: In-flow, Outflow, and Beyond

Venous stents are being used with increasing frequency, with a multitude of dedicated venous stents now well established or emerging onto the market. This review explores the multifaceted aspects of venous stenting. We discuss the history of venous stents, indications for their use, the imaging required before, during and after stenting, as well as some technical tips and tricks which we have found to be helpful in our own daily practice with a particular focus on iliofemoral venous stenting. Ultimately, this article seeks to enhance the understanding of venous stenting, offering insights into what we feel are best practices, challenges, and prospects for improved patient outcomes.

Deep Venous Thrombosis in Acute Pancreatitis Is Associated with High Mortality: A Prospective Study

BACKGROUND

Incidence and risk factors for the development of extremity deep vein thrombosis (eDVT) in admitted patients of acute pancreatitis have been rarely explored.

AIMS

To identify the incidence of eDVT and to explore role of clinical scores for predicting eDVT in admitted patients of acute pancreatitis.

METHODS

We prospectively enrolled admitted patients of acute pancreatitis and performed a weekly eDVT screen for the duration of their admission. Well's score and Padua's score were also calculated weekly. The incidence of venous thrombosis (eDVT and splanchnic thrombosis based on contrast-enhanced CT scan abdomen) was noted, and the risk factors were determined using multivariate analysis. The correlation between Well's score, Padua's score, and development of DVT was calculated using Pearson's correlation.

RESULTS

Of the 102 patients of acute pancreatitis enrolled, 73.5% of patients had necrotizing pancreatitis. Total of 46 patients (45.1%) developed thrombosis: 43 patients had splanchnic vein thrombosis; 5 patients had eDVT; and 1 patient had pulmonary embolism. Patients with eDVT had higher BISAP score (2.6 ± 0.9 vs 1.7 ± 0.8; p = 0.039), requirement of mechanical ventilation (60% vs 8.2%; p = 0.008), and mortality (60% vs 12.4%; p = 0.022). Well's score of ≥ 2 had sensitivity and specificity of 80% and 96.9% for prediction of eDVT and it had better correlation with the development of eDVT compared to Pauda's score.

CONCLUSION

Incidence of DVT is 5% in patients with acute pancreatitis requiring admission. It is associated with higher disease severity and mortality. The Well's score is useful to predict the development of eDVT in routine clinical practice.

High Rate of Venous Thromboembolism in Severe Pediatric Intestinal Failure

OBJECTIVE

To quantify the rate of venous thromboembolism (VTE) in patients with pediatric intestinal failure and identify associated risk factors.

STUDY DESIGN

We performed a retrospective cohort study in pediatric patients (<21 years old) with severe pediatric intestinal failure (≥90 consecutive days of parenteral nutrition) secondary to short bowel syndrome who were treated from 2014 to 2021 at an interdisciplinary intestinal rehabilitation program. The primary outcome was the incidence of VTE. Multivariable regression was performed to identify independent clinical predictors of VTE.

RESULTS

A total of 263 patients (59.7% male) met the criteria for inclusion. The cumulative incidence of VTE was 28.1%, with a rate of 0.32 VTEs per 1000 catheter-days. On univariate analysis, the number of catheter days, number of catheters, and history of central line-associated blood stream infection were associated with VTE. On multivariable logistic regression, a higher number of catheters was an independent risk factor for VTE (aOR, 1.17; 95% CI, 1.06-1.29). Additionally, earlier gestational age was a risk factor for VTE such that every week decrease in gestational age conferred a 9% increased risk of VTE (aOR, 1.09; 95% CI, 1.02-1.16).

CONCLUSIONS

In this retrospective study, 28.1% of patients with severe pediatric intestinal failure developed VTE; the number of catheters and early gestational age were noted to be independent risk factors for VTE. This high incidence of VTE highlights the need to investigate VTE in pediatric intestinal failure prospectively, including the potential benefit of prophylactic anticoagulation.

Assessment of Lower Limb Deep Vein Thrombosis: Characterization and Associated Risk Factors Using Triplex Doppler Imaging

Background

Deep vein thrombosis (DVT) is a common health problem. Accurate diagnosis of DVT is essential to avoid potentially fatal acute consequences of pulmonary embolism.

Aim

The study aims to assess deep venous thrombosis (DVT) of the lower limbs and to analyze the related risk factors.

Methods

This is a retrospective study including 60 patients who were examined using Triplex Doppler imaging. The patients were referred to the imaging departments with symptoms of lower limb DVT. The risk of DVT was expressed as an odds ratio (OR) with 95% confidence interval. Multiple logistic regression analysis was used to detect the independent risk factors. P value <0.05 was considered a significant statistic.

Results

Among the Saudi patients in Najran, acute DVT was more prevalent than chronic one (56.7% vs 38.3%), while subacute is less frequent (5%). DVTs are more prevalent in females than males (60% vs 40%) and most commonly affect patients older than 40. DVTs affect the left lower limb veins more than the right limb (75% vs 15%) and are less frequent on both sides (10%). The left popliteal vein (PV) and left common femoral vein (CFV) were the most common sites for acute DVTs. Binary logistic analysis revealed the independent risk factors for developing lower extremity DVT; malignancy (OR = 2.84, 95% CI = 0.518-15.513), surgery (OR = 2.66, 95% CI = 0.411-17.281), trauma (OR = 2.30, 95% CI = 0.452-11.658), and diabetes and hypertension (OR = 1.53, 95% CI = 0.335-6.969).

Conclusion

Acute lower limb DVT was more prevalent than chronic one. Malignancy, surgery, trauma, diabetes mellitus, and hypertension were the most common risk factors for lower limb DVTs. Left popliteal and left common femoral veins were the most common sites of acute DVTs.

Asymptomatic and symptomatic deep venous thrombosis in hospitalized acutely ill medical patients: risk factors and therapeutic implications

BACKGROUND

Acutely ill medical patients experience deep venous thrombosis (DVT) during the hospitalization, however the time course of DVT is still unclear.

OBJECTIVES

To evaluate risk factors in acutely ill hospitalized medical patients for proximal asymptomatic DVT (ADVT) and symptomatic DVT (SDVT) at admission and discharge.

PATIENTS/METHODS

In this prospective observational study, consecutive acutely ill medical patients (hospitalized mainly for acute medical disease as infections, neoplasm, anemia, heart failure) underwent compression ultrasonography (CUS) of proximal lower limb veins within 48 h from admission and at discharge to diagnose ADVT and SDVT. Covid-19 patients, anticoagulant therapy, surgical procedures, acute SDVT, and acute pulmonary embolism, were exclusion criteria. Biographical characteristics at hospitalization, D-Dimer (assessed by ELISA)) and DD-improve score.

RESULTS

Of 2,100 patients (1002 females, 998 males, age 71 ± 16 years) 58 (2.7%) had proximal ADVT at admission. Logistic regression analysis showed that age, and active cancer were independently associated with ADVT at admission. The median length of hospitalization was 10 days [interquartile range: 6-15]. During the hospital stay, 6 patients (0.3%) with a negative CUS at admission experienced DVT (2 SDVT and 4 ADVT). In the subgroup of patients (n = 1118), in whom D-dimer was measured at admission, D-Dimer and IMPROVE-DD score were associated with ADVT at admission (n = 37) and with all DVT (n = 42) at discharge. ROC curve defined an IMPROVE-DD score of 2.5 as the optimal cut-off for discriminating patients with and without thrombotic events.

CONCLUSIONS

We provide evidence of early development of ADVT in unselected acutely ill medical patients suggesting the need of investigating patients by CUS immediately after hospital admission (within 48 h). Advanced age, active cancer, known thrombophilia and increased IMPROVE-DD score may identify patients at risk. The benefit of anticoagulation needs to be investigated in patients with these specific risk factors and negative CUS at admission.

TRIAL REGISTRATION

NCT03157843.

Distribution of Lower Extremity Deep Vein Thrombosis and Implications for Limited Compression Ultrasound Examinations

BACKGROUND

Limited compression bedside ultrasonography (LCUS) including two-point, three-point, and extended compression examinations have become increasingly popular among emergency physicians to assess for lower extremity deep venous thrombosis (DVT).

OBJECTIVE

Our objective in this study was to determine the prevalence and distribution of lower extremity DVT in sites identified by complete duplex ultrasonography (CDUS) that may potentially be missed using limited compression ultrasonography techniques.

METHODS

This was a retrospective, multicenter study conducted at 12 hospitals within the Northwell Health system over a span of 4 years. Study participants (emergency department patients) underwent CDUS to assess for possible DVT. Images were reviewed and interpreted by radiologists and vascular surgeons at each of the participating institutions.

RESULTS

A total of 42,487 CDUS examinations were performed, of which 3383 were positive for DVT. DVTs were deemed to be acute in 2664 (79%) and chronic in the remaining 21% on the basis of comparison with previous studies and appearance of the vein. Of the acute DVTs, 136 (5.1%) were confined to the common femoral vein, 116 (4.4%) to the femoral vein, 8 (0.3%) to deep femoral vein, 213 (8.0%) to popliteal vein, and 934 (35.1) to calf veins alone.

CONCLUSIONS

In our study, a significant number of DVTs were identified in sites that may have been potentially missed on LCUS examinations, thereby supporting the use of complete duplex ultrasonography when available.

Optimized acoustic streaming generated at oblique incident angles to improve ultrasound thrombolysis effect

BACKGROUND

Combined with thrombolytic drugs and/or microbubbles (MBs), ultrasound (US) has been regarded as a useful tool for thrombolysis treatment by taking its advantages of non-invasive, non-ionization, low cost and accurate targeting of tissues deep in body. Recently, low-intensity pulsed ultrasound (LIPUS), which can cause fewer complications by stable cavitation and acoustic streaming other than more violent effects, has attracted broad attention.

PURPOSE

However, the thrombolysis effect in practice might not achieve expectation because there is not an ideal parallel multilayer structure between the skin and the targeted vessel. Therefore, the current work aims to better elucidate the influence of US incident angle on the generation of acoustic streaming and thrombolysis effect.

METHODS

Systemic numerical and experimental studies, viz., finite element modeling (FEM), particle image velocimetry (PIV) and in vitro thrombolysis measurements, were performed to estimate the acoustical/streaming field pattern, maximum flow velocity and shear stress on the surface of thrombus, as well as the lysis rate generated at different conditions. These methods aim at verifying the hypothesis that streaming-induced vortices can further accelerate the dissolution of the thrombus and optimized thrombolysis effected can be achieved by adjusting US incident angles.

RESULTS

The pool data results showed that the variation trends of the flow velocity and shear stress obtained from FEM simulation and PIV experiments are qualitatively consistent with each other. There exists an optimal incident angle that can maximize the flow velocity and shear stress on the surface of thrombus, so that superior stirring and mixing effect can be generated. Furthermore, as the flow velocity and shear stress on thrombus surface are both highly correlated with the thrombolysis effect (the correlation coefficient R1 = 0.988, R2 = 0.958, respectively), the peak value of lysis rate (increase by at least 5.02%) also occurred at 10°.

CONCLUSIONS

The current results demonstrated that, with appropriately determined incident angle, higher thrombolysis rate could be achieved without increasing the driving pressure. It may shed the light on future US thrombolysis planning strategy that, if combined with other advanced technologies (e.g., machine-learning-based image analysis and image-guided adaptive US emission modulation), more efficient thrombolytic effect could be realized while minimizing undesired side-effects caused by excessively high pressure. This article is protected by copyright. All rights reserved.

A Rare Case of Limb-Threatening Injury Secondary to Extrinsic Vascular Compression Following Crocodile Bite

Crocodile bites lead to fatal and nonfatal outcomes in humans. Mugger crocodiles (Crocodylus palustris) and saltwater crocodiles (Crocodylus porosus) are common in India. Most crocodile bites can cause severe injuries, especially to the extremities, due to the substantial bite force of the crocodile, which typically leads to extensive tissue damage, fractures, amputations, and vascular injuries. We report the case of a crocodile bite victim who presented with features of acute limb ischemia, was found to have vascular thrombosis of the common femoral artery, and was experiencing complete compression of the femoral vein due to external vascular compression by a hematoma. We discuss various injury mechanisms sustained in crocodile bites and the roles of point-of-care ultrasound and continuous tomography angiography, which could help identify these injuries. After thrombectomy and hematoma evacuation the patient recovered and was discharged without any physical dysfunction.

Deep vein thrombosis in the thigh: MR imaging in two cases with atypical presentations

Deep vein thrombosis (DVT) is a common clinical problem affecting the lower extremities. Prompt imaging of suspected DVT is helpful for rapid diagnosis and proper treatment. However, patients without clear predisposing factors for DVT may be directed to alternative diagnoses of a musculoskeletal disorder. The few case reports and studies of magnetic resonance (MR) imaging of unsuspected DVT are limited to the calf and knee. Here, we report two cases with a rare presentation of thigh MR imaging of unsuspected DVT. Identifying branching, abnormal intraluminal signals on fluid-sensitive imaging, or rim-enhancing tubular structures within the edema of the thigh muscle is important for differentiating intramuscular DVT from other thigh pathologies.

Central Venous Catheter-related Thrombosis in a Dialysis Patient: A Case Report

Hemodialysis is one of the treatment modalities for advanced kidney disease and can help an individual live an active life despite failing kidneys. Although it improves the quality of life, it is not completely risk-free. It has several complications, among which, thrombus formation is common. We report a case of a 63-year-old man who presented at our institution for regular hemodialysis with recurrent arteriovenous graft failure. Because doppler ultrasound is a non-invasive procedure that can identify a thrombus in a vein, it is the best initial option for patients with internal jugular vein thrombosis. The use of ultrasound not only can guide a catheter pathway but can also help in early diagnosis and prevent complications following catheterization in a vein with a thrombus.

Keywords

central venous catheterization; chronic kidney disease; hemodialysis; thrombus.

Imaging to intervention: Thoracic outlet syndrome

Thoracic outlet syndrome (TOS) is a clinical disorder resulting from compression of the neurovascular bundle of the lower neck and upper chest. TOS can be categorized into neurogenic, venous, and arterial subtypes which result from anatomical compression of the brachial plexus, subclavian vein, and subclavian artery, respectively. This can lead to neurogenic pain as well as vascular injury with thrombosis and thromboembolism. Interventional and diagnostic radiologists play a critical role in the imaging diagnosis and treatment of vascular TOS. Prompt imaging and endovascular management with surgical collaboration has been shown to provide the most successful and long-lasting clinical outcomes, from vessel patency to symptom relief. In this article, we review the anatomy and clinical presentations of TOS as well as the initial imaging modalities used for diagnosis. Furthermore, we detail the role of the diagnostic and interventional radiologist in the management of TOS, including pre-procedure and endovascular interventions, along with medical and surgical treatments. PRECIS: Diagnostic and Interventional Radiologists play a key role in diagnosis and management of vascular thoracic outlet syndromes and are critical for timely and successful outcomes.

Ultrasonographic findings of abdominal thrombosis in dogs

ABSTRACT This retrospective case series study describes the clinical and vascular ultrasound findings of 26 dogs diagnosed with abdominal thrombosis. Images were selected based on the detection of intravascular echogenic thrombus or the absence of vascular flow on color Doppler, confirmed by surgery or necropsy. Images were acquired using the Mylab 40 model, with linear and microconvex multifrequency probes. All the reports were evaluated along with the corresponding images by a veterinary diagnostic imaging radiologist. The ultrasonographic aspects evaluated were echogenicity (92.3%), anechogenicity (7.7%), vascularization (11.5%), mineralization (15.4%), and recanalization (7.7%) of the thrombosis. The vascular and hemodynamic findings were dilation of the affected vein (57.7%), total occlusion of blood flow (30.8%), presence of turbulent flow (65.38%), and visualization of smoke signal (blood flow detected as moving echogenic points in dynamic bidimensional mode) (11.5%). Neoplasms (19 cases) and nephropathies (13 cases) were the most common clinical conditions in the affected dogs. Eleven cases of vascular invasion due to adrenal neoplasms were identified. The results indicate that the vascular ultrasound examination is an important method for diagnosis, as 23 of the 26 cases did not show any clinical signs of thrombosis.

Indirect CT venography of the lower extremities: impact of scan delay and patient factors on contrast enhancement and examination quality

OBJECTIVES

Indirect computed tomography venography (CTV) is often the next imaging modality for deep vein thrombosis (DVT) when sonography is inconclusive. Our aim was to investigate the impact of scan delay and patient factors on contrast enhancement (CE) and examination quality in CTV.

METHODS

Patients with clinical suspicion or clinical mimics of DVT in one large hospital were enrolled. Age, sex, body weight, height, heart rate, systolic blood pressure and cardiac output were registered. CTV of the popliteal veins was obtained at 30 s intervals at 30-210 s delays. The proportions of examinations with CE exceeding predefined cut-offs were estimated and subjective examination quality was rated. Changes in CE with time, and associations between patient factors and time to peak contrast enhancement (TPCE) were modelled with mixed effects non-linear and linear regression, respectively.

RESULTS

The CE increased with increasing scan delay and reached a plateau from 120 to 210 s. The percentages of examinations achieving enhancement above cut-offs across all thresholds from 70 to 100 HU were higher at 120 s compared to 90 s (p < 0.001). After 120 s, there were no differences across scan delays for any thresholds. No patient factors showed a significant effect on TPCE. The percentage of examinations rated as acceptable was higher at 120 s compared to 90 s (p < 0.001). After 120 s, there were no statistically significant differences across scan delays.

CONCLUSIONS

No patient factors were associated with TPCE in CTV. A fixed scan delay of 120-210 s yielded the best examination quality.

KEY POINTS

• Contrast enhancement reached a plateau at scan delay between 90 and 120 s. • A scan delay of 120-210 s yielded the best examination quality. • No patient factors were associated with time to peak contrast enhancement.

Morphologic change in deep venous thrombosis in the lower extremity after therapeutic anticoagulation

Background

To evaluate the anticoagulant treatment response in venous thrombi with different morphologies (size, shape, and echogenicity) by measuring the change in thrombus thickness.

Materials and methods

This was a retrospective cohort study of 97 lower extremity DVT patients diagnosed by venous ultrasound between March 2014 and February 2018. The demographics, clinical risk factors, anticoagulant treatment, and ultrasound findings at the first diagnosis and 2–6 months after treatment were evaluated.

Results

The anticoagulant treatment with LMWH followed by VKAs showed a significant decrease in the mean maximum difference in lower extremity DVT thrombus thickness compared with VKAs alone (P-value < 0.001). After adjustment by treatment, the thrombi found in dilated veins showed a significant decrease in the thickness of such thrombi compared with those found in small veins: 4 mm vs. 0 mm (Coef. = 3, 95% CI: 1.9, 4.1 and P-value < 0.001). Anechoic and hypoechoic thrombi showed a significant decrease in the thickness compared with hyperechoic thrombi: 5 mm vs. 0 mm (Coef. = 4, 95% CI: 3.25, 4.74 and P-value < 0.001) and 3 mm vs. 0 mm (Coef. = 2, 95% CI: 1.34, 42.66 and P-value < 0.001), respectively. Concentric thrombi showed a significant decrease in thickness compared with eccentric thrombi: 4 mm vs. 0 mm (Coef. = 2, 95% CI: 1.45, 2.55 and P-value < 0.001).

Conclusion

The anticoagulant treatment with LMWH followed by VKAs shows a significant decrease in lower extremity DVT thrombus thickness compared with VKAs alone. After adjustment by treatment, the morphologic finding of acute thrombi shows a significantly decreased thickness compared with the morphologic finding of chronic thrombi.

A clinical decision framework to guide the outpatient treatment of emergency department patients diagnosed with acute pulmonary embolism or deep vein thrombosis: Results from a multidisciplinary consensus panel

The outpatient treatment of select emergency department patients with acute pulmonary embolism (PE) or deep vein thrombosis (DVT) has been shown to be safe, cost effective and associated with high patient satisfaction. Despite this, outpatient PE and DVT treatment remains uncommon. To address this, the American College of Emergency Physicians assembled a multidisciplinary team of content experts to provide evidence-based recommendations and practical advice to help clinicians safely treat patients with low-risk PE and DVT without hospitalization. The emergency clinician must stratify the patient's risk of clinical decompensation due to their PE or DVT as well as their risk of bleeding due to anticoagulation. The clinician must also select and start an anticoagulant and ensure that the patient has access to the medication in a timely manner. Reliable follow-up is critical, and the patient must also be educated about signs or symptoms that should prompt a return to the emergency department. To facilitate access to these recommendations, the consensus panel also created 2 web-based "point-of-care tools."

Patients with right lower extremity deep vein thrombosis have a higher risk of symptomatic pulmonary embolism: a retrospective study of 1585 patients

OBJECTIVE

To determine the risk for pulmonary embolism (PE) and explore the relationship between the site of thrombosis and PE in patients with acute lower extremity deep vein thrombosis (DVT).

METHODS

1585 hospitalized patients first diagnosed with acute lower extremity DVT were investigated retrospectively. The patients were divided into two groups: the non-PE group (Group 1) and the PE group (Group 2). Then, Group 2 was divided into two subgroups: asymptomatic pulmonary embolism (asPE, Group 2a) and symptomatic pulmonary embolism (sPE, Group 2b). Kaplan-Meier curves and logistic regression analysis were used to explore the relevant risk factors for PE.

RESULTS

Among 1585 patients, 458 patients suffered from PE, accounting for 28.9%. 102 (22.3%) of them had the typical clinical manifestations of PE and were defined as sPE, and the remaining 356 (77.7%) patients were classified as asPE. Patients with proximal lower extremity DVT were significantly more predominant in the PE group than in the non-PE group (92.8% vs. 86.2%, p<0.001). Moreover, in Group 2, patients with typical PE manifestations showed a higher proportion of patients with right lower extremity DVT than left lower extremity DVT (26.7% vs. 17.7%, P=0.035), and bilateral lower extremity DVT than unilateral DVT (44.1% vs. 20.5%, p<0.001). By multivariate analysis, alcohol consumption (OR, 1.824; 95% CI, 1.194-2.787; p=0.005), heart failure (OR, 2.345; 95% CI, 1.560-3.526; p<0.001), proximal DVT (OR, 2.096; 95% CI,1.407-3.123; p<0.001) were independent risk factors for PE.

CONCLUSION

Patients with proximal acute lower extremity DVT were more likely to suffer from PE than those with distal DVT. Patients with right acute lower extremity DVT had a higher risk of sPE than patients with left acute lower extremity DVT. Alcohol consumption and heart failure were associated with the occurrence of PE in patients with acute lower extremity DVT.

Mastocytosis-A Review of Disease Spectrum with Imaging Correlation

Simple Summary

In this review will discuss the clinical presentation, pathophysiology, and role of imaging in detection and extent estimation of the systemic involvement of the disease, in addition to demonstration of appearance on varying imaging modalities. Familiarity with the potential imaging findings associated with mastocytosis can aid in early disease diagnosis and classification and accordingly can lead directing further work up and better management.

Abstract

Mastocytosis is a rare disorder due to the abnormal proliferation of clonal mast cells. Mast cells exist in most tissues, mature in situ from hematopoietic stem cells and develop unique characteristics of local effector cells. Mastocytosis develops by activation mutation of the KIT surface receptor which is involved in the proliferation of a number of cell lines such as mast cells, germ cells, melanocytes, and hematopoietic cells. It manifests as two main categories: cutaneous mastocytosis and systemic mastocytosis. Imaging can play an important role in detection and characterization of the disease manifestation, not only by radiography and bone scans, but also magnetic resonance imaging and computed tomography, which can be more sensitive in the assessment of distinctive disease patterns. Radiologists should be aware of various appearances of this disease to better facilitate diagnosis and patient management. Accordingly, this review will discuss the clinical presentation, pathophysiology, and role of imaging in detection and extent estimation of the systemic involvement of the disease, in addition to demonstration of appearance on varying imaging modalities. Familiarity with the potential imaging findings associated with mastocytosis can aid in early disease diagnosis and classification and accordingly can lead directing further work up and better management.

Review of COVID-19, part 2: Musculoskeletal and neuroimaging manifestations including vascular involvement of the aorta and extremities

The coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world resulting in severe morbidity, mortality and economic hardship, altering the landscape of healthcare forever. Its devastating and most frequent thoracic and cardiac manifestations have been well reported since the start of the pandemic. Its extra-thoracic manifestations are myriad and understanding them is critical in diagnosis and disease management. The role of radiology is growing in the second wave and second year of the pandemic as the multiorgan manifestations of COVID-19 continue to unfold. Musculoskeletal, neurologic and vascular disease processes account for a significant number of COVID-19 complications and understanding their frequency, clinical sequelae and imaging manifestations is vital in guiding management and improving overall survival. The authors aim to provide a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19. In Part I, abdominal manifestations of COVID-19 in adults and multisystem inflammatory syndrome in children will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

MiR-296-5p ameliorates deep venous thrombosis by inactivating S100A4

Deep venous thrombosis is one of the most common venous thromboembolic diseases and has a low cure rate and a high postoperative recurrence rate. Furthermore, emerging evidence indicates that microRNAs are involved in deep venous thrombosis. miR-296-5p is an important microRNA that plays a critical role in various cellular functions, and S100A4 is closely related to vascular function. miR-296-5p is downregulated in deep venous thrombosis patients, and its predicted target S100A4 is upregulated in deep venous thrombosis patients. Therefore, it was hypothesized that miR-296-5p may play a vital role in the development of deep venous thrombosis by targeting S100A4. An Ox-LDL-stimulated HUVEC and deep venous thrombosis mouse model was employed to detect the biological functions of miR-296-5p and S100A4. Dual luciferase reporter assays and pull-down assays were used to authenticate the interaction between miR-296-5p and S100A4. ELISA and Western blotting were employed to detect the protein levels of thrombosis-related factors and the endothelial-to-mesenchymal transition (EndMT)-related factors. The miR-296-5p levels were reduced, while the S100A4 levels were enhanced in deep venous thrombosis patients, and the miR-296-5p levels were negatively correlated with the S100A4 levels in deep venous thrombosis patients. miR-296-5p suppressed S100A4 expression by targeting the 3' UTR of S100A4. MiR-296-5p knockdown accelerated ox-LDL-induced HUVEC apoptosis, oxidative stress, thrombosis-related factor expression, and EndMT, while S100A4 knockdown antagonized these effects in ox-LDL-induced HUVECs. S100A4 knockdown reversed the effect induced by miR-296-5p knockdown. Moreover, the in vivo studies revealed that miR-296-5p knockdown in deep venous thrombosis mice exacerbated deep venous thrombosis formation, whereas S100A4 knockdown had the opposite effect. These results indicate that elevated miR-296-5p inhibits deep venous thrombosis formation by inhibiting S100A4 expression. Both miR-296-5p and S100A4 may be potential diagnostic markers and therapeutic targets for deep venous thrombosis.

Iatrogenic superior vena cava syndrome with concomitant deep vein thrombosis of azygos and hemiazygos veins

Iatrogenic superior vena cava syndrome (SVCs) represents an emergent diagnostic entity and its correlation with deep vein thrombosis is extremely rare. Recently, the increased use of indwelling lines, pacemakers and intracardiac devices has led to more cases of SVC syndrome also associated with a higher frequency of DVT. We report an unusual complication in a 74-year-old female, who has been undergoing hemodialysis via CVC for 14 years, who referred at our Emergency Department complaining of shortness of breath, headache, face and neck swelling. She underwent chest Computed Tomography Angiography (CTA), that showed a thrombus extending from the superior vena cava to the azygos and hemiazygos veins. Acute SVCs should be suspected in emergency settings in symptomatic patients with indwelling central lines, catheters and pacemakers. CTA represents an accurate and quick imaging modality for the diagnosis and the assessment of the extension of the thrombus.

Efficacy of Shear Wave Elastography in the Differentiation of Acute and Subacute Deep Venous Thrombosis

ABSTRACT

It is important to know the age of clot formation to determine an appropriate treatment for deep vein thrombosis (DVT). The present study aims to differentiate between acute and subacute DVT using the shear wave elastography (SWE) technique. Patients with complaints no longer than 4 weeks and who were found to have early-stage (acute-subacute) thrombus on ultrasound (US) between January 2020 and May 2020 were included in the study. All of the patients underwent SWE using a Philips Healthcare EPIQ 5 Ultrasound System Inc. device with a high-resolution linear US probe (eL18-4, 22-2 MHz). Included in the study were 50 patients, including 23 with acute DVT and 27 with subacute DVT. Of the patients, 22 were women and 28 were men, and the mean age was 46.32 ± 11.33 years (range: 24-74 years). The mean SWE value was 2.63± 0.16 (2.39-2.96) in patients with acute DVT and 3.34± 0.31 (2.65-3.88) in patients with subacute DVT. The findings were statistically significant in the comparison of the 2 groups using an independent samples t test (P < 0.001). In the receiver operating characteristic analysis, the area under the curve was found to be 97.6%. When the cutoff value was taken as 2.85 according to the area under the curve, sensitivity was found to be 96.3%, and specificity was 91.3%. Thrombus stage plays a critical role in treatment decisions in DVT in the lower extremities. The present study reveals that the shear wave US elastography technique can be used to discriminate between acute and subacute DVT.

Usefulness of triggered non-contrast-enhanced magnetic resonance angiography in assessing lower extremity venous disease

Although venous duplex ultrasonography (USG) is reliable for diagnosing lower extremity venous disease (LEVD), cross-sectional imaging studies were usually required before intervention or surgery. Patients of LEVD with renal insufficiency usually restrict the use of contrast-enhanced imaging modalities. In seeking an alternative imaging solution for these patients, we explore the clinical utility of triggered angiography non-contrast-enhanced magnetic resonance imaging (TRANCE-MRI) in the assessment of LEVD.We collected data from patients presenting to a tertiary wound-care center with symptoms of LEVD from April 2017-November 2019. Each participant underwent baseline USG followed by TRANCE-MRI on a 1.5T MR scanner (Philips Ingenia, Philips Healthcare, Best, The Netherlands). Inter-rater reliability was measured using Cohen's kappa (κ).All 80 participants (mean age, 61.9 ± 14.8 years; 35 males, 45 females) were assessed and were classified into one of five disease groups, deep vein thrombosis (n = 38), venous static ulcer (n = 16), symptomatic varicose veins (n = 18), recurrent varicose veins (n = 3), and lymphoedema (n = 5). The inter-rater reliability between TRANCE-MRI and doppler USG showed substantial agreement (κ, 0.73). The sensitivity, specificity, and accuracy of TRANCE-MRI were 90.5%, 88.1%, and 88.8%, respectively. In 59 (73.8%) USG-negative patients, we were able to diagnose positive findings (deep venous thrombosis, n = 7; varicose veins, n = 15; lymphedema, n = 10; iliac vein compression with thrombosis, n = 6; external venous compression, n = 5; vena cava anomaly, n = 2; occult peripheral artery disease, n = 5; ccluded bypass graft, n = 1) by using TRANCE-MRI. Of these, 9 (15.3%) patients underwent additional vascular surgery based on positive TRANCE-MRI findings.TRANCE technique provides the limb's entire venous drainage in clear images without background contamination by associated arterial imaging. Additionally, simultaneous evaluation of bilateral lower extremities can help determine the lesion's exact site. Although TRANCE-MRI can provide MR arteriography and MR venography, we recommend performing only MR venography in symptomatic LEVD patients because the incidence of occult arterial disease is low.

Photoacoustic imaging as a highly efficient and precise imaging strategy for the evaluation of brain diseases

Photoacoustic imaging (PAI) is an emerging imaging strategy with a unique combination of rich optical contrasts, high ultrasound spatial resolution, and deep penetration depth without ionizing radiation. Taking advantage of the features mentioned above, PAI has been widely applied to preclinical studies in diverse fields, such as vascular biology, cardiology, neurology, ophthalmology, dermatology, gastroenterology, and oncology. Among various biomedical applications, photoacoustic brain imaging has great importance due to the brain's complex anatomy and the variability of brain disease. In this review, we aimed to introduce a novel and effective imaging modality for diagnosing brain diseases. Firstly, a brief overview of two major types of PAI system was provided. Then, PAI's major preclinical applications in brain diseases were introduced, including early diagnosis of brain tumors, subtle changes in the chemotherapy response, epileptic activity and brain injury, foreign body, and brain plaque. Finally, a perspective of the remaining challenges of PAI was given for future advancements.

In vivo Multi-scale Photoacoustic Imaging Guided Photothermal Therapy of Cervical Cancer based on Customized Laser System and Targeted Nanoparticles

BACKGROUND

Effective treatment strategy for cervical carcinoma is subject to the limitation of its anatomical location and histological characteristics. Comprehensive imaging before cervical carcinoma treatment is of great significance for the patients. Current imaging methods cannot meet the requirements of high resolution, deep imaging depth and non-invasive imaging at the same time. Fortunately, Photoacoustic imaging (PAI) is a novel imaging method that combines rich optical contrast, high ultrasonic spatial resolution, and deep penetration depth in a single modality. Moreover, PAI-guided photothermal therapy (PTT) by aid of targeting nanoparticles is an emerging and effective cancer treatment in recent years.

METHODS

Here, strong near-infrared region (NIR) absorption-conjugated polymer PIIGDTS (PD) nanoparticles with folic acid (FA) modification (namely, PD-FA) that targeted at Hela cell were specifically designed as cervical tumor imaging contrast agents and photothermal agents.

RESULTS

The obtained PD-FA nanoparticles exhibited admirable photoacoustic contrast-enhancing ability and desirable PTT behavior with the photothermal conversion efficiency as high as 62.6% in vitro. Furthermore, the PAI performance and PTT efficiency were tested in HeLa tumor-bearing nude mice after injection of PD-FA nanoparticles. In vivo multi-scale, PAI provided B-san and 3D dimension imaging for intuitive and comprehensive information of Hela tumor. Moreover, the Hela tumor can be completely eliminated within 18 days after PTT, with no toxicity and side effects.

CONCLUSION

In summary, PD-FA injection combined with PAI and PTT systems provides a novel powerful tool for early diagnosis and precise treatment of cervical cancer.

Time-efficient and contrast-free magnetic resonance imaging approach to the diagnosis of deep vein thrombosis on black-blood gradient-echo sequence: a pilot study

Background

Black-blood thrombus imaging (BTI) has shown to be advantageous for the diagnosis of deep vein thrombosis (DVT). However, previous techniques using fast spin echo have a high specific absorption rate. As DANTE (delay alternating with nutation for tailored excitation) black-blood preparation can suppress blood flows over a broad range of velocities, we hypothesized that a DANTE black-blood preparation combined with a fast low-angle shot (FLASH) gradient-echo readout-DANTE-FLASH could be used to diagnose DVT.

Methods

Eleven healthy volunteers and 30 suspected DVT patients were recruited to undergo DANTE-FLASH and magnetic resonance direct thrombus imaging (MRDTI). The suspected DVT patients were also examined by ultrasound (US). For the segment level, a total of 1,066 venous vessel segments were analyzed. Using US and MRDTI as the references, the sensitivity (SE), specificity (SP), positive and negative predictive values (PPV and NPV), and accuracy (ACC) of DANTE-FLASH were calculated. To quantitatively compare image quality between DANTE-FLASH and MRDTI, image signal-to-noise ratio (SNR), apparent contrast-to-noise ratio (CNR) between muscle and the venous lumen, and the apparent CNR between the thrombus and venous lumen were measured. Additionally, diagnostic confidence, image quality, and clot burden were also evaluated.

Results

Using the consensus results of US and MRDTI as a standard reference, the diagnostic SE, SP, PPV, NPV, and ACC of DANTE-FLASH for the 2 readers were 97.0% and 93.2%, 99.0% and 98.2%, 93.4% and 87.9%, 99.6% and 99.0%, and 98.8% and 97.6%, respectively. According to the image quantitative analysis results, DANTE-FLASH demonstrated higher image SNR and CNR than MRDTI. The image quality and diagnostic confidence scores of DANTE-FLASH were higher than MRDTI (3.66±0.44 vs. 3.52±0.52, P<0.001, and 3.84±0.36 vs. 3.76±0.41, P<0.001). There was excellent agreement between DANTE-FLASH and MRDTI on clot burden evaluation.

Conclusions

DANTE-FLASH provided better image quality than MRDTI and accurately detected thrombi. It may, therefore, serve as a safe and convenient alternative for the diagnosis of DVT.

Increased deep vein thrombosis cases during the COVID-19 quarantine

OBJECTIVE

The aim of this study was to compare the number of deep vein thrombosis (DVT) cases during the quarantine period for COVID-19 to that of the last year.

METHODS

This study was conducted as a single-center and retrospective study. All hospital admissions during April 2020 and May 2020 were screened from the hospital records, and DVT cases were recorded. Likewise, all hospital admissions during April 2019 and May 2019 were screened, and DVT cases were noted. DVT cases of both years were compared.

RESULTS

Among 480931 patients admitted to our hospital in April 2019 and May 2019, DVT was detected in 82 patients (0.017%) (47 males, 35 females) with a mean age of 56.99 ± 9.1 years (ranges 39 to 79 years). Besides, among 145101 patients admitted to our hospital in April 2020 and May 2020, DVT was detected in 123 patients (0.084%) (51 males, 72 females) with a mean age of 58.64 ± 8.9 years (ranges 40 to 83 years). Despite the decrease in the total number of patients admitted to the hospital, there was a significant increase in the number of DVT patients. Interestingly, there were only two symptomatic pulmonary-embolism cases in the 2019 period, whereas there were seven symptomatic pulmonary embolisms secondary to DVT in the 2020 period. Unfortunately, one patient died due to pulmonary embolism secondary to DVT in 2020. The previous history of DVT was remarkable in patients admitted during the COVID-19 confinement.

CONCLUSION

In conclusion, COVID-19 confinement seems to be associated with increased rates of DVT. Strict preventive measures such as exercise training or prophylactic drug use should be considered to prevent immobility-related DVT during the COVID-19 quarantine.

Secondary Anticoagulation Prophylaxis for Catheter-Related Thrombosis in Pediatric Intestinal Failure: Comparison of Short- Vs Long-Term Treatment Protocols

INTRODUCTION

Catheter-related thrombosis (CRT) is a devastating complication of central venous catheters in children with intestinal failure (IF), but the optimal preventive therapy of CRT is unknown. This study assessed the efficacy and safety of 2 protocols of secondary anticoagulation prophylaxis with low-molecular-weight heparin (LMWH).

METHODS

This is a comparative cohort study of children from 2 IF programs who received secondary anticoagulation prophylaxis with LMWH for CRT. The short-term protocol group (N = 13) received therapeutic dosing until thrombus resolution or ≤3 months. In the long-term protocol group (N = 26), prophylactic dosing continued until line removal. Patients underwent routine annual vascular ultrasound and were followed for ≥1 year. The primary outcome was development of secondary thrombosis; post hoc analysis assessed rates of secondary thrombosis at 12 months.

RESULTS

Patient demographics were similar between groups. Secondary thrombosis occurred in 8 of 13 (62%) patients in the short-term group and in 9 of 26 (35%) in the long-term protocol group (P = .019) in a median time of 144.5 and 689 days, respectively (P = .01). Secondary thrombosis within 12 months occurred in 7 of 13 (54%, short term) and 2 of 26 (8%, long term) patients (P = .001). Secondary thrombosis was associated with catheter replacements (23.5 vs 5.5 catheters per 1000 catheter days; P = .016) and longer daily parenteral nutrition (PN) infusion (24 vs 15.25 hours; P = .044). Compliance was good (>80% of doses) in 92% of patients.

CONCLUSIONS

Long-term secondary anticoagulation prophylaxis with LMWH reduces the incidence of secondary thrombosis and should be considered in children with CRT that require PN for prolonged periods of time.

Prevalence and predictors of alternative diagnoses on whole-leg ultrasound negative for acute deep venous thrombosis

Background

To investigate the prevalence, spectrum, and predictors of alternative diagnoses explaining leg symptoms in patients negative for suspected acute deep venous thrombosis (DVT), which can be detected with whole-leg ultrasound.

Methods

We retrospectively analyzed a cohort of 789 patients (median age 70 years, 50.6% women) evaluated with a whole-leg ultrasound examination for suspected acute DVT within one year. All findings in the radiology report were analyzed and electronic chart review was performed to collect clinical information.

Results

Ultrasound was negative for acute DVT in 531 patients (67.3%). Among these, alternative diagnoses explaining leg symptoms were seen in 349 patients (65.7%). The most frequent alternative diagnoses were chronic venous insufficiency (147 patients, 27.7%), followed by lymphedema (48 patients, 9.0%) and chronic post-thrombotic changes (41 patients, 7.7%). Patients with alternative diagnoses were older (median 71 vs. 66 years, p = 0.0226), as well as more likely to present with leg swelling (39.5% vs. 23.1%, p = 0.0002), difference in leg circumference (25.5% vs. 14.8%, p = 0.0055) and redness (7.7% vs. 2.7%, p = 0.0213) than patients without alternative diagnosis. Independent predictors of finding alternative diagnoses on whole-leg ultrasound were older age (odds ratio 1.014 per year, p = 0.0119), leg swelling (OR 1.949, p = 0.0020) and history of previous DVT (OR 2.235, p = 0.0154).

Conclusions

Alternative diagnoses explaining leg symptoms can be detected on whole-leg ultrasound in two thirds of patients with no evidence of acute DVT. Our data supports performing a comprehensive ultrasound evaluation beyond the venous system, particularly, in older patients, who present with leg swelling and a past history of DVT.

Downregulation of interleukin-6 and C-reactive protein underlies a novel inhibitory role of microRNA-136-5p in acute lower extremity deep vein thrombosis

Deep vein thrombosis (DVT) comprises a critical and common health condition with high incidence, mortality, and long-term adverse sequelae. Several differentially expressed microRNAs (miRNAs) have emerged as promising prognostic markers in DVT. The present study intended to explore the functional relevance of miR-136-5p in acute lower extremity DVT (LEDVT). Rat models of acute LEDVT were established and miR-136-5p expression was altered by agomir or antagomir to assess its effects. In addition, in vitro gain- and loss-experiments, prior to exposure to CoCl₂, were performed to investigate effects of miR-136-5p on human umbilical vein endothelial cell (HUVEC) apoptosis and levels of interleukin-6 (IL-6) and C-reactive protein (CRP). miR-136-5p was downregulated, whereas IL-6 and CRP were elevated in acute LEDVT patients. Notably, miR-136-5p was confirmed to target both IL-6 and CRP. Overexpression of miR-136-5p led to reduced length, weight, and ratio of weight to length of the venous thrombus. Furthermore, overexpressed miR-136-5p downregulated the expression of IL-6 and CRP, consequently inhibiting HUVEC apoptosis. Conjointly, our data indicate that the overexpression of miR-136-5p has the potential to bind to the 3’-UTR in the mRNAs for IL-6 and CRP and mitigate acute LEDVT, which provides a basis for new therapeutic targets in acute LEDVT treatment.

High Signal Intensity on Diffusion-Weighted Images Reflects Acute Phase of Deep Vein Thrombus

The effects of antithrombotic therapy on deep vein thrombosis (DVT) can be affected by thrombus age, which cannot be reliably determined by noninvasive imaging modalities. We investigated whether magnetic resonance (MR) diffusion-weighted imaging (DWI) can localize and determine the age of venous thrombus in patients with DVT, animal models, and human blood in vitro. Signal intensity (SI) on DWI and the apparent diffusion coefficient (ADC) of thrombi were assessed in eight patients with DVT using a 1.5-T MR imaging (MRI) system. We assessed the organizing processes as venous thrombus developed in the rabbit jugular vein using a 3.0-T MRI system over time. We also assessed MRI signals of human blood in vitro using the 1.5-T MRI system. Venous thrombi were detected by DWI as areas of high or mixed high and iso SI in all patients. The ADCs were lower in the proximal, than in the distal portion of the thrombi. The thrombi of rabbit jugular veins histologically organized in a time-dependent manner, with high SI on DWI at 4 hours, mixed high and iso SI at 1 and 2 weeks, and iso SI at 3 weeks. The ADC correlated negatively with erythrocyte content, and positively with smooth muscle cells, macrophages, hemosiderin, and collagen content. MRI signals of human blood in vitro showed that ADCs were affected by erythrocyte content, but not by blood clotting. MR-DWI can detect venous thrombus, and high SI on DWI accompanied by a low ADC might reflect erythrocyte-rich, acute-phase thrombi.

Validation of the adjusted global antiphospholipid syndrome score in a single centre cohort of APS patients from Turkey

The adjusted global antiphospholipid syndrome score (aGAPSS) is a recently developed thrombotic risk assessment score that considers the antiphospholipid antibody (aPL) profile and conventional cardiovascular risk factors. In this retrospective study, we aimed to evaluate the validity of the aGAPSS in predicting clinical manifestations (criteria and extra-criteria) of antiphospholipid syndrome (APS) in a single centre cohort of patients. Ninety-eight patients with APS ± systemic lupus erythematosus (SLE) were classified according to clinical manifestations as vascular thrombosis (VT), pregnancy morbidity (PM) or both (VT + PM). The aGAPSS was calculated for each patient as previously defined. Mean aGAPSS of the cohort was calculated as 10.2 ± 3.8. Significantly higher aGAPSS values were seen in VT (n = 58) and VT + PM (n = 29) groups when compared to PM (n = 11) group (10.6 ± 3.7 vs 7.4 ± 2.9, P = 0.005; 10.7 ± 4 vs 7.4 ± 2.9, P = 0.008, respectively), mainly due to lower frequencies of cardiovascular risk factors in PM. Higher aGAPPS values were also associated with recurrent thrombosis (11.6 ± 3.7 vs 9.9 ± 3.6, P = 0.04). Regarding extra-criteria manifestations, patients with livedo reticularis (n = 11) and APS nephropathy (n = 9) had significantly higher aGAPSS values (12.9 ± 3.4 vs 9.9 ± 3.7, P = 0.02; 12.4 ± 2.9 vs 10 ± 3.8, P = 0.04, respectively). The computed AUC demonstrated that aGAPSS values ≥10 had the best diagnostic accuracy for thrombosis. Our results suggest that patients with higher aGAPSS values are at higher risk for developing vascular thrombosis (either first event or recurrence) and extra-criteria manifestations, especially livedo reticularis and APS nephropathy.