Staging and Prognosis of Deep Venous Thrombosis of Lower Extremities

Study Overview
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Brief Summary
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Deep venous thrombosis (DVT) is a venous reflux disorder caused by abnormal coagulation of blood in the deep vein, which usually occurs in the lower extremities. After thrombosis, venous valve function is often destroyed, causing lower limb swelling, ulcers and other congestive diseases, affecting the quality of life of patients; thrombus shedding is also easy to cause pulmonary embolism, serious cases can lead to sudden death. Therefore, the accurate diagnosis and curative effect evaluation of DVT are of great significance to the prognosis of patients. At present, the treatment of DVT includes systematic thrombolysis and catheter contact thrombolysis, among which oral drug thrombolysis has certain advantages in clinical application. However, in the process of thrombosis, the composition of thrombus is different in different periods, thus, defining the staging of thrombus plays an important role in the decision-making of drug treatment. In view of the high resolution of magnetic resonance imaging of soft tissue, thrombus can be directly imaged. Therefore, this project will take the staging diagnosis of deep venous thrombosis as the starting point. Through the development of magnetic resonance imaging, this paper tries to solve the problem of evaluating the therapeutic effect of deep venous thrombosis in clinic.

Detailed Description
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Deep venous thrombosis (DVT) is a venous reflux disorder caused by abnormal blood coagulation in the deep vein, which usually occurs in the lower extremities. DVT is common in patients with limb immobilization (such as after major orthopedic surgery), severe trauma, tumor, coma or long-term bedridden patients. After thrombosis, venous valve function is often destroyed, causing lower limb swelling, ulcers and other congestive diseases, affecting the quality of life of patients; thrombus shedding is also easy to cause pulmonary embolism, serious cases can lead to sudden death. In the process of thrombosis, the components of thrombus are different in different stages. in the acute stage of thrombosis, the consumption of blood fibroses is less, mainly in the thrombolytic therapy of activating plasminogen; in the subacute and chronic phase of thrombosis, the consumption of fibrinolytic enzyme is more, anticoagulant therapy is needed to prolong the clotting time. Therefore, defining the staging of thrombus is the key to make a reasonable treatment plan and improve the therapeutic effect of DVT. The guidelines recommend that for patients with moderate or high likelihood of DVT, if two consecutive ultrasound examinations are negative, further X-ray venography, CT venography or magnetic resonance venous thrombosis direct imaging are recommended. Among them, magnetic resonance thrombus direct imaging depends on the content of methemoglobin in the body and will not produce radiation to the human body. it can not only accurately judge the thrombus in the pelvic and inferior vena cava, but also show the details of the changes in the vein wall or lumen. Therefore, magnetic resonance thrombus direct imaging has a certain potential in the differential diagnosis of acute, subacute and old thrombus. In this study, we will use magnetic resonance thrombus direct imaging to stage and judge the efficacy of drug treatment, in order to provide help for clinic.

Official Title
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Staging Diagnosis and Prognosis of Lower Extremity Deep Venous Thrombosis Based on Magnetic Resonance Imaging: a Prospective Study

Conditions
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Venous Thrombosis

Intervention / Treatment
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* Other: MRI examination


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: More than 18 years old Suspected deep venous thrombosis of lower extremities No treatment related to deep venous thrombosis of lower extremities Exclusion Criteria: Contraindication of magnetic resonance imaging Previous history of deep venous thrombosis History of allergy to magnetic resonance contrast agents

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Acute thrombus group<br>Within 14 days after onset | Other: MRI examination<br>* Magnetic resonance thrombography is used to determine the location of thrombus, quantify the thrombus and determine its stage.<br>|
| Subacute thrombus group<br>During 15-30 days after onset | Other: MRI examination<br>* Magnetic resonance thrombography is used to determine the location of thrombus, quantify the thrombus and determine its stage.<br>|
| Chronic thrombosis group<br>More than 15-30 days after onset | Other: MRI examination<br>* Magnetic resonance thrombography is used to determine the location of thrombus, quantify the thrombus and determine its stage.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Thrombus-muscle signal-to-noise ratio | Quantitative analysis of thrombus was performed by magnetic resonance thrombography for the first time, and the curative effect was evaluated again 3 months after clinical treatment. | The interval between two MRI examinations per patient is 3 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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MRI, Venous Thrombosis, Staging, Prognosis