How is Pulmonary Embolism Diagnosed?

Pulmonary embolism (PE) is diagnosed based on your medical history, a physical exam, and test results.

Doctors who treat patients in the emergency room often are the ones to diagnose PE with the help of a radiologist. A radiologist is a doctor who deals with x rays and other similar tests.

Medical History and Physical Exam

To diagnose PE, the doctor will ask about your medical history. He or she will want to:  

• Find out your deep vein thrombosis (DVT) and PE risk factors
• See how likely it is that you could have PE
• Rule out other possible causes for your symptoms

Your doctor also will do a physical exam. During the exam, he or she will check your legs for signs of DVT. He or she also will check your blood pressure and your heart and lungs.

Diagnostic Tests

Many tests can help diagnose PE. Which tests you have will depend on how you feel when you get to the hospital, your risk factors, available testing options, and other conditions you could possibly have. You may have one or more of the following tests.

Ultrasound

Doctors can use ultrasound to look for blood clots in your legs. Ultrasound uses sound waves to check blood flow in your veins.

For this test, gel is put on the skin of your legs. A hand-held device called a transducer is moved back and forth over the affected areas. The transducer gives off ultrasound waves and detects their echoes as they bounce off the vein walls and blood cells.

A computer turns the echoes into a picture on a computer screen, allowing the doctor to see blood flow in your legs. If the doctor finds blood clots in the deep veins of your legs, he or she will recommend treatment.

DVT and PE both are treated with the same medicines.

Computed Tomography Scans

Doctors can use computed tomography (to-MOG-rah-fee) scans, or CT scans, to look for blood clots in the lungs and legs.

For this test, dye is injected into a vein in your arm. The dye makes the blood vessels in your lungs and legs show up on x-ray images. You’ll lie on a table, and an x-ray tube will rotate around you. The tube will take pictures from many angles.

This test allows doctors to detect most cases of PE. The test only takes a few minutes. Results are available shortly after the scan is done.

Lung Ventilation/Perfusion Scan

A lung ventilation/perfusion scan, or VQ scan, uses a radioactive substance to show how well oxygen and blood are flowing to all areas of your lungs. This test can help detect PE.

Pulmonary Angiography

Pulmonary angiography (an-jee-OG-rah-fee) is another test used to diagnose PE. This test isn’t available at all hospitals, and a trained specialist must do the test.

For this test, a flexible tube called a catheter is threaded through the groin (upper thigh) or arm to the blood vessels in the lungs. Dye is injected into the blood vessels through the catheter.

X-ray pictures are taken to show blood flowing through the blood vessels in the lungs. If a blood clot is found, your doctor may use the catheter to remove it or deliver medicine to dissolve it.

Blood Tests

Certain blood tests may help your doctor find out whether you’re likely to have PE.

A D-dimer test measures a substance in the blood that’s released when a blood clot breaks down. High levels of the substance may mean a clot is present. If your test is normal and you have few risk factors, PE isn’t likely.

Other blood tests check for inherited disorders that cause blood clots. Blood tests also can measure the amount of oxygen and carbon dioxide in your blood. A clot in a blood vessel in your lungs may lower the level of oxygen in your blood.

Other Tests

To rule out other possible causes of your symptoms, your doctor may use one or more of the following tests.

• Echocardiography (echo). This test uses sound waves to create a moving picture of your heart. Doctors use echo to check heart function and detect blood clots inside the heart.
• EKG (electrocardiogram). An EKG is a simple, painless test that detects and records the heart’s electrical activity.
• Chest x ray. This test creates pictures of your lungs, heart, large arteries, ribs, and diaphragm (the muscle below your lungs).
• Chest MRI (magnetic resonance imaging). This test uses radio waves and magnetic fields to create pictures of organs and structures inside the body. MRI often can provide more information than an x ray.

Source: National Heart, Lung, and Blood Institute, National Institutes of Health.

How to know if you have a blood clot: Symptoms and treatment

Being aware of the signs and symptoms of blood clots can help people seek treatment if they experience them.

Blood clots are semisolid clumps of blood that form in veins or arteries.

A blood clot may be stationary (known as a thrombus) and block the flow of blood. Or, it might break free (known as an embolism) and travel through the body.

Keep reading for more information on the signs and symptoms of blood clots and how a doctor may treat them.

Share on PinterestTenderness or pain in the leg can be a symptom of a blood clot.

Certain people are at higher risk of developing a blood clot. According to the American Society of Hematology (ASH), factors that increase a person’s risk of developing blood clots include:

• taking oral contraceptives
• immobility, for example, during long hospital stays
• having obesity
• smoking
• being over the age of 60 years
• family history of blood clots
• pregnancy
• previous central line placement
• certain cancers
• trauma
• chronic inflammatory diseases
• diabetes

People at risk for developing blood clots should be aware of the associated signs and symptoms. According to the American Blood Clot Association, symptoms vary depending on the type of blood clot.

DVT symptoms

Deep vein thrombosis (DVT) is a clot that typically occurs in a major vein in the leg, but it can also develop in the pelvis or arm.

DVT may not cause any symptoms, but if symptoms do occur, they can include:

• warmth at the site of the clot
• tenderness or pain in the affected leg or arm
• swelling in the affected leg and foot or arm and hand
• skin turning red or purple

Symptoms are often local to the blood clot and only affect one arm or leg. The National Blood Clot Alliance add that the pain or discomfort of this type of blood clot may be similar to the sensation of a pulled muscle.

Pulmonary embolism

A pulmonary embolism occurs when a clot or part of a clot travels through the veins and ends up in the lungs. This condition can be deadly.

According to the American Blood Clot Association, some common symptoms of a pulmonary embolism include:

• sharp pain in the chest, particularly when taking a deep breath
• a cough that produces blood
• fever
• dizziness
• rapid pulse
• sudden shortness of breath
• unexplained sweating

A person should seek emergency help immediately if they experience any signs of a pulmonary embolism.

Arterial clots

Arterial clots typically produce symptoms quickly because they begin cutting off oxygen to organs faster than other types of blood clots. They can cause various symptoms and complications, including heart attack, stroke, severe pain, and paralysis.

Other locations

Although DVT and pulmonary embolisms are common, blood clots can occur in other areas of the body.

According to the ASH, blood clots in other parts of the body may cause the following symptoms:

• Abdomen: Pain in the abdomen, vomiting, or diarrhea.
• Brain: Trouble speaking, weakness in the face or arms, issues with vision, dizziness, or severe headache.
• Heart: Heaviness in the chest, chest pain, shortness of breath, nausea, feeling of lightheadedness, or discomfort in the upper body.

The diagnostic process can vary depending on the location of the suspected clot.

A doctor may ask questions about the person’s symptoms and perform a physical examination.

According to the National Blood Clot Alliance, some typical tests include:

• ultrasound, which doctors typically use to diagnose DVT
• venography, which uses a dye to show blood flow in the veins
• MRI scan
• pulmonary angiogram, in which doctors use dye and an X-ray of the chest to determine whether a pulmonary embolism is present

Doctors may use a CT angiography test to check for clots in the head, neck, chest, or abdomen. The test involves the injection of a contrast material into the blood and computer imaging to show blood flow and reveal any clots.

A doctor may order an X-ray of the chest to rule out other possible causes of some pulmonary embolism symptoms, such as pneumonia.

Treating blood clots involves reducing the size of the clot and preventing new clots from forming.

Typical treatments for blood clots include:

• anticoagulant medications called blood thinners, which help prevent new clots and stop existing clots from growing
• thrombolytic therapy to dissolve clots
• compression stockings
• vena cava filters, which are small devices that a surgeon can insert into veins to prevent a clot from traveling to the lungs

A person should talk to their doctor about their treatment options. When using medications, they should take the dosages that their doctor prescribed.

Certain medications, such as blood thinners, can help treat blood clots and prevent further clots from forming. Compression socks are also a helpful preventive measure.

Although not all blood clots are avoidable, a person can take steps to help prevent them. According to the Agency for Healthcare Research and Quality, these steps include:

• raising the legs 6 inches above the heart on occasion during bed rest
• wearing loose-fitting stockings, clothes, or socks
• staying active and following an exercise regimen
• wearing compression stockings regularly
• limiting salt in the diet as much as possible
• shifting positions frequently when stationary for extended periods
• avoiding sitting or standing for more than 1 hour at a time
• taking all medication as the doctor prescribed
• avoiding placing pillows under the knees
• refraining from crossing the legs
• trying to avoid bumping or injuring the legs

Blood clots can cause serious medical issues. If a blood clot breaks free, it can move to the lungs, heart, or brain, blocking blood flow to these vital organs. A person may experience a stroke or heart attack.

Blood clots are common in pregnancy, often due to limited mobility. If a blood clot occurs during pregnancy, it can lead to complications such as:

• placental insufficiency, which means that the placenta does not provide enough nutrients and oxygen to the fetus
• a blood clot in the placenta, which can cause harm to the fetus
• intrauterine growth restriction, which prevents the fetus from growing properly

These possible complications are in addition to those that are common in all people, including:

• thrombosis or a blockage, such as DVT or cerebral vein thrombosis (CVT), which occurs when the clot forms in the brain
• stroke
• pulmonary embolism
• heart attack
• venous thromboembolism

Blood clots can form almost anywhere in the veins or arteries. If they occur, they can cause complications such as heart attack and stroke.

People should be aware of their risk factors for developing a blood clot, which can include obesity, being stationary for extended periods, and pregnancy.

People should talk to their doctor if they experience symptoms that could be due to a blood clot.

causes, symptoms, diagnosis, tests, treatment, prevention

Thrombosis – complete or partial blockage of the vessel lumen by a parietal or mobile thrombus. A thrombus is a dense blood clot that appears as a result of a change in its fluidity. Normally, thrombus formation is a protective mechanism. Damage to the vascular wall entails a slowdown in blood flow, the accumulation of platelets around the damage. The thrombus literally “darns” the vessel wall.

Classical causes of thrombus formation are described by Vihrov’s triad: damage to the vascular wall, slowing of blood flow, and changes in blood properties [3]. Some thrombi (they are called emboli) are able to move to narrower sections of the vessel, which clog completely or partially. Every year, about 25 million people die from thrombosis, and even more face trophic disorders caused by blood clots [3].

Types of vascular thrombosis

Thrombosis of the lower extremities is the most common, but the greatest danger is pulmonary embolism – PE – and disseminated intravascular coagulation syndrome – DIC.

Arterial thrombosis develops when its lumen is blocked by a thrombus or embolus. Clinical signs are determined by the site where such a blockage occurred, an organ or tissue that is poorly supplied with blood or not supplied with it at all. If the blockage with impaired patency of the vessel occurs slowly, “spare”, collateral, vessels open, which alleviates the clinical symptoms of arterial thrombosis [3]. Arterial thrombosis occurs more often in middle-aged and elderly men [7].

Venous thrombosis varies depending on the location of the lesion for deep or superficial vein thrombosis and pulmonary embolism. Among all cardiovascular pathologies, venous thrombosis ranks third in frequency of occurrence, second only to coronary artery disease and atherosclerosis. The third place in the structure of causes of death is PE. Starting from the age of 40, the risk of developing venous thrombosis doubles every 10 years [5].

Two types of damage to the veins of the lower extremities are described: phlebothrombosis (primary thrombosis, the thrombus is not firmly fixed) and thrombophlebitis (secondary thrombosis against the background of inflammation of the vessel wall, the thrombus is firmly fixed) [6]. Thrombophlebitis is more often associated with superficial vein thrombosis [2]. The larger the vein affected by thrombosis, the brighter its clinical manifestations. The surrounding tissues are compressed by stasis of blood, since the blood stays at the site of occlusion, but does not move towards the heart. Venous clots tend to break off and spread with the blood stream (thromboemboli). When they enter the vital organs, life-threatening conditions develop [3].

Causes of thrombosis

Common causes of thrombosis formation are described above. Arterial thrombosis begins with the formation of atheroma – an atherosclerotic plaque. Platelets accumulate around it. The plaque itself may be harmless, but when its surface is injured, dense blood clots form at the site of the tear. This process is called “atherothrombosis” [3, 7]. Venous thromboses are formed when the rheological properties of blood change or as a reaction to inflammation of the vascular wall [5].

Thrombosis risk factors

Internal:

• arterial hypertension [7];
• pregnancy, childbirth, postpartum period [3];
• biochemical changes in blood [2,3,5,7];
• vasculitis [2];
• age over 40 [5];
• congenital thrombophilia, thrombosis, varicose veins of the lower extremities [3,5];
• congestive heart failure [5, 6];
• malignant neoplasms, radiotherapy and chemotherapy [3];
• strokes [3, 6];
• myeloproliferation [2, 5, 7];
• nephrotic syndrome and renal failure [5, 6, 7];
• obesity (BMI over 30) [3];
• myocardial infarction [6];
• diabetes mellitus [6, 7];
• systemic lupus erythematosus [2];
• chronic pulmonary diseases [3];
• enterocolitis [5].

External:

• heroin addiction [2];
• hormone therapy [3,5];
• dehydration with vomiting, diarrhea, increased sweating, direct lack of fluid [6];
• immobilization [3];
• trips by plane, bus or seated car [3];
• infectious diseases, including COVID-19 [1, 3, 5, 9];
• catheterization of central and peripheral veins [2, 5];
• smoking [6, 7];
• sedentary lifestyle [3];
• operations [3];
• fractures of large bones, other injuries [3];
• taking oral contraceptives [5];
• taking Diazepam, Amiodarone, Vancomycin [2];
• sclerotherapy and thermal ablation [2];
• condition after joint replacement [3];
• holding an uncomfortable posture [3].

Thrombosis Clinic

Symptoms of thrombosis may be general, regardless of location, or specific. Common symptoms include pain on movement and at rest, limited mobility, and reduced function of the affected organ or tissue.

Symptoms of impaired arterial patency (acute thrombosis, or gradual impairment of vessel patency):

• BP asymmetry when measured on both arms [7];
• pale skin turning into cyanosis [7];
• pain at rest at night [7];
• pain on movement in the thigh, buttock, leg, foot, shooting or aching [7];
• sleep disorders [7];
• numbness, cold extremity [7];
• absence of peripheral pulsation [7];
• necrosis (necrosis) of affected tissues, trophic ulcers, gangrene [7];
• intermittent claudication [7].

Symptoms of venous thrombosis:

• pain [6];
• edema, soft and asymmetric [6];
• blue skin (skin cyanosis) [6];
• fever of the skin of the extremities [6];
• increased sensitivity and thickening in the projection of the superficial veins [2];
• post-inflammatory hyperpigmentation [2];
• dilated saphenous veins [6];
• erythema [2].

Sometimes the only symptom of venous thrombosis is PE [6].

Thrombosis diagnostics

Primary diagnosis is based on a detailed history and anthropometry (calf or thigh circumference). Wells scales are used for the diagnosis of acute thrombosis and the diagnosis of PE [8,9].

Imaging includes vein compression or duplex scanning, venous compression Doppler, impedance plethysmography, pulmonoangiography, radiopaque or MRI phlebography [6,9], CT and MRI angiography [7,9].

For the diagnosis of arterial thrombosis, physical tests (6-minute walk test, treadmill test), determination of pulsation of superficial arteries (dorsal arteries), duplex scanning of arteries of the extremities, angiography (X-ray of a vessel filled with a radiopaque substance) and measurement of transcutaneous tension are used oxygen [7].

Thrombosis tests

A significant role in the timely diagnosis of thrombosis is played by laboratory parameters. Thus, guidelines for the management of patients with a new coronavirus infection provide for the stratification of the risk of coagulopathy in patients with COVID-19based on simple laboratory tests: D-dimer, prothrombin time, platelet count, fibrinogen level [1,9].

CBC detects inflammation. It also determines the level of platelets, that is, the very substrate of thrombosis.

An increased level of C-reactive protein also indicates the level of inflammation in the blood and the risk of thrombosis.

Biochemical analysis primarily shows the level of blood glucose. It can be used to judge the presence of diabetes, one of the most serious risk factors for thrombosis.

Also, biochemical analysis is able to determine the level of protein C, which also characterizes the severity of the risk of thrombosis.

Elevated blood homocysteine ​​is also a proven risk of thrombosis leading to miscarriage and cardiovascular events (heart attacks and strokes).

D-dimer is a laboratory marker of fibrin formation [8]. It also indicates the presence of inflammation, like C-reactive protein. D-dimer levels are a benchmark for COVID-19and its complications, including those associated with thrombosis.

It is possible to take tests according to the complex program “Thrombosis”, which includes the determination of the levels of Antithrombin-III, D-dimer and genetic factors of cardiac diseases and the level of platelets. This program allows you to determine the fact of an accomplished thrombosis somewhere in the body, as well as determine the genetic predisposition to it. Such a program, as well as other analyzes, is offered by the CITILAB network of clinics.

Additional determination of the level of homocysteine, C-reactive protein will help determine the biochemical risk of thrombosis.

Treatment and prevention of thrombosis

Treatment of thrombosis includes anticoagulant and antiplatelet therapy, thrombolytic therapy, installation of an inferior vena cava cava filter, and surgical removal of a thrombus [5]. It is necessary to keep in mind the complications of anticoagulant therapy: major bleeding, heparin-induced thrombocytopenia and warfarin-induced skin necrosis [5]. NSAIDs are used to reduce the risk of continued thrombus formation [2]. For the purpose of secondary prevention, small doses of heparin are prescribed.

Non-drug methods of treatment are also prescribed – elastic bandaging, compression stockings, local hypothermia and exercise therapy [2, 4].

Thrombosis prophylaxis includes a number of interventions used in situations of increased risk of thrombosis.

Primary prevention of atherothrombosis:

• systematic physical activity in the form of walking or morning exercises;
• BP control, maintenance of working blood pressure below 140/90 mmHg;
• blood sugar control (less than 6 mmol/l), early detection and treatment of diabetes mellitus;
• weight loss, body mass index less than 25 kg per m2;
• restricted cholesterol and high-density fat diet (total cholesterol less than 5 mmol/l), fruits and vegetables;
• smoking cessation [3,7].

Primary prevention of venous thrombosis:

• compression underwear;
• bandaging with elastic bandages;
• drink plenty of fluids, especially after surgery;
• regular exercise, walking, especially when traveling;
• prohibition of alcohol and sleeping pills in large doses;
• prohibition of the use of squeezing shoes and clothing [2,5,6].

Sometimes, for periods of high risk, anticoagulants are prescribed a few days before the flight. Aspirin to take in such cases does not make sense [5].

References

1. Agreed position of experts of the Eurasian Association of Therapists on some new mechanisms of COVID-19 pathogenesis: focus on hemostasis, blood transfusion issues and the blood gas transport system / G.P. Arutyunov, N.A. Koziolova, E.I. Tarlovskaya, A.G. Arutyunov, N.Yu Grigorieva and others// Cardiology. 2020;60(6). DOI: 10.18087/cardio.2020.5.n1132.
2. Thrombophlebitis (thrombosis of superficial veins): modern standards for diagnosis and treatment / V.Yu. Bogachev, B.V. Boldin, O.V. Jenina, V.N. Lobanov // Hospital-replacing technologies: Ambulatory surgery. 2016.- 3-4 (63-64) – P.16-23.
3. Modern problems of thrombosis of arteries and veins / I.N. Bokarev, L.V. Popova / / Practical Medicine, 2014. – No. 6 (82) -C13-17.
4. Treatment of thrombophlebitis. Current recommendations and clinical practice / P. F. Kravtsov, K.V. Mazaishvili, S.M. Markin, H.M. Kurginyan // Thrombosis, hemostasis and rheology, 2020 No. 2 – C 68-72.
5. Venous thrombosis: modern treatment / P.S. Laguta // Atherothrombosis, 2015 – No. 2- P. 7-16.
6. Deep vein thrombosis of the lower extremities / A.K. Lebedev, O.Yu. Kuznetsova // Russian family doctor, 2015.
7. National guidelines for the diagnosis and treatment of diseases of the arteries of the lower extremities, Association of Cardiovascular Surgeons of Russia, Russian Society of Angiologists and Vascular Surgeons, Russian Society of Surgeons, Russian Society of Cardiology, Russian Association of Endocrinologists, M, 2019.
8. Diagnosis and pharmacotherapy of acute venous thrombosis / N.V. Sturov, G.N. –S.19-22.
9. Management of venous thromboembolism during the COVID-19 pandemic// V.Ya. Khryshchanovich // News of Surgery, 2020.- vol.

Does MRI show blood clots – is it visible on MRI of the brain, in the leg

In the study of the human body, the method of magnetic resonance imaging (MRI) is often used. It allows you to quickly check if there are signs of any diseases and changes that require prompt treatment.

The method also allows visualization of the human circulatory system. At the same time, at an early stage, it is possible to understand whether there are signs of pathologies that can potentially threaten not only health, but also human life.

The use of MRI helps to visualize various characteristics of blood vessels, which include:

• The condition of the walls.
• Tonus.
• Clearance.

The technology is one of the most successful when it comes to understanding whether blood clots form in the circulatory system. At the same time, to improve the level of visualization quality, doctors recommend using contrast enhancement.

It helps to significantly improve the quality of the resulting image, helps to understand whether any treatment is needed.

When to do an MRI to look for a blood clot

A blood clot is a blood clot that can occur in the human body for a variety of reasons. If present, there is a great danger of obstruction of blood circulation, violation of the integrity of the veins and blood vessels.

This can lead not only to the formation of many types of diseases, but also to death if the person does not receive the necessary treatment.

Usually, if blood clots are suspected, an MRI is prescribed by a phlebologist after a comprehensive examination. The list of alternative methods includes ultrasound and CT, but for many patients such tools turn out to be much less informative and do not allow an accurate diagnosis.

There are several signs that you may have blood clots and need an MRI:

• Swelling. Usually manifests itself in the legs or arms. Primary localization is observed in the place where the blockage of the vessel occurs. Then the swelling begins to rapidly spread to the rest of the limbs.
• Convulsions. Most often they appear in the legs and they say that blood circulation has been disturbed for some reason.
• Severe sudden pains. This symptom is accompanied by deep vein thrombosis. Pain is strong, pulsating in nature, can increase or subside in waves.
• Skin discoloration. As circulation becomes significantly worse, the skin near the affected areas may noticeably change color, become pale, bluish, or become very red.
• Change in skin temperature. The area next to the affected area becomes much hotter, in some cases, severe itching is formed.
• Problems with the gastrointestinal tract. This is not the most common symptom that indicates damage to mesenteric vessels by thrombosis. As a result, blood circulation in the intestine becomes much worse. Many patients begin to complain of severe bouts of nausea, vomiting, and indigestion.
• Abdominal pain. It also becomes a consequence of poor patency of the mesenteric vessels. Pain is often accompanied by bloating, increased gas, and diarrhea. Usually aggravated after eating.

Also, a patient can be sent for MRI according to the results of tests if they find indicators of a strong thickening of the blood, a decrease in the level of saturation.

The main causes of blood clots in the body

The practice of our center shows that different categories of patients apply for MRI of blood vessels to search for blood clots. It should be understood that the process of blood clotting is normal for the body.

Thus, restoration of the normal state of the vessel as a result of its damage, or for quick and safe tissue regeneration, is ensured.

But there are many factors that cause thrombosis to take a pathological course. These include poor endothelial health at the cellular level, hypercirculation, and blood flow problems.

Very often, against the background of malfunctions in the human hemostasis system, the process of blood coagulation increases significantly. Against this background, the activity of fibrinolysis becomes less. A blood clot is created, which begins to get bigger and bigger – the layers overlap each other.

With the development of an embolism, there is a noticeable narrowing of the vessel, and its patency becomes worse. The use of magnetic resonance imaging allows not only to identify the very fact of the presence of a problem, but also to draw conclusions about what led to its occurrence.

Thus, the treatment process becomes much more effective.

Why is thrombosis formed? There are many reasons that stimulate the appearance of such a disease. These include the following:

• Vascular injury. Thrombi are often formed if, for some external reason, the integrity of the vascular wall is compromised.
• Surgical interventions. Operations can stimulate the appearance of a blood clot as one of the side factors of the recovery process in the body.
• Taking medicines. Many potent drugs cause thrombosis. These include hormonal drugs, oral contraceptives, antihypertensive drugs of various types.
• Large body mass. Obesity almost always causes poor blood circulation.
• Disturbed metabolism. Becomes a consequence of past or chronic diseases.
• Sedentary lifestyle.