Diagnosis of DVT and PE
The diagnosis of deep vein thrombosis (DVT) or pulmonary embolism (PE) requires special tests that can only be performed by a doctor. That is why it is important for you to seek medical care if you experience any of the symptoms of DVT or PE. Some of the tests that may be performed are listed below.
DVT is often diagnosed using:
- Duplex ultrasound—It uses sound waves to evaluate the flow of blood in the veins.
- Venography—If the duplex ultrasound does not provide a clear diagnosis, a venogram, a type of X ray, is used to look at the veins to see if clots are present.
- D-dimer—A blood test that can be used to rule out a clot.
DVT also can be diagnosed using the following, less frequently used, tests:
- In many cases, magnetic resonance imaging (MRI) can provide information that would not show up on an x-ray. This test is being used more frequently to diagnose DVT.
- A computed tomography scan is a special type of x-ray that can provide pictures of structures inside the body. However, this test is rarely used to diagnose DVT.
Tests to find the location of and damage to the lungs caused by a PE include:
- Computerized tomography (CT scan) of the lung, a special type of x-ray that can provide pictures of structures inside the body.
- Pulmonary ventilation or perfusion scan, a special test looks at how the lung is working and if it is getting enough blood.
- Pulmonary angiogram, the injection of a dye into the heart and then an x-ray, to look for clots in the lung.
Diagnosis Can Be Difficult
Unfortunately, there are other conditions whose symptoms are similar to those of DVT and PE. For example, muscle strains and swelling of veins close to the skin can mimic the symptoms of DVT. Heart attack and pneumonia have symptoms similar to those of PE. Therefore, it is difficult to diagnose either condition without tests.
A chromosome contains a single, long piece of DNA with many different genes. Every human cell contains 23 pairs of chromosomes. There are 22 pairs of numbered chromosomes, called autosomes, and one pair of sex chromosomes, which can be XX or XY. Each pair contains two chromosomes, one from each parent, which means that children get half of their chromosomes from their mother and half from their father.
A gene is a part of DNA that carries the information needed to make a protein. People inherit one copy of each gene from their mother and one copy from their father. The genes that a person inherits from his or her parents can determine many things. For example, genes affect what a person will look like and whether the person might have certain diseases.
DNA is made up of two strands that wind around each other and looks like a twisting ladder. A DNA strand is made up of four different “bases” arranged in different orders. These bases are T (thymine), A (adenine), C (cytosine), and G (guanine). DNA is “read” by the order of the bases, that is by the order of the Ts, Cs, Gs, and As. The specific order, or sequence, of these bases determines the exact information carried in each gene (for example, instructions for making a specific protein). DNA has the same structure in every gene and in almost all living things.
A mutation is a change in a DNA sequence. DNA mutations in a gene can change what protein is made. Mutations present in the eggs and sperm (germline mutations) can be passed on from parent to child, while mutations that occur in body cells (somatic mutations) cannot be inherited.
A protein is made up of building blocks called amino acids. The main role of DNA is to act as the instructions for making proteins. It is actually proteins that make up most of the structures in our bodies and perform most of life’s functions. For example, proteins make up hair and skin. Proteins in our eyes change shape in response to light so we can see. Proteins in our bodies break down food. Proteins are made in cells and are the major parts of cells, which are the vital working units of all living things.
- Centers for Disease Control and Prevention
National Center on Birth Defects and Developmental Disabilities
Division of Blood Disorders
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