Blood Clot FAQs - Testing and Diagnosis

Q. How is a Deep Vein Thrombosis (DVT) diagnosed?

A. Most often, ultrasound is used to diagnose blood clots in the leg veins. This is a non-invasive test. If the results are not definitive, then venography (an invasive test using contrast dye) or MRI (magnetic resonance imaging) may be used.

Q. How is a Pulmonary Embolism (PE) diagnosed?

A. If the VQ scan does not identify a clot, but one is still suspected, a pulmonary angiogram is performed. A catheter is threaded through a vein in the groin, passed through the heart, and into the pulmonary artery. Contrast dye is then injected and X-rays are taken to monitor the blood flow in the lung. The angiogram will give a definite diagnosis as to the presence of a clot.

Occasionally, an echocardiogram will show abnormalities in heart function, particularly in the right ventricle, as it meets resistance in pumping blood into the lungs.

Q. Is the Ventilation-Perfusion VQ scan the best non-invasive method for detecting a PE?

A. It is the best current non-invasive technique for detecting a PE. Spiral CT (computed tomography) imaging is a new non-invasive technique being developed and has potential for replacing the VQ scan.

Q. Why did I get a chest X-ray?

A. To rule out pneumonia, another common cause of chest pain and breathing difficulty.

Q. Is it common for a Pulmonary Embolism (PE) to be misdiagnosed as a pulled muscle, pleurisy, anxiety, asthma, etc?

A. Yes. PE mimics many other diseases and is particularly difficult to diagnose.

Understanding Genetics of Thrombophilia / Inheritance & Testing - More Resources

Genetics of Thrombophilia/Inheritance

	PDF/Printable	Key Points
Public Health Genetics Unit- University of Cambridge December 9, 2003	Only through highlighting and printing	Factor V Leiden thrombophilia; other genetic thrombophilias; gene-environment interactions; genetic testing and screening for thrombophilia; population screening; links
www.fvleiden.org; written by Liz Varga	Yes	Explains how genes relate to thrombophilia; FVL and prothrombin; testing of family members; inheritance patterns;
Deb Smith; written by a list member Jennifer Rosenberg	Printable from screen	Understanding heterozygous/homozygous; heredity;
www.fvleiden.org #1 - By Dr. Moll #2 - By Dr. Moll	Printable from screen	Q and A about inheritance (homozygous/heterozygous); confusion over test results

Testing for Thrombophilias

	PDF/Printable	Key Points
American College of Medical Genetics October 31, 2000	Only by highlighting screen	Recommendations pertaining to genetic testing for factor V Leiden; Written for healthcare professionals
www.fvleiden.org Answered by Dr. Moll	Only off screen	Discussion of testing of family members for genetic thrombophilia abnormalities

Genetic Discrimination Resources

	PDF/Printable	Key Points
Question and Answer: Thrombophilia and health and Life Insurance (answered by NBCA Medical and Scientific Advisory Board Members)	Printable (highlight only)	Question and answer section on health and life insurance and inherited thrombophilias; Written by NBCA’s Medical and Scientific Advisory Board members, Dr. Stephan Moll and Elizabeth Varga.
Brochure "Genetic Information, Privacy and Discrimination"-Produced by the National Society of Genetic Counselors and FORCE (Facing Our Risk of Cancer Empowered)	Yes	What is genetic information? What is genetic discrimination? Are there laws to protect against genetic discrimination? Is genetic discrimination a widespread problem? Who is at risk for genetic discrimination? Where can I go if I feel I have been a victim of genetic discrimination?
Genetic Discrimination Resources - The National Society of Genetic Counselors	N/A - Links to resources	Relevant, up-to-date information about the positions of professional organizations, genetic discrimination research and current and proposed legislation. The resources address the social implications of genetic discrimination within the contexts of the workplace, health insurance and life insurance.
National Human Genome Research Institute -Privacy and Discrimination page	Printable	Information of privacy of genetic information and genetic discrimination in health insurance or employment.

Article Last Updated November 7, 2008