The purpose of this study is to see if the investigators can use ultrasound imaging to determine the type of clots in patients to help better manage their care.

Deep vein thrombosis (DVT) is a blood clot and is a common illness that can result in pain and death if not recognized and treated well. Death can occur when the venous clots break off and form pulmonary emboli (PE), which can block the arteries of the lungs. DVT and PE most often complicate the course of sick patients but may also affect healthy persons. DVT can also be a chronic disease. In those instances in which DVT and PE develop, in addition to the death risk, hospitalization is drawn out and healthcare costs are increased. Therefore, the purpose of this study is to see if we can use ultrasound imaging to determine the type of clots in patients to help better manage their care.

Inclusion Criteria:

• Male or female subjects who have a diagnosis of chronic DVT that is at least 2 weeks old and are free from an acute DVT on top of your chronic DVT.
• Male and female patients who have been diagnosed with an acute blood clot by the Diagnostic Vascular Lab and w/symptoms occurring within the previous 2 weeks.
• Patients under the age of 18 who give assent (permission) and whose parents give consent.
• Adult patients who give consent.

Exclusion Criteria:

• None