The Terminology- SNOMED CTÂ®, an Evolving Clinical Reference Terminology. SNOMEDÂ® is the Systemized Nomenclature of Medicine. It is a controlled medical terminology (CMT). At its simplest, a SNOMED is a coded vocabulary of medical concepts and expressions used in healthcare.
The partial thromboplastin time (PTT) is a screening test that helps evaluate a person's ability to appropriately form blood clots. It measures the number of seconds it takes for a clot to form in a person's sample of blood after substances (reagents) are added.
1 For this reason, PTT testing may be performed as part of a clotting disorder panel to help investigate recurrent miscarriages or diagnose antiphospholipid syndrome (APS) . 2  A variation of the PTT called the LA-sensitive PTT may be used for this purpose.