Imaging Vessel<unk>  is typically detected by angiography, but can also be detected by duplex ultrasound and other imaging techniques. As "late loss" Conceptual schematic illustrating effectiveness of endovascular interventions on lumen diameter to improve blood flow as represented by acute gain, late loss<unk> , and net gain. Late loss is synonymous with<unk> , and literally means loss of the lumen after a procedure intended to open the vessel. It measures either the percent (relative) or absolute change in minimum luminal diameter (MLD) over the months following a vascular procedure, such as the implantation of a stent-graft. Late loss is one metric that is useful in determining the effectiveness of vascular interventions in clinical trials for either an individual patient or a group of patients. But late loss is only part of the terminology in describing the outcomes of vascular interventions. For instance, the implantation of a stent-graft will first provide an acute gain in lumen diameter. In other words, there is an immediate gain in lumen size because the implanted stent opens up the vessel. However, over time, the body's inflammatory immune response (described below in the "Causes" section) reacts to the stent-graft via smooth muscle proliferation, etc., which literally pushes the stent-graft back, narrowing the vessel and losing at least a percentage of what was previously gained, or late loss. The net gain of lumen diameter is the difference between acute gain and late loss, and is a measure of stent-graft effectiveness. Percent diameter<unk>  Percent diameter<unk>  (or just percent diameter stenosis) is a measure observed in individual patients and is typically calculated as the difference between the minimal (or minimum) luminal diameter (MLD) from the target reference vessel diameter (RVD), divided by the RVD, and multiplied by 100 to get the percentage of stenosis. It is an important measure needed to calculate binary<unk>  (see Binary<unk>  section below). The RVD is typically calculated by averaging the MLD of the healthy part of the vessel both proximal and distal to the vessel lesion. There is some controversy of the accuracy of observing the lesion MLD itself, since many atherosclerotic lesions may create uneven "hills and valleys" within the lumen, making a true MLD difficult to obtain or estimate. Some research indicates calculating "area stenosis" is also a valid measure of actual vessel stenosis compared to diameter stenosis alone, but this requires additional analysis because a tracing of the lumen border must be performed. However, there are computer programs available to automatically perform this function. It may be helpful to obtain both percent diameter and area percent stenosis, especially since the two percentages may not always correlate with each other. An occlusion, or the blocking of all blood flow through a vessel, is considered 100% percent diameter stenosis. Binary<unk>  Binary<unk>  is traditionally defined as a reduction in the percent diameter stenosis of 50% or more (≥50%). It is also known as just "binary stenosis". The term "binary" means that patients are placed in 2 groups, those who have ≥50% stenosis and those who have <50% stenosis. Binary<unk>  is an epidemiological method of analyzing percent diameter stenosis for observing not only an individual patient, but also performing statistical techniques on group of patients to determine averages (descriptive measures of central tendency) or as a predictive variable.
Restenosis
Side strain
Splenosis
Dysplasia
Cavitation 
Subluxation
Anaplasia
Friction