The core laboratory reviewed all screening/baseline, filter implantation, conversion eligibility assessment, conversion, and 6-month follow-up images, with the exception of the ultrasounds. (The core laboratory recommended ultrasound images be evaluated by the expert sonographers at the sites). Additionally, any images taken as a result of a suspected filter-related adverse event or technical complication, with the exception of ultrasounds, were also sent to the core laboratory for review.