Inferior vena cava (IVC) filters are percutaneously inserted intravascular devices to trap clots arising in the peripheral venous system so they do not reach the heart. The original "classic" device was the stainless steel Greenfield™ filter developed in 1973. It is still available in modified form (from Boston Scientific) but has been largely supplanted by numerous other devices. Except for the stainless steel Bird's Nest® filter (Cook Medical), nearly all other IVC filters today are made of titanium or nonferromagnetic alloys (Nitinol or Elgiloy/Phylox). All are considered MR Conditional at 1.5T and/or 3.0T.
The spontaneous migration rate of properly implanted modern IVC filters is approximately 1%. At one time some experts recommended waiting 6 weeks before subjecting a patient with a stainless steel filter to MRI, but there now seems no reason to treat these filters any differently from those made of non-ferromagnetic materials and scan them immediately after implantation. There is no experimental or clinical evidence that MR imaging at 3.0T or below increases the risk of IVC filter migration.
Advanced Discussion (show/hide)»
No supplementary material yet. Check back soon!
References
Princewill K, Awan OA, Ali MM, et al. Inferior vena cava filters: a contemporary review. Appl Radiol 2011 available at this on-line link
Watanabe AT, Teitelbaum GP, Gomes AS, Roehm Jr JOF. MR imaging of the bird’s nest filter. Radiology 1990;177:578-579.
Winokur RS, Bassik N, Madoff DC, Trost D. Radiologists’ field guide to retrievable and convertible inferior vena cava filters. AJR Am J Roentgenol 2019; 213:768-777. [DOI LINK]
Princewill K, Awan OA, Ali MM, et al. Inferior vena cava filters: a contemporary review. Appl Radiol 2011 available at this on-line link
Watanabe AT, Teitelbaum GP, Gomes AS, Roehm Jr JOF. MR imaging of the bird’s nest filter. Radiology 1990;177:578-579.
Winokur RS, Bassik N, Madoff DC, Trost D. Radiologists’ field guide to retrievable and convertible inferior vena cava filters. AJR Am J Roentgenol 2019; 213:768-777. [DOI LINK]
Related Questions
Are all stents and stent grafts safe to scan? Isn't there a waiting period after implantation?
Are all stents and stent grafts safe to scan? Isn't there a waiting period after implantation?