Abstract: An apparatus for marking the location of a void of body tissue created by a biopsy consists of a deployment catheter having an axial catheter lumen and distal opening. A resilient imaging marker which is self-biased into an expanded state and compactable into a compacted state is axially received in its compacted state in the catheter lumen. The plunger is axially received in the lumen of the deployment catheter and is axially advancable between a deploying position and a deployed position. The plunger has a leading end configured to drive the imaging marker out the distal opening of the deployment catheter upon axial advancement of the plunger form the deploying position to the deployed position. A method for marking a location of a void of body tissue created by a biopsy includes providing a deployment catheter having an axial lumen and a distal opening with an imaging marker in the axial lumen. The distal opening of the catheter is advanced to the void of body tissue.