Stereotactic localization mammography: interpreting the check film

Stereotactic mammography is used to ensure accurate needle placement when localizing nonpalpable breast lesions. Once the localization needle is inserted into the breast, it is recommended that its position should be checked with a further stereo-image film. The interpretation of these check films can prove difficult. This paper describes how to detect and correct needle placement errors on check stereo-image films obtained during stereotactic localization procedures. The data presented relate directly to the CGR Stereotix and do not apply to the Siemens stereotactic equipment. The results are presented in a series of diagrams demonstrating the various types of errors in needle placement. Errors in needle depth produce particularly subtle signs.