The difficult biopsy: let's make it easier.

Image-guided percutaneous biopsies of abdominal and pelvic organs are an integral part of the daily practice of many radiologists. Fortunately, most image-guided percutaneous biopsies are straightforward. At times, however, image-guided percutaneous biopsies can be technically challenging due to various factors, including proximity of surrounding vessels or organs, "moving targets" due to respiratory motion, or difficulties in detecting lesions with certain imaging modalities. The purpose of this manuscript is to discuss techniques that can be utilized to increase the successful biopsy of "difficult" lesions. Choices of imaging modality for guiding needle placement will be discussed, as will the use of alternative access routes such as transgluteal, transvaginal, and other transorgan approaches. Factors to improve the accessibility of lesions, including patient positioning and the timing of contrast injections that improve lesion detection, will be discussed.