E2372. Pushing the Probe to its Limits: Ultrasound-Guided Biopsy of Challenging and Deep Abdominopelvic Target
  1. Edward Lawrence; University of Wisconsin - Madison School of Medicine and Public Health
  2. Meg Lubner; University of Wisconsin - Madison School of Medicine and Public Health
  3. Perry Pickhardt; University of Wisconsin - Madison School of Medicine and Public Health
  4. Michael Hartung; University of Wisconsin - Madison School of Medicine and Public Health
Percutaneous ultrasound-guided biopsies have become standard of practice for tissue diagnosis in the abdomen and pelvis for many sites including liver, kidney, and peripheral nodal stations. Many additional targets at first glance may appear difficult or impossible to safely biopsy by ultrasound due to interposed bowel loops or vasculature, deep positioning, or lack of operator experience; however, by optimizing technique, it is often possible to safely and efficiently use ultrasound guidance for sampling deep or difficult targets that normally would be considered for CT-guided or surgical/endoscopic biopsy. The purpose of this exhibit is to discuss technical aspects of ultrasound-guided biopsies that can be optimized for challenging or deep targets using a case-based approach.

Educational Goals / Teaching Points
1. Review key planning and technical factors that affect the success of percutaneous ultrasound-guided biopsies 2. Learn ‘tip and tricks’ about how to optimize your ultrasound-guided biopsies for challenging or deep abdominopelvic targets 3. Review a case examples of successful ultrasound-guided biopsies of challenging or atypical targets commonly reserved for CT or surgical biopsy.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
1. Patient positioning can allow for both improved sonographic visibility of the biopsy target and allow for safe access to deep targets, and is often determined by an iterative and collaborative process with the assisting sonographer. 2. CT planning at the time of biopsy can play an important role in helping to determine the optimal patient and probe positioning for smaller or mobile targets. 3. The ability to apply firm pressure with the sonographic probe allows for targets that are deep on CT to be significantly closer to the skin and thus readily accessible to ultrasound-guided biopsy. 4. The use of microbubble ultrasound contrast can improve visibility of small targets both for pre-biopsy planning or for real-time administration during the biopsy itself 5. Examples of ‘deep’ targets that often can be approached using ultrasound include periaortic, iliac and mesenteric lymph nodes, retroperitoneal and mesenteric masses, and pelvic masses.

Deep and challenging abdominopelvic biopsy targets typically reserved for CT-guided or surgical biopsy can often be successfully biopsied using ultrasound guidance by optimizing patient positioning, technical factors, and taking advantage of firm probe pressure.