Ultrasound Approach for PCNL: Foundations and Tips

How to cite: Berger J. Ultrasound Approach for PCNL: Foundations and Tips. Grand Rounds in Urology. November 13, 2025. Accessed Feb 2026. https://grandroundsinurology.com/ultrasound-approach-for-pcnl-foundations-and-tips/

Summary

Jonathan Berger, MD, MPH, FACS, Scripps Memorial Hospital, La Jolla, California, provides a practical, step-by-step introduction to ultrasound-guided access for percutaneous nephrolithotomy (PCNL), focusing on fundamentals that allow ultrasound to be incorporated reliably into everyday practice.

Dr. Berger begins with clear learning objectives centered on ultrasound “knobology,” renal scanning fundamentals, calyx identification, and needle visualization. Dr. Berger introduces knobology in a practical, approachable way, underscoring that mastering a few core controls, rather than every dial, determines image quality and procedural success. Frequency, depth, and gain are identified as the three most important parameters. Lower frequencies are recommended for renal imaging to ensure adequate penetration, while depth and gain should be adjusted so the kidney occupies most of the screen.

Dr. Berger outlines a reproducible scanning approach. Probe placement is described using consistent anatomic landmarks. Subtle medial movement, rotation, and fanning are demonstrated as the keys to bringing the kidney into view. Establishing this routine scanning pattern is presented as the foundational skill for ultrasound-guided renal access.

Target calyx selection is explained. With the probe positioned posteriorly, the posterior calyx appears closest to the probe and near the top of the ultrasound screen. The use of retrograde access to instill fluid or air is discussed as a way to enhance calyceal visualization, particularly in decompressed systems.

Needle advancement under ultrasound guidance is reviewed with emphasis on keeping the needle in plane rather than chasing it with the probe. Dr. Berger explains that tissue distortion often provides better visual feedback than the needle shaft itself. Fluoroscopy is presented as a confirmatory tool when needed, particularly to verify calyceal entry.

Dr. Berger shares safety-focused tips, including recognition of adjacent structures such as the pleura, liver, and spleen, and reinforces the core message that if the kidney and calyx are visualized, safe access can be achieved.

About the 32nd Annual Perspectives in Urology: Point Counterpoint conference: Presented by Program Chair and Grand Rounds in Urology Editor-in-Chief E. David Crawford, MD, this conference brought together leading experts in urology, medical oncology, and radiation oncology to discuss and debate the latest topics in genitourinary cancers, primarily prostate cancer and bladder cancer. This interactive conference offered topical lectures, pro/con debates, interesting-case presentations, interactive panel discussions, and interactive audience and faculty networking.