for people ages 18 years and up (full criteria)
study started
estimated completion
Principal Investigator
by Thomas Chi, MD
Headshot of Thomas Chi
Thomas Chi



This study will be a randomized controlled study comparing the use of two clinical management strategies in nephrostomy tube management following percutaneous nephrolithotomy (PCNL). The first strategy entails using contrast-enhanced ultrasound (CEUS) to evaluate the renal collecting system (1). This is a new imaging approach applying ultrasound machines with special software in combination with intraluminal ultrasound contrast agent (Lumason) injection, which is an FDA-approved ultrasound contrast agent (2). The second strategy is a nephrostomy tube capping trial combined with low dose non-contrast computed tomography (CT) scan, one of the most frequently utilized clinical management strategies currently used in clinical practice (3).

Official Title

Contrast-enhanced Ultrasound Versus CT Scan for Kidney Stone Patient


This is a multi-center, randomized controlled study comparing the use of CEUS to CT scan plus capping trial immediately following PCNL. A total recruitment target of 1,046 subjects is planned and participants will be randomized into one of the two study arms. 1. Contrast-enhanced ultrasound (CEUS) arm: On postoperative day 1 (unless not clinically indicated), each subject will undergo CEUS with an administration of Lumason via their pre-placed nephrostomy tube. 2. Non-contrast CT scan plus capping trial arm: On postoperative day 1 (unless not clinically indicated), subjects' pre-placed nephrostomy tube will be capped and they will undergo a low dose non-contrast abdominal CT scan. Subsequently, nephrostomy tubes will be managed based on the results from these studies by the treating surgeon. Screening data will be reviewed to determine subject eligibility. Subjects who meet all inclusion criteria and none of the exclusion criteria will be entered into the study. The following investigational regimen will be used only in the CEUS arm: Experimental Investigation: Lumason at a 2 mL single dose, repeatable once at the time of imaging as needed. Subjects will be exposed to the randomization schema for 1 day during which they will undergo one of the two diagnostic imaging pathways. After that imaging study is complete, clinical care will proceed as per norm. Clinical and imaging data will be prospectively collected from the time of initial presentation until 6 months after surgery. The total duration of the study is expected to be 5 years to reach target accrual. Therefore, the investigators anticipate that the total duration of this study will be 4 years and 6 months for patient recruitment with the final 6 months used for collecting follow up data.


Ultrasonography Nephrolithiasis Contrast-enhanced ultrasound Percutaneous nephrolithotomy Kidney Calculi CEUS Non-contrast CT scan Capping trial


You can join if…

Open to people ages 18 years and up

  • Age of 18 years or older.
  • Renal and/or ureteral stone of any size diagnosed either by ultrasound or CT scan and requiring surgical treatment with percutaneous removal (PCNL).

You CAN'T join if...

  • A second stage PCNL is planned or expected after surgery, entailing that postoperative tube management is pre-determined.
  • Subjects with serious illness likely to cause death within the next 5 years, so as to exclude significant metabolic derangements that might lead to adverse surgical outcome.
  • Subjects with a history of hypersensitivity reactions to sulfur hexafluoride lipid microsphere components or to any of the inactive ingredients in Lumason
  • Pregnancy, which is a contraindication to both CT scan and ultrasound contrast injection.

Lead Scientist at UCSF

  • Thomas Chi, MD
    Professor, Urology. Authored (or co-authored) 119 research publications. Research interests: Nephrolithiasis · Benign Prostatic Hypertrophy (BPH) · Ultrasound · Minimally Invasive Surgery · Laparoscopy.


not yet accepting patients
Start Date
Completion Date
University of California, San Francisco
Phase 2
Study Type
Last Updated