A Phase 2 interventional study of Definity contrast during ultrasound in Kidney; Obstruction and Renal Obstruction, sponsored by University of Michigan. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-10-02.
Sponsored by University of Michigan · Phase 2, Interventional, and Diagnostic
This research is studying Definity ultrasound contrast agent, which is already approved by the Food and Drug Administration (FDA) for the ultrasound evaluation of the liver and heart. This research will investigate the ability to use ultrasound imaging with ultrasound contrast agents to evaluate kidney obstruction.
Eligible participants that are enrolled will have two visits (one before and one after the planned surgery to relieve the kidney obstruction).
55 studies on the registry are indexed under Hydronephrosis; 9 are open to participants now.
This study's enrollment of 10 is below the median of 100 across 23 interventional studies indexed under Hydronephrosis.
Browse Hydronephrosis studies →University of Michigan is the lead sponsor of 1,506 studies on the registry; 192 are open to participants now.
Of its 169 completed or terminated interventional studies of FDA-regulated products, 133 (79%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Drug: Definity contrast during ultrasound
Participants will undergo an ultrasound contrast evaluation of both kidneys. This will include placement of an intravenous (IV) catheter in a vein and the delivery of Definity ultrasound contrast agent through the IV. Imaging will be completed for each kidney. The proposed total dose for adult patients will not exceed 20 microliters/kilograms (kg). Each individual dose not to exceed 10 microliters/kg. At initiation of patient studies, the dose will start at 10 microliters/kg for the first injection and a second 10 microliters/kg dose to evaluate the contralateral kidney. However, if ultrasound findings in patient studies demonstrate a dose that is too high (unable to make accurate ultrasound assessment), the dose will be reduced.
Also known as: Perflutren Lipid Microsphere
Time to peak (TTP) ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Peak intensity (PI) ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Mean transit time (MTT) ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Area under the curve (AUC) ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Ratio of plateau and peak intensity ultrasound Measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Contrast arrival time (AT) ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Enhanced slope ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Fall time (FT) ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Time from peak to baseline (TPB) ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Final plateau intensity ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Initial intrarenal microcirculatory transmit time ultrasound measurements
Differences in ultrasound contrast measurements between obstructed and normal kidneys
Time frame: Immediately after contrast injected (approximately 30 minutes)
Plan to share: No
No publications or documents are linked to this record.
Ran from Dec 2021 to primary completion in Sep 2025, 45 months.
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This study is completed, as verified in Oct 2025. You cannot join it, but the record below documents what was studied.
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