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NCT Number: NCT06921733

Ultrasound Localization Microscopy in Patient With Congenital Anomalies of the Kidney and Urinary Tract (CAKUT)

This clinical study aims to non-invasively visualize perfusion and microvascularization, as well as individual glomeruli, using Ultrasound Localization Microscopy (ULM) and CEUS in patients with congenital anomalies of the kidney and urinary tract (CAKUT).

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Key information

Conditions

Congenital Anomalies of Kidney and Urinary Tract Cakut Hydronephrosis Congenital Lower Urinary Tract Obstruction, Congenital Multicystic renal dysplasia, bilateral Ureteropelvic Junction Obstruction

Age range

0 month–6 year

Sex eligibility

All sexes

Study type

Observational

Primary location

FAU Erlangen-Nuernberg,

Erlangen, Bavaria, 91054, Germany

Location status: Recruiting

Location contact

Dr. med. Alina Hilger

CONTACT

[email protected]

PD Dr. med. Dr. rer. biol. Hum. Adrian Regensburger

CONTACT

[email protected]

About this study

Congenital anomalies of the kidney and urinary tract (CAKUT) affect 0.5% of newborns and account for 20% of all congenital malformations. These conditions are associated with chronic kidney failure, a need for dialysis, and significantly increased mortality (30 times higher than healthy peers) and morbidity. Patients with CAKUT face substantial health and socioeconomic burdens due to lifelong therapy requirements. In Europe, CAKUT is the leading cause of dialysis-dependent chronic kidney failure.

All CAKUT disorders arise in utero, interfering with kidney development and leading to reduced nephron formation. Many congenital kidney anomalies are diagnosed via prenatal ultrasound. These anomalies include ureteropelvic junction obstruction, often presenting as unilateral hydronephrosis, and posterior urethral valves, which can be associated with megacystis and bilateral hydronephrosis. The resulting urinary obstruction can cause pressure damage to kidney tissue during fetal development, further reducing functional nephron mass. Postnatally, ongoing pressure damage can lead to renal remodeling. The decreased nephron mass and remodeling increase the long-term risk of kidney insufficiency, which is currently assessed only by serum creatinine levels-these are delayed and less sensitive in infants and young children. Reliable biomarkers for reduced nephron mass or renal remodeling to predict chronic kidney injury risk in CAKUT patients are currently lacking. Currently, the actual pressure impact of sonographically detectable urinary obstruction can only be assessed through urine flow patterns using MAG-3 scintigraphy. However, this method is dependent on kidney function, which can affect the uptake and excretion of the radiopharmaceutical and subsequently influence the evaluation of results.

The intravenous use of ultrasound contrast enhancers as an aid opens up the possibility of recording the tissue perfusion of the kidneys, including the smallest vessels, independent of the kidney function. This could provide significantly more information compared to conventional methods and expand our knowledge of the pathophysiology and individual status of tissue perfusion in patients.

In this clinical study, the new CEUS measurement and imaging technique will be used after the kidney scintigraphy. A contrast agent (SonoVue®) will be administered during the routine ultrasound examination and improved tissue visualization will be achieved. The aim is to gain new insights into kidney perfusion as part of the treatment and to better assess the extent of organ damage in the individual patient through more specific vascular imaging. Finally, the aim is to compare diagnostic and prognostic methods with the currently recommended measures. The CEUS is to be examined as a possible diagnostic imaging tool and possibly a supplement to existing diagnostic methods.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Minimum Age 1 Month Maximum Age 6 Years Indication for MAG3 Scintigraphy of the Kidney Congenital Anomalies of the Kidney and Urinary Tract Obstruction Diagnosis Availability of the qualified examiner Consent of the parents/legal guardians

Exclusion criteria

Lack of consent of at least one parent

Treatment and study plan

Contrast enhanced ultrasound imaging (CEUS) and post processing with ULM

Device

CEUS is a contrast based ultrasound technique and ULM (Ultrasound Localization Microscopy) is a post-processing bioinformatical method to quantify microvascular architecture and perfusion dynamics.

Primary outcomes

  1. CEUS Measurement1

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    PE (Peak-Enhancement)

  2. CEUS Time intensity curves

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    All CEUS outcomes will be generated in order to achieve time intensity curves in contrast enhanced ultrasound analysis

  3. CEUS Measurement2

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    WiAUC (Wash-in Area Under the Curve (AUC(TI: TTP)))

  4. CEUS Measurement4

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    RT (Rise Time)

  5. CEUS Measurement5

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    mTT (mean Transit Time local) (mTT-TI))

  6. CEUS Measurement6

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    TTP (Time to Peak)

  7. CEUS Measurement7

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    WiR (Wash-in-Rate )

  8. CEUS Measurement8

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    WiPI (Wash-in Perfusion Index (WiAUC/RT))

  9. CEUS Measurement9

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    WoAUC (Wash-out AUC (AUC(TTP:TO)))

  10. CEUS Measurement10

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    WiWoAUC (Wash-in- und Wash-out-AUC (WiAUC+WoAUC))

  11. CEUS Measurement11

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    FT (Fall Time - (TO-TTP))

  12. CEUS Measurement12

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    WOR (Wash-out-Rate) QOF (Quality Of Fit between the echo-power signal and f(t)

  13. CEUS Measurement13

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    QOF (Quality Of Fit between the echo-power signal and f(t)

  14. Visualization and quantification of kidney perfusion with CEUS

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    CEUS imaging for kidney perfusion in CAKUT

  15. Visualization and quantification of kidney mikrovaskularisation with ULM

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    ULM imaging for kidney perfusion and mikrovaskularisation in CAKUT

  16. Visualization and quantification of glomeruli in the kidney with ULM

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    ULM imaging for glomeruli in the kidney

Secondary outcomes

  1. ULM and Ultrasound

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with sonographic parameters (including Resistance Index (RI), flow velocity).

  2. ULM and CEUS

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with parameters of contrast-enhanced ultrasound (CEUS).

  3. ULM and Biopsy

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (including the number of segmented glomeruli) with histological parameters.

  4. ULM on affected and unaffected kidney

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Comparison of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) between the affected and unaffected kidney in the same patient.

  5. ULM and Scintigraphy

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with parameters from renal scintigraphy (e.g., perfusion parameters).

  6. Pressure changes with CEUS

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Visualization of pressure changes in the kidney using the vascular architecture visualized by CEUS and parameters of quantified microvascular perfusion dynamics.

  7. Pressure changes with ULM

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Visualization of pressure changes in the kidney using the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics.

  8. Comparison of the kidney before and after intervention with ULM

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Comparison of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) before and after intervention

  9. ULM on different diagnoses

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Comparison of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) between different diagnoses.

  10. ULM on clinical outcomes

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Correlation and comparison of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with clinical criteria and clinical outcomes (surgical success).

  11. Correlation between ULM and laboratory parameters

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with laboratory parameters (including kidney function parameters, inflammatory markers, and immunological parameters).

  12. Assessment of renal function GFR

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    GFR (ml/min/1,73 m2)

  13. Assessment of renal function urea

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    urea (mg/dl)

  14. Assessment of renal function urinary status

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    standardized urinary status

  15. Assesment of renal function kreatininekinase

    Time frame: Baseline and follow up (1-31 days after routine surgery if indicated)

    kreatininekinase (U/l)

Study contacts

Contact information is provided by the study sponsor or research team.

Dr. med. Alina Hilger

CONTACT

[email protected]

Regensburger Regensburger, PD Dr. med. Dr. rer. biol. Hum

CONTACT

[email protected]

091318541732

Sponsors and collaborators

Lead sponsor

University of Erlangen-Nürnberg Medical School

Other

Registry information

Official study title

Non-invasive Evaluation of Kidneys in Patient With Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) Using Ultrasound Localization Microscopy

Acronym: Search_CAKUT

Important dates

Study start
2025
Primary completion
2025
Study completion
2027
First posted
Apr 10, 2025
Registry last updated
Sep 17, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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