Contrast-enhanced dynamic MR nephrography using the TurboFLASH navigator-gating technique in children

Area of Science:

• Radiology
• Pediatric Imaging
• Medical Imaging Technology

Background:

• Assessing renal morphology, excretion, and split renal function in pediatric patients is crucial for diagnosis and management.
• Traditional methods like MAG3 scintigraphy involve radioactive tracers, posing potential risks, especially in children.
• There is a need for non-invasive imaging techniques offering comprehensive renal assessment with high diagnostic accuracy.

Purpose of the Study:

• To evaluate the feasibility of a navigator-gated TurboFLASH MRI protocol for comprehensive assessment of renal morphology, excretion, and split renal function in pediatric patients.
• To compare the diagnostic performance of the developed MRI protocol against MAG3 scintigraphy for split renal function.
• To determine the clinical utility and ease of integration of this MRI protocol into routine pediatric imaging.

Main Methods:

• Implementation of a navigator-gated T1-weighted single-slice TurboFLASH sequence for dynamic MR urography and nephrography.
• Development of a protocol for assessing urinary excretion and split renal function using gadolinium (Gd) DTPA bolus clearance.
• Evaluation of 10 pediatric patients (14 months to 14 years) with various renal indications, comparing MRI findings with MAG3 scintigraphy.

Main Results:

• The MRI protocol, including dynamic urography and split renal function assessment, required 50-60 minutes plus 10 minutes for post-processing.
• Static and dynamic MR urography provided sufficient diagnostic quality for renal morphology and excretion, showing diagnostic compliance with scintigraphy.
• MRI and scintigraphy demonstrated highly similar results for split renal function, with a correlation coefficient of R=0.968.

Conclusions:

• The developed MRI protocol is robust, easy to perform on a clinical 1.5 T MRI system, and rapid for evaluation and post-processing.
• This navigator-gated TurboFLASH MRI technique is suitable for routine clinical integration in pediatric imaging.
• Compared to scintigraphy, MRI offers superior spatial resolution and valuable complementary information for managing pediatric patients without using radioactive tracers.