A modified two-compartment model for measurement of renal function using dynamic contrast-enhanced computed...

Area of Science:

• Nephrology
• Radiology
• Medical Imaging

Background:

• Assessing single-kidney glomerular filtration rate (GFR) and perfusion is crucial for diagnosing and managing kidney diseases.
• Dynamic contrast-enhanced computed tomography (DCE-CT) offers potential for non-invasive kidney function evaluation.
• Existing models for DCE-CT analysis require validation for specific clinical applications like single-kidney measurements.

Purpose of the Study:

• To validate and adapt a modified two-compartment model for measuring human single-kidney GFR and perfusion using DCE-CT.
• To compare the performance of the adapted model against established methods for GFR and perfusion assessment.

Main Methods:

• A prospective study involving 38 patients with essential hypertension or atherosclerotic renal artery stenosis (ARAS).
• Renal DCE-CT was performed, and data analyzed using a modified two-compartment model.
• Iothalamate clearance measured reference total GFR, apportioned to single-kidney GFR by renal blood flow; conventional deconvolution calculated perfusion.
• Validation involved Pearson correlation and Bland-Altman analysis for GFR and perfusion reproducibility.

Main Results:

• The two-compartment model and iothalamate clearance identified lower GFR in stenotic kidneys of ARAS patients.
• DCE-CT derived GFR closely matched iothalamate clearance (r=0.94).
• Inter-observer variability for model-derived GFR was minimal (r=0.97), and perfusion agreement was good under specific conditions.

Conclusions:

• The adapted two-compartment model accurately reflects contrast dynamics in DCE-CT.
• This model provides a reliable tool for measuring human single-kidney GFR and perfusion.
• DCE-CT with this model holds promise for improved kidney function assessment in clinical practice.