Relationship between the renal apparent diffusion coefficient and glomerular filtration rate: preliminary experience

Area of Science:

• Nephrology
• Radiology
• Biomedical Imaging

Background:

• Kidney function assessment is crucial for diagnosing and managing renal diseases.
• Glomerular filtration rate (GFR) is a key indicator of kidney function.
• Diffusion-weighted MRI (DWI) offers a non-invasive method to evaluate tissue microstructure.

Purpose of the Study:

• To determine the relationship between apparent diffusion coefficients (ADCs) measured by DWI and split glomerular filtration rate (GFR).
• To assess the diagnostic potential of DWI-derived ADCs in evaluating renal function impairment.

Main Methods:

• Diffusion-weighted MRI (DWI) was performed on 55 patients using a 1.5 T MR unit.
• Apparent diffusion coefficients (ADCs) were calculated from regions of interest in the renal parenchyma.
• Split GFR was measured using (99m)Tc-DTPA scintigraphy (Gates' method), categorizing kidneys into four functional groups.

Main Results:

• A statistically significant difference in mean renal ADCs was observed across the four GFR groups (P < 0.001).
• Mean renal ADCs decreased progressively with increasing renal impairment.
• A strong positive correlation (r = 0.709) was found between ADCs and split GFR.

Conclusions:

• Apparent diffusion coefficients (ADCs) are significantly lower in kidneys with impaired function compared to normal kidneys.
• DWI-derived ADCs show a positive correlation with split GFR, suggesting their utility in assessing renal function.
• DWI may serve as a valuable non-invasive tool for evaluating kidney function and detecting renal impairment.