Methods for measuring GFR with technetium-99m-DTPA: an analysis of several common methods.

Area of Science:

• Nuclear medicine
• Renal physiology
• Diagnostic imaging

Background:

• Glomerular filtration rate (GFR) is a key indicator of kidney function.
• Accurate GFR measurement is essential for diagnosing and managing renal diseases.
• Various scintigraphic methods exist for GFR assessment, but their reliability varies.

Purpose of the Study:

• To evaluate the accuracy of commonly used scintigraphic methods for GFR measurement in adult patients.
• To identify the most reliable scintigraphic techniques for determining GFR across a range of renal function.

Main Methods:

• Evaluation of forty-three adult patients with diverse age and renal function.
• Comparison of scintigraphic GFR measurement techniques including Russell's two-sample plasma, Jackson's urinary, Russell's one-sample plasma, Fawdry's volume of distribution, a terminal slope method, and Gates' renal uptake method.

Main Results:

• Russell's two-sample plasma and Jackson's urinary methods demonstrated the highest overall accuracy.
• Russell's one-sample plasma, Fawdry's volume of distribution, and terminal slope methods were less reliable, particularly at low GFRs (0-60 ml/min).
• Gates' renal uptake method showed poor correlation across all GFR levels.

Conclusions:

• The Russell two-sample plasma and Jackson urinary methods are recommended as primary scintigraphic techniques for GFR determination.
• These methods can be used complementarily for robust GFR assessment.
• Less reliable methods should be used with caution, especially in patients with impaired renal function.