99m Tc-DTPA dynamic SPECT/CT renogram in adults: feasibility and diagnostic benefit

Area of Science:

• Nuclear Medicine
• Radiology
• Nephrology

Background:

• Dynamic renography is crucial for assessing renal function and split renal function.
• Conventional planar renography has limitations in accuracy and anatomical detail.

Purpose of the Study:

• To evaluate the feasibility and advantages of 99m Tc-DTPA dynamic SPECT/CT renography in adults.
• To compare its diagnostic performance against established methods.

Main Methods:

• Fifty-five adult patients underwent 99m Tc-DTPA planar renogram, planar 99m Tc-DMSA scan, and attenuation-corrected dynamic 99m Tc-DTPA SPECT/CT (DSPECT(AC)) renogram.
• Glomerular filtration rate (GFR) was calculated using Cr-51 EDTA.
• DSPECT(AC) parameters were compared with planar renogram, 99m Tc-DMSA for split renal function, and Cr-51 EDTA for GFR.

Main Results:

• DSPECT(AC) yielded good image quality with strong correlations for renogram parameters (r=0.959–0.933) compared to planar methods.
• Split renal function calculation by DSPECT(AC) showed perfect correlation (r=0.968) in cases with significant inter-kidney differences, outperforming planar renography (r=0.843).
• DSPECT(AC) early kidney uptake correlated better with reference GFR (r=0.789) than the Gates' method (r=0.642), with integrated anatomical information from CT.

Conclusions:

• 99m Tc-DTPA dynamic SPECT/CT renography is feasible using standard SPECT/CT systems.
• This technique enables accurate split renal function assessment and provides valuable anatomical context.
• It offers a more precise approximation of GFR compared to the Gates' method, enhancing diagnostic utility.