The Agreement Between Current Stone Analysis Techniques and SEM-EDAX in Urolithiasis

Area of Science:

• Urology
• Analytical Chemistry
• Materials Science

Background:

• Urinary stone analysis is crucial for diagnosis and treatment.
• Infrared spectroscopy (IR) and X-ray diffraction (XRD) are guideline-recommended methods.
• Clinical laboratories require efficient and accurate stone analysis techniques.

Purpose of the Study:

• To practically compare X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) for urinary stone analysis.
• To evaluate these methods against a reference standard (SEM-EDAX).
• To establish an optimal analysis method for clinical laboratories.

Main Methods:

• Analyzed 60 kidney stones using Scanning Electron Microscopy with Elemental Distribution Analysis X-ray (SEM-EDAX) as the reference.
• Compared SEM-EDAX results with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and wet chemical analysis.

Main Results:

• XRD showed the highest agreement (93%) with SEM-EDAX.
• FTIR agreement was 81% overall, with acceptable results for calcium oxalate stones (90%) but lower for uric acid (65%) and cystine (76%) stones.
• Wet chemical analysis had the lowest agreement (71%).

Conclusions:

• XRD is more reliable than FTIR for urinary stone analysis.
• FTIR is a more cost-effective option for routine clinical use.
• Current wet chemical analysis methods are inadequate and should be replaced with more accurate techniques.