RENAL STONE ANALYSIS : FTIR, the METHOD OF CHOICE Dr Sunita Kapoor MBBS, DNB. Path, MNAMS DGO, MS. Biomed.Sc,,BITS Pilani PGDHM,  NIHFW Director & Lab Head, City X- Ray & Scan Clinic Director, Neogenetics laboratory CEO, City Imaging & clinical labs Technical Assessor, NABL

Nephrolithiasis Nephrolithiasis is a recurrent condition with considerable morbidity. Knowledge of kidney stone composition and is the key for establishing the etiology of stone disease. Accurate identification of all components present in calculi is necessary for understanding mechanism of urolithiasis

Analysis of calculus Identifying the crystalline form is very useful for planning therapy, Uric acid & Cystine calculi need medical therapy only. The purpose of stone analysis is qualitative differentiation of all stone components and their semiquantitative determination. A number of analytical methods may be applied to stone analysis, but only a few of them are able to quickly and easily provide extensive information on both stone structure and composition relevant for clinical diagnosis

Fourier Transform Infrared (FTIR spectroscopy) method FTIR is a popular and reliable method for in vitro quantitative analysis of calculi. It is a specific, rapid, and versatile method, which uses IR radiation Assessment of renal calculi by means of a computerized IR spectrometer has the advantage that it greatly reduces the likelihood of errors because of operator bias in the subjective interpretation of spectral data.

FTIR Advantages of FTIR: Moderate cost Quick Examination Efficient Accurate All calculi must be accurately analysed before treatment Determines exact quantitation of stone constituents Moderate cost Quick Examination Identifies organic components or non crystalline substances, eg purines, proteins or fat and drug metabolites also Semiquantitative evaluation possible applying search match functions

OTHER METHODS FOR STONE ANALYSIS Wet chemical analysis: can only identify the presence of individual ions and radicals without differentiating a specific compound in many stone types and mixtures   Thermogravimetry (TGA) Limitations of TGA are that it requires large amount of material for optimal resolution. Optic Polarising Microscopy It uses the principle of interaction of polarised light with crystals of stones and is cumbersome. Scanning Electron microscopy Technique for the study of morphology of urinary calculi. X-Ray Powder Diffraction (XRD) X-ray powder diffraction uses monochromatic X-rays for identifying the constituents of a renal stone based on the unique diffraction patterns produced by a crystalline material. Radiation intensive.

Conclusion Treatment of urinary stone can be painful, stone removal often requires surgery, and renal failure occurs in about 3% of patients. Furthermore, the recurrence rates may be as high as 10 % to 23 % per year and may reach 50% within 5 years if a proper management, stone analysis, and follow-up are not applied

Take home message !! Test the stone, and test it with the best method: “ F T I R “ THANK YOU !!!