Preliminary feasibility study of FTIR microscopic mapping system for the rapid detection of the composited components of prostatic calculi

Awareness of the chemical composition of prostatic calculi is of great importance for pathogenesis of prostatic lithiasis, the feasibility of FTIR microspectroscopic mapping system used for rapidly screening and detecting the real composited components of prostatic calculi in a short time was initially evaluated. Prostatic calculi were retrieved during transurethral resection of the prostate from nine patients diagnosed having benign prostatic hyperplasia with lower urinary tract symptoms. The level of serum prostatic-specific antigen was within 0-12.63 ng/ml. The calculi samples were examined and compared using FTIR microspectroscopic mapping system, or the traditional FTIR and Raman microspectroscopies. The traditional FTIR microspectroscopic results indicate that nine calculi samples mainly consisted of carbonated HA (hydroxyapatite), but calcium oxalate (undifferentiated) might be also detected in some samples. However, Raman spectral results could detect three components, HA, COM (calcium oxalate monohydrate) or COD (calcium oxalate dihydrate) separated in nine samples. Different compositions in the prostatic calculi were obtained by both spectroscopic detections with manual single-point random analysis implying that both manually traditional methods were failed to provide the real chemical composition of the prostatic calculi in a short time. The FTIR microscopic mapping system via point-by-point mapping analysis evidenced that it could rapidly detect all the complicated components distributed within the prostatic calculi rather than uncertain components detected by traditional FTIR or Raman microspectroscopy. More studies should be carried out in future. This preliminary result suggests that the FTIR mapping better characterizes the stone composition over single-point FTIR and Raman microscopic analysis in prostatic calculi.