Ultrastructural Analysis of Urinary Stones by Microfocus Computed Tomography and Comparison with Chemical Analysis

Abstract

Objective: To investigate the ultra-structure of urinary system stones using micro-focus computed tomography (MCT), which makes non-destructive analysis and to compare with wet chemical analysis. Methods: This study was carried out at the Ankara Train­ing and Research hospital. Renal stones, removed from 30 patients during percutaneous nephrolithotomy (PNL) surgery, were included in the study. The stones were blindly evaluated by the specialists with MCT and chemi­cal analysis. Results: The comparison of the stone components be­tween chemical analysis and MCT, showed that the rate of consistence was very low (p<0.001). There was no significant relationship between the components of stone and its heterogeneity or homogeneity. No significant dif­ference was found between the stones with single com­ponent and those with multiple components in terms of its 3D structure being homogenous or heterogeneous and the presence of voids (p>0.05). It was also seen that there was no significant relation between its 3D structure being heterogeneous or homogenous. Conclusion: The stone analysis with MCT is a time con­suming and costly method. This method is useful to un­derstand the mechanisms of stone formation and an im­portant guide to develop the future treatment modalities.

Keywords

• Computed tomography, micro, urinary stone analysis, urolithiasis

Üriner Sistem Taşlarının Mikrofokus Bilgisayarlı Tomografi ile Ultrastrüktürel Yapısının Analizi ve Kimyasal Analizle Karşılaştırılması

Abstract

Amaç: Mikro bilgisayarlı tomografi (MCT) yöntemiyle üriner sistem taşlarının non- destruktif olarak ultrastrüktürel yapısının incelenmesi ve kimyasal analiz ile karşılaştırılması amaçlanmıştır Yöntemler: Bu çalışma Ankara Eğitim ve Araştırma Hastanesinde etik kurul onamını takiben yapıldı. Perkutan nefrolitotomi sırasında 30 hastadan çıkarılan intakt taşlar çalışmaya dahil edildi. Taşlar MCT ve takiben kimyasal analiz yöntemleriyle analiz edildi. Bulgular: Kimyasal analiz ile elde edilen taş komponentleriyle MCT ile tespit edilen taş komponentleri arasında bire-bir uyum değerlendirildiğinde uyum oranının istatistiksel olarak çok düşük olduğu görülmüştür (p<0,001). MCT yöntemine göre taşların içerdiği her bir bileşen yönünden taşın üç boyutlu (3D) yapısının homojen veya heterojen olma sıklığında istatistiksel olarak anlamlı değişimin olmadığı görülmüştür. Tek ve çoklu içeriğe sahip olan taşlar arasında taşın üç boyutlu yapısının homojen/heterojen olma sıklığında ve içerdikleri havada boşluk olup olmaması oranlarında istatistiksel olarak anlamlı farklılık bulunmamıştır (p>0,05). Ayrıca taşın üç boyutlu yapısıyla içeriğinin homojen ya da heterojen olması arasında bağlantı saptanamamıştır. Sonuç: Mikro bilgisayarlı tomografi ile taş analizinin oldukça zaman alıcı ve çok yüksek maliyetli bir yöntem olduğu görülmektedir. Bu yöntemin taş oluşum mekanizmaları ve gelecekte yapılabilecek tedavi yöntemlerine faydası olabileceği düşünülmektedir.

Keywords

• Bilgisayarlı tomografi, mikro, üriner taş analizi, ürolitiyazis

References

1. 1. Zarse CA, McAteer JA, Sommer AJ, et al. Nondestructive analysis of urinary calculi using micro computed tomography. BMC Urol 2004;4:15
2. 2. Basiri A, Taheri M, Taheri F. What is the state of the stone analysis techniques in urolithiasis? Urol J 2012;9:445-454.
3. 3. Kasidas GP, Samuell CT, Weir TB. Renal stone analysis: why and how? Ann Clin Biochem 2004;41:91-97.
4. 4. Kim SC, Hatt EK, Lingeman JE, et al. Cystine: helical computerized tomography characterization of rough and smooth calculi in vitro. J Urol 2005;174:1468-1470.
5. 5. Huri E, Tatar I, Germiyanoglu C, et al. Evaluation of urinary stones ex vivo with micro-computed tomography: preliminary results of an investigational technique. Urol J 2011;8:185-190.
6. 6. Krambeck AE, Lingeman JE, McAteer JA, et al. Analysis of mixed stones is prone to error: a study with US laboratories using micro CT for verification of sample content. Urol Res 2010;38:469-475.
7. 7. Zarse CA, McAteer JA, Tann M, et al. Helical computed tomography accurately reports urinary stone composition using attenuation values: in vitro verification using high-resolution micro-computed tomography calibrated to fourier transform infrared microspectroscopy. Urology 2004;63:828-833.
8. 8. Hyacinth P, Rajamohanan K, Marickar FY, et al. A study of the ultrastructure of urinary calculi by scanning electron microscopy. Urol Res 1984;12:227-230.

9. 9. Silva SF, Matos DC, Silva SL, et al. Chemical and morphological analysis of kidney stones: a double-blind comparative study Acta Cir Bras. 2010;25:444-448.
10. 10. Bhatta KM, Prien EL Jr, Dretler SP. Cystine calculi--rough and smooth: a new clinical distinction. J Urol 1989;142:937- 940.
11. 11. Williams JC Jr, Hameed T, Jackson ME, et al. Fragility of brushite stones in shock wave lithotripsy: absence of correlation with computerized tomography visible structure. J Urol 2012;188:996-1001.
12. 12. Leger P, Daudon M, Magnier M. [In vitro test of piezoelectric lithotripsy with ultrasound detection using an EDAP LT 01 lithotripser]. J Urol (Paris) 1990;96:353-364.
13. 13. Williams JC Jr, Zarse CA, Jackson ME, et al. Variability of protein content in calcium oxalate monohydrate stones. J Endourol 2006;20:560-564.
14. 14. Miller NL, Williams JC Jr, Evan AP, et al. In idiopathic calcium oxalate stone-formers, unattached stones show evidence of having originated as attached stones on Randall’s plaque. BJU Int 2010;105:242-245.
15. 15. Motley G, Dalrymple N, Keesling C, et al. Hounsfield unit density in the determination of urinary stone composition. Urology 2001;58:170-173.
16. 16. Kilinç İ, Özmen CA, Akay H, et al. The comparison of ultrasonography and non enhanced helical computed tomography in the diagnosis of ureteral calculi. Dicle Med J 2007;34:82-87
17. 17. Ketelslegers E, Van Beers BE. Urinary calculi: improved detection and characterization with thin-slice multidetector CT. Eur Radiol 2006;16:161-165.
18. 18. Williams JC Jr, Paterson RF, Kopecky KK, et al. High resolution detection of internal structure of renal calculi by helical computerized tomography. J Urol 2002;167:322-326.
19. 19. Hillman BJ, Drach GW, Tracey P, Gaines JA. Computed tomographic analysis of renal calculi. AJR Am J Roentgenol 1984;142:549-552.
20. 20. Mostafavi MR, Ernst RD, Saltzman B. Accurate determination of chemical composition of urinary calculi by spiral computerized tomography. J Urol 1998;159:673-675.