Urological Research

, Volume 35, Issue 4, pp 201–206

CT visible internal stone structure, but not Hounsfield unit value, of calcium oxalate monohydrate (COM) calculi predicts lithotripsy fragility in vitro

  • Chad A. Zarse
  • Tariq A. Hameed
  • Molly E. Jackson
  • Yuri A. Pishchalnikov
  • James E. Lingeman
  • James A. McAteer
  • James C. WilliamsJr
Original Paper


Calcium oxalate monohydrate (COM) stones are often resistant to breakage using shock wave (SW) lithotripsy. It would be useful to identify by computed tomography (CT) those COM stones that are susceptible to SW’s. For this study, 47 COM stones (4–10 mm in diameter) were scanned with micro CT to verify composition and also for assessment of heterogeneity (presence of pronounced lobulation, voids, or apatite inclusions) by blinded observers. Stones were then placed in water and scanned using 64-channel helical CT. As with micro CT, heterogeneity was assessed by blinded observers, using high-bone viewing windows. Then stones were broken in a lithotripter (Dornier Doli-50) over 2 mm mesh, and SW’s counted. Results showed that classification of stones using micro CT was highly repeatable among observers (κ = 0.81), and also predictive of stone fragility. Stones graded as homogeneous required 1,874 ± 821 SW/g for comminution, while stones with visible structure required half as many SW/g, 912 ± 678. Similarly, when stones were graded by appearance on helical CT, classification was repeatable (κ = 0.40), and homogeneous stones required more SW’s for comminution than did heterogeneous stones (1,702 ± 993 SW/g, compared to 907 ± 773). Stone fragility normalized to stone size did not correlate with Hounsfield units (P = 0.85). In conclusion, COM stones of homogeneous structure require almost twice as many SW’s to comminute than stones of similar mineral composition that exhibit internal structural features that are visible by CT. This suggests that stone fragility in patients could be predicted using pre-treatment CT imaging. The findings also show that Hounsfield unit values of COM stones did not correlate with stone fragility. Thus, it is stone morphology, rather than X-ray attenuation, which correlates with fragility to SW’s in this common stone type.


Kidney calculi Tomography, X-ray computed Micro CT 


  1. 1.
    Schubert G (2006) Stone analysis. Urol Res 34:146–150PubMedCrossRefGoogle Scholar
  2. 2.
    Daudon M, Donsimoni R, Hennequin C, Fellahi S, Le Moel G, Paris M, Troupel S, Lacour B (1995) Sex and age-related composition of 10617 calculi analyzed by infrared-spectroscopy. Urol Res 23:319–326PubMedCrossRefGoogle Scholar
  3. 3.
    Bon D, Dore B, Irani J, Marroncle M, Aubert J (1996) Radiographic prognostic criteria for extracorporeal shock-wave lithotripsy: a study of 485 patients. Urology 48:556–560; discussion 560–551PubMedCrossRefGoogle Scholar
  4. 4.
    Dretler SP (1988) Stone fragility-a new therapeutic distinction. J Urol 139:1124–1127PubMedGoogle Scholar
  5. 5.
    Williams JC Jr., Saw KC, Paterson RF, Hatt EK, McAteer JA, Lingeman JE (2003) Variability of renal stone fragility in shock wave lithotripsy. Urology 61:1092–1096PubMedCrossRefGoogle Scholar
  6. 6.
    Williams JC Jr., Kim SC, Zarse CA, McAteer JA, Lingeman JE (2004) Progress in the use of helical CT for imaging urinary calculi. J Endourol 18:937–941PubMedCrossRefGoogle Scholar
  7. 7.
    Evan AP, Willis LR, Lingeman JE, McAteer JA (1998) Renal trauma and the risk of long-term complications in shock wave lithotripsy. Nephron 78:1–8PubMedCrossRefGoogle Scholar
  8. 8.
    Dretler SP, Spencer BA (2001) CT and stone fragility. J Endourol 15:31–36PubMedCrossRefGoogle Scholar
  9. 9.
    Joseph P, Mandal AK, Singh SK, Mandal P, Sankhwar SN, Sharma SK (2002) Computerized tomography attenuation value of renal calculus: can it predict successful fragmentation of the calculus by extracorporeal shock wave lithotripsy? A preliminary study. J Urol 167:1968–1971PubMedCrossRefGoogle Scholar
  10. 10.
    Pareek G, Armenakas NA, Fracchia JA (2003) Hounsfield units on computerized tomography predict stone-free rates after extracorporeal shock wave lithotripsy. J Urol 169:1679–1681PubMedCrossRefGoogle Scholar
  11. 11.
    Gupta NP, Ansari MS, Kesarvani P, Kapoor A, Mukhopadhyay S (2005) Role of computed tomography with no contrast medium enhancement in predicting the outcome of extracorporeal shock wave lithotripsy for urinary calculi. BJU Int 95:1285–1288PubMedCrossRefGoogle Scholar
  12. 12.
    Magnuson WJ, Tomera KM, Lance RS (2005) Hounsfield unit density accurately predicts ESWL success. Alaska Med 47:6–9PubMedGoogle Scholar
  13. 13.
    Wang L-J, Wong Y-C, Chuang C-K, Chu S-H, Chen C-S, See L-C, Chiang Y-J (2005) Predictions of outcomes of renal stones after extracorporeal shock wave lithotripsy from stone characteristics determined by unenhanced helical computed tomography: a multivariate analysis. Eur Radiol 15:2238–2243PubMedCrossRefGoogle Scholar
  14. 14.
    Yoshida S, Hayashi T, Ikeda J, Yoshinaga A, Ohno R, Ishii N, Okada T, Osada H, Honda N, Yamada T (2006) Role of volume and attenuation value histogram of urinary stone on noncontrast helical computed tomography as predictor of fragility by extracorporeal shock wave lithotripsy. Urology 68:33–37PubMedCrossRefGoogle Scholar
  15. 15.
    Saw KC, McAteer JA, Fineberg NS, Monga AG, Chua GT, Lingeman JE, Williams JC Jr (2000) Calcium stone fragility is predicted by helical CT attenuation values. J Endourol 14:471–474PubMedCrossRefGoogle Scholar
  16. 16.
    Williams JC Jr., Zarse CA, Jackson ME, Lingeman JE, McAteer JA (2007) Using helical CT to predict stone fragility in shock wave lithotripsy (SWL). In: Evan AP, Lingeman JE, Williams JC Jr (eds) Renal stone disease: proceedings of the first international urolithiasis research symposium.. American Institute of Physics, Melville Google Scholar
  17. 17.
    Nakada SY, Hoff DG, Attai S, Heisey D, Blankenbaker D, Pozniak M (2000) Determination of stone composition by noncontrast spiral computed tomography in the clinical setting. Urology 55:816–819PubMedCrossRefGoogle Scholar
  18. 18.
    Williams JC Jr., Paterson RF, Kopecky KK, Lingeman JE, McAteer JA (2002) High resolution detection of internal structure in renal calculi by helical computerized tomography. J Urol 167:322–326PubMedCrossRefGoogle Scholar
  19. 19.
    Bellin M-F, Renard-Penna R, Conort P, Bissery A, Meric JB, Daudon M, Mallet A, Richard F, Grenier P (2004) Helical CT evaluation of the chemical composition of urinary tract calculi with a discriminant analysis of CT-attenuation values and density. Eur Radiol 14:2134–2140PubMedCrossRefGoogle Scholar
  20. 20.
    Zarse CA, McAteer JA, Sommer AJ, Kim SC, Hatt EK, Lingeman JE, Evan AP, Williams JC Jr (2004) Nondestructive analysis of urinary calculi using micro computed tomography. BMC Urology 4:15PubMedCrossRefGoogle Scholar
  21. 21.
    Saw KC, McAteer JA, Monga AG, Chua GT, Lingeman JE, Williams JC Jr (2000) Helical CT of urinary calculi: effect of stone composition, stone size, and scan collimation. AJR Am J Roentgenol 175:329–332PubMedGoogle Scholar
  22. 22.
    Fleiss JL (1971) Measuring nominal scale agreement among many raters. Psychol Bull 76:378–381CrossRefGoogle Scholar
  23. 23.
    Kundel HL, Polansky M (2003) Measurement of observer agreement. Radiology 228:303–308PubMedCrossRefGoogle Scholar
  24. 24.
    Lingeman JE, Delius M, Evan AP, Gupta M, Sarica K, Strohmaier W, McAteer JA, Williams JC Jr (2003) Committee 8: bioeffects and physical mechanisms of SW effects in SWL. In: Segura J, Conort P, Khoury S, Pak C, Preminger GM, Tolley D (eds) Stone disease 1st international consultation in stone disease. Health Publications, ParisGoogle Scholar
  25. 25.
    Krambeck AE, Gettman MT, Rohlinger AL, Lohse CM, Patterson DE, Segura JW (2006) Diabetes mellitus and hypertension associated with shock wave lithotripsy of renal and proximal ureteral stones at 19 years follow-up. J Urol 175:1742–1747PubMedCrossRefGoogle Scholar
  26. 26.
    Dretler SP, Polykoff G (1996) Calcium oxalate stone morphology: fine tuning our therapeutic distinctions. J Urol 155:828–833PubMedCrossRefGoogle Scholar
  27. 27.
    Cleveland RO, Tello JS (2004) Effect of the diameter and the sound speed of a kidney stone on the acoustic field induced by shock waves. Acoust Res Lett Online 5:37–43CrossRefGoogle Scholar
  28. 28.
    Cleveland RO, Sapozhnikov OA (2005) Modeling elastic wave propagation in kidney stones with application to shock wave lithotripsy. J Acoust Soc Am 118:2667–2676PubMedCrossRefGoogle Scholar
  29. 29.
    Sapozhnikov OA, Maxwell AD, MacConaghy B, Bailey MR (2007) A mechanistic analysis of stone fracture in lithotripsy. J Acoust Soc Am 121:1190–1202PubMedCrossRefGoogle Scholar
  30. 30.
    Zhu S, Cocks FH, Preminger GM, Zhong P (2002) The role of stress waves and cavitation in stone comminution in shock wave lithotripsy. Ultrasound Med Biol 28:661–671PubMedCrossRefGoogle Scholar
  31. 31.
    McAteer JA, Williams JC Jr., Cleveland RO, Van Cauwelaert J, Bailey MR, Lifshitz DA, Evan AP (2005) Ultracal-30 gypsum artificial stones for research on the mechanisms of stone breakage in shock wave lithotripsy. Urol Res 33:429–434PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Chad A. Zarse
    • 1
  • Tariq A. Hameed
    • 2
  • Molly E. Jackson
    • 1
  • Yuri A. Pishchalnikov
    • 1
  • James E. Lingeman
    • 3
  • James A. McAteer
    • 1
  • James C. WilliamsJr
    • 1
  1. 1.Department of Anatomy and Cell BiologyIndiana University School of MedicineIndianapolisUSA
  2. 2.Department of RadiologyIndiana University School of MedicineIndianapolisUSA
  3. 3.Methodist Hospital Institute for Kidney Stone DiseaseIndianapolisUSA

Personalised recommendations