title: In-Vivo relation between CT attenuation value and shockwave fragmentation.
abstract: OBJECTIVE
  To use CT attenuation numbers as a means of determining the susceptibility of an artificial stone to in-vivo fragmentation with extracorporeal shockwave lithotripsy (SWL).
  
  
  METHODS
  Four types of artificial kidney stones having different CT attenuation values were used. One randomly selected stone was implanted in the renal pelvis of a kidney of 12 young pigs and exposed in vivo to 2500 shockwaves (21 kV) using an electrohydraulic lithotripter. Bilateral nephrectomy was performed after SWL. Fragments were strained through a mesh with a 3.1-mm grid, and the debris left on the mesh was dried and weighed. Fragmentation coefficients (FCs) were associated with CT attenuation values using a statistical model.
  
  
  RESULTS
  The relation between FC and CT number was significant, indicating that as CT attenuation increases, FC is reduced. Larger stone fragments were obtained from stones with higher CT numbers. Initial stone weight was not a significant explanation for variations in FC.
  
  
  CONCLUSIONS
  The CT values could be helpful in selecting patients for SWL in the future. However, other parameters such as stone porosity, shape, and roughness also will have to be considered.
authors: Nuevo Hospital Civil, Universidad de Guadalajara, Guadalajara, Jalisco, C.T. 44340 México.
authors: Fernando
authors: F
authors: Hurtado
authors: Jorge
authors: J
authors: Gutiérrez
authors: Eduardo
authors: E
authors: Castaño-Tostado
authors: Julio
authors: J
authors: Bustos
authors: Enrique
authors: E
authors: Mues
authors: María
authors: M
authors: Del Sol Quintero
authors: Arturo
authors: A
authors: Méndez
authors: Achim M
authors: AM
authors: Loske
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D007669:Kidney Calculi / Q000000981:diagnostic imaging* / Q000628:therapy*; D008096:Lithotripsy; D008297:Male; D008954:Models, Biological; D015233:Models, Statistical; D009392:Nephrectomy; D013552:Swine; D014057:Tomography, X-Ray Computed