title: Fractal dimension in quantifying the degree of myocardial cellular rejection after cardiac transplantation.
abstract: BACKGROUND
  The term "Fractal" is derived from the Latin fractus meaning "irregular" or "broken" considering the observed structure with a non-integer dimension. There are many studies which employed the Fractal Dimension (FD) as a diagnostic tool. One of the most common methods for its study is the "Box Counting Method".
  
  
  OBJECTIVE
  The aim of the present study was to try to establish the contribution of FD in the quantification of myocardial cellular rejection after cardiac transplantation.
  
  
  METHODS
  Microscopic digital images were captured at 800x600 resolution (magnification 100x). FD was calculated with the aid of "ImageJ software" with adaptations. The classification of the degrees of rejection was in agreement with the "International Society for Heart and Lung Transplantation" (ISHLT 2004). The final report of the degree of rejection was confirmed and redefined after an exhaustive review of the slides by an external experienced pathologist. 658 slides were evaluated with the following distribution among the degrees of rejection (R): 335 (0R); 214 (1R); 70 (2R); 39 (3R). The data were statistically analyzed with Kruskal-Wallis tests and ROC curves being considered significant values of P < 0.05.
  
  
  RESULTS
  There was significant statistical difference between the various degrees of rejection with the exception of R3 versus R2. The same trend was observed in applying the ROC curve.
  
  
  CONCLUSIONS
  FD may contribute to the assessment of myocardial cellular rejection. Higher values are directly associated with progressively higher degrees of rejection. This may help in decision making of doubtful cases and those which contemplate the intensification of immunosuppressive medication.
authors: São José do Rio Preto Medical School, FAMERP, São José do Rio Preto, SP, Brasil. mfgodoy@netsite.com.br
authors: Roberto Douglas
authors: RD
authors: Moreira
authors: Antonio Roberto
authors: AR
authors: Moriel
authors: Luiz Otávio
authors: LO
authors: Murta Junior
authors: Leandro Alves
authors: LA
authors: Neves
authors: Moacir Fernandes de
authors: MF
authors: Godoy
mesh_terms: D001706:Biopsy; D017709:Fractals; D006084:Graft Rejection / Q000473:pathology*; D016027:Heart Transplantation / Q000473:pathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D015588:Observer Variation; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity