title: Contrast enhanced ultrasonography (CEUS) in the characterization of tumor microcirculation. Validation of the procedure in the animal experimental model.
abstract: OBJECTIVE
  The aims of this study are the development of a contrast enhanced ultrasonography (CEUS) protocol for rats' evaluation and the assessment of the potential benefits of CEUS in Walker 256 tumor rats.
  
  
  METHODS
  In the study were used 36 albino Wistar rats grafted subcutaneously with Walker 256 tumor. The implementation of the ultrasound (US) guided injection technique (30 subjects - group A) was performed between 4 to 8 weeks after implantation. The contrast agent (CA) - Sono Vue (Bracco) - was administered either into the lateral vein of the tail or directly into the heart under US guidance. The US validation, focusing on CEUS (6 subjects - group B) was realized at 4 to 6 weeks after implantation. The US procedures aimed to obtain morphological (2D), vascular (color Doppler and pulsed Doppler) and angiospecific functional data (CEUS). The Vevo 2100 equipment was used for US and Time Intensity Curves (TIC) were analyzed with Sonoliver (TomTec). The tumor specimens which were resected after the last study underwent a pathology exam.
  
  
  RESULTS
  A number of 23 successfully CEUS explorations were performed in 17 subjects (11 in group A and 6 in group B). Nineteen rats could not be evaluated (in 8 cases the tumor was not viable; 4 subjects died during CA administration; in 4 cases the administration line could not be obtained). In group B, CEUS was performed in 6 subjects at 4 weeks after implantation and in 5 subjects at 6 weeks. The statistical analysis of the TIC parameters identified significant differences between the Time to Peak, mean Transit Time and Rise Time parameters of the muscles and those of the tumor.
  
  
  CONCLUSIONS
  CEUS was easily implemented on the studied tumor model and is adequate for the evaluation of tumor vascularity. US guided intracardiac administration of the CA is an easy and reproducible procedure. If the examination is performed at defined time intervals it detects the alterations within the tumor circulatory bed.
authors.affiliation: Department of Prosthetic Dentistry and Dental Materials. Division of Dental Propaedeutics, "Iuliu Hatieganu" Universiy of Medicine and Pharmacy, Cluj-Napoca, Romania.
authors.forename: Alexandru Florin
authors.initials: AF
authors.lastname: Badea
authors.forename: Attila
authors.initials: A
authors.lastname: Tamas-Szora
authors.forename: Simona
authors.initials: S
authors.lastname: Clichici
authors.forename: Mihai
authors.initials: M
authors.lastname: Socaciu
authors.forename: Alexandru Flaviu
authors.initials: AF
authors.lastname: Tăbăran
authors.forename: Grigore
authors.initials: G
authors.lastname: Băciut
authors.forename: Cornel
authors.initials: C
authors.lastname: Cătoi
authors.forename: Adriana
authors.initials: A
authors.lastname: Mureşan
authors.forename: Mircea
authors.initials: M
authors.lastname: Buruian
authors.forename: Radu
authors.initials: R
authors.lastname: Badea
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D045744:Cell Line, Tumor; D003287:Contrast Media; D008297:Male; D008833:Microcirculation; D055806:Microvessels / Q000000981:diagnostic imaging*; D009374:Neoplasms, Experimental / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging* / Q000503:physiopathology; D010743:Phospholipids; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013459:Sulfur Hexafluoride; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D010743:Phospholipids; C420843:contrast agent BR1; D013459:Sulfur Hexafluoride