title: Ultrasonographic, thermographic and histologic evaluation of MNU-induced mammary tumors in female Sprague-Dawley rats.
abstract: BACKGROUND
  As the worldwide breast cancer burden increases, non-invasive tools, such as ultrasonography and thermography are being increasingly sought after. N-methyl-N-nitrosourea-induced rat mammary tumors are important tools to investigate the usefulness of such imaging techniques.
  
  
  OBJECTIVE
  This study aimed to integrate both ultrasonographic and thermographic approaches to the vascularization and the superficial temperature of chemically-induced rat mammary tumors.
  
  
  METHODS
  Twenty-five female Sprague-Dawley rats were divided into two groups: group I (intraperitoneally administered with N-methyl-N-nitrosourea) and group II (control group). Thirty-five weeks after the administration of the carcinogen, mammary tumors were evaluated using Power Doppler, B Flow and Contrast-enhanced ultrasound, thermography and histology analyses.
  
  
  RESULTS
  Group I animals showed an average of 2.5 mammary tumors per animal, mostly papillary and cribriform non-invasive carcinomas. B Flow detected higher counts of colour pixels than Power Doppler. Contrast-enhanced ultrasound analysis showed a centripetal enhancement order of contrast agent and clear margins. Maximum tumor temperature and thermal amplitude determined by thermography were significantly correlated with tumor volume and with color pixel density, determined by Power Doppler.
  
  
  CONCLUSIONS
  B Flow was more sensitive than Power Doppler in detecting tumor vessels, but Power Doppler correlates with thermographic data concerning superficial temperature and may reflect tumor angiogenesis.
authors.affiliation: Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro, Vila Real, Portugal.
authors.forename: A I
authors.initials: AI
authors.lastname: Faustino-Rocha
authors.forename: A
authors.initials: A
authors.lastname: Silva
authors.forename: J
authors.initials: J
authors.lastname: Gabriel
authors.forename: C I
authors.initials: CI
authors.lastname: Teixeira-Guedes
authors.forename: C
authors.initials: C
authors.lastname: Lopes
authors.forename: R
authors.initials: R
authors.lastname: Gil da Costa
authors.forename: A
authors.initials: A
authors.lastname: Gama
authors.forename: R
authors.initials: R
authors.lastname: Ferreira
authors.forename: P A
authors.initials: PA
authors.lastname: Oliveira
authors.forename: M
authors.initials: M
authors.lastname: Ginja
mesh_terms: D000818:Animals; D005260:Female; D007274:Injections, Intraperitoneal; D008325:Mammary Neoplasms, Experimental / Q000098:blood supply / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology*; D008770:Methylnitrosourea / Q000633:toxicity*; D009389:Neovascularization, Pathologic / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013817:Thermography; D014463:Ultrasonography
chemical_list: D008770:Methylnitrosourea
keywords: Mammary tumors; Rat; Vascularization