title: [Preoperative sonographic diagnosis of melanoma--comparison of 7.5- and 20-MHz sonography].
abstract: OBJECTIVE
  High-frequency sonography has become extremely helpful for the preoperative assessment of malignant melanoma. The purpose of this study was to compare the preoperative vertical tumour thickness as assessed by 7.5 MHz as well as 20 MHz ultrasound probes to the postoperative tumour thickness as determined histomorphometrically.
  
  
  METHODS
  249 patients with malignant melanoma were studied using a conventional 7.5 MHz ultrasound machine (since 1987) or a high-frequency 20 MHz ultrasound imaging system (since 1991).
  
  
  RESULTS
  The correspondence of the sonographically assessed tumour thickness with the thickness assessed by histomorphometry was significantly better for high-frequency sonography (r = 0.94) as compared to conventional sonography (r = 0.76). For stages pT3 and pT4, however, this difference was not significant.
  
  
  CONCLUSIONS
  Based on these data, high-frequency sonography should be given preference in the preoperative assessment of malignant melanoma over conventional 7.5 MHz ultrasound. However, for stages pT3 and pT4 both methods offer similarly reliable results.
authors.affiliation: Klinik und Poliklinik für Dermatologie und Venerologie, Otto-von-Guericke-Universität Magdeburg.
authors.forename: J
authors.initials: J
authors.lastname: Ulrich
authors.forename: S
authors.initials: S
authors.lastname: Petereit
authors.forename: H
authors.initials: H
authors.lastname: Gollnick
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D014463:Ultrasonography / Q000295:instrumentation* / Q000379:methods
vernacular_title: Präoperative sonographische Melanomdiagnostik--Vergleich von 7,5- und 20-MHz-Sonographie.