title: Preoperative ultrasonic assessment of thin melanocytic skin lesions using a 100-MHz ultrasound transducer: a comparative study.
abstract: BACKGROUND
  It has been shown that tumor thickness (TT) of melanocytic skin lesions (MSL) of less than 1 mm vertical thickness assessed by 20 MHz are often incorrectly evaluated.
  
  
  OBJECTIVE
  We aimed to evaluate the accuracy of 100-MHz ultrasound for the determination of TT of thin MSL, compared with conventional 20-MHz ultrasound and histologic findings.
  
  
  METHODS
  Thirty-seven patients with 50 suspicious MSL, including tumor diameter up to 1 cm and maximum vertical TT of less than 1 mm, were recruited. The agreement between the histologically and ultrasographically measured TT was analyzed using Bland and Altman plots.
  
  
  RESULTS
  Compared to histology, 20-MHz ultrasound (33.9 microm) as well as 100-MHz (16 microm) resulted in overestimation of TT that was twofold higher for 20-MHz ultrasound. The latter also revealed wider 95% limits of agreement (4.9 to 63 microm) than 100-MHz ultrasound (3.5 to 28.7 microm).
  
  
  CONCLUSIONS
  Analysis of agreement clearly demonstrated that the performance of 100-MHz ultrasound is superior to conventional 20-MHz ultrasound, even though a relatively small positive bias was observed in 100-MHz ultrasound, indicating a systematic error. We consider 100-MHz ultrasound a useful tool for the noninvasive determination of TT of thin MSL in vivo.
authors.affiliation: Department of Dermatology, Ruhr-University Bochum, Bochum, Germany. t.gambichler@klinikum-bochum.de
authors.forename: Thilo
authors.initials: T
authors.lastname: Gambichler
authors.forename: Georg
authors.initials: G
authors.lastname: Moussa
authors.forename: Katharina
authors.initials: K
authors.lastname: Bahrenberg
authors.forename: Michael
authors.initials: M
authors.lastname: Vogt
authors.forename: Helmut
authors.initials: H
authors.lastname: Ermert
authors.forename: Dirk
authors.initials: D
authors.lastname: Weyhe
authors.forename: Peter
authors.initials: P
authors.lastname: Altmeyer
authors.forename: Klaus
authors.initials: K
authors.lastname: Hoffmann
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D009506:Nevus / Q000000981:diagnostic imaging* / Q000473:pathology*; D011300:Preoperative Care / Q000295:instrumentation* / Q000379:methods; D011446:Prospective Studies; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D014159:Transducers; D014463:Ultrasonography