title: Automated Estimation of Melanocytic Skin Tumor Thickness by Ultrasonic Radiofrequency Data.
abstract: OBJECTIVE
  High-frequency (>20-MHz) ultrasound (US) is a noninvasive preoperative tool for assessment of melanocytic skin tumor thickness. Ultrasonic melanocytic skin tumor thickness estimation is not always easy and is related to the experience of the clinician. In this article, we present an automated thickness measurement method based on time-frequency analysis of US radiofrequency signals.
  
  
  METHODS
  The study was performed on 52 thin (≤1-mm) melanocytic skin tumors (46 melanocytic nevi and 6 melanomas). Radiofrequency signals were obtained with a single-element focused transducer (fundamental frequency, 22 MHz; bandwidth, 12-28 MHz). The radiofrequency data were analyzed in the time-frequency domain to make the tumor boundaries more noticeable. The thicknesses of the tumors were evaluated by 3 different metrics: histologically measured Breslow thickness, manually measured US thickness, and automatically measured US thickness.
  
  
  RESULTS
  The results showed a higher correlation coefficient between the automatically measured US thickness and Breslow thickness (r= 0.83; P< .0001) than the manually measured US thickness (r = 0.68; P < .0001). The sensitivity of the automated tumor thickness measurement algorithm was 96.55%, and the specificity was 78.26% compared with histologic measurement. The sensitivity of the manually measured US thickness was 75.86%, and the specificity was 73.91%.
  
  
  CONCLUSIONS
  The efficient automated tumor thickness measurement method developed could be used as a tool for preoperative assessment of melanocytic skin tumor thickness.
authors.affiliation: Ultrasound Institute, Kaunas University of Technology, Kaunas, Lithuania kristina.andrekute@ktu.lt kristina.andrekute@stud.ktu.edu.
authors.forename: Kristina
authors.initials: K
authors.lastname: Andrekute
authors.affiliation: Department of Skin and Venereal Diseases, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Skaidra
authors.initials: S
authors.lastname: Valiukeviciene
authors.affiliation: Ultrasound Institute, Kaunas University of Technology, Kaunas, Lithuania.
authors.forename: Renaldas
authors.initials: R
authors.lastname: Raisutis
authors.affiliation: Department of Skin and Venereal Diseases, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Gintare
authors.initials: G
authors.lastname: Linkeviciute
authors.affiliation: Department of Pathologic Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Jurgita
authors.initials: J
authors.lastname: Makstiene
authors.affiliation: Department of Skin and Venereal Diseases, Lithuanian University of Health Sciences, Kaunas, Lithuania.
authors.forename: Renata
authors.initials: R
authors.lastname: Kliunkiene
mesh_terms: D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*
keywords: boundary detection; high-frequency ultrasound; integrated backscattering; melanoma thickness; superficial structures; time-frequency analysis