title: Tissue harmonic imaging, frequency compound imaging, and conventional imaging: use and benefit in breast sonography.
abstract: OBJECTIVE
  The purpose of this study was to evaluate different sonographic settings (tissue harmonic, frequency compounding, and conventional imaging) and to determine which setting optimizes breast lesion detection and lesion characterization.
  
  
  METHODS
  Four hundred thirteen consecutive breast lesions (249 benign and 164 malignant) were evaluated by sonography using 4 different modes (conventional imaging at 14 MHz, tissue harmonic imaging at 14 MHz [THI], and frequency compound imaging at 10 MHz [CI10] and 14 MHz [CI14]). The images were reviewed by consensus by 2 breast radiologists. For each image, the lesion was graded for conspicuity, mass margin assessment, echo texture assessment, overall image quality, and posterior acoustic features.
  
  
  RESULTS
  For lesion conspicuity, THI and CI14 were better than conventional imaging (P < .01) and CI10 (P < .01) particularly against a fatty background (P < .01 for THI versus conventional for a fatty background versus P = .13 for a dense background). Frequency compound imaging at 10 MHz performed the best in echo texture assessment (P < .01), as well as overall image quality (P < .01). For margin assessment, CI10 performed better for deep and large (> or =1.5-cm) lesions, whereas CI14 performed better for small (<1.5-cm) and superficial lesions. Finally, THI and CI14 increased posterior shadowing (P < .01) and posterior enhancement (P < .01).
  
  
  CONCLUSIONS
  The standard breast examination incorporates 2 distinct processes, lesion detection and lesion characterization. With respect to detection, THI is useful, especially in fatty breasts. With respect to characterization, compound imaging improves lesion echo texture assessment. No single setting in isolation can provide the necessary optimized information for both of these tasks. As such, a combination approach is best.
authors.affiliation: Department of Radiology, McGill University Health Center, Montreal General Hospital, Montreal, QC, Canada. benoit.mesurolle@muhc.mcgill.ca
authors.forename: Benoît
authors.initials: B
authors.lastname: Mesurolle
authors.forename: Tarek
authors.initials: T
authors.lastname: Helou
authors.forename: Mona
authors.initials: M
authors.lastname: El-Khoury
authors.forename: Michael
authors.initials: M
authors.lastname: Edwardes
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Sutton
authors.forename: Ellen
authors.initials: E
authors.lastname: Kao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D016014:Linear Models; D008875:Middle Aged; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016217:Ultrasonography, Mammary / Q000379:methods*