title: Sound speed correction in ultrasound imaging.
abstract: A constant sound speed of 1.54 mm/micros is generally used by ultrasound imaging systems for delay and timing. However, the body's sound speed in-homogeneity can lead to defocusing and increased clutter. To provide an improvement using standard transducers, the sound speed used in delay and timing was computed using different sound speeds. We observed improvement in lateral resolution and clutter in phantom, OB, abdominal, and breast imaging. In OB and abdominal imaging using a 4 MHz curved array, 1.48 mm/micros provided higher image quality in many situations. In breast with an 8 MHz linear array, 1.44 mm/micros provided better images in some cases. To provide an automated way to determine and adjust the sound speed used by the imaging system, an algorithm was developed that determines the sound speed that produces the best overall lateral image quality by analyzing the spatial frequency content in a single B-mode frame of channel data using images reconstructed using various trial sound speeds. The metric produced correlates well with the observed best lateral image quality.
authors.affiliation: Zonare Medical Systems, 1061 Terra Bella Ave., Mountain View, CA 94043, USA. djn@zonare.com <djn@zonare.com>
authors.forename: David
authors.initials: D
authors.lastname: Napolitano
authors.forename: Ching-Hua
authors.initials: CH
authors.lastname: Chou
authors.forename: Glen
authors.initials: G
authors.lastname: McLaughlin
authors.forename: Ting-Lan
authors.initials: TL
authors.lastname: Ji
authors.forename: Larry
authors.initials: L
authors.lastname: Mo
authors.forename: Derek
authors.initials: D
authors.lastname: DeBusschere
authors.forename: Robert
authors.initials: R
authors.lastname: Steins
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003198:Computer Simulation; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*