ECR 2010 / C-0418
Sensitivity and specificity of breast sonoelasticity imaging utilizing color elastography and strain ratio measurements
Keywords:
Breast, Ultrasound
Authors:
T. R. Kumm, J. R. Grajo, A. Chau, T. Tucker, M. Szabunio; Tampa, FL/US
DOI:
10.1594/ecr2010/C-0418
Methods and Materials
- Patients referred for ultrasound guided biopsy of one or more breast lesions were included in this study after informed consent was given. All subjects were evaluated on the same date of biopsy.
- Hitachi Hi Vision 900 Ultrasound was used for elastography score (ES) images and strain ratio (SR) measurements.
- Elastography system operators/readers were considered newcomers to the technique, but received technical training prior to study initiation.
- For elastography scoring, lesions were assigned a score using the five–point visual system (Fig 1) from Ueno, et. al. [3]. The ES was considered test negative if scored 0, 1 or 2; while a score of 3, 4 or 5 was considered test positive.
- A score of "0" was seen in simple cysts (Fig 2).
- Calculation of the SR value (Fig 3) represented the strain measured in the lesion as compared to adjacent adipose tissue. Lesion strain was measured by selecting a region of interest (ROI) from the the lesion, and was expressed as “ST–ave LESION”. A corresponding ROI of adjacent fat tissue was selected as “ST–ave FAT”.
- The SR value was calculated according to the equation: ST–ave Fat/ST–ave Lesion = SR. A lesion was considered SR test negative if the ratio was <4.5; while a ratio of ≥4.5 was considered SR test positive.
- Sensitivity, specificity, negative/positive predictive values, and accuracy were calculated. Core needle (14 gauge) or excisional biopsy result was used as the standard.