Jacqueline A. Shipley

Three-dimensional ultrasound imaging of mammary ducts in lactating women: a feasibility study.

Objective. The main function of the breast is to produce milk for offspring. As such, the ductal system, which carries milk from the milk‐secreting glands (alveoli) to the nipple, is central to the natural function of the breast. The ductal system is also the region in which many malignancies originate and spread. In this study, we aimed to assess the feasibility of manual mapping of ductal systems from 3‐dimensional (3D) ultrasound data and to evaluate the structures found with respect to conventional understanding of breast anatomy and physiology. Methods. Three‐dimensional ultrasound data of the breast were acquired using a mechanical system, which captures data in a conical shape covering most of the breast without excessive compression. Manual mapping of the ductal system was performed using custom software for data from 4 lactating volunteers. Results. Observational results are presented for ultrasound data from the 4 lactating volunteers. For all volunteers, only a small number of ductal structures were engorged with milk, suggesting that the lactiferous activity of the breast may be localized. These enlarged ducts were predominantly found in the inferior lateral quadrant of each breast. The observation was also made that the enlarged, milk‐storing parts of the duct were spread throughout the ductal system and not directly below the nipple as conventional anatomy suggests. Conclusions. Ultrasound visualization of the 3D structure of milk‐laden ducts in an uncompressed breast has been shown. Using manual tracing, it was possible to track milk‐laden ducts of diameters less than 1 mm.

Evaluation of experimental methods for assessing safety for ultrasound radiation force elastography

Standard test tools have been evaluated for the assessment of safety associated with a prototype transducer intended for a novel radiation force elastographic imaging system. In particular, safety has been evaluated by direct measurement of temperature rise, using a standard thermal test object, and detection of inertial cavitation from acoustic emission. These direct measurements have been compared with values of the thermal index and mechanical index, calculated from acoustic measurements in water using standard formulae. It is concluded that measurements using a thermal test object can be an effective alternative to the calculation of thermal index for evaluating thermal hazard. Measurement of the threshold for cavitation was subject to considerable variability, and it is concluded that the mechanical index still remains the preferred standard means for assessing cavitation hazard.

Automatic mammary duct detection in 3d ultrasound

This paper presents a method for the initial detection of ductal structures within 3D ultrasound images using second-order shape measurements. The desire to detect ducts is motivated in a number of way, principally as step in the detection and assessment of ductal carcinoma in-situ. Detection is performed by measuring the variation of the local second-order shape from a prototype shape corresponding to a perfect tube. We believe this work is the first demonstration of the ability to detect sections of duct automatically in ultrasound images. The detection is performed with a view to employing vessel tracking method to delineate the full ductal structure.

P2E-4 Transient Ultrasound Radiation Force Elastography. Preliminary Comparison with Surface Palpation Elastography

The use of impulsive acoustic radiation force for transient strain imaging was investigated. A series of experiments were performed in order to evaluate the performances of the technique on gelatin phantoms containing inclusions and to determine a range of applications where radiation force elastography may be useful compared with static elastography. Inside the gelatin phantoms slip boundaries, soft and stiff inclusions were placed. A focused ultrasound transducer was used to apply localised radiation force to a small volume of tissue mimic (100 mm3) for durations of 8 ms. A conventional real-time ultrasound imaging probe was used to obtain radio frequency echo signals. The resulting strains were mapped using ultrasound correlation-based methods. The instantaneous strain immediately following cessation of the radiation force was observed at depth within inhomogeneous gels. The highly localized and transient strain that is produced at depth permits the sensing of variations in tissue elastic properties that are difficult to detect with conventional elastography, due to greater independence from boundary conditions

2260: Transient ultrasound radiation force elastography: A preliminary comparison with surface palpation elastography

The use of impulsive acoustic radiation force for transient strain imaging was investigated. A series of experiments were performed in order to evaluate the performances of the technique on gelatin phantoms containing inclusions and to determine a range of applications where radiation force elastography may be useful compared with static elastography. Inside the gelatin phantoms slip boundaries, soft and stiff inclusions were placed. A focused ultrasound transducer was used to apply localised radiation force to a small volume of tissue mimic (100 mm3) for durations of 8 ms. A conventional real-time ultrasound imaging probe was used to obtain radio frequency echo signals. The resulting strains were mapped using ultrasound correlation-based methods. The instantaneous strain immediately following cessation of the radiation force was observed at depth within inhomogeneous gels. The highly localized and transient strain that is produced at depth permits the sensing of variations in tissue elastic properties that are difficult to detect with conventional elastography, due to greater independence from boundary conditions

Transient ultrasound elastography for breast cancer diagnosis using impulsive radiation force: an in vitro study

The use of impulsive acoustic radiation force for strain imaging was investigated. A focused ultrasound transducer was used to apply localised radiation force to a small volume of tissue mimic (100 mm 3 ) for durations of 8 ms. A conventional real-time ultrasound imaging probe was used to obtain echo signals. The resulting strains were mapped using ultrasound correlation-based methods. The instantaneous strain immediately following cessation of the radiation force was observed at depth within homogeneous gels and within stiff inclusions, and was seen to vary approximately linearly with the Youngs modulus of the material. The highly localised and transient strain that is produced may permit the sensing of variations in tissue elastic properties that are difficult to detect with conventional elastography, due to greater independence from boundary conditions. For example, the characteristic, bi-directional, high strain artefacts due to stress concentration, often seen with static elastography at tissue-inclusion interfaces, do not appear using the transient radiation force strain imaging technique.