MR imaging-guided breast localization system with medial or lateral access.

Purpose: To evaluate the degree of error of the authors' magnetic resonance (MR) imaging-guided needle localization system for biopsy of suspicious lesions visualized only with MR imaging, by using both prospectively recorded and retrospectively reviewed data, including MR imaging lesion coordinates as the reference standard, and to determine whether any lesion or breast characteristics affect this error.

Materials And Methods: Institutional review board approval, along with informed consent, was obtained as directed by the board. In 31 patients (age range, 34-64 years; mean age, 54.

Observation of nonlinear shear wave propagation using magnetic resonance elastography.

MR elastography (MRE) is an MRI modality that is increasingly being used to image tissue elasticity throughout the body. One MRE technique that has received a great deal of attention is based on visualizing shear waves, which reveal stiffness by virtue of their local wavelength. However, the shape of propagating shear waves can also provide valuable information about the nonlinear stress-strain behavior of tissue.

Measuring the elastic modulus of ex vivo small tissue samples.

Over the past decade, several methods have been proposed to image tissue elasticity based on imaging methods collectively called elastography. While progress in developing these systems has been rapid, the basic understanding of tissue properties to interpret elastography images is generally lacking. To address this limitation, we developed a system to measure the Young's modulus of small soft tissue specimens.

Multifrequency ultrasound transducers for conformal interstitial thermal therapy.

Control over the pattern of thermal damage generated by interstitial ultrasound heating applicators can be enhanced by changing the ultrasound frequency during heating. The ability to change transmission frequency from a single transducer through the use of high impedance front layers was investigated in this study. The transmission spectrum of multifrequency transducers was calculated using the KLM equivalent circuit model and verified with experimental measurements on prototype transducers.