On the resolution of subsurface atomic force microscopy and its implications for subsurface feature sizing.

Ultrasound atomic force microscopy (AFM) has received considerable interest due to its subsurface imaging capabilities, particularly for nanostructure imaging. The local contact stiffness variation due to the presence of a subsurface feature is the origin of the imaging contrast. Several research studies have demonstrated subsurface imaging capabilities with promising resolution.

Twente Photoacoustic Mammoscope 2: system overview and three-dimensional vascular network images in healthy breasts.

We present the Twente Photoacoustic Mammoscope 2, a photoacoustic breast imaging system employing a tomographic configuration. It images one breast pendant inside an imaging tank filled with water while a woman lies prone on a bed. A dual-head laser (755 and 1064 nm) illuminates the breast with one beam directed at the nipple and nine beams directed at the sides.

Mapping buried nanostructures using subsurface ultrasonic resonance force microscopy.

Nondestructive subsurface nanoimaging of buried nanostructures is considered to be extremely challenging and is essential for the reliable manufacturing of nanotechnology products such as three-dimensional (3D) transistors, 3D NAND memory, and future quantum electronics. In scanning probe microscopy (SPM), a microcantilever with a sharp tip can measure the properties of a surface with nanometer resolution. SPM combined with ultrasound excitation, known as ultrasound SPM, has shown the capability to image buried nanoscale features.

The state of the art in breast imaging using the Twente Photoacoustic Mammoscope: results from 31 measurements on malignancies.

Objectives: Photoacoustic mammography is potentially an ideal technique, however, the amount of patient data is limited. To further our understanding of the in vivo performance of the method and to guide further research and development, we imaged 33 breast malignancies using the research system - the Twente Photoacoustic Mammoscope (PAM).

Methods: Thirty-one patients participated in this retrospective, observational study.

Appearance of breast cysts in planar geometry photoacoustic mammography using 1064-nm excitation.

In the search for improved imaging modalities for detection and diagnosis of breast cancer, a high negative prediction value is also important. Photoacoustic (optoacoustic) imaging is a relatively new technique that has high potential for visualizing breast malignancies, but little is known about the photoacoustic appearance of benign lesions. In this work, we investigate the visibility of benign breast cysts in forward-mode photoacoustic mammography using 1064-nm light, as currently applied in the Twente photoacoustic mammoscope.

Design and evaluation of a laboratory prototype system for 3D photoacoustic full breast tomography.

Photoacoustic imaging can visualize vascularization-driven optical absorption contrast with great potential for breast cancer detection and diagnosis. State-of-the-art photoacoustic breast imaging systems are promising but are limited either by only a 2D imaging capability or by an insufficient imaging field-of-view (FOV). We present a laboratory prototype system designed for 3D photoacoustic full breast tomography, and comprehensively characterize it and evaluate its performance in imaging phantoms.

Photoacoustic needle: minimally invasive guidance to biopsy.

We introduce a needle probe based on photoacoustics (PA) to extend the scope of optical needle methods in guiding biopsies. Pulsed light is coupled to an optical fiber in a needle to be inserted in tissue, and PA signals are detected using an ultrasound imager used for needle guidance. This PA needle samples large volumes and possesses an imaging component so that sites forward and off-axis of the fiber are surveyed.

A new acoustic lens material for large area detectors in photoacoustic breast tomography.

Objectives: We introduce a new acoustic lens material for photoacoustic tomography (PAT) to improve lateral resolution while possessing excellent acoustic acoustic impedance matching with tissue to minimize lens induced image artifacts.

Background: A large surface area detector due to its high sensitivity is preferable to detect weak signals in photoacoustic mammography. The lateral resolution is then limited by the narrow acceptance angle of such detectors.

An optimized ultrasound detector for photoacoustic breast tomography.

Purpose: Photoacoustic imaging has proven to be able to detect vascularization-driven optical absorption contrast associated with tumors. In order to detect breast tumors located a few centimeter deep in tissue, a sensitive ultrasound detector is of crucial importance for photoacoustic mammography. Further, because the expected photoacoustic frequency bandwidth (a few MHz to tens of kHz) is inversely proportional to the dimensions of light absorbing structures (0.

Poly(vinyl alcohol) gels as photoacoustic breast phantoms revisited.

A popular phantom in photoacoustic imaging is poly(vinyl alcohol) (PVA) hydrogel fabricated by freezing and thawing (F-T) aqueous solutions of PVA. The material possesses acoustic and optical properties similar to those of tissue. Earlier work characterized PVA gels in small test specimens where temperature distributions during F-T are relatively homogeneous.

Passive element enriched photoacoustic computed tomography (PER PACT) for simultaneous imaging of acoustic propagation properties and light absorption.

We present a 'hybrid' imaging approach which can image both light absorption properties and acoustic transmission properties of an object in a two-dimensional slice using a computed tomography (CT) photoacoustic imager. The ultrasound transmission measurement method uses a strong optical absorber of small cross-section placed in the path of the light illuminating the sample. This absorber, which we call a passive element acts as a source of ultrasound.