C. Hansen

Bio: C. Hansen is an academic researcher from Ruhr University Bochum. The author has contributed to research in topics: Imaging phantom & Perfusion scanning. The author has an hindex of 10, co-authored 38 publications receiving 478 citations.

An ultrasound research interface for a clinical system

Abstract: Under a contract with the National Cancer Institute, we have developed a research interface to an ultrasound system. This ultrasound research interface (URI) is an optional feature providing several basic capabilities not normally available on a clinical scanner. The URI can store high-quality beamformed radio-frequency data to file for off-line processing. Also, through an integrated user interface, the user is provided additional control over the B-mode receive aperture and color flow ensemble size. A third major capability is the ability to record and playback macro files. In this paper, we describe the URI and illustrate its use on three research examples: elastography, computed tomography, and spatial compounding

Errata - An ultrasound research interface for a clinical system

Abstract: Under a contract with the National Cancer Institute, we have developed a research interface to an ultrasound system. This ultrasound research interface (URI) is an optional feature providing several basic capabilities not normally available on a clinical scanner. The URI can store high-quality beamformed radio-frequency data to file for off-line processing. Also, through an integrated user interface, the user is provided additional control over the B-mode receive aperture and color flow ensemble size. A third major capability is the ability to record and playback macro files. In this paper, we describe the URI and illustrate its use on three research examples: elastography, computed tomography, and spatial compounding

Feasibility of contrast-enhanced sonography during resection of cerebral tumours: initial results of a prospective study.

Abstract: The aim of this study was to adapt the ultrasonographical techniques developed for brain perfusion imaging to an intraoperative setting for topographic diagnosis of cerebral tumours During surgery, the patients underwent contrast-enhanced ultrasonography (phase inversion harmonic imaging, bolus kinetic, fitted model function) Endocavity curved array (65EC10, 65 MHz) was used intraoperatively The ultrasound contrast agent SonoVue (Bracco) was administered IV as a bolus injection Off-line, time-intensity curves as well as perfusion maps were calculated and parameters such as peak intensity were locally extracted to characterise perfusion Seven patients with brain tumours of different histologic types were subjected to contrast-enhanced ultrasonography during surgery Tissue differentiation with contrast agent was superior to conventional B-mode ultrasound imaging Intraoperative contrast-enhanced ultrasonography enabled visualisation of cerebral tumours in high spatial resolution

Spatial compounding with tissue harmonic images and monostatic synthetic aperture reconstruction

Abstract: A high precision mechanical add-on module was realized to implement a transmission tomography system around a commercial analog ultrasound system. The modular nature of the add-on lets it be used, however, more universally. Without enormous effort the module could be programmed to be coupled to a fully digital high end commercial ultrasound system. A Siemens Antares was used for this work, which allows the acquisition of RF data of high quality B-scans and tissue harmonic imaging (THI) over the Axius Direct Ultrasound Research Interface (URI). This possibility was exploited to explore some more intricate processing options for image compounding in addition to the conventional spatial compounding approach. Several compounding schemes were implemented. One of the two new strategies for compounding consists of calculation of a compound image from the THI data, as the latter is known to possess a better contrast and lateral resolution. While the RF data acquired from various transducer positions provides all the essential input for monostatic synthetic aperture focusing (SAFT), the other strategy was to implement SAFT imaging. The effect of inhomogeneous speed of sound was studies carefully and two different schemes were implemented to overcome the problems of image registration arising from it. The algorithms were tested on polypropylene fiber phantoms in water and ethylene glycol. While the monostatic synthetic aperture reconstruction technique was found to be best in enhancing signal to noise ratio, the speckle reduction was notably better for the THI compounding scheme than that of the conventional compounding strategy. The resulting spatial resolution of the compound images was comparable for the latter two cases and the former technique outperformed the other ones in this respect.

The EFSUMB Guidelines and Recommendations on the Clinical Practice of Contrast Enhanced Ultrasound (CEUS): Update 2011 on non-hepatic applications

Abstract: Authors F. Piscaglia1, C. Nolsøe2, C. F. Dietrich3, D. O. Cosgrove4, O. H. Gilja5, M. Bachmann Nielsen6, T. Albrecht7, L. Barozzi8, M. Bertolotto9, O. Catalano10, M. Claudon11, D. A. Clevert12, J. M. Correas13, M. D’Onofrio14, F. M. Drudi15, J. Eyding16, M. Giovannini17, M. Hocke18, A. Ignee19, E. M. Jung20, A. S. Klauser21, N. Lassau22, E. Leen23, G. Mathis24, A. Saftoiu25, G. Seidel26, P. S. Sidhu27, G. ter. Haar28, D. Timmerman29, H. P. Weskott30

The EFSUMB guidelines and recommendations for the clinical practice of contrast-enhanced ultrasound (CEUS) in Non-Hepatic Applications: Update 2017 (Long Version)

Abstract: The updated version of the EFSUMB guidelines on the application of non-hepatic contrast-enhanced ultrasound (CEUS) deals with the use of microbubble ultrasound contrast outside the liver in the many established and emerging applications.

Mass Spectrometry Imaging: A Review of Emerging Advancements and Future Insights.

Abstract: Mass spectrometry imaging (MSI) is a powerful tool that enables untargeted investigations into the spatial distribution of molecular species in a variety of samples. It has the capability to image thousands of molecules, such as metabolites, lipids, peptides, proteins, and glycans, in a single experiment without labeling. The combination of information gained from mass spectrometry (MS) and visualization of spatial distributions in thin sample sections makes this a valuable chemical analysis tool useful for biological specimen characterization. After minimal but careful sample preparation, the general setup of an MSI experiment involves defining an (x, y) grid over the surface of the sample, with the grid area chosen by the user. The mass spectrometer then ionizes the molecules on the surface of the sample and collects a mass spectrum at each pixel on the section, with the resulting spatial resolution defined by the pixel size. After collecting the spectra, computational software can be used to select an ...

Short-lag spatial coherence of backscattered echoes: imaging characteristics

Abstract: Conventional ultrasound images are formed by delay-and-sum beamforming of the backscattered echoes received by individual elements of the transducer aperture. Although the delay-and-sum beamformer is well suited for ultrasound image formation, it is corrupted by speckle noise and challenged by acoustic clutter and phase aberration. We propose an alternative method of imaging utilizing the short-lag spatial coherence (SLSC) of the backscattered echoes. Compared with matched B-mode images, SLSC images demonstrate superior SNR and contrast-to-noise ratio in simulated and experimental speckle-generating phantom targets, but are shown to be challenged by limited point target conspicuity. Matched B-mode and SLSC images of a human thyroid are presented. The challenges and opportunities of real-time implementation of SLSC imaging are discussed.