Biomedical subjects

M C Rorke

Publications and source records attributed to M C Rorke.

3 recordsLinked to original sources

PubMed1993

Three-dimensional imaging for diagnostic ultrasound in dermatology.

BACKGROUND: Visual examination and cutaneous biopsies, two major tools in dermatologic diagnosis, do not provide structural information regarding the entire tissue volume. OBJECTIVE: Our purpose was to develop a high-resolution ultrasound system that quickly, with minimal operator interaction, displays structural data on the entire tissue volume. METHODS: A prototype ultrasound B-scan system was developed and operated at nominal center frequencies between 35 and 50 MHz, with computer processing of data to produce three-dimensional images. These images displayed as three-dimensional "blocks" can be sectioned to provide multiple images of internal structure (i.e., "acoustic biopsies"). RESULTS: B-scans and associated three-dimensional images were obtained from assorted skin sites in selected patients. CONCLUSION: This technique provides a valuable diagnostic tool that is now being further evaluated.

Adult↗

PubMed1988

Comparison of theoretical scattering results and ultrasonic data from clinical liver examinations.

A theoretical analysis of soft-tissue ultrasonic scattering has been used to formulate specific results describing spectral parameters for tissue characterization. Results are applicable to clinical liver examinations. Three spectral parameters are mathematically expressed in terms of acoustic attenuation and the effective sizes, concentrations, and relative acoustic impedances of tissue scatters. Results from a clinical data base are shown to agree well with analytical results for each spectral parameter. Agreement is found for: spectral shapes; effects of attenuation; and correlations between parameters. Images of three spectral parameters are presented and their gray-scale features are evaluated with reference to analytical results.

Humans↗

PubMed1985

Focal and diffuse liver disease studied by quantitative microstructural sonography.

Quantitative microstructural sonography differs from conventional sonography in several ways. The frequency as well as the amplitude of echoes is recorded and assessed using spectral analysis techniques. The effects of diffraction of the ultrasound beam are calibrated, as are the transfer characteristics of the system. Studies of patients with alcoholic liver disease revealed significantly increased attenuation, heterogeneity of scatterers, and local scattering strength in those with severe disease; in contrast, patients with mild cirrhosis exhibited decreased local scattering strength compared to normal individuals. Using retrospective three-parameter discriminant analysis, 23 out of 24 patients were successfully categorized, suggesting that the parameters used were capable of measuring microstructural changes associated with these disease states. Parameters varied widely among 6 types of hepatic tumors, suggesting that this method may offer promise in distinguishing tumors from normal cases and alcoholic liver disease as well as from each other. Further applications and evaluation of this method appear justified.

Adenoma, Bile Duct↗