PubMed Health⌕ Search

Biomedical subjects

M Garcia-Schürmann

Publications and source records attributed to M Garcia-Schürmann.

3 recordsLinked to original sources
PubMed2003

Ultrasonic tissue characterization for prostate diagnostics: spectral parameters vs. texture parameters.

An ultrasonic multi-feature tissue characterizing system for the detection of prostate cancer is presented. The system is based on the processing of radio frequency (RF) ultrasonic echo data. Data from 100 patients was acquired in a clinical study. Parameters are extracted from the RF echo data and classified using two adaptive network-based fuzzy inference systems (FIS) working in parallel as a nonlinear classifier. Next to spectral parameters, conventional texture parameters are calculated using demodulated and log-compressed echo data. In the first approach, the classifier is trained on both, spectral and texture parameters. In the second approach, the classifier is only trained on texture parameters. Classification results of both approaches are compared and it is demonstrated, that only the use of spectral parameters yields satisfying classification results. Results of a minimum distance classifier (MDC) are presented for comparison with the fuzzy inference system. For the final fuzzy inference systems used in this approach, the area under the ROC curve is between 84% and 86% for the combined approach and between 70% and 74% for the approach based on texture parameters only.

Aged↗
PubMed2000

[Ultrasound elastography of the prostate. A new technique for tumor detection].

AIM: Prostate tumours are often of harder consistency than the surrounding tissue. During digital rectal examination, this fact can be used not only to detect hypertrophy but also localized hardenings. The examination by digital palpation is inaccurate and, even in combination with PSA-value and a transrectal ultrasonic examination, the result is often not reliable. Ultrasound elastography enables us to measure and visualize the elastic properties of a tissue region and is a useful supplement to the examination by digital palpation. Ultrasound elastography is able to measure and visualize the elastic properties of a tissue region, therefore it is a useful supplement to commonly used diagnostic procedures. METHOD: We have developed a new system for elastographic prostate diagnosis which can be used during the transrectal ultrasonic examination. During the examination a sequence of ultrasonic images is acquired while the organ is slightly compressed by the ultrasound probe. Using numerical analysis of image pairs for the acquired sequence we calculate the tissue strain which represents the spatial elasticity distribution of a specific cross-section of the organ. This enables us to distinguish hard areas in the tissue. Image artifacts resulting from lateral motion components, i.e., orthogonal to the direction of the applied force, are compensated for by a special approach. RESULTS: We present results obtained from a typical elastography phantom and also the first in vivo images from patients who were undergoing radical prostatectomy. Our images prove that ultrasound elastography has the potential to detect malignant tissue areas, which are inconspicuous in the B-mode image. Our findings are confirmed by the corresponding histological specimens.

Elasticity↗