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M L Silbiger

Publications and source records attributed to M L Silbiger.

44 records · Page 3Linked to original sources
PubMedDate not supplied

Digital mammography: M-channel quadrature mirror filters (QMFs) for microcalcification extraction.

Multiresolution methods are reported for feature extraction in breast cancer screening using digital mammography. The initial application is directed at the detection of microcalcification clusters (MCCs). Quadrature mirror filter (QMF) banks, using both two and three channel are proposed for the first time for both multiresolution decomposition and reconstruction. These filters are specifically tailored for automatic extraction of MCCs. The QMF multiresolution methods are compared to two channel tree structured wavelet transforms (TSWTs) methods previously reported. The QMF filters are preceded by an advanced tree structured nonlinear filter for noise suppression, prior to feature extraction, in order to minimize the false positive (FP) detection rate in digital mammography. The relative performance of these methods were evaluated using both simulated images and fifteen representative digitized mammograms containing biopsy proven microcalcification clusters. Similar high sensitivity (true positive (TP) detection rate (100%) and high specificity (0.6 average false positive (FP) MCC's/image) were observed, substantially better than more traditional approaches using single scale filters. The three channel QMF method, however, demonstrated better detail preservation of MCC's extracted compared to the two channel method. Detail preservation is important for the characterization of MCC's or individual microcalcifications in cancer screening.

Algorithms↗
PubMedDate not supplied

MR imaging of spinal cord hemangioblastoma associated with syringomyelia.

A case of isolated spinal cord hemangioblastoma with associated extensive syringohydromyelia, which was evaluated by myelography, postmyelographic CT, magnetic resonance (MR), and angiography is presented. The specific preoperative and postoperative advantages of MR are given as well as a brief review of the literature.

Adult↗
PubMedDate not supplied

MR evaluation of flow in a ventricular shunt phantom with in vivo correlation.

The ability of magnetic resonance (MR) imaging to potentially distinguish areas of fluid in motion from areas of static fluid would seem to make it possible to differentiate functioning ventriculoperitoneal shunts from non-functioning shunts in hydrocephalic patients. To test this hypothesis, a standard adult ventricular shunt system including tubing and flow control valve was tested and imaged in vitro in a flow phantom on a 1.5 T magnet with flow rates of 0, 22, 1.00, 0.50, and 0.25 ml/min. A flow void sign was present in the flow control valve on mildly and heavily T2-weighted images at all four flow rates and absent when the flow rate was 0 ml/min. In addition, we were able to image a flow void sign in the flow control valve of a patient with a functioning ventricular shunt, as well as to demonstrate absence of the flow void sign in the flow control valve in a patient with an obstructed ventricular shunt. This data suggest that MR imaging of the flow control valve in patients with ventricular shunts could yield valuable information on shunt patency.

Adolescent↗
PubMedDate not supplied

PC-based multiparameter full-color display for tissue segmentation in MRI of adnexal masses.

OBJECTIVE: Our purpose was to apply full-color composite generation methods to multiparameter MRI to assess the ability of the technique to quantitatively segment clinically important anatomic and pathologic tissues. MATERIALS AND METHODS: With use of a personal computer with a 386 microprocessor and full-color (24 bit) graphics display capabilities, custom and commercially available image-processing softwares were applied to spatially aligned multiparameter SE MR image sets obtained from six patients undergoing diagnostic work-up for suspected adnexal or pelvic masses to generate intensity-based color composites. To quantitatively assess the ability of this technique to differentially segment anatomically and pathologically confirmed tissue types into unique color regions within the full-color spectrum, color image analysis was performed on the multiparameter color composites within each patient case, and the results were compared using 95% confidence intervals. RESULTS: Based on the results of pathologic correlation and color image analysis, the generation of full-color composites represents a feasible technique for compressing the diverse tissue contrast data present in multiparameter MR images of adnexal masses. CONCLUSION: With this technique, it is possible to generate composites that simultaneously display uniquely color-coded anatomic and pathologic tissue information within the context of partially natural-appearing images.

Adnexal Diseases↗
PubMedDate not supplied

Anterior approach for CT-guided biopsy of skull base and parapharyngeal space lesions.

At our institution we use an anterior approach to biopsy of the parapharyngeal space or skull base lesions because it provides more direct access than the traditional lateral approach through the mandibular notch. The anterior approach follows a course lateral to the alveolar ridge of the maxilla and lateral pterygoid plate, and inferior to the zygomatic process of the maxilla. Biopsy was performed on 15 patients with either a skull base or a parapharyngeal space mass, none of which could be palpated externally or through the oral cavity by the ear, nose, and throat surgeon. In 12 patients the needle biopsy correlated with the surgical pathology. Three needle biopsies were nondiagnostic.

Biopsy, Needle↗
PubMedDate not supplied

Innovations to assure the future of academic radiology.

The changing patterns of reimbursement for medical education mandate that academic medical centers explore all avenues of financial support available to them to encourage growth and modernization of facilities and programs. A major concern is acquisition of capital for such improvement. Nontraditional sources of funding--both internal and external--must be used. Limited partnerships, joint ventures, business trusts, and subsidiary corporations are but a few of the opportunities available. Blending the programmatic direction of academic radiology departments with available capital resources will allow necessary growth in the years ahead.

Academic Medical Centers↗