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Biomedical subjects

J T Ziewacz

Publications and source records attributed to J T Ziewacz.

4 recordsLinked to original sources

The difficult breast.

Mammography is used to screen the population for breast cancer but often is inconclusive. There are several developing techniques to further assess the breast before biopsy that may decrease the number of benign biopsies. These include ultrasound, nuclear medicine, and MR imaging. When a biopsy is deemed necessary, there are several methods used to obtain tissue that are less invasive and less costly than open biopsy. This evolving area of breast evaluation is now filled with great expectation and uncertain future.

Biopsy↗

Pressures in a simulated breast subjected to compression forces comparable to those of mammography. Work in Progress.

PURPOSE: To determine the magnitude and distribution of pressures in breast models subjected to mammographic compression forces. MATERIALS AND METHODS: A vinyl-wrapped, unleavened-bread-dough breast model was compressed. Pressures in the dough models were measured with a strain gauge connected to a water-filled sensor. RESULTS: Under broad compression, pressures were uniform (range, 2.76-22.06 kPa [0.4-3.2 psi]). Spot compression increased pressures by as much as 60%. Pressures dropped sharply outside of paddle margins. No pressure differentials were found near small, deep simulated masses. The pressure of large masses increased by 50% when subjected to full compression force. Vigorous digital palpation resulted in a pressure of more than 41.40 kPa (6 psi). CONCLUSION: General pressures were mild and uniform. Internal pressures varied inversely with the area to which force was applied. Pressure dissemination was restricted by the cohesive binder and allowed zones of greater pressure to form directly under the applied force. The surrounding matrix disseminated pressure and protected small masses; large masses, bearing the force of the paddle, were exposed to greater pressure. Digital palpation administered high pressures.

Biomechanical Phenomena↗

Unusual scintigraphic findings in a case of treated monostotic Paget's disease.

A 72-year-old woman with Paget's disease underwent therapy with EHDP for 5 years. A Tc-99m MDP bone scan demonstrated an unusual image in the right femur. The upper one third of the femur was thickened, bowed, and had diffuse and mild uptake. This corresponded to radiographic findings of mixed or chronic Paget's disease. A long area of intense and homogenous uptake was found immediately distal, and with a sharp demarcation. Alterations typical of the lytic phase of Paget's disease were seen on radiographs. The overall lesion in this patient thus demonstrated two distinct patterns, both radiographically and on bone imaging. It is conjectural whether this was related to the chronic use of a diphosphonate in therapy.

Aged↗