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Biomedical subjects

G Edelstein

Publications and source records attributed to G Edelstein.

24 records · Page 2Linked to original sources
PubMedDate not supplied

CT observation of rib abnormalities: spectrum of findings.

The CT studies in 63 patients in which rib abnormality was identified or excluded were retrospectively analyzed. The CT features were detailed and correlated with other available radiographic findings as well as clinical data. Contiguous spread of tumor to rib or metastasis to rib characteristically showed subtle or complete segmental lytic rib destruction. An accompanying extrapleural soft tissue mass was frequently seen with metastatic disease and myeloma. In nine patients CT showed rib destruction that had been obscured on chest radiography by heart, diaphragm, mass, or pleural effusion. Other imaging studies prompted consideration of neoplasm in seven patients in whom CT clearly showed benign post-traumatic or developmental lesions. Six patients had a clinically suspected chest wall mass excluded, leading to the diagnosis of Tietze syndrome. The ribs should be carefully inspected on all CT studies of the thorax and upper abdomen. Computed tomography is helpful when other imaging techniques, such as rib films or isotopic bone scans, have not resolved the question of clinically or radiographically suspected rib abnormality.

Adolescent↗
PubMedDate not supplied

Effects of hyperthermia on bone. I. Heating rate patterns induced by microwave irradiation in bone and muscle phantoms.

We describe the initial heating rate patterns generated by microwave irradiation of 915 MHz, with constant power output, in muscle-equivalent phantoms containing a freshly excised bone, and compared with those in phantoms consisting of muscle-equivalent gel only. At 1 cm depth the muscle was cooler in the centre of the field when bone was present underneath. Also, the orientation of the bone in the field had a pronounced effect on the heating rate profiles in the overlying muscle: when the long axis of the bone was parallel to E field, a hot area in the centre of the field was observed; after rotation of the applicator by 90 degrees so that the long axis of the bone was perpendicular to the E field, more homogeneous heating was obtained along most of the field. In contrast, the heating patterns obtained in the cortex of the bone at similar depth (1.3 cm) were not substantially influenced by its orientation in the field. Depending on field location, the heating rate of the cortical bone closest to the applicator was within 50-75% of the SAR in muscle at the same depth. We believe that these data may be useful for the extension of such measurements in vivo, to permit the effective application of hyperthermia, with or without radiation, in the treatment of bone lesions.

Bone Neoplasms↗
PubMedDate not supplied

Effects of hyperthermia on bone. II. Heating of bone in vivo and stimulation of bone growth.

Previous studies in vitro have shown that it is possible to achieve comparable temperature distribution in bone and the adjacent soft tissues, under appropriate experimental conditions. The objective of the present work was to determine the effects of hyperthermia on bone in vivo. In order to obtain direct temperature measurements in bone, catheters were surgically installed on top of and inside the medullary cavity of the femur of normal rabbits. The thighs were irradiated with 915 MHz microwaves for 45 min, once or twice a week. The temperatures on and inside the bone were maintained between 42.5 and 44.0 degrees C; the resulting temperatures in the muscle were within 1.0 degrees C at depths equidistant from the applicator. After four to six treatments the femora were excised for histopathological examination. New trabecular bone was deposited around the catheters; most bone components including periosteum, osteoid, and fully calcified matrix could be seen. Large numbers of osteoblasts and osteoclasts lined the trabecular surfaces, and numerous cement lines were visible, running in all directions, indicating extensive bone deposition and remodelling. In contrast, control bones (catheters installed--no hyperthermia) showed much less ossification, with many areas of thin incomplete osteoid. Further, bones treated with hyperthermia only (no surgical trauma) showed no such changes. Thus, it appears that following an initial insult, hyperthermia promotes bone deposition.

Animals↗