Biomedical subjects

S Black-Schaffer

Publications and source records attributed to S Black-Schaffer.

4 recordsLinked to original sources

PubMed1995

Current issues in telepathology.

Telepathology involves rendering diagnostic opinions on specimens at remote locations using computer and telecommunications technologies. Consultations are a routine practice pattern in pathology, as there is a large amount of diagnostic and prognostic information available from the examination of biopsy material that requires an extensive knowledge of diseases and their clinical implications. Pathologists therefore frequently request opinions from those who subspecialize in various diseases. The use of video technology to examine and consult on microscopical slides has been validated, although sparsely and with a number of technical issues as yet unresolved. There are two principal paradigms for telepathology: remote dynamic screening by robotic video microscopy and remote diagnosis from selected still video microscopical images. The former is more appealing to most pathologists; however, it requires very high speed telecommunications links that are expensive and may not be available in a given location. The latter method entails a significant reduction in the data on which the diagnosis is rendered, as one is dependent on the fields selected at the remote location. In addition, there are hybrid systems that combine limited robotic capabilities with high-resolution still images. Image compression can increase the number of images that can be transmitted over an otherwise-limiting telecommunications infrastructure. JPEG is the current standard for such compression. Despite certain limitations, telepathology has been demonstrated successfully at several sites around the world. As this technology matures, systems will offer higher resolution, standardization of file formats, and better compression at lower cost.

Computer Communication Networks↗

PubMed1994

Making global telemedicine practical and affordable: demonstrations from the Middle East.

OBJECTIVE: The purpose of this study was to demonstrate the first use of voice-grade telephone lines for the international transmission of both high-resolution digital images (radiology and pathology) and video in near real-time. MATERIALS AND METHODS: Eight live demonstrations were performed from the United Arab Emirates and the Kingdom of Saudi Arabia at the invitation of the respective ministries of health. Thirty radiologic studies (CT, MR, and radiographs) were digitized, compressed, and transmitted to Cambridge, MA, where they were interpreted on diagnostic workstations (1792 x 2252 display matrix) by a team of subspecialist radiologists. Near real-time image transmission was achieved by combining wavelet-based image compression (average compression ratio of 23:1) and multiplexing technology that used four phone lines simultaneously. During each demonstration, one pathology image was transmitted from Cambridge to the demonstration site, where it was interpreted by a visiting pathologist. Video-conferencing was implemented with a 64-kilobits-per-sec leased line from the United Arab Emirates and with four multiplexed telephone lines from Saudi Arabia. RESULTS: For teleradiology and telepathology, transmission times ranged from 2-5 min per image. Image fidelity was judged to be of diagnostic quality in all transmitted cases. The video link to the United Arab Emirates was highly reliable. Bandwidth for videoconferencing from Saudi Arabia was marginal on four voice-grade telephone lines, resulting in some downtime (10-20%). Live consultations provided by subspecialists in Cambridge assisted in the management of patients at both venues. The system was well received by both the referring physicians in the Middle East and the participants in the United States. CONCLUSION: Image compression and multiplexing technologies enabled high-resolution teleradiology and telepathology as well as real-time video consultations over international telephone lines. While telecommunications systems are advancing rapidly in many parts of the world, those areas most in need of telemedicine services are likely to be the last to upgrade their telecommunications infrastructures. This "proof of concept" article outlines a practical and affordable approach that makes telemedicine more accessible to underserved areas worldwide.

Humans↗

PubMed1979

Rhabdomyosarcoma of infancy and childhood. Problems of morphologic classification.

The classification of the histologic types of rhabdomyosarcoma is based on poorly defined criteria. This has resulted in marked disparities in studies reported from different institutions, as well as difficulties in assessment of the clinical behavior of the different histologic types. A retrospective morphologic analysis of 36 consecutive cases of rhabdomyosarcoma of childhood was undertaken according to predefined and strict guidelines for diagnosis. Undeflecting adherence to such criteria identified the embryonal type as the most common form, and the alveolar variant as a distinct clinicopathologic entity with a much more aggressive course; it also resulted in a large proportion (approximately one-fourth) of sarcomas of undertermined histogenesis. In spite of either prolonged follow-up observation with repeated biopsies, autopsy study, or electron-microscopic study of tumor tissue, no evidence could be obtained to substantiate the rhabdomyogenic derivation of the latter group of neoplasms. Precise systematization of the morphology of these cases may be contingent upon careful inventory of their fine structural features; current classifications appear to have disregarded the morphologic heterogeneity of this group of tumors.

Adolescent↗

PubMedDate not supplied

Diagnosis of thymoma by needle biopsy.

One cutting needle biopsy specimen and six fine needle aspiration biopsy specimens of thymomas were studied in order to define diagnostic criteria for this entity in biopsy material. Two of the cases demonstrated a mixed pattern of epithelial cells and lymphocytes while epithelial cells predominated in four cases and lymphocytes in one. Tumors composed of a conspicuous admixture of benign-appearing epithelial cells and mature lymphocytes were easily diagnosed. Neoplasms composed primarily of one cell type also displayed distinctive cytologic features that correlated with the histopathologic appearance of the resected tumors and permitted a diagnosis. Immunocytochemical demonstration of keratin and T6 proved useful in confirming the biphasic pattern of epithelial cells and cortical thymocytes that is characteristic of thymoma.

Adult↗