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Biomedical subjects

W J Howland

Publications and source records attributed to W J Howland.

At least 19 recordsLinked to original sources
PubMed1986

Educational objectives for diagnostic radiology residency training.

A method of teaching radiology residents by identification of general and specific objectives to be accomplished during each time segment of the four-year training program has been developed. The objectives are incorporated into an educational contract that is signed by the resident and rotation director at the beginning of each rotation. The objectives are specific so that attainment can be evaluated. This gives definition to both the resident and the teacher.

Internship and Residency↗
PubMed1985

Organ system radiology. Instruction of sophomore medical students.

During a six-year period we have evolved a method of teaching organ system radiology to sophomore medical students. This involves didactic and clinical sessions with small group discussions and activities central to the program. The course is designed to present a bridging course between the basic medical sciences and the clinical sciences and to better prepare students for their patient care responsibilities.

Education, Medical, Undergraduate↗
PubMed1980

Postradiation atrophy of mature bone.

The growing number of oncological patients subjected to radiogherapy require the diagnostic radiologist to be aware of expected bone changes following irradiation and the differentiation of this entity from metastasis. The primary event of radiation damage to bone is atrophy and true necrosis of bone is uncommon. The postradiation atrophic changes of bone are the result of combined cellular and vascular damage, the former being more important. The damage to the osteoblast resulting in decreased matrix production is apparently the primary histopathologic event. Radiation damaged bone is susceptible to superimposed complications of fracture, infection, necrosis, and sarcoma. The primary radiographic evidence of atrophy, localized osteopenia, is late in appearing, mainly because of the relative insensitivity of radiographs in detecting demineralization. Contrary to former views, the mature bone is quite radiosensitive and reacts quickly to even small doses of radiation. In vivo midrodensitometric analysis and radionuclide bone and bone marrow scans can reveal early changes following irradiation. The differentiation of postirradiation atrophy and metastasis may be difficult. Biopsy should be the last resort because of the possibility of causing true necrosis in atrophic bone by trauma and infection.

Atrophy↗
PubMed1977

Linearity of exposure with indicated time and current for diagnostic radiography units.

Quality control in diagnostic radiography begins with production of predictable exposures. The authors describe a technique which permits determination of the variation of mR/mAs for the entire diagnostic range of times and currents in only about 1 hour. The mR/mAs in newly installed units has been shown to vary by as much as +/- 50% compared to institutional acceptance levels of +/- 10%. Records of annual surveys and acceptance tests from 31 medical facilities, including 293 radiographic and fluoroscopic units, are reviewed, and effects of small variations in mAs on radiographic quality are shown.

Humans↗
PubMed1975

Limitations of bone scanning in clinical oncology.

Radioisotope bone scanning is frequently used as the major, and sometimes the only, diagnostic test for neoplasia in bone. While the evidence is convincing that bone scans are frequently more sensitive than roentgenographic bone surveys for detection of metastatic bone disease, there are false-negative results for a variety of reasons, and positive findings must be interpreted with caution. Scans also appear more limited than roentgenograms in their usefulness for evaluating changes in abnormal bone structure. Case histories and discussion are offered to indicate that usually both radioisotope bone scans and roentgenographic bone surveys should be obtained for initial screening and subsequent assessment of bone metastases.

Adult↗
PubMed1975

Postirradiation atrophic changes of bone and related complications.

The sequence of radiographically visible changes about the shoulder girdle following irradiation was analyzed in 49 patients who received 200 kV irradiation, in 50 who received 25 MeV betatron photon irradiation, and in 20 who received cobalt-60 irradiation. The changes were dose related and were most evident in the kilovoltage group, but also occurred following megavoltage therapy. Atrophic changes may be complicated by fracture, true necrosis, true osteitis or sarcoma. These atrophic changes have clinical significance similar to the atrophic changes that occur in skin and mucous membranes. The terms radionecrosis and radiation osteitis as applied to these changes should be abandoned since they imply a more serious process than is actually present. Biopsy should be avoided if possible since trauma and secondary infection could lead to true necrosis.

Atrophy↗