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Biomedical subjects

A E Kirkpatrick

Publications and source records attributed to A E Kirkpatrick.

35 records · Page 2Linked to original sources
PubMed1989

Films, screens and cassettes for mammography.

Various film-screen combinations intended for mammography have been compared for image quality and for dose. Image quality was assessed as in an earlier paper, using a test object having details which are both realistic and quantitative. Relative doses required to give film densities of 1.0 were measured. The Kodak MinR-MinR combination was taken as a standard against which others were compared, and in general a lower dose was accompanied by poorer image quality. The Fuji NH film with Fuji Hi-Mammo screen was the sole exception, giving slightly better image quality at about half the dose required by the MinR combination. A number of cassettes were also compared with each other and with evacuated envelopes. The Dupont Cronex cassette and three carbon-fibre fronted cassettes all performed well in image quality.

Equipment Design↗
PubMed1989

Effect of retrograde aminophylline administration on calcium and phosphate solubility in neonatal total parenteral nutrient solutions.

The effect of retrograde administration of aminophylline injection on calcium and phosphate solubility in neonatal total parenteral nutrient (TPN) solutions was studied. Neonatal TPN solutions containing two amino acids solutions in three concentrations (Travasol 1% and 2% and TrophAmine 2%) were formulated. Calcium and phosphate salts were added to achieve calcium concentrations of 10, 15, 20, 25, 30, or 40 meq/L and phosphorus concentrations of 10, 15, 20, 25, 30, or 40 mmol/L. Samples were inspected visually after 18-24 hours; solutions free of precipitation were then infused through two parallel syringe-pump systems designed to simulate clinical conditions for TPN solution administration to a 1-kg neonate. To one system, a 7.5-mg aminophylline dose was added as a manual retrograde injection; sterile water for injection was added as a manual retrograde injection to the other system. The solutions were inspected throughout a one-hour infusion period for precipitate formation in the i.v. apparatus, and the pH of the effluents was determined. Concurrent aminophylline administration resulted in visible precipitate in all but a few of the solutions tested. The solution containing Travasol 2%, calcium 10 meq/L, and phosphorus 10 mmol/L remained clear, as did the solutions containing TrophAmine 2% and the following concentrations of calcium and phosphorus: calcium 10 meq/L and phosphorus 10, 15, or 20 mmol/L; calcium 15 meq/L and phosphorus 10 or 15 mmol/L; and calcium 20 meq/L and phosphorus 10 or 15 mmol/L. An average increase in pH of 0.63 unit was noted in all solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminophylline↗
PubMed1988

Film processing for mammography.

The effect of processing time and temperature on image quality in mammograms was investigated over the ranges 2.5-4 min and 30-36 degrees C. Image quality results from seven processors of different manufacture and different processing methods, operated at a range of times and temperatures, showed the same image quality except for one which received little use. Effects of these parameters on the patient dose required were also considered, longer times up to 4 min and higher temperatures up to 36 degrees C being advantageous. No variation was found with processor design or mechanism of action. Implications for screening programmes are briefly discussed and an optimum regime of 3.5 min and 36 degrees C is suggested.

Mammography↗
PubMed1987

Computed tomogram myelography in cervical spondylosis.

Nine patients with severe and prolonged signs and symptoms due to cervical spondylosis had myelography followed by a CT Scan using the same injection of intrathecal contrast. All patients had radiographic changes of cervical spine degeneration and were being considered for exploration and fusion of the anterior cervical spine. All patients had a full clinical evaluation, EMG studies and plain radiographs taken prior to their CT Scan. EMG readings showed several levels of compression in three patients but did not indicate a single level in any. Plain radiography showed multiple level involvement in every patient. Myelography indicated significant indentation in three of five patients with clinical signs but did not demonstrate root cut off in any case. CT Myelography indicated the degree of Lushka and facet joint involvement, indentation, exit foramen encroachment, and the degree of spinal stenosis at the involved segment. In three patients, the findings at operation correlated closely with the CT Scans. Myelography failed to indicate the presence of significant osteophytes in these two cases.

Adult↗
PubMed1987

A comparative study of films and screens for mammography.

Ten films and six screens suitable for mammography have been compared for image quality using a realistic quantitative phantom under controlled conditions. The best screen was Min R (Kodak), but three black and white films, Min R (Kodak), Fuji II NC (Fuji) and MR3 (Agfa-Gevaert), scored highly. Patient dose was also considered and, with these three films, small gains in image quality were balanced by small increases in dose. Medichrome Blue film, however, gave the highest score of all, and did so for a dose that was less than the highest. These results were confirmed on a second phantom of entirely different design.

Female↗
PubMed1986

Specimen radiology of excised breast lesions.

The value of specimen radiology in the surgical management of palpable breast lesions was assessed in 100 consecutive patients undergoing excision of a palpable breast lump. Only 41 per cent of palpable breast lesions were demonstrable as a radiological abnormality on the excised specimen. The greatest sensitivity was found for lesions which proved to be malignant. Only 27 of 88 benign palpable breast lesions were radiologically visible in the specimen. Surprisingly, only 8 of 13 fibroadenomas were identified as discrete opacities. No residual breast lump was detected on clinical examination in patients reviewed postoperatively, including those patients who had a demonstrable preoperative mammographic abnormality and a negative specimen radiograph. We conclude that specimen radiology does not contribute to the surgical management of palpable breast lesions.

Biopsy↗
PubMed1984

The Edinburgh randomised trial of screening for breast cancer: description of method.

Edinburgh was selected as one of the centres in the UK Seven-year Trial of Breast Screening of women aged 45-65 which began in 1979. Subsequently, our study was extended to a randomised trial with its own control population within the city. Half the practices were randomly allocated for screening, giving a cluster sampling of women. The total number in the trial is 65,000. Women with previously diagnosed breast cancer are excluded. Women allocated for screening are invited to the clinic and screened according to the procedures specified in the U.K. protocol, having clinical examination every year and mammography on alternate years. The two modalities of screening are assessed independently and the role of nurses is being evaluated. Breast cancer incidence is monitored by pathology register and the local cancer registry office and deaths from the General Register office. Long-term follow-up will be obtained through flagging at NHS Central Register. To determine the value of screening, standard statistical methods will be used to compare breast cancer mortality rates in the whole of the screening population with that of the controls. This trial has a power of 83% of detecting a reduction in mortality of 35% after 7 years of follow-up and a power of 95% of detecting a similar reduction at 10 years (alpha = 0.05, one-sided test).

Breast Neoplasms↗
PubMed1984

Oblique-view mammography: adequacy for screening. Work in progress.

Single oblique-view mammography has been recommended for screening purposes. The authors present data indicating that using the oblique view only can allow 11% of cancers to remain undetected. The smallest and potentially curable cancers are most likely to be overlooked in this way; any possible benefit of screening is thereby reduced. Data are also presented to show that 39% of women may require other views, for reasons not necessarily related to cancer detection. It is therefore recommended that all women have four-view mammography (oblique plus craniocaudal views of each breast) at their first screening visit.

Breast Neoplasms↗
PubMed1983

Localization and excision of occult breast lesions.

Between 1976 and 1982, 190 non-palpable mammographic abnormalities considered to be suspicious of malignancy were excised using a needle localization technique. The indications for biopsy, technique for localization, method for confirmation of excision and histopathological preparation are presented. The histopathological diagnosis of these lesions were 150 benign and 40 malignant. There was no clear correlation between the mammographic appearances and the occurrence of cancer. Compared with 100 consecutive women with palpable breast cancer the impalpable and mammographically detected tumours were smaller, more often non-invasive and associated with negative axillary nodes.

Adult↗
PubMed1983

Microcalcification and its relationship to cancer of the breast: experience in a screening clinic.

The mammograms and specimen radiographs of 45 women in whom the presence of microcalcification played a major part in the decision to biopsy, were studied to determine possible distinguishing features. A mammographic lesion of 150 mm2 or less with an irregular density and five or more calcific particles, especially if palpable, was very likely to be an invasive carcinoma. With improved resolution, it should become possible to distinguish those calcifications covering 150 mm2 or less in the mammograms which are associated with parenchymal structures and those that are associated with stromal elements. Features that may potentially distinguish some benign parenchymal calcifications and those parenchymal calcifications associated with non-invasive malignancy are described. There will probably remain a few benign parenchymal associated calcifications which are identical to the calcifications associated with non-invasive cancer. Implications for improvement in technique are considered.

Aged↗
PubMed1982

Breast localization biopsy.

Nineteen localization biopsies were performed on eighteen women, where routine mammography revealed impalpable abnormalities. These abnormalities are described and the results of biopsy given. Six carcinomas were detected, all of which were shown to have no evidence of metastatic disease.

Biopsy↗
PubMedDate not supplied

A mobile breast screening project in Scotland: lessons learned for national screening.

In 1986, a project was undertaken to determine the feasibility and cost of screening for breast cancer, using single oblique view mammography. Screening was offered to women aged between 40 and 65, on an open access basis, to those living in rural areas near Edinburgh. This article reports on: the logistical difficulties encountered; the costs of mobile screening; a comparison of costs when screening from a static centre; and, identifies factors found to influence attendance rates. The lessons learned from the project were incorporated into the planning of the mobile van operating in the South-East of Scotland Screening Programme, part of the National Breast Screening Programme; comparisons, where possible, have been included.

Adult↗