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Biomedical subjects

G D Dodd

Publications and source records attributed to G D Dodd.

At least 109 records · Page 6Linked to original sources
PubMed1985

The air contrast barium enema--indications and validity.

The double-contrast barium enema is a highly accurate and readily available procedure which is capable of diagnosing benign and malignant disease of the colon at an early state. The level of accuracy is a function of the radiologist's knowledge and willingness to assume complete responsibility for the patient. While reasonable results may be obtained with the high-kilovoltage single-contrast method, it is our opinion that the double contrast examination is the more sensitive procedure and therefore the technique of choice. The double-contrast examination ideally compliments the colonoscope and offers an alternative method for initial survey procedures or low cost follow-up examinations.

Adenoma↗
PubMed1984

Mammography. State of the art.

In recent years, the criticism of mammography as a diagnostic and/or survey procedure has decreased, primarily due to the perception that there has been an increase in quality and a concomitant decrease in risk. A review of the physical changes in mammographic equipment, the characteristics of current image receptors and dosimetry indicates that this assumption is correct. The results of the examination of 280,000 women from the Breast Cancer Detection Demonstration Project centers also support this conclusion. When all factors are considered it is reasonable to conclude that the potential benefits of mammography far outweigh the minimal risk incurred by the examination.

Adult↗
PubMed1984

A double blind, placebo controlled study of piroxicam in the management of acute musculoskeletal disorders.

General Practitioners from the United Kingdom produced data on 1,282 patients with acute soft tissue injury treated with either piroxicam (Feldene) or matching placebo for a period of up to two weeks. The dosage of piroxicam was 40 mg for the first 2 days and 20 mg daily thereafter. Clinical assessment included pain, swelling, limitation of active and passive movement and overall assessment of efficacy and toleration. Piroxicam was significantly better than placebo in improving patient signs and symptoms, and in its overall efficacy (P less than 0.001); 87% of piroxicam treated patients had excellent or good responses, compared to 53% of placebo treated patients. On analysis of four of the most commonly occurring diagnoses (injuries of ankle, knee, shoulder, back) patients with moderate or severe pain showed a significant improvement on treatment with piroxicam. Physicians' overall assessment of toleration showed no evidence of differences between treatments. Over 90% of patients in both treatment groups had good or excellent toleration. Withdrawals due to side effects were 3% and 2.5% respectively for piroxicam and placebo treated patients.

Ankle Injuries↗
PubMed1982

Evaluation of 12 colon-cleansing regimens with single-contrast barium enema.

In a study of patient preparation for barium enemas, 1,435 patients were examined at six different institutions with 12 different preparation protocols. There were 2,870 films evaluated a total of 7,839 times by seven different radiologists who were blind to both the institution and the preparations used. The statistical design, randomization, and analysis of the data obtained was performed by one of the authors, a statistician, and the following conclusions were made: Dulcolax (bisacodyl) plus 2 L tapwater enema is better than all the other protocols in all parts of the colon for both genders and all ages. Dulcolax or castor oil or X-Prep, each with 2 L water enema, are logically similar and better than the other protocols. Water enema only or castor oil only are the least effective protocols.

Barium Sulfate↗
PubMed1982

Preferential coronary arterial drug delivery.

A transcatheter technique for administering drugs preferentially to the canine left coronary circulation is described. The method involves pulsed, diastolic, small-volume (0.2 ml) injections through a specially designed aortic cusp catheter. In order to evaluate preferential delivery to the coronary circulation, papaverine was administered using this technique and compared to intravenous delivery. Left circumflex and carotid arterial blood flow, as well as systemic arterial pressure, were simultaneously measured. In eight of ten animals studied, diastolic aortic cusp administration of the drug for periods of up to 30 minutes increased circumflex flow an average of 136%, increased carotid arterial flow 22%, and decreased systemic arterial pressure 18%. Intravenous delivery increased circumflex flow an average of 34%, increased carotid flow 41%, and decreased systemic arterial pressure 13%. The technique has immediate research and potential clinical application as a means of preferentially delivering diagnostic or therapeutic agents, such as thrombolytics, to the coronary circulation.

Journal Article↗
PubMed1981

Radiation detection and diagnosis of breast cancer.

The value of mammography in the symptomatic patient has been adequately documented, but its use as a detection procedure remains a question. Risk-benefit ratios, based primarily upon the study carried out by the Health Insurance Plan of Greater New York, have suggested that the technique has little value in individuals under age 50. Emphasis has been placed upon the possible carcinogenic effects of radiation as compared with the efficacy of mammography and the questionable influence of early diagnosis upon end results. Although technical advances have substantially reduced the exposure of the patient to radiation, the possibility of significant information loss as the result of these developments has been considered a potential drawback to their routine use. All of these factors have served to diminish both public and professional acceptance of the examination. Although current data do not allow complete resolution of these problems, certain conclusions may be drawn and trends established. The sum of these may indicate that minimal dose mammography is an accurate, low-risk procedure, capable of significantly altering the natural history of breast cancer. Whether or not the examination should be routinely used in women under age 50 remains open to question since the lack of experimental controls prohibits validation of the technique in terms of reduced mortality rates. Documentation of increased survival rates may partially assist in the established of a reliable risk-benefit ratio, but will not satisfy the statistical requirements of eliminating lead-bias, and self-selection. These questions may be resolved by studies now underway.

Adult↗
PubMed1979

The opossum as an animal model for studying radiation esophagitis.

Six opossums were evaluated as a possible animal model of radiation esophagitis. In a single exposure to the esophagus, four animals received 60Co radiation of various doses; two served as controls. Pre- and postirradiation evaluations using fiberoptic endoscopy, mucosal biopsy, barium esophagography, and manometry were performed. Esophagitis developed at one week in irradiated animals. Opossums receiving 17.5, 20, and 22.5 Gy (1,750; 2,000; and 2,250 rad) became anorexic one week postirradiation, and abnormal motility subsequently developed. The controls and the animal receiving 15 Gy (1,500 rad) remained normal. Histological changes in the irradiated opossum esophagus resembled those found in humans.

Animals↗
PubMed1979

Magnification mammography: evaluation of screen-film and xeroradiographic techniques.

An x-ray unit designed for conventional nonmagnification and magnification mammography has been evaluated in terms of image quality and corresponding radiation exposure levels. The technical advantages of the radiographic magnification technique can result in improved image quality and reduction of the recording-system noise. The microfocal spot allows 1.5 x magnification mammograms with minimal geometric unsharpness. However, the magnification technique requires an increased radiation dose to the breast, compared to conventional nonmagnification techniques. An additional radiation dose may be required for screen-film magnification views because of reciprocity law failure due to long exposure times. The increased-dose limitation and the small dimensions of the recording-system cassettes have precluded the use of magnification in place of nonmagnified images for routine mammographic examination. The magnification technique has proved to be beneficial in selected cases.

Female↗
PubMed1978

A method of evaluating and minimizing geometric unsharpness for mammographic X-ray units.

A method for measuring and minimizing the effects of geometric unsharpness in mammography involves using a star resolution pattern to determine the equivalent focal spot size of mammographic x-ray units. With this measurement, the limit of resolution at any plane within the breast and the focal spot-to-object distance necessary to obtain the desired limit of resolution are determined. Six mammographic x-ray units were evaluated with this technique. Results show that the resolution capability of four of these units is limited by geometric unsharpness, such that the resolution capability of present mammographic recording systems is not fully utilized.

Mammography↗
PubMed1977

Present status of thermography, ultrasound and mammography in breast cancer detection.

Various biophysical methods have been utilized in the diagnosis of breast cancer. To date the best results have been obtained with x-ray mammography. Ultrasound and thermography have great appeal as non-destructive techniques but, in the present state of development, are of limited use. The spatial resolution presently obtainable in ultrasonograms is inadequate for the detection of subclinical cancer and thermography is also of questionable reliability. While an overall true positive rate of 70% to 75% may be anticipated with thermography, the bulk of false negatives would seem to occur in those tumors most amenable to therapy, i.e., subclinical cancers. The "false positive" rate of thermography is also excessive, but would be acceptable for establishing a high risk group if true positive rates could be improved. At present thermography finds its greatest use as an adjunct to mammography and physical examination; it should not be used as the sole modality in a screening program. The efficacy of mammography can be readily demonstrated but the propriety of its use as a screening device has been questioned. This is primarily related to the possible carcinogenic effect of radiation at diagnostic levels. Although the carcinogenic effect is unproven, the dose in radiologic procedures should be kept to a minimum consistent with adequate images. The present state of the art would indicate that the risk, if any, is minimal as contrasted with the natural incidence of breast cancer and the results of early diagnosis and treatment.

Adult↗
PubMed1977

Changes in the lymphatic dynamics after retroperitoneal lymph node dissection.

Lymphatic dynamics in the retroperitoneal space are altered after retroperitoneal lymph node dissection. Obstruction with or without visible collaterals is seen frequently. Lymphaticovenous communications and lymphocysts are also common findings. The immediate sequelae are of minor importance, although the mass effect of lymphocysts may be serious. The collateral pathways and lymphaticovenous anastomoses may result in the appearance of metastases in unusual sites.

Adolescent↗