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Biomedical subjects

C D Teates

Publications and source records attributed to C D Teates.

At least 55 records · Page 3Linked to original sources
PubMed1983

Effects of percutaneous transluminal angioplasty on renal plasma flow.

Percutaneous transluminal angioplasty is being used with increasing frequency for the treatment of renal artery stenosis. Several noninvasive techniques that utilize radioactive tracers have been used for monitoring the effects of angioplasty and progression of disease. Forty-one patients were studied before and after renal angioplasty by using renograms and fractionated measurements of effect renal plasma flow. Although there were striking examples of improvement in effective renal plasma flow following angioplasty, this was not a consistent finding. There was a tendency for effective renal plasma flow to revert to the baseline level on follow-up studies. Cure of hypertension was more likely in patients without renal insufficiency and in patients with shorter periods of sustained hypertension. Fractionated effective renal plasma flow studies did not reliably differentiate patients who were cured from those who were improved nor were we able to delineate clearly those requiring repeat dilatation. Nevertheless, this technique is useful for noninvasively measuring fractionated renal function in the immediate postoperative or postdilatation recovery period and for detecting the difference between occlusion of the renal artery and transient renal insufficiency due to contrast material. Also, long-term measurement of fractionated function has value in following potential progression of the basic disease process.

Adult↗
PubMed1983

Emission tomography of the kidney.

Single photon emission computerized tomography (SPECT) was done on two patients with suspected renal masses. Nuclear scintigraphy was equivocal on two tumors readily identified by SPECT. Single photon tomography is cost effective and increases the reliability of nuclear scintigraphy.

Adenocarcinoma↗
PubMed1981

Ventilation-perfusion imaging and pulmonary angiography: changing pattern of use.

The hospitals and departmental records of the University of Virginia Medical Center from 1976 to 1980 show an increasing frequency of ventilation studies relative to perfusion studies and a decrease in frequency of ventilation-perfusion diagnosis of pulmonary embolus. Pulmonary angiograms have increased from one per 68 nuclear studies to one per 14. A review of 70 patients with correlating angiography or autopsy shows that 89% of nuclear studies were accurate. We have revised our interpretation criteria and indications for pulmonary angiography.

Angiography↗
PubMed1981

Percutaneous transluminal angioplasty in patients with renal artery stenosis: follow-up studies.

Fifty renal artery stenoses in 38 hypertensive patients were treated with percutaneous transluminal angioplasty. Follow-up over a period of 1 to 24 months (mean, 9 mo.), including angiography, renal vein renin determinations, and radionuclide flow studies, were performed in 24 patients (32 stenoses). The initial dilatation was successful in 90% of stenoses and redilatation was necessary in 22% with a success rate of 84%. The mean systolic pressure decreased by 65.83 mm Hg and the mean diastolic pressure by 35.88 mm Hg in response to the treatment. Sixteen patients were cured, 18 were felt to have better control of blood pressure on medication, and 4 were not helped. Percutaneous transluminal angioplasty appears to be a technically feasible and clinically effective method of treating renovascular hypertension.

Adolescent↗
PubMed1981

Spatial and temporal quantitation of plane thallium myocardial images.

A computer method has been developed to determine the relative initial uptake and segmental washout rates of thallium-201 from sequential myocardial images. Initial images in multiple projections are obtained at 10 min after thallium-201 injection, and delayed images 2-3 hr after injection. A modified interpolative method was used to construct a background reference plane, and net myocardial counts was used to construct a background reference plane, and net myocardial counts above this reference plane were determined from multiple count profiles. Washout rates were determined by linear regression of time-activity curves constructed from the sequential images. In this approach, both relative temporal as well as relative spatial quantitation is performed. Data from 25 normal subjects were used to establish numerical criteria and normal ranges for relative focal defects and abnormal segmental washout slopes. Normal ranges were set to include the 90-percentile limits of the distribution of values obtained from the normal population. From these values we derived a quantitative criterion for thallium scan interpretation that can be used for analysis and interpretation of scintigrams in clinical situations.

Adult↗
PubMed1981

Quantitative thallium-201 exercise scintigraphy for detection of coronary artery disease.

In 140 patients with chest pain quantitation of regional myocardial TI-201 activity was performed by serial scintigraphic images after treadmill exercise. Criteria for an abnormal thallium scintigram included: (a) greater than or equal to 25% persisted reduction in TI-201 uptake in anterolateral, anteroseptal, posterolateral, and inferoapical segments, or greater than or equal to 35% reduction in the inferior segment; (b) an initial defect with delayed redistribution; and (c) abnormal TI-201 washout. Of 110 patients with significant coronary artery disease (CAD), 100 had abnormal TI-201 scintigrams, while 27 of 30 patients with angiographically normal coronary arteries had normal scintigrams; 91% sensitivity, 90% specificity, and 97% predictive accuracy. Sensitivity and specificity were not significantly different when the 95 patients with diagnostic (greater than or equal to 85% maximum heart rate) and 45 with inconclusive (less than or equal to 85% maximum HR) Ex tests were compared. Comparison of qualitative and quantitative image analyses in a subset of these patients showed that both specificity and multivessel disease prediction were greater when the quantitative approach was used (90 against 73% and 78 against 39%, respectively). Sensitivity for CAD detection was reduced by 10% with visual interpretation alone. Thus, quantitative exercise TI-201 scintigraphy appears highly sensitive and specific for CAD detection in patients with chest pain.

Adult↗
PubMed1980

A systems approach to the management of radiation accidents.

Management of radiation accident patients should have a multidisciplinary approach that includes all health professionals as well as members of public safety agencies. Emergency plans for radiation accidents include detection of the ionizing radiation, patient evacuation, resuscitation, and decontamination. The resuscitated patient should be transported to a radiation control area located outside but adjacent to the emergency department. Ideally this area is accessed through an entrance separate from that used for the main flow of daily emergency department patients. The hospital staff, provided with protective clothing, dosimeters, and preprinted guidelines, continues the resuscitation and definitive care of the patient. This system approach to the management of radiation accidents may be tailored to meet the specific needs of other emergency medical systems.

Accidents↗
PubMed1980

Bone scanning in detecting soft tissue abnormalities.

With bone scanning, as in other imaging modalities, important clues may be overlooked if attention is too much forcused on the major features displayed. In discussing bone scanning we have avoided the more obvious focal bone abnormalities and addressed our observations to peripheral changes, predominantly of soft tissues.

Bone and Bones↗
PubMed1980

Percutaneous transluminal dilatation of the renal arteries: techniques and results.

The techniques and results of percutaneous transluminal angioplasty (TPA) of the renal arteries were evaluated in 20 hypertensive patients with 25 renal artery stenoses. Follow-up angiograms have been obtained in nine patients. Many patients had evidence of both essential and angiotensinogenic hypertension. Eleven patients had evidence of severe diffuse atherosclerotic disease, and nine patients had evidence of renal insufficiency. The mean systolic pressures before and after PTA were 203.80 and 150.30, respectively. The mean diastolic pressures before and after PTA were 117.45 and 85.95, respectively. Ten patients were cured. Six patients with long histories of hypertension and a recent increase in blood pressure were classified as having blood pressure easier to control with antihypertensive medication following PTA. Three patients failed to respond to PTA, and one patient was a technical failure. The advantages of this technique include avoidance of general anesthesia and a major surgical procedure, decreased cost, and a shortened hospital stay. The technique can be easily repeated if necessary, and future surgical intervention is not precluded if the method is unsuccessful.

Adult↗
PubMed1980

Falciform ligament: varieties of imaging experience.

The falciform ligament is commonly imaged by various modalities available to most radiologists. When displayed, its diagnostic value is limited, but knowledge of its appearance as encountered on different examinations is useful, lest pathologic significance be applied to its appearance.

Humans↗
PubMed1980

Prediction of postoperative respiratory function in patients undergoing lung resection.

Using xenon-133 radiospirometry and formulae devised on geometric grounds, the authors predicted postoperative lung function in 12 patients who underwent lobectomy, wedge resection, or pneumonectomy for suspected carcinoma. No correlation was found, however, between preoperative, predicted, and postoperative lung function and immediate postoperative morbidity and mortality.

Aged↗
PubMed1980

Gallium-67 citrate imaging in head and neck tumors: report of Cooperative Group.

This report summarizes the experiences of the Oak Ridge Associated Universities Cooperative Group with the scanning of head and neck cancer using carrier-free gallium-67 citrate. Central nervous system and thyroid tumors and lymphomas were excluded. Fifty-six percent of primary head and neck tumors and their metastases were detected in 65 patients. The detection rates for primary and metastatic lesions were similar. Results of 1306 scans on patients with many types of cancer and suspicion of head and neck involvement indicate that a positive gallium scan was associated with tumor involvement five to nine times as often as no tumor, but a negative scan cannot reliably rule out involvement. In head and neck tumors, both primary and metastatic, lesions over 3 cm in diameter had a significantly higher detection rate than smaller lesions. Previous radiation or surgery did not affect accuracy.

False Negative Reactions↗
PubMed1979

Radionuclide bone imaging as a means of differentiating loosening and infection in patients with a painful total hip prosthesis.

Twenty patients with 23 painful total hip prostheses were examined by radionuclide imaging (20 cases), arthrography (11 cases), needle aspiration (9 cases), and surgery (19 cases) for the purpose of assessing loosening and/or infection. Bone imaging was most accurate, showing three main distributions of activity: (a) ectopic calcification, (b) focal increased activity at the upper and lower ends of the femoral prosthesis, and (c) diffuse activity. These findings suggest that infection and loosening can be differentiated in many instances. None of the patients with focal activity had infection, compared to 2 of the 3 patients with diffuse uptake.

Bone Diseases↗