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T F Meaney

Publications and source records attributed to T F Meaney.

At least 37 records · Page 2Linked to original sources
PubMed1983

Simultaneous structural and functional imaging of the transplant kidney using digital subtraction angiography.

We herein describe our preliminary experience with digital subtraction angiography in the noninvasive evaluation of renal transplant structure and function. A single digital subtraction angiography study was obtained in 38 patients with transplant kidneys and various levels of renal function. The main renal artery was demonstrated well in all studies. Stored digital information was used to generate appearance and clearance rates of contrast medium to produce a functional renal image. There was good correlation between the functional image pattern on digital subtraction angiography and the known degree of renal functional impairment. No adverse effects resulted from the small dose of intravenous contrast material used for angiography. This initial study suggests that digital subtraction angiography is a rapid, safe and noninvasive method for visualization of the transplant kidney, and can afford clinically relevant structural and functional information.

Adult↗
PubMed1983

Nuclear magnetic resonance (NMR) imaging in the evaluation of the liver: a preliminary experience.

To determine the usefulness of nuclear magnetic resonance (NMR) in evaluation of the liver, 19 examinations were performed. A variety of pathological conditions were examined, and correlation was obtained with computed tomography, ultrasound, and radionuclide liver/spleen scanning. Nuclear magnetic resonance was as sensitive as the correlating imaging modalities in the detection of focal disease. Parenchymal abnormalities could be detected only in hemochromatosis. Several patients with diffuse disease did demonstrate evidence of portal hypertension, but no characteristic findings were noted within the liver parenchyma. Our preliminary investigation did not include T1 and T2 values and it is hoped that these will allow greater diagnostic utility in the detection of diffuse parenchymal disease.

Hemochromatosis↗
PubMed1983

The effects of nuclear magnetic resonance on patients with cardiac pacemakers.

The effect of nuclear magnetic resonance (NMR) imaging on six representative cardiac pacemakers was studied. The results indicate that the threshold for initiating the asynchronous mode of a pacemaker is 17 gauss. Radiofrequency levels are present in an NMR unit and may confuse or possibly inhibit demand pacemakers, although sensing circuitry is normally provided with electromagnetic interference discrimination. Time-varying magnetic fields can generate pulse amplitudes and frequencies to mimic cardiac activity. A serious limitation in the possibility of imaging a patient with a pacemaker would be the alteration of normal pulsing parameters due to time-varying magnetic fields.

Magnetic Resonance Spectroscopy↗
PubMed1983

Anatomic and functional imaging of congenital heart disease with digital subtraction angiography.

Digital subtraction angiography (DSA) of the heart was performed in 54 patients for the evaluation of congenital heart disorders. DSA produced high-quality diagnostic images and accurate physiologic shunt data that compared favorably with catheter angiography and nuclear medicine studies. Retrospective analysis of this series of patients indicated that DSA studies contributed sufficient information to shorten significantly or modify cardiac catheterization in 85% (79/93) of the defects that were identified. Interatrial septal defects were particularly well diagnosed, with identification occurring in 10 of 10 cases, whereas intraventricular septal defects were identified in only 6 of 9 patients. Evaluation of postsurgical patients was accurate in 19 of 20 cases.

Adolescent↗
PubMed1983

Intravenous digital subtraction angiography: peripheral versus central injection of contrast material.

Central and peripheral intravenous injections of contrast material for digital subtraction angiography were compared in 30 patients. With 40 ml of contrast material, visualization of the carotid bifurcations was as good with the peripheral as with the central injection. A more consistently high-quality examination of the small intracranial vessels was obtained with the central injection.

Arm↗
PubMed1982

Digital subtraction angiography for postoperative evaluation of renal arterial reconstruction.

Digital subtraction angiography after peripheral intravenous injection of contrast material is a new method to evaluate the cardiovascular system. Digital subtraction angiography was obtained postoperatively in 21 patients undergoing renal revascularization for treatment of hypertension and/or preservation of renal function. Digital subtraction angiography provided excellent visualization of the reconstructed renal arterial supply in all cases. The advantages and limitations of this technique in the evaluation of patients with renovascular disorders are discussed.

Aged↗
PubMed1981

Digital subtraction angiography of the abdominal aorta and renal arteries. Comparison with conventional aortography.

Digital subtraction angiography (DSA) was used to study the cardiovascular system in more than 400 patients and was specifically compared with conventional angiography of the aorta and renal arteries in 30 patients. For the renal arteries, the overall accuracy of DSA was 71% (50/70). Excluding 11 cases of inadequate visualization of the renal arteries on DSA, the sensitivity of the new technique was 93% (55/59) and the specificity 91.5% (54/59). Aortic disease, including intravascular clots and occlusions, was faithfully delineated by DSA.

Angiography↗
PubMed1981

Imaging capability of an experimental digital subtraction angiography unit.

We evaluated an experimental digital subtraction unit in terms of field uniformity, linearity of signal response to x-radiation, response of the log amplifier, and imaging capability as measured with the Rose phantom. For comparison, conventional film subtraction phantom measurements were made. Our results indicate that this unit exhibits greater sensitivity to contrast media than conventional film subtraction units.

Angiography↗
PubMed1980

Contribution of computed tomography to relative costs in the operative management of patients with renal cell carcinoma.

Relative costs in 14 patients undergoing operative treatment for primary renal carcinoma were anlayzed to determine the contribution of "little ticket" items relative to so-called "high technology" items, such as computed tomography (CT). The major contributing categories of cost were daily room charges, physican fees, and charges for laboratory and pharmacy. In most of the categories, a large variation was encountered, primarily due to patient and disease-related factors. CT was a minor factor in cost.

Adenocarcinoma↗
PubMed1980

Detection of low-contrast lesions in computed body tomography: an experimental study of simulated lesions.

Observer accuracy in the identification of low-contrast objects in computed tomography (CT) was studied. Thresholds were established for detection of lesions of various sizes and attenuation differences in CT images produced at different radiation doses. Noise reduction was important in identifying certain types of lesions. Detection was not accurate when the standard deviation of the mean of an organ exceeded the difference in the means of the lesion and the surround region.

Humans↗
PubMed1980

Percutaneous transhepatic cholangiography: comparison of success and risk using 19- versus 22-gauge needles.

Percutaneous transhepatic cholangiography has become a well accepted and safe method of examining the biliary system. Recent reports emphasize the use of thin-guage Chiba needle, citing increased safety and accuracy, while others express preference for the larger sheathed needle for therapeutic drainage. A total of 80 procedures in 72 patients was reviewed to determine success rates relative to needle size in dilated or nondilated ducts. With a dilated biliary system, procedures using the large needle were successful in 92% (24/26) of the procedures versus 80.8% (21/26) using the Chiba needle; the differences were not statistically significant. Chiba needle studies were successful in 41.7% (10/24) of patients with nondilated ducts. The number of studies of nondilated ducts with the large needle was small and not statistically significant. Complication rates were comparable. Recommendations are made for needle choice in various patients.

Adult↗
PubMed1980

Digital subtraction angiography of the human cardiovascular system.

Initial clinical application of a system for digital subtraction angiography (DSA) to the human cardiovascular system in 88 patients is reported. The equipment consisted of a specially designed computer system integrated with a fluoroscopic and radiographic apparatus for digitization, manipulation, and display of data. After intravenous injection of contrast material, adequate visualization of the heart and carotid, thoracic, abdominal, and femoral arteries was obtained with sufficient quality to obviate conventional angiography in many clinical settings. In this mode, nonselective opacification is obtained. However, DSA was also used to extend the capability of selective angiography. The availability of quantitative information permitted the determination of rates of transit of contrast material in various organs which may give insights of their physiologic performance.

Aneurysm↗
PubMed1979

A new simplified approach to the diagnosis of pheochromocytoma.

Blood catecholamine assays have been used for diagnosis and computerized axial tomography for localization of proved pheochromocytomas in a series of 16 patients. Blood catecholamine assays were obtained in 15 of the patients and were significantly elevated in every instance. Successful localization of the tumor was accomplished by excretory urography in only 40 per cent of the cases, by selective angiography in 84 per cent of the cases and by abdominal computerized axial tomography in 84 per cent of the cases studied. In 4 patients preoperative identification and localization of tumor were correctly determined by computerized axial tomography alone. Data in this series suggest that the diagnosis and localization of pheochromocytoma usually can be accomplished by a simple test and body scan. More elaborate and sometimes hazardous studies should be necessary only in exceptional cases, usually with tumors less than 3 cm. in diameter.

Adrenal Gland Neoplasms↗
PubMed1979

A simplified, cost-effective approach to the diagnosis of pheochromocytoma.

Plasma catecholamines have been used for diagnosis and computerized tomography scanning for localization in 21 patients with proved pheochromocytoma. Blood catecholamines were obtained in 20 of the patients and were elevated significantly in every instance. Successful localization of the tumor was accomplished by excretory urography in only 47% of the cases, by selective angiography in 85% and by abdominal computerized tomography scanning in 88%. In 7 patients preoperative identification and localization of the tumor were determined correctly by computerized tomography scanning alone. Data in our series suggest that the diagnosis and localization of pheochromocytoma can be accomplished usually by a simple blood test and body scan. More elaborate and sometimes hazardous studies should be necessary only in exceptional cases, usually with tumors less than 3 cm. in diameter.

Adrenal Gland Neoplasms↗