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Biomedical subjects

T F Meaney

Publications and source records attributed to T F Meaney.

At least 19 recordsLinked to original sources
PubMed1989

Therapeutic response of breast carcinoma monitored by 31P MRS in situ.

In situ phosphorous MRS was employed to study the metabolites of normal and cancerous breasts, and the alterations of tumor response to therapy. In a group of 7 normal volunteers and 12 patients, the total mobile phosphate content of breast carcinomas was found to be at least two to three times higher than that of the normal breast measured off menstruation. The metabolite profiles of normal and tumorous breasts are coarsely similar. In both cases the intracellular pH (pHi) was either neutral or slightly alkaline (pH greater than 7.0). Prior to treatments, the metabolite levels of phosphoryl monoester-to-ATP ratio of breast neoplasms were higher than those of the controls and decreased after the patients received a few treatments while the pHi fluctuated at a value greater than 7.0. The phosphoryl diester-to-ATP ratio also demonstrated to a lesser extent a decreasing trend in response to therapy.

Breast↗
PubMed1989

Monitoring therapeutic response of human superficial tumors using phase-encoded spectroscopy.

A one-dimensional phase-encoded spectroscopy sequence was implemented on a GE 1.5-T Signa imager and the feasibility of its application to monitor the 31P metabolites of superficial tumors was demonstrated. Serial 31P spectra of 1-cm slices with adequate signal-to-noise ratio and insignificant T2 weighting can be obtained in 28 min. The degree of "bleeding" effect was reduced with increased phase-encoding steps.

Adult↗
PubMed1989

Radiologic methods of bile duct stone extraction.

Fluoroscopically guided extraction of retained common duct calculi through a T-tube tract has a high success rate, low complication rate, and negligible mortality rate. It is not unduly uncomfortable and can be performed on an outpatient basis. The only disadvantage is a wait of approximately 6 weeks after surgery to let the T-tube sinus tract mature. If no T tube is present, endoscopic sphincterotomy is usually the treatment of choice. In difficult cases, the radiologist may be able to assist the endoscopist by placing a wire across the sphincter through a percutaneous transhepatic route. If endoscopic sphincterotomy is not successful or feasible, an attempt at percutaneous stone removal can be made from a transhepatic approach. A variety of new devices and dissolution agents is becoming available for stone fragmentation or reduction.

Bile Duct Diseases↗
PubMed1989

The decline of diagnostic radiology: call to action. 1989 Dotter lecture.

Major socioeconomic changes in the practice of medicine in the past 2 decades have had a great impact on diagnostic radiology and have encouraged other physicians and entrepreneurs to enter many areas of this specialty. Major alterations in the practice of diagnostic radiology will be required if the specialty is to survive. Diagnostic radiologists must move from a position of dependency to self-sufficiency by encouraging patients to access their services and talents directly.

Diagnostic Imaging↗
PubMed1989

Invasive radiology.

The history of invasive radiology is a history of cooperative effort of scientists in physics and chemistry, of engineers in academic settings and industry and of the medical community. Research and development in the technological sciences opened doors to clinical application. Clinical imperatives drove research and development. Parallel advances in catheters, contrast materials and radiologic equipment came together to permit invasive radiologists to pursue advances in diagnosis and therapy, in a setting of patient safety.

Humans↗
PubMed1989

Human neoplasm pH and response to radiation therapy: P-31 MR spectroscopy studies in situ.

Thirty-five human neoplasms from various sites and of various histologic types and stages were examined with phosphorus-31 magnetic resonance spectroscopy in situ. The tumors included 13 squamous cell carcinomas of the head and neck (lymph nodes), eight Hodgkin lymphomas, six non-Hodgkin lymphomas, four carcinomas of the breast, one melanoma, one sarcoma, one neuroblastoma, and one mucoepidermoid sarcoma of the salivary glands. Thirty-four of the neoplasms had normal to slightly alkaline pH before irradiation. During fractionated radiation therapy, the pH stayed in a range of from near neutral to alkaline and rose to 7.6-8.0 at several time points of radiation therapy for some tumors. These results suggest that most tumor cells in human neoplasms are well oxygenated and that only a negligible fraction are chronic hypoxic cells. The fluctuating alkaline pH during radiation therapy occurred regardless of the responsiveness of the treated tumors.

Carcinoma, Squamous Cell↗
PubMed1985

Gated cardiac magnetic resonance structural imaging: optimization by electronic axial rotation.

Most magnetic resonance imaging has used body orthogonal axes with the Z axis placed along the length of the body and the X and Y axes at right angles to the body. This orientation is not optimum for the heart; visualization of sections along the short and long cardiac axes would best define cardiac structural detail and functional status. The new orientation was accomplished by selection of electronic angulation of the magnetic fields for each subject rather than by attempting to approximate the cardiac axes by altering the position of the patient. This technique improved visualization of comparative wall segments, valvular structures, and the true four-chamber view of the heart, and also gave the best visualization of the pericardium. In addition, more accurate estimates of chamber size and myocardial mass can be made from the short-axis orientation, since the sections are orthogonal to the myocardium.

Cardiomegaly↗
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↗
PubMed1978

Computed tomography-guided biopsy. I. Overview.

The authors are preparing a series of communications on CT-guided biopsy procedures to be published in future issues of this journal. The present article, which previously appeared in the Cleveland Clinic Quarterly, is intended to serve as an introduction to the concept of CT-guided biopsies. Because the principles of the biopsy procedure remain the same, we do not believe that a "rewrite" of the previously published article would be required. We hope that by presenting this article and subsequent articles concerning the use of CT-guided biopsies, the reader will acquire an appreciation of the proper role of this exciting new technique in comparison to the available imaging modalities. We believe that as individuals become more experienced with the imaging capabilities of these CT devices, they will want to develop the technique of obtaining biopsy confirmation of the imaging diagnosis.

Abscess↗
PubMed1977

Body computed tomography: a clinically important and efficacious radiologic procedure.

In the institutions represented by the authors, more than 7,500 body CT examinations have been performed. Body CT has been found to be particularly useful in solving specific problems, especially when other diagnostic procedures yield confusiing results. Radiologists and their collegues, and not governmental agencies and insurance companies, should define the experimental, research and clinical usefulness of computed tomography.

Humans↗
PubMed1977

Definitive role of CT scanning of the pancreas. The second year's experience.

In a group of 188 patients, 192 computed tomographic (CT) scans of the pancreas were done, and the diagnostic accuracy of CT determined relative to other modalities. CT was the most effective method of detecting neoplastic and inflammatory diseases. The full extent of the disease process, including involvement of the retroperitoneum and metastasis to the liver, was visualized with one examination. Calcification and cystic collections associated with pancreatitis were also clearly seen.

Adenocarcinoma↗
PubMed1977

CT detection and aspiration of abdominal abscesses.

Computed tomography (CT) is effective in detecting intraabdominal abscesses. Loculations of fluid and extraluminal gas are clearly localized in relation to other organs. Of 22 abscess in this series, CT successfully detected 20; comparative information with gallium, techneticum, and ultrasound scans is presented. In addition to localizing these collections, CT can be used to guide needle aspiration and drainage procedures. Three sizes of needles were used to aspirate specimens and/or provide drainage. This was accomplished successfully in 12 of 14 CT-guided procedures.

Abdomen↗