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Biomedical subjects

D F Adams

Publications and source records attributed to D F Adams.

At least 91 records · Page 5Linked to original sources
PubMed1982

How safe is the coronary angiogram?

The pertinent literature on complications of selective coronary angiography has been reviewed. Three reports that describe the incidence of major complications in large patient groups are presented for comparative analysis of their results and used as a baseline for consideration of factors that may affect variations between the actual and reported rate of complications. It is recommended that agreement be reached on formulating national standards for the performance of the examination, taking into account the best data available.

Age Factors↗
PubMed1982

Computed tomography versus ultrasound of the adrenal gland: a prospective study.

A prospective study of the accuracy of computed tomography (CT) and ultrasound was undertaken in 112 consecutive patients with suspected adrenal disease. CT had a sensitivity of 84% (47/56), a specificity of 98% (55/56), and an accuracy of 90%. Ultrasound had a sensitivity of 79% (22/28), a specificity of 61% (14/23), and an overall accuracy of 70%. When patients with Cushing disease and adrenal hyperplasia were excluded, and only masses such as pheochromocytoma, adenoma, and carcinoma were considered, the sensitivity of both CT and ultrasound was increased. Receiver operating characteristic (ROC) curves differed for CT and ultrasound, and strongly supported the diagnostic superiority of CT.

Adrenal Gland Diseases↗
PubMed1982

A prospective evaluation of computed tomography and ultrasound of the pancreas.

A prospective cooperative study was performed to assess the relative efficacy of computed tomography (CT) and ultrasound in detecting and identifying pancreatic lesions. Of the 279 patients in the study, 146 were found to have a normal pancreas, and 133 had an abnormal pancreas. All patients underwent both CT and ultrasound examinations. Forty-four ultrasound examinations were technically unsatisfactory. When these suboptimal examinations were excluded, CT had a sensitivity of 0.87 and a specificity of 0.90 in detecting an abnormal pancreas. Ultrasound had a sensitivity of 0.69 and a specificity of 0.82. In detecting a lesion and identifying it as malignant or inflammatory, CT had a sensitivity of 0.84 and ultrasound had a sensitivity of 0.56. It is concluded that CT is the method of choice for detecting a pancreatic lesion, assessing its extent, and defining its etiology.

False Negative Reactions↗
PubMed1982

Balloon occlusion superior mesenteric arteriography for improved venous opacification: a clinical trial.

Balloon occlusion superior mesenteric arteriography and nonocclusion superior mesenteric arteriography were compared prospectively and retrospectively for adequacy of mesenteric and portal venous visualization. Prospective, occlusion studies in 20 patients were uniformly judged of excellent visual quality, while retrospectively, only 30% of nonocclusion studies from 20 other patients were considered optimal. In 10 of the patients who had balloon occlusion superior mesenteric arteriography, the procedure was preceded by a control nonocclusion superior mesenteric arteriography study. In only two (20%) patients was the nonocclusion study rated of excellent visual quality. Each study was assessed a rating of 0-3, according to how well the mesenteric and portal venous system visualized. Prospectively, all 20 balloon occlusion superior mesenteric arteriography studies were given the highest obtainable rating (3). Retrospectively, only six (30%) 20 nonocclusion superior mesenteric arteriography studies received a rating of 3; hence, 14 (70%) of the nonocclusion studies were rated less than excellent in visual quality when looked at retrospectively. No complications occurred with balloon occlusion superior mesenteric arteriography, and the occlusion procedure consistently gave excellent visualization of the mesenteric and portal venous anatomy.

Angiography↗
PubMed1981

Hepatic contrast agents for computed tomography: high atomic number particulate material.

We used a stepwise approach to identify, design, synthesize, and test new high atomic number particulate contrast agents that would be especially well suited for use with computed tomography (CT). Our goal was to produce extremely radiopaque compounds with highly selective biodistribution to the normal liver. In this way, dose requirements could be lessened and toxicity minimized. Suspensions of cerium, gadolinium, and dysprosium oxide particles and silver iodide colloid were tested and compared with standard agents. All four experimental agents were selectively concentrated in the reticuloendothelial systems of rats and rabbits. These compounds produced greater and longer opacification of normal livers and larger liver-to-tumor differences in rabbits with hepatic tumors than did equivalent amounts of standard, iodinated agents. Lesions as small as 5 mm were visible with CT. These experimental materials have favorable characteristics as hepatic contrast agents, but their toxicity and long term retention may limit clinical use.

Animals↗
PubMed1981

Time requirements in performing body CT studies.

In computed tomography (CT), whole body examinations take 1.5 times as long as head studies. In 73 patients (11 thoracic studies, 25 abdominal examinations, 31 CT scans of abdomen and pelvis, and 6 examinations of pelvis alone), the average time for a CT study was 136 min. The active part of the procedure lasted 60 min. Seventy-six minutes were idle time. The physician's involvement in body CT was estimated to be 53 min for an average study, when scans were taken before and after administration of contrast material. There are time differences in body CT of various anatomic regions (thorax, 40 min; abdomen, 66 min; pelvic, 52 min). The complexity of body CT, the equipment of a CT department, and the approach to diagnosis are responsible for time requirements and physician's involvement in whole body CT.

Humans↗
PubMed1981

Complications of angiography.

This study was designed to assess the complications of angiography, including transfemoral, transaxillary, and translumbar approaches. Detailed questionnaires were completed by radiologists at 514 of the 2,066 hospitals surveyed. The radiologists reported on the complications of 118,591 examinations. The overall arteriography complication rates were: transfemoral 1.73%, translumbar 2.89%, and transaxillary 3.29%. Thirty deaths were reported, eight of which were caused by aortic dissection or aneurysm rupture. Among the three techniques, there was no difference in the incidence of cardiac complications. There were significantly more neurologic complications, including seizures, in the transaxillary group than there were in either the transfemoral or translumbar groups. Similarly, hemorrhage, arterial obstruction, and pseudoaneurysms were more common with the transaxillary technique than with either of the other approaches. Vessel perforation and extraluminal contrast material were seen most frequently with the translumbar technique. Overall, between the two selective approaches, the transfemoral route carried a significantly smaller risk of complications than the transaxillary approach. There was an inverse relationship between complication rate and the annual number of arteriograms obtained. This was most striking in hospitals without residency training programs. The complications of adrenal venography, peripheral venography, pedal lymphography, and of studies for suspected pheochromocytoma were also assessed.

Adrenal Gland Neoplasms↗
PubMed1981

A prospective study of computed tomography, ultrasound, and gallium imaging in patients with fever.

Computed tomography, ultrasound, and 67Ga-citrate imaging were analyzed prospectively in patients thought to have a focal source of sepsis. They were divided into three groups: (a) postoperative, fever greater than or equal to 38.3 degrees C; (b) fever greater than or equal to 38.3 degrees C for less than four weeks, unrelated to surgery; and (c) any fever present for more than four weeks. ROC curves showed no significant difference in the ability of the three modalities to differentiate focal from nonfocal sources of sepsis. If any two examinations were used and either study was abnormal, the sensitivity increased from about 60% to nearly 90% while the false-positive rate increased from about 15% to 25%. When focal disease was diagnosed only if two examinations were abnormal, the false-positive ratio dropped to nearly zero but the sensitivity fell to below 40%. The authors concluded tha all three modalities have a similar ability to detect sepsis and that sensitivity can be increased by using any two of them.

Fever↗
PubMed1981

Organ hyperthermia: experimental selective perfusion.

The technical feasibility of selectively changing internal organ temperatures using balloon catheter perfusion was investigated. The liver or kidney temperatures were measured during the perfusion of cold or heated saline or preheated blood into the afferent vessels. Hyperthermic perfusion of the renal artery distal to an occlusion balloon catheter raised the kidney temperature to 43 degrees C. The hepatic arterial perfusion caused small changes in the liver temperature, whereas, with portal venous perfusion, the liver could be heated to 43 degrees C. Selective heating of the left hepatic lobe could be achieved by selective perfusion of the left portal vein. The potential therapeutic application of this technique is described.

Animals↗
PubMed1980

Classification of the radiological morphology of the mitral valve. Differentiation between true and pseudoprolapse.

The morphology of the mitral valve apparatus was assessed on 100 normal left ventriculograms. Four distinct types of mitral valve were identified according to the position of the mitral fulcrum (the point of attachment of the leaflets to the annulus) and the configuration of the adjacent left ventricular wall (left ventricular fornix) during diastole. Types I and II closely simulated prolapse of the mitral valve (pseudoprolapse) in the right anterior oblique projection during the ejection period. Measurements showed that contraction of the ventricle failed to reduce the diameter of the mitral valve annulus in 26 per cent of normal left ventricles.

Angiocardiography↗
PubMed1980

Experimental myocardial ischemia. IV. Shape and volume changes during "isolvolumetric relaxation" in normal and ischemic ventricles.

Shape and volume changes were studied in mongrel dogs between end-systole and mitral valve opening (MVO). Biplane left ventricular cineangiograms were performed at 200 frames/sec. The dogs were studied during the control state and during regional myocardial ischemia produced by balloon occlusion of the left anterior descending coronary artery. Outward wall motion, called pre-inflow relaxation (PIR), occurred in all 10 dogs in the control state, most frequently in the apical (seven of 10) and equatorial planes (seven of 10). PIR was seen less frequently during ischemia (13 of 40 measurements vs 19 of 40 measurements during control state), usually in the basal plane (five of 10). The ventricular volume between end-systole and MVO increased in all 10 dogs during the control state (mean increment 4.4 +/- 0.7 ml). Volume increased in eight of 10 dogs during ischemia (mean increment 3.0 +/+ 1.1 ml). The characteristic patterns of wall motion occurring between end-systole and MVO are altered by regional myocardial ischemia. During ischemia PIR occurs in segments of the myocardium with normal perfusion, but usually not in ischemic segments. Biplane ventricular volume between end-systole and MVO increased in 18 of 20 measurements (mean increment 3.6 +/- 0.9 ml).

Animals↗
PubMed1979

Complications of coronary arteriography: a follow-up report.

A nationwide survey of complications due to coronary arteriography during 1973--74 yielded responses from 176 hospitals (89,079 coronary arteriograms). The overall mortality rate was 0.14% (brachial, 0.12%; femoral, 0.16%). In the brachial group, the mortality rate was three times as high for non-heparinized as for heparinized patients. In institutions performing fewer than 100 examinations per year, the combined incidence of death, myocardial infarction, and cerebral embolism was five times higher than in institutions performing more than 400 examinations per year. Left main coronary artery or three-vessel disease was present in most patients who died of the procedure. Compared to a previous survey of 1970--71, there was a profound decrease in significant complications (including death, myocardial infarction, and cerebral embolism) and entry site complications such as thrombosis. A reduction in mortality with the femoral technique since 1971 was not accounted for by heparinization and may reflect increasing experience with the method and shorter angiographic times.

Aneurysm↗
PubMed1979

Significance of reduced regional myocardial blood flow in asynergic areas evaluated with intervention ventriculography. Results of studies combining washout of xenon-133 and postextrasystolic potentiation.

Nineteen patients with coronary artery disease were studied to determine the significance of reduced regional myocardial blood flow (50 ml/min per 100 g or less) in areas of abnormal wall motion. Regional myocardial blood flow was measured in four regions of the left ventricle with an Anger camera after the injection xenon-133 into the left main coronary artery. Abnormal wall motion was evaluated with biplane left ventriculography at rest and during postextrasystolic potentiation, a potent inotropic stimulus. Abnormal wall motion was defined as hemiaxis shortening of less than 20 percent. Four hemiaxes were designated as corresponding to the four regions of myocardial blood flow. Of 76 hemiaxes evaluated in the 19 patients, 54 manifested normal wall motion and 22 abnormal wall motion; 8 of the 22 hemiaxes had reduced regional myocardial bood flow. In these 8, hemiaxis shortening increased 6 +/- 2 percent (mean +/- standard error of the mean) above values at rest during postextrasystolic potentiation (with normalization of hemiaxis shortening in only 1 of the 8), compared with an increase of 19 +/- 4 percent (P less than 0.001) in the 12 hemiaxes with borderline regional myocardial blood flow (with normalization of hemiaxis shortening in 9 of the 12, P less than 0.05). These results indicate that the presence of reduced regional myocardial blood flow in areas of abnormal wall motion usually predicts a poor response to post-extrasystolic potentiation, whereas abnormal wall motion without reduced regional myocardial blood flow usually predicts a good response. The combination of reduced regional myocardial blood flow and abnormal wall motion suggests scarred and nonviable myocardium.

Adult↗
PubMed1979

beta-Adrenoceptor-blocking agents and the kidney: effect of nadolol and propranolol on the renal circulation.

1 Nadolol was administered intravenously to five hypertensive patients and three healthy volunteers in balance on a 10 mEq sodium intake. 2 Nadolol (0.3-10.0 micrograms/kg) induced a significant, dose-related increase in renal blood flow, measured with radioxenon, with a maximum increase of 72 +/- 4 ml/100g/min (26%) at 3.0 micrograms/kg. 3 Heart rate and plasma renin activity decreased significantly over the same dose range. 4 The renal vascular response to nadolol contrasts sharply with those found with other beta-adrenoceptor-blocking agents. 5 The magnitude of the increase in renal blood flow, its time-course and the parallel fall in plasma renin activity raise the possibility that the renal vasodilation reflects the reversal of angiotensin's influence on the renal arterial bed.

Adrenergic beta-Antagonists↗