Specific binding of 99MTc-antimyosin to necrotic human myocardium: clinicopathologic correlations.
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Aged↗
Biomedical subjects
J C Crawley
Publications and source records attributed to J C Crawley.
Assessment of right ventricular function with nonimaging first pass ventriculography and comparison of results with gamma camera studies.
A new technique has been developed for measuring right ventricular function by nonimaging first pass ventriculography. The right ventricular ejection fraction (RVEF) obtained by non-imaging first pass ventriculography was compared with that obtained by gamma camera first pass and equilibrium ventriculography. The data has demonstrated that the correlation of RVEFs obtained by the nonimaging nuclear cardiac probe and by gamma camera first pass ventriculography in 15 subjects was comparable (r = 0.93). There was also a good correlation between RVEFs obtained by the nonimaging nuclear probe and by equilibrium gated blood pool studies in 33 subjects (r = 0.89). RVEF was significantly reduced in 15 patients with right ventricular and/or inferior myocardial infarction compared to normal subjects (28 +/- 9% v. 45 +/- 9%). The data suggests that nonimaging probes may be used for assessing right ventricular function accurately.
Adult↗
Indium-111-antimyosin images compared with triphenyl tetrazolium chloride staining in a patient six days after myocardial infarction.
The results of indium-111 (111In) antimyosin imaging during life and the findings on postmortem imaging and triphenyl tetrazolium chloride (TTC) staining of the heart are reported from a patient who received 111In-antimyosin on the sixth day following myocardial infarction and died after imaging the next day. The planar images obtained during life showed abnormal 111In-antimyosin uptake in the posterior, lateral, and apical walls of the left ventricle. Autopsy revealed extensive infarction of the left ventricular lateral and posterior walls with cardiac rupture, which was the cause of sudden death. Direct imaging of the sliced specimen of heart revealed abnormal tracer uptake in the lateral and posterior walls of the left ventricle, which correlated closely with the area of necrosis outlined by TTC staining. Our results confirm the experimental findings that antimyosin antibody binds specifically to the acute irreversibly damaged myocardial cells. A high degree of tracer uptake can be seen even when 111In-antimyosin is injected six days postinfarction.
Aged↗
New developments in the field of acute myocardial infarction imaging.
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Antibodies, Monoclonal↗
SPECT using Bremsstrahlung to quantify 90Y uptake in Baker's cysts: its application in radiation synovectomy of the knee.
The use of SPECT with Bremsstrahlung radiation has been investigated in studies on patients undergoing 90Y therapy for persistent synovitis of the knee. In particular, its value in the estimation of 90Y uptake into Baker's cysts was assessed and, to this end, realistic 'knee phantoms' were employed in order to calibrate for cysts of different size. Problems associated with the measurement of the extensive Bremsstrahlung spectrum and the estimation of cyst volume have been discussed. It is shown that, although the apparent volume of a cyst is markedly dependent on the chosen count rate threshold, volumes greater than about 30 ml can be estimated with reasonable accuracy using a threshold of 50%. The uptake of 90Y in cysts, measured on 3 occasions within the first 2 days in 10 patients, showed wide variation (0%-40%) between patients and was poorly related to the size of cysts on arthrograms and to the clinical response to therapy. In these studies, the ability to analyse SPECT slices provided a distinct advantage over planar imaging for discriminating between 90Y uptake in cysts and adjacent sites. Retention of 90Y in the total knee was also widely variable, with losses of 2%-38% observed 2 days after injection which, in general, were not fully accounted for by uptake in liver or lymph nodes. The changing distribution of 90Y colloid in the knee during the first two days, as observed in some patients, might explain part of the discrepancy.
Aged↗
Use of single photon emission computed tomography (SPECT) to study the distribution of 90Y in patients with Baker's cysts and persistent synovitis of the knee.
The presence of a Baker's cyst may diminish the therapeutic effect of intra-articular 90Y treatment to the knee joint. SPECT (single photon emission computed tomography) was used in 10 patients with Baker's cysts, treated with intra-articular 90Y for persistent synovitis of the knee, to measure the amount of radioisotope within the cyst. Comparison was made with the arthrographic appearances. The likelihood or extent of uptake into Baker's cysts of 90Y injected into the synovial cavity of the knee was not predictable from arthrograms. Deposition of 90Y in cysts was variable, ranging from little or no measurable uptake to a substantial proportion of the administered activity (40% in one case out of 10). It did not appear to relate to clinical response. The low mean uptake (6.3%) in cysts of nine out of 10 patients was probably insignificant in view of the large uncertainty in the prediction of synovial radiation dose.
Humans↗
Animal and human studies of a new 99mTc labelled phosphine-isocyanide complex with possible applications to radionuclide ventriculography.
A new 99mTc-phosphine-isocyanide complex with the general structure [99mTc (DEPE)2(CNR)2]+ has been synthesised and tested in animals and one human. In three animal species (rat, rabbit, dog), the complex is an efficient myocardial imaging agent, while in humans it remains in the blood pool. The complex is 100% protein bound in animals and humans, but whereas in humans it is attached to a 51.5 kdalton protein (probably prealbumin), in rabbits it appears to be bound to a larger macromolecule (M.W. greater than 100 kdalton). The efficiency of the complex for blood pool labelling was tested in a human volunteer and compared with the standard in vivo red cell labelling technique with stannous pyrophosphate. A satisfactory radionuclide angiogram could be performed with less than 370 MBq of the complex. The count rate for the complex (cps/MBq) was 15% higher than that obtained with the labelled red cells and the absence of splenic activity was notable. In humans this complex appears to be an efficient blood pool labelling agent which might be useful for radionuclide ventriculography.
Animals↗
A new method of imaging the right ventricle using peripheral vein infusion of xenon 127.
We report the development of a new method for obtaining right ventriculograms using the peripheral intravenous infusion of a new tracer, 127Xe dissolved in saline. This tracer has a half life of 36 days, emits 172 keV and 203 keV photons, and is completely cleared by the lungs during pulmonary transit. The right ventricle can therefore be imaged free from interfering activity in the systemic circulation. The technique was used in 11 normal subjects and the results compared with those obtained using first pass and gated equilibrium blood pool angiography with 99mTc. Excellent images of the right ventricle were obtained and the tricuspid and pulmonary valve planes could be easily identified. This imaging technique has significant advantages over existing methods for the noninvasive assessment of right ventricular function.
Adult↗
Dopamine D2 receptors in schizophrenia studied in vivo.
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Adult↗
Technetium-99m labelled porphyrin as an imaging agent for occult infections and inflammation.
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Crohn Disease↗
Uptake of 77Br-spiperone in the striata of schizophrenic patients and controls.
Twelve patients with a diagnosis of schizophrenia and thirteen control subjects were injected with 77Br-bromospiperone and scanned using single photon emission tomography after 16 h. Although a statistically significant increase in patients by comparison with controls could be demonstrated, wide variations in specific activity of the ligand preclude a firm conclusion. In two patients but no controls an asymmetry in striatal uptake was noted, the uptake on the left being less than that on the right.
Adult↗
Tissue distribution of liposomes exhibiting long half-lives in the circulation after intravenous injection.
The previously established direct relationship between long half-life of uncharged small unilamellar liposomes in the circulation of injected animals and reduced permeability to entrapped solutes in the presence of blood plasma was investigated further. It was found that vesicle size and surface charge override state of membrane permeability in determining rates of vesicle clearance. Thus, half-lives of liposomes that were practically impermeable in plasma were much shorter for larger vesicles or vesicles with a negative charge on their surface. 111In-labelled bleomycin-containing small unilamellar liposomes with long half-lives accumulated in the liver after injection to a much lesser extent (e.g., 26%) than similar liposomes (55% of the dose) exhibiting a shorter half-life. Much of the injected long-lived liposomes (about 35%) were recovered in the carcass of the animals. Scanning of the carcasses revealed quantitative accumulation of radioactivity in the bones, presumably the phagocytic cells of the bone marrow. Long-lived liposomes appear suitable for drug delivery to, or imaging of the bone marrow.
Animals↗
The diagnostic value of liver scanning in The Gambia.
A simple radioisotope scanner was used in a study of liver diseases in The Gambia. Scans were of value in localizing areas for biopsy or aspiration and in defining the liver in the presence of gross ascites. Although the scan was not helpful in diagnosis it provided a measure of the size of filling defects during treatment.
Carcinoma, Hepatocellular↗
Isotope renography and urinary schistosomiasis: a study in a Gambian community.
A transportable apparatus for isotope renography, which allowed deconvolution analysis, was used to study the prevalence and prognosis of abnormalities associated with urinary schistosomiasis. Before carrying out studies in a heavily infected community, observations were made in a non-endemic area to allow derivation of criteria for abnormality. Comparison of the findings in the two areas showed that changes suggesting urinary tract obstruction were more common in the endemic area in subjects between nine and 45 years but not in older subjects. Measurements of effective renal plasma flow showed renal function was impaired in the endemic area in subjects older than 17 years but not in younger subjects. In the endemic area the results of renography were unrelated to the urinary egg count of the subjects examined, but there was an improvement in the abnormal renograms in a group of subjects aged between nine and 20 years who were re-examined a year after treatment with metrifonate. Follow-up data about 316 subjects was obtained two years after renography. Nine subjects had died, including four of the five subjects with abnormalities suggesting both obstruction and over-all loss of renal function. These findings, which are comparable to the results of similar studies using radiological techniques, suggest urinary schistosomiasis may be a significant cause of mortality in adults in intensely infected communities.
Adolescent↗
Detection of high risk coronary artery disease by thallium imaging.
One hundred and three patients who underwent coronary arteriography were studied by thallium imaging and the results analysed by Bayesian principles to assess the usefulness of semiquantitative stress thallium imaging for predicting the presence or absence of multivessel coronary disease. Significant disease was found in 80 patients, of whom 77 had abnormal thallium scans (sensitivity 96%). Thallium images were normal in 15 of 23 patients with no significant disease (specificity 65%). Multiple thallium segmental defects were found to be 90% sensitive and 65% specific for multivessel coronary artery disease and were present in 80% of patients with left main stem disease and in 93% of patients with triple vessel disease. A single thallium defect or normal scan excluded multivessel, left main, and triple vessel disease with 81%, 94%, and 91% predictive accuracy respectively. By Bayesian analysis the predictive accuracy for excluding multivessel disease was greater than 90% in patients with a pretest probability of multivessel disease of less than or equal to 40%. Coronary arteriography to exclude multivessel disease is therefore unnecessary in a high proportion of patients with known or suspected coronary artery disease.
Adult↗
Acute and chronic effects of sustained action buccal nitroglycerin in severe congestive heart failure.
Vasodilators, such as nitroglycerin, have been widely used in the treatment of acute and chronic heart failure for therapeutic manipulation of the venous and arterial circulations to improve left ventricular function. We have tested the efficacy of a new formulation for sustained release buccal delivery of nitroglycerin (biological life 5-6 hr) in 21 patients with severe congestive heart failure due to ischaemic cardiomyopathy using maximal treadmill exercise testing and radionuclide angiography. A single-blind placebo-controlled acute and an open chronic phase (4 weeks) of treatment were employed. The mean dose was 23.4 mg daily, and clinical assessment suggested significant improvement in 15 patients. The mean ejection fraction (placebo) of 14.1% +/- 1.6 SEM increased to 19.1% +/- 1.7 (acute) and to 21.6% +/- 1.7 (chronic treatment) (P less than 0.001; n = 16). The mean exercise time increased from 3.02 +/- 0.4 min (basal) to 5.95 +/- 0.6 min (chronic) (P less than 0.001). Segmental wall motion abnormality was shown to improve after treatment for 4 weeks. There were no major side effects. Nine patients were reassessed after 24 weeks on the same regimen; exercise time and left ventricular ejection fraction were similar to the 4-week period, thus demonstrating a sustained improvement in cardiac function and functional capacity. A worthwhile functional and objective haemodynamic improvement was demonstrated in these patients with severe chronic congestive heart failure. This mode of treatment may have useful therapeutic value in the management of patients with a wide range of ischaemic heart failure.
Adult↗
Influence of left ventricular function and severity of coronary artery disease on exercise-induced pulmonary thallium-201 uptake.
Pulmonary uptake of thallium-201 during exercise was measured in 58 patients with coronary artery disease and compared with the results from 21 patients with normal coronary arteries and 5 normal volunteers. A quantitative method was used to assess the pulmonary thallium uptake relative to cardiac activity (heart/lung ratio). This ratio was calculated for exercise and for redistribution imaging. The mean exercise heart/lung ratio for the group with coronary artery disease was 1.43 +/- 0.36 SD (n = 58); and for the "normal" group was 2.76 +/- 0.41 (n = 26) (P less than 0.001). Increased pulmonary uptake after exercise in the coronary disease group was reversible (mean redistribution heart/lung = 1.96 +/- 0.37 SD; P less than 0.001). The exercise heart/lung ratio differed significantly between groups with single-, two- and three-vessel disease; patients with and without prior infarction; and patients with exercise-induced ST segment depression and elevation. Linear regression analysis between ejection fraction calculated from equilibrium radionuclide angiography at rest and the exercise heart/lung ratio in the coronary artery disease group gave the equation: exercise heart/lung = 0.857 +/- 0.014 ejection fraction for n = 58; r = 0.695; P less than 0.001. It would appear that the exercise heart/lung ratio is a simple and valuable non-invasive index which should be used as part of routine thallium scan interpretation to provide additional information on left ventricular function after exercise and as an indicator of the severity of obstructive coronary artery disease.
Adult↗
A non-invasive technique for continuous monitoring of left ventricular function using a new solid state mercuric iodide radiation detector.
A miniature solid-state mercuric iodide (HgI2) nuclear probe detector has been developed in conjunction with a computerized nuclear probe (Nuclear Stethoscope) to enable continuous non-invasive monitoring of left ventricular function using 99Tc-labelled equilibrium blood pool techniques. Left ventricular ejection fraction was measured in 54 patients undergoing radionuclide angiography with a gamma-camera and with the Nuclear Stethoscope and a good correlation was obtained between both techniques (r = 0.94, n = 54, P less than 0.001). The prototype mercuric iodide detector was compared with the sodium iodide detector of the Nuclear Stethoscope and a study in 41 consecutive patients demonstrated a good correlation for the measurement of ejection fraction, ejection rate, peak filling rate and time to peak filling rate (r = 0.94, 0.89, 0.90 and 0.78 respectively). It may be possible to adapt the mercuric iodide detector for continuous non-invasive monitoring of left ventricular performance in critically ill patients and during physiological or pharmacological interventions.
Adult↗