sodium-pertechnetate-tc-99m and Lung-Diseases--Obstructive

Pulmonary embolism remains a major cause of morbidity and mortality, being responsible for an estimated 200,000 deaths per annum in the USA and 21,000 per annum in the UK. Lung scintigraphy is in many instances the investigation of choice in suspected pulmonary thromboembolism. A normal perfusion lung scan excludes pulmonary embolism. An abnormal perfusion scan, while being sensitive, is of low specificity for the diagnosis of pulmonary embolism and needs to be complemented with a ventilation study. Lung ventilation has been studied using inert gases of radiolabelled aerosols. The new radiopharmaceutical 99Tcm-Technegas is a suspension of 99Tcm-labelled, ultrafine, carbon particles produced in an atmosphere of high-purity argon. The size of the particles is of the order of 0.005-0.2 microns, which assures good peripheral penetration and alveolar deposition. After inhalation, static images in multiple projections may be acquired. The resultant images are of excellent technical quality and several publications have shown the value of Technegas images as an adjunct to perfusion imaging in suspected pulmonary thromboembolism. Studies comparing Technegas images with other ventilatory radiopharmaceuticals have in the majority of instances reported comparable diagnostic qualities.

Topics: Administration, Inhalation; Aerosols; Humans; Lung Diseases, Obstructive; Oximetry; Particle Size; Pulmonary Alveoli; Pulmonary Embolism; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Lung scintigraphy is primarily used to diagnose pulmonary embolism. Ventilation imaging is often performed using (99m)Tc-DTPA or Technegas, an ultrafine dispersion of (99m)Tc-labeled carbon. Despite the common use of these radioaerosols, they have not been compared in an intraindividual study, and not with ventilation-perfusion (V/P) SPECT. The aim of the present head-to-head study was to systematically investigate differences in ventilation studies performed with (99m)Tc-diethylenetriaminepentaacetate (DTPA) and Technegas.. Sixty-three patients, 28 without and 35 with obstructive lung disease, were examined with V/P SPECT using both (99m)Tc-DTPA and Technegas. V/P SPECT images were randomized and assessed independently by 2 masked physicians according to a predefined scoring system. A paired comparison was performed using the Wilcoxon signed-rank test.. In both obstructive and nonobstructive disease, the overall unevenness of radiotracer deposition and the degree of central deposition were more pronounced in (99m)Tc-DTPA than Technegas studies. Because of better peripheral penetration, the extent of reverse mismatch was less when Technegas was used. Additionally, in obstructive disease, the degree of focal deposition in distal airways was more pronounced with (99m)Tc-DTPA. Mismatched perfusion defects were more frequently found with Technegas in obstructive disease.. This intraindividual comparative study shows that Technegas is the preferred radioaerosol, particularly in obstructive disease.

Topics: Aged; Female; Humans; Image Processing, Computer-Assisted; Lung; Lung Diseases; Lung Diseases, Obstructive; Male; Middle Aged; Pulmonary Disease, Chronic Obstructive; Pulmonary Embolism; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m; Technetium Tc 99m Pentetate; Tomography, Emission-Computed, Single-Photon

We evaluated 12 patients with stable chronic airflow obstruction (CAO) and no clinical evidence of left ventricular disease to determine the effects of oral digoxin on exercise capacity (VO2 max) and on right ventricular pump function during exercise. In this randomized, double blind, placebo controlled, cross-over study, patients performed exercise tests and underwent measurement of ejection fractions after two weeks of therapy with oral digoxin (0.25 mg/day) and after two weeks of placebo. Incremental upright exercise testing to a symptom-limited maximum was performed on a cycle ergometer. Right and left ventricular ejection fractions (RVEF, LVEF) were obtained in the supine position at rest and at approximately 75 percent of the maximum workload by gated equilibrium radionuclide angiography. All patients had abnormal right ventricular function, manifested either by a low resting RVEF (less than 45 percent) or a subnormal response to exercise (less than 5 percent increase). The small increases in RVEF with digoxin (mean +/- SE) at rest (44 +/- 5 vs 41 +/- 4 percent) and during exercise (46 +/- 4 vs 44 +/- 3 percent) did not achieve statistical significance. With digoxin, small increases in exercise duration (10.0 +/- 1.5 vs 9.0 +/- 1.4 min), maximum workload achieved (48 +/- 6 vs 42 +/- 5 W), VO2 max (0.85 +/- 0.06 vs 0.81 +/- 0.06 L/min), and oxygen-pulse (O2-P) (6.6 +/- 0.5 vs 6.3 +/- 0.4 ml/beat) occurred. Only the increase in O2-P was significant (p less than 0.05). From this study we conclude that digoxin does not significantly improve exercise capacity in severe chronic airflow obstruction with impaired right ventricular function, nor does it improve RVEF either at rest or during supine submaximal exercise.

Topics: Digoxin; Exercise Test; Heart; Heart Ventricles; Humans; Lung Diseases, Obstructive; Middle Aged; Physical Exertion; Radionuclide Imaging; Respiratory Function Tests; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium

A distinctive feature of cerebral blood circulation in patients with chronic non-specific lung diseases (CNLD) complicated with chronic pulmonary heart (CPH) is a pronounced disturbance of cerebral venous drainage without a reliable reduction of both cerebral circulation and blood flow in common carotid arteries. Correlation between the degree of venous drainage disturbance and an extent of CNLD was found. Atherosclerotic damage of major arteries of the head in patients with ischemic stroke (IS) and CNLD was less marked. A comparative comprehensive study of the state of cerebral circulation was performed in two groups of patients. Predominance of the disturbance of venous outflow was found in the patients with IS and CNLD. The volumetric blood flow reduction prevailed in a group of patients with IS due to carotid occlusion. There was no significant difference in local cerebral circulation between the two groups. Obviously the disturbance of venous outflow causes the decrease of cerebral blood circulation in patients with CNLD, therefore "venous stroke" is possible in some patients with CNLD. Poor prognosis of IS in patients with CNLD and CPH is registered. It is stated that venous drainage disturbance and volumetric blood flow reduction in common carotids are main factors affecting progress and outcome of IS.

Topics: Aged; Asthma; Brain; Carotid Artery, Common; Cerebrovascular Circulation; Cerebrovascular Disorders; Female; Hemodynamics; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Pulmonary Heart Disease; Radionuclide Imaging; Radiopharmaceuticals; Respiratory Function Tests; Sodium Pertechnetate Tc 99m

Topics: Australia; Evaluation Studies as Topic; Humans; Lung Diseases; Lung Diseases, Obstructive; Pulmonary Embolism; Radionuclide Imaging; Respiratory Function Tests; Sodium Pertechnetate Tc 99m; Surveys and Questionnaires

Technegas (TG), an ultrafine dispersion of carbon aggregates labelled with 99mTechnetium (99mTc), has been recently introduced for clinical imaging of lung ventilation. In 12 selected subjects with severe chronic airflow limitation (FEV1 = 0.89 +/- 0.22; mean +/- SD, l) we have studied the regional intrapulmonary distribution of TG and compared it quantitatively with that of 133Xenon (133Xe). A 133Xe equilibration image was acquired for 10-15 s during a breathhold at total lung capacity (TLC). Six subjects (Group 1) inspired 100 ml boli of TG or 133Xe from functional residual capacity (FRC) and another 6 subjects (Group 2) inspired 1.0 l of labelled gas from FRC followed by air to TLC at a constant flow rate less than 0.5 l.s-1. Lung images were then acquired with the chest position rigorously controlled. From the equilibration image, upper, middle, lower, central and peripheral regions were defined. Relative regional fractional concentrations (RFC) were then calculated using the equilibration image to correct for ventilated lung volume. In addition, in four of the Group 2 subjects, each lung image was divided into multiple regions (12-17 per lung). The RFC were then calculated as above (RFCM). The highest and lowest RFC were not significantly different between 133Xe and TG in either Group 1 or Group 2 subjects. Similarly the RFCM analysis showed no systematic difference between 133Xe and TG. The ratio of peripheral to central RFC constitutes a penetration index which for TG was 0.99 +/- 0.23 that of 133Xe. Our results indicate that even in the presence of severe airflow limitation the radiolabelled tracer TG mimics the regional distribution of a real gas.

Topics: Aged; Graphite; Humans; Lung; Lung Diseases, Obstructive; Male; Middle Aged; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The role and utility of equilibrium radionuclide angiocardiography was estimated in non-invasive diagnosis of patients with Chronic Obstructive Pulmonary Disease (COPD). In 26 healthy subjects the average value of Right Ventricular Ejection Fraction (RVEF) was 54.8 +/- 7.2, versus 40.89 +/- 7.85 in 37 patients with COPD. Right heart catheterization was performed on 9 patients with COPD, randomly chosen, to analyze the correlation between RVEF values and average Pulmonary Artery Pressure (PAP) values: the correlation index was significantly high (r = 0.80). Moreover, an important agreement was observed between RVEF and PaCO2 values (r = 0.77).

Topics: Adult; Aged; Blood Pressure; Female; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Pulmonary Artery; Radionuclide Angiography; Radionuclide Ventriculography; Respiratory Function Tests; Sodium Pertechnetate Tc 99m; Stroke Volume

Eleven patients, with advanced chronic obstructive lung disease (COLD), received an infusion of the calcium antagonist felodipine at a rate of 0.9 mg/h. Pulmonary and systemic vascular resistances (PVR and SVR) at rest were reduced by 18% (p less than 0.05) and 33% (p less than 0.001), respectively. Cardiac output increased by 33%. The right ventricular and left ventricular ejection fractions (RVEF and LVEF), measured by equilibrium gated radionuclide ventriculography, increased by 32% (p less than 0.01) and 25% (p less than 0.01), respectively. During exercise both PVR and SVR fell by a mean of 30% (p less than 0.01). RVEF and LVEF both increased by about 14% (p less than 0.05 and p less than 0.01). After three months of oral felodipine treatment, a dose-related decrease in PVR was noted at rest (r = -0.83) compared with pretreatment values. There was an increase in RVEF which correlated to a reduction in PVR (r = -0.76). Three patients discontinued the trial due to side effects. It is concluded that the reduction of PVR induced by felodipine is accompanied by an improvement in right heart function as measured by ejection fraction measurements.

Topics: Aged; Cardiac Output; Felodipine; Female; Heart; Hemodynamics; Humans; Lung Diseases, Obstructive; Male; Middle Aged; Nitrendipine; Radionuclide Imaging; Sodium Pertechnetate Tc 99m; Time Factors

The authors presented some data on possibilities of a comprehensive study of permeability of the bronchopulmonary structures, ventilation and the pulmonary-capillary blood flow of the lungs in children and adolescents using aerosol pulmobronchoscintigraphy with 99mTc-pertechnetate aerosol for which purpose a special MEDI-61 apparatus was employed for the first time. A total of 100 patients were examined, of them 25 by using 2 methods. Proceeding from an analysis of the results of the comprehensive study of children and adolescents with chronic pulmonary diseases it has been concluded that this method is objective, informative and provides exhaustive information on the state of bronchial permeability and pulmonary-capillary blood flow. The method also permits a preliminary selection of patients and substantiation of indications for administration of complex instrumental methods of investigation of the bronchial tree under narcosis.

Topics: Adolescent; Aerosols; Bronchi; Child; Female; Humans; Lung; Lung Diseases, Obstructive; Male; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The authors have provided a comparative analysis of various modifications of radionuclide ventriculography and assessment of their potentialities for clinical use. A total of 120 patients with chronic nonspecific lung diseases, coronary heart disease and rheumatic heart disease were examined. It was established that the most accurate information to assess myocardial contractility was obtained by a method of the determination of the ejection fraction by the "activity-time" curve with a fixed zone of interest, and the universal patient's position was the left front oblique projection. The right ventricular ejection fraction was determined in parallel with the study of the left ventricular ejection fraction characterizing myocardial contractility in cardiovascular pathology. The study of the former extended significantly the potentialities of radionuclide ventriculography, allowed the assessment of the hemodynamic state of the lesser circulation and compensatory potentialities of the right ventricle of the heart in cardiopulmonary pathology.

Topics: Adult; Aged; Coronary Disease; Heart; Humans; Lung Diseases, Obstructive; Middle Aged; Myocardial Contraction; Radionuclide Imaging; Rheumatic Heart Disease; Sodium Pertechnetate Tc 99m; Stroke Volume

Topics: Cardiology; Cardiomyopathies; Heart; Heart Function Tests; Heart Valve Diseases; Humans; Lung Diseases, Obstructive; Myocardial Infarction; Nuclear Medicine; Prognosis; Quality Control; Radiation Dosage; Radioisotopes; Reference Values; Sodium Pertechnetate Tc 99m; Terminology as Topic; Tomography, Emission-Computed

The acute effects of intravenously administered hydralazine on pulmonary hemodynamics and ejection radionuclide angiography were evaluated in 9 patients with chronic airflow obstruction (forced expiratory volume in one second, 1.2 +/- 0.8 L, mean +/- SD), pulmonary hypertension (mean pulmonary artery pressure (PAP), 29 +/- 13 mmHg), and sleep hypoxemia (maximal sleep desaturation, 20 +/- 16%). The effect of hydralazine was measured during both normoxia and hypoxia and compared with the effect of hyperoxia. Hydralazine increased cardiac index from 3.7 +/- 0.2 to 4.5 +/- 0.8 L/min/m2 (mean +/- SE, p less than 0.05, n = 9), but there were no significant changes in PAP (29 +/- 4 to 32 +/- 4 mmHg), mean pulmonary vascular resistance index (PVRI) (390 +/- 80 to 360 +/- 80 dyn.s.cm.-5.m2), mean right ventricular stroke work index (12.7 +/- 2.7 to 15.0 +/- 2.2 g.m/m2), and mean pulmonary capillary wedge pressure (12 +/- 1 to 12 +/- 2 mmHg). Mean right ventricular ejection fraction and mean right ventricular end diastolic volume also were not changed after treatment with hydralazine. Hyperoxia was used to assess the reversibility of pulmonary hypertension and to compare this with hydralazine. Hyperoxia increased arterial oxygen saturation (SaO2) from 91 +/- 1 to 96 +/- 1% and decreased the cardiac index from 3.8 +/- 0.1 to 3.1 +/- 0.2 L/min/m2 (p less than 0.02, n = 6) but, as with hydralazine, there was no significant change in PAP (28 +/- 6 to 25 +/- 6 mmHg) and PVRI (350 +/- 120 to 360 +/- 80 dyn.s.cm-5).m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Angiography; Female; Hemodynamics; Humans; Hydralazine; Hypertension, Pulmonary; Lung Diseases, Obstructive; Male; Middle Aged; Oxygen; Pulmonary Wedge Pressure; Sodium Pertechnetate Tc 99m; Stroke Volume; Technetium; Vascular Resistance

Topics: Cardiac Output; Cardiomyopathies; Coronary Circulation; Coronary Disease; Coronary Vessels; Heart; Heart Diseases; Heart Valve Diseases; Heart Ventricles; Humans; International Cooperation; Lung Diseases, Obstructive; Myocardial Infarction; Perfusion; Quality Control; Radionuclide Imaging; Reference Values; Societies, Medical; Sodium Pertechnetate Tc 99m; Terminology as Topic; Tomography, Emission-Computed; World Health Organization